diff --git a/app/api/api_root.rb b/app/api/api_root.rb
index bde5f02365..c13975473b 100644
--- a/app/api/api_root.rb
+++ b/app/api/api_root.rb
@@ -58,8 +58,10 @@ class ApiRoot < Grape::API
   mount GroupSetsApi
   mount LearningOutcomesApi
   mount LearningAlignmentApi
+  mount NotificationsApi
   mount ProjectsApi
   mount SettingsApi
+  mount StaffGrantExtensionApi
   mount StudentsApi
   mount Submission::PortfolioApi
   mount Submission::PortfolioEvidenceApi
@@ -100,6 +102,7 @@ class ApiRoot < Grape::API
   AuthenticationHelpers.add_auth_to LearningOutcomesApi
   AuthenticationHelpers.add_auth_to LearningAlignmentApi
   AuthenticationHelpers.add_auth_to ProjectsApi
+  AuthenticationHelpers.add_auth_to StaffGrantExtensionApi
   AuthenticationHelpers.add_auth_to StudentsApi
   AuthenticationHelpers.add_auth_to Submission::PortfolioApi
   AuthenticationHelpers.add_auth_to Submission::PortfolioEvidenceApi
diff --git a/app/api/extension_comments_api.rb b/app/api/extension_comments_api.rb
index 3bde9171de..966d69e6ff 100644
--- a/app/api/extension_comments_api.rb
+++ b/app/api/extension_comments_api.rb
@@ -10,25 +10,21 @@ class ExtensionCommentsApi < Grape::API
     requires :weeks_requested, type: Integer, desc: 'The details of the request'
   end
   post '/projects/:project_id/task_def_id/:task_definition_id/request_extension' do
-    project = Project.find(params[:project_id])
-    task_definition = project.unit.task_definitions.find(params[:task_definition_id])
-    task = project.task_for_task_definition(task_definition)
-
-    # check permissions using specific permission has with addition of request extension if allowed in unit
-    unless authorise? current_user, task, :request_extension, ->(role, perm_hash, other) { task.specific_permission_hash(role, perm_hash, other) }
-      error!({ error: 'Not authorised to request an extension for this task' }, 403)
+    # Use the ExtensionService to handle the extension request
+    result = ExtensionService.grant_extension(
+      params[:project_id],
+      params[:task_definition_id],
+      current_user,
+      params[:weeks_requested],
+      params[:comment]
+    )
+
+    # Handle the service response
+    if result[:success]
+      present result[:result].serialize(current_user), Grape::Presenters::Presenter
+    else
+      error!({ error: result[:error] }, result[:status])
     end
-
-    error!({ error: 'Extension weeks can not be 0.' }, 403) if params[:weeks_requested] == 0
-
-    max_duration = task.weeks_can_extend
-    duration = params[:weeks_requested]
-    duration = max_duration unless params[:weeks_requested] <= max_duration
-
-    error!({ error: 'Extensions cannot be granted beyond task deadline.' }, 403) if duration <= 0
-
-    result = task.apply_for_extension(current_user, params[:comment], duration)
-    present result.serialize(current_user), Grape::Presenters::Presenter
   end
 
   desc 'Assess an extension for a task'
diff --git a/app/api/notifications_api.rb b/app/api/notifications_api.rb
new file mode 100644
index 0000000000..371b08c5b9
--- /dev/null
+++ b/app/api/notifications_api.rb
@@ -0,0 +1,29 @@
+class NotificationsApi < Grape::API
+  helpers AuthenticationHelpers
+  helpers AuthorisationHelpers
+
+  before do
+    authenticated?
+  end
+
+  desc 'Get current user notifications'
+  get '/notifications' do
+    notifications = current_user.notifications.order(created_at: :desc)
+    # Return array of notifications as JSON (id and message only)
+    notifications.as_json(only: [:id, :message])
+  end
+
+  desc 'Delete user notification by id'
+  delete '/notifications/:id' do
+    notification = current_user.notifications.find_by(id: params[:id])
+    error!({ error: 'Notification not found' }, 404) unless notification
+    notification.destroy
+    status 204
+  end
+
+  desc 'Delete all user notifications'
+  delete '/notifications' do
+    current_user.notifications.delete_all
+    status 204
+  end
+end
diff --git a/app/api/staff_grant_extension_api.rb b/app/api/staff_grant_extension_api.rb
new file mode 100644
index 0000000000..e63c3360d5
--- /dev/null
+++ b/app/api/staff_grant_extension_api.rb
@@ -0,0 +1,176 @@
+require 'grape'
+
+#
+# API endpoint for staff to grant extensions to multiple students at once
+#
+class StaffGrantExtensionApi < Grape::API
+  helpers AuthenticationHelpers
+  helpers AuthorisationHelpers
+  helpers DbHelpers
+
+  before do
+    authenticated?
+    error!({
+      error: 'Not authorized to grant extensions',
+      code: 'UNAUTHORIZED',
+      details: {}
+    }, 403) unless current_user.has_tutor_capability?
+  end
+
+  desc 'Grant extensions to multiple students',
+       detail: 'This endpoint allows staff to grant extensions to multiple students at once for a specific task. The operation is atomic - either all extensions are granted or none are. Students not found in the unit are automatically skipped without affecting the transaction.',
+       success: [
+         { code: 201, message: 'Extensions granted successfully' }
+       ],
+       failure: [
+         { code: 400, message: 'Some extensions failed to be granted' },
+         { code: 403, message: 'Not authorized to grant extensions for this unit' },
+         { code: 404, message: 'Unit or task definition not found' },
+         { code: 500, message: 'Internal server error' }
+       ],
+       response: {
+         successful: [
+           {
+             student_id: 'Integer - ID of the student',
+             project_id: 'Integer - ID of the project',
+             weeks_requested: 'Integer - Number of weeks extension granted',
+             extension_response: 'String - Human readable message with new due date',
+             task_status: 'String - Updated status of the task'
+           }
+         ],
+         failed: [
+           {
+             student_id: 'Integer - ID of the student',
+             project_id: 'Integer - ID of the project',
+             error: 'String - Error message explaining why extension failed'
+           }
+         ],
+         skipped: [
+           {
+             student_id: 'Integer - ID of the student',
+             reason: 'String - Reason why the student was skipped'
+           }
+         ]
+       }
+  params do
+    requires :student_ids, type: Array[Integer], desc: 'List of student IDs to grant extensions to'
+    requires :task_definition_id, type: Integer, desc: 'Task definition ID'
+    requires :weeks_requested, type: Integer, desc: 'Number of weeks to extend by (1-4)'
+    requires :comment, type: String, desc: 'Reason for extension (max 300 characters)'
+  end
+  post '/units/:unit_id/staff-grant-extension' do
+    unit = Unit.find(params[:unit_id])
+    task_definition = unit.task_definitions.find(params[:task_definition_id])
+
+    # Use transaction to ensure atomic operation
+    ActiveRecord::Base.transaction do
+      results = {
+        successful: [],
+        failed: [],
+        skipped: []
+      }
+
+      params[:student_ids].each do |student_id|
+        # Find project for this student in the unit
+        project = unit.projects.find_by(user_id: student_id)
+        if project.nil?
+          results[:skipped] << {
+            student_id: student_id,
+            reason: 'Student not found in unit'
+          }
+          next
+        end
+
+        result = ExtensionService.grant_extension(
+          project.id,
+          task_definition.id,
+          current_user,
+          params[:weeks_requested],
+          params[:comment],
+          true # is_staff_grant = true
+        )
+
+        if result[:success]
+          extension_comment = result[:result]
+          results[:successful] << {
+            student_id: student_id,
+            project_id: project.id,
+            weeks_requested: extension_comment.extension_weeks,
+            extension_response: extension_comment.extension_response,
+            task_status: extension_comment.task.status,
+            extension_comment: extension_comment  # Store internally for notifications
+          }
+        else
+          results[:failed] << {
+            student_id: student_id,
+            project_id: project.id,
+            error: result[:error]
+          }
+          # If it's a validation error (403), raise it immediately
+          error!({ error: result[:error] }, result[:status]) if result[:status] == 403
+        end
+      end
+
+      # If any extensions failed (but not due to validation), rollback the entire transaction
+      if results[:failed].any?
+        error!({ error: 'Some extensions failed to be granted', results: results }, 400)
+      end
+
+      # Send notifications only if successful and after processing all students
+      if results[:successful].any?
+        # Use the extension comments directly from the service results (thread-safe)
+        successful_extensions = results[:successful].map do |result|
+          extension_comment = result[:extension_comment]
+          if extension_comment.nil?
+            Rails.logger.warn "No extension comment found for project #{result[:project_id]}"
+            nil
+          else
+            Rails.logger.debug "Using extension comment: #{extension_comment.id} for project #{result[:project_id]}"
+            extension_comment
+          end
+        end
+
+        # Filter out any nil results in case a comment wasn't found
+        successful_extensions.compact!
+        Rails.logger.info "Processing #{successful_extensions.count} successful extensions for notifications"
+
+        if successful_extensions.any?
+          begin
+            Rails.logger.info "Sending extension notifications for #{successful_extensions.count} extensions"
+            NotificationsMailer.extension_granted(
+              successful_extensions,
+              current_user,
+              params[:student_ids].count,
+              results[:failed],
+              true # is_staff_grant = true
+            ).deliver_now
+            Rails.logger.info "Extension notifications sent successfully"
+          rescue => e
+            Rails.logger.error "Failed to send extension notifications: #{e.message}"
+            Rails.logger.error e.backtrace.join("\n")
+            # Don't fail the entire request if email fails, but log the error
+          end
+
+          # Create in-system notifications for successful extensions
+          results[:successful].each do |result|
+            student = User.find_by(id: result[:student_id])
+            next unless student
+
+            Notification.create!(
+              user_id: student.id,
+              message: "#{unit.code}: You were granted an extension for task '#{task_definition.name}'."
+            )
+          end
+        end
+      end
+
+      status 201
+      present results, with: Grape::Presenters::Presenter
+    end
+
+  rescue ActiveRecord::RecordNotFound
+    error!({ error: 'Unit or task definition not found' }, 404)
+  rescue StandardError
+    error!({ error: 'An unexpected error occurred' }, 500)
+  end
+end
diff --git a/app/mailers/notifications_mailer.rb b/app/mailers/notifications_mailer.rb
index 741fa18b8e..47941c1e35 100644
--- a/app/mailers/notifications_mailer.rb
+++ b/app/mailers/notifications_mailer.rb
@@ -1,7 +1,17 @@
 class NotificationsMailer < ActionMailer::Base
+
+  # Load configuration values at class level
+  def self.doubtfire_host
+    Doubtfire::Application.config.institution[:host] || 'doubtfire.deakin.edu.au'
+  end
+
+  def self.doubtfire_product_name
+    Doubtfire::Application.config.institution[:product_name] || 'Doubtfire'
+  end
+
   def add_general
-    @doubtfire_host = Doubtfire::Application.config.institution[:host]
-    @doubtfire_product_name = Doubtfire::Application.config.institution[:product_name]
+    @doubtfire_host = self.class.doubtfire_host
+    @doubtfire_product_name = self.class.doubtfire_product_name
     @unsubscribe_url = "#{@doubtfire_host}/#/home?notifications"
   end
 
@@ -88,6 +98,72 @@ def this_these(num)
     end
   end
 
+  # Sends a summary email to the staff member who granted the extensions
+  def extension_granted_summary(extensions, granted_by, total_selected, failed_extensions = [])
+    @granted_by = granted_by
+    @extensions = extensions
+    @total_selected = total_selected
+    @failed_extensions = failed_extensions
+    @unit = extensions.any? ? extensions.first.task.unit : nil
+    @is_tutor = true
+
+    add_general
+
+    email_with_name = %("#{@granted_by.name}" <#{@granted_by.email}>)
+    # Set explicit from address using product name and a default sender
+    from_address = %("#{self.class.doubtfire_product_name}" <no-reply@#{self.class.doubtfire_host}>)
+
+    mail(
+      to: email_with_name,
+      from: from_address,
+      subject: @unit ? "#{@unit.name}: Staff Grant Extensions" : "Staff Grant Extensions",
+      template_name: 'extension_granted'
+    )
+  end
+
+  # Sends a notification to a student about their granted extension
+  def extension_granted_notification(extension, granted_by)
+    @granted_by = granted_by
+    @extension = extension
+    @task = extension.task
+    @student = extension.project.student
+    @is_tutor = false
+
+    add_general
+
+    email_with_name = %("#{@student.name}" <#{@student.email}>)
+    tutor_email = %("#{@granted_by.name}" <#{@granted_by.email}>)
+
+    mail(
+      to: email_with_name,
+      from: tutor_email,
+      subject: "#{@task.unit.name}: Extension granted for #{@task.task_definition.name}",
+      template_name: 'extension_granted'
+    )
+  end
+
+  # Main method to handle extension notifications from staff
+  def extension_granted(extensions, granted_by, total_selected, failed_extensions = [], is_staff_grant = false)
+    # Only send notifications for staff-granted bulk extensions
+    return unless is_staff_grant && (extensions.any? || failed_extensions.any?)
+
+    begin
+      # Send summary to staff member who granted the extensions
+      NotificationsMailer.extension_granted_summary(extensions, granted_by, total_selected, failed_extensions).deliver_now
+
+      # Send individual notifications only to students who have enabled email notifications
+      extensions.each do |extension|
+        student = extension.project.student
+        if student.receive_task_notifications
+          NotificationsMailer.extension_granted_notification(extension, granted_by).deliver_now
+        end
+      end
+    rescue => e
+      Rails.logger.error "Failed to send extension notifications: #{e.message}"
+      Rails.logger.error e.backtrace.join("\n")
+    end
+  end
+
   helper_method :top_task_desc
   helper_method :were_was
   helper_method :are_is
diff --git a/app/models/notification.rb b/app/models/notification.rb
new file mode 100644
index 0000000000..c99183b196
--- /dev/null
+++ b/app/models/notification.rb
@@ -0,0 +1,3 @@
+class Notification < ApplicationRecord
+  belongs_to :user
+end
diff --git a/app/models/unit.rb b/app/models/unit.rb
index 175e62c790..69a3bc5310 100644
--- a/app/models/unit.rb
+++ b/app/models/unit.rb
@@ -28,7 +28,8 @@ def self.permissions
       :download_stats,
       :download_unit_csv,
       :download_grades,
-      :exceed_capacity
+      :exceed_capacity,
+      :grant_extensions
     ]
 
     # What can convenors do with units?
@@ -48,7 +49,8 @@ def self.permissions
       :download_grades,
       :rollover_unit,
       :exceed_capacity,
-      :perform_overseer_assessment_test
+      :perform_overseer_assessment_test,
+      :grant_extensions
     ]
 
     # What can admin do with units?
diff --git a/app/models/user.rb b/app/models/user.rb
index 6e016badfd..ebc43f003a 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -136,6 +136,7 @@ def token_for_text?(a_token)
   has_many    :projects, dependent: :destroy
   has_many    :auth_tokens, dependent: :destroy
   has_one     :webcal, dependent: :destroy
+  has_many    :notifications, dependent: :destroy
 
   # Model validations/constraints
   validates :first_name,  presence: true
diff --git a/app/services/extension_service.rb b/app/services/extension_service.rb
new file mode 100644
index 0000000000..01af8cc4c4
--- /dev/null
+++ b/app/services/extension_service.rb
@@ -0,0 +1,52 @@
+class ExtensionService
+  def self.grant_extension(project_id, task_definition_id, user, weeks_requested, comment, is_staff_grant = false)
+    # Find project and task
+    project = Project.find(project_id)
+    task_definition = project.unit.task_definitions.find(task_definition_id)
+    task = project.task_for_task_definition(task_definition)
+
+    # ===== Common Validation Logic (used by both endpoints) =====
+    # Validate extension weeks
+    return { success: false, error: 'Extension weeks cannot be 0', status: 403 } if weeks_requested == 0
+
+    # Calculate max duration
+    max_duration = task.weeks_can_extend
+    duration = weeks_requested
+    duration = max_duration unless weeks_requested <= max_duration
+
+    # Check if extension would exceed deadline
+    return { success: false, error: 'Extensions cannot be granted beyond task deadline', status: 403 } if duration <= 0
+
+    # ===== Student-Initiated Extension Logic (current endpoint) =====
+    unless is_staff_grant
+      # Check task-level authorization for student requests with specific permission hash
+      unless AuthorisationHelpers.authorise?(user, task, :request_extension, ->(role, perm_hash, other) { task.specific_permission_hash(role, perm_hash, other) })
+        return { success: false, error: 'Not authorised to request an extension for this task', status: 403 }
+      end
+    end
+
+    # ===== Staff Grant Logic (new endpoint) =====
+    if is_staff_grant
+      # Check unit-level authorization for staff grants
+      unless AuthorisationHelpers.authorise?(user, project.unit, :grant_extensions)
+        return { success: false, error: 'Not authorised to grant extensions for this unit', status: 403 }
+      end
+    end
+
+    # ===== Common Extension Logic =====
+    # Apply the extension
+    result = task.apply_for_extension(user, comment, duration)
+
+    # Auto-approve if it's a staff grant
+    if is_staff_grant
+      extension_comment = result.becomes(ExtensionComment)
+      extension_comment.assess_extension(user, true, true)
+    end
+
+    { success: true, result: result, status: 201 }
+  rescue ActiveRecord::RecordNotFound => e
+    { success: false, error: 'Task or project not found', status: 404 }
+  rescue StandardError => e
+    { success: false, error: e.message, status: 500 }
+  end
+end
diff --git a/app/views/notifications_mailer/extension_granted.html.erb b/app/views/notifications_mailer/extension_granted.html.erb
new file mode 100644
index 0000000000..d3eb9a397d
--- /dev/null
+++ b/app/views/notifications_mailer/extension_granted.html.erb
@@ -0,0 +1,124 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <meta content='text/html; charset=UTF-8' http-equiv='Content-Type' />
+    <style>
+      body {
+        font-family: Arial, sans-serif;
+        line-height: 1.6;
+        color: #333;
+        max-width: 600px;
+        margin: 0 auto;
+        padding: 20px;
+      }
+      .header {
+        background-color: #f8f9fa;
+        padding: 20px;
+        border-radius: 5px;
+        margin-bottom: 20px;
+      }
+      .content {
+        padding: 20px;
+      }
+      .footer {
+        margin-top: 20px;
+        padding-top: 20px;
+        border-top: 1px solid #eee;
+        font-size: 0.9em;
+        color: #666;
+      }
+      table {
+        width: 100%;
+        border-collapse: collapse;
+        margin: 20px 0;
+      }
+      th, td {
+        padding: 12px;
+        text-align: left;
+        border-bottom: 1px solid #ddd;
+      }
+      th {
+        background-color: #f8f9fa;
+      }
+      .success {
+        color: #28a745;
+      }
+      .error {
+        color: #dc3545;
+      }
+    </style>
+  </head>
+  <body>
+    <div class="header">
+      <h2>Extension Granted</h2>
+    </div>
+
+    <div class="content">
+      <% if @is_tutor %>
+        <p>You have granted extensions for the following students:</p>
+
+        <table>
+          <thead>
+            <tr>
+              <th>Student</th>
+              <th>Task</th>
+              <th>New Due Date</th>
+            </tr>
+          </thead>
+          <tbody>
+            <% @extensions.each do |extension| %>
+              <tr>
+                <td><%= extension.project.student.name %></td>
+                <td><%= extension.task.task_definition.name %></td>
+                <td><%= extension.task.due_date.strftime("%d %b %Y") %></td>
+              </tr>
+            <% end %>
+          </tbody>
+        </table>
+
+        <% if @failed_extensions.any? %>
+          <h3>Failed Extensions</h3>
+          <table>
+            <thead>
+              <tr>
+                <th>Student ID</th>
+                <th>Error</th>
+              </tr>
+            </thead>
+            <tbody>
+              <% @failed_extensions.each do |failed| %>
+                <tr>
+                  <td><%= failed[:student_id] %></td>
+                  <td class="error"><%= failed[:error] %></td>
+                </tr>
+              <% end %>
+            </tbody>
+          </table>
+        <% end %>
+
+        <p>Total students selected: <%= @total_selected %></p>
+        <p>Successfully granted: <%= @extensions.count %></p>
+        <% if @failed_extensions.any? %>
+          <p>Failed: <%= @failed_extensions.count %></p>
+        <% end %>
+      <% else %>
+        <p>Dear <%= @student.name %>,</p>
+
+        <p>An extension has been granted for your task: <strong><%= @task.task_definition.name %></strong></p>
+
+        <p>Details:</p>
+        <ul>
+          <li>New due date: <%= @task.due_date.strftime("%d %b %Y") %></li>
+          <li>Granted by: <%= @granted_by.name %></li>
+          <% if @extension.comment.present? %>
+            <li>Comment: <%= @extension.comment %></li>
+          <% end %>
+        </ul>
+      <% end %>
+    </div>
+
+    <div class="footer">
+      <p>This is an automated message from Doubtfire.</p>
+    </div>
+  </body>
+</html>
diff --git a/app/views/notifications_mailer/extension_granted.text.erb b/app/views/notifications_mailer/extension_granted.text.erb
new file mode 100644
index 0000000000..f1d9864653
--- /dev/null
+++ b/app/views/notifications_mailer/extension_granted.text.erb
@@ -0,0 +1,38 @@
+<% if @is_tutor %>
+You have granted extensions for the following students:
+
+Extensions granted:
+<% @extensions.each do |extension| %>
+- <%= extension.project.student.name %>: <%= extension.task.task_definition.name %>
+  New due date: <%= extension.task.due_date.strftime("%B %d, %Y") %>
+<% end %>
+
+Summary:
+- Total selected for extension: <%= @total_selected %>
+- Successfully granted: <%= @extensions.count %>
+<% if @failed_extensions.present? %>
+- Failed to grant: <%= @failed_extensions.count %>
+
+Failed extensions:
+<% @failed_extensions.each do |failed| %>
+- Student ID <%= failed[:student_id] %>: <%= failed[:error] %>
+<% end %>
+<% end %>
+<% else %>
+Dear <%= @student.name %>,
+
+An extension has been granted for your task: <%= @task.task_definition.name %>
+
+Details:
+- New due date: <%= @task.due_date.strftime("%B %d, %Y") %>
+- Granted by: <%= @granted_by.name %>
+<% if @extension.comment.present? %>
+- Comment: <%= @extension.comment %>
+<% end %>
+<% end %>
+
+Cheers,
+The <%= @doubtfire_product_name %> Team
+
+---
+To unsubscribe from these notifications, visit: <%= @unsubscribe_url %>
diff --git a/config/environments/test.rb b/config/environments/test.rb
index a497efc063..80ebf16776 100644
--- a/config/environments/test.rb
+++ b/config/environments/test.rb
@@ -27,6 +27,9 @@
   # The :test delivery method accumulates sent emails in the
   # ActionMailer::Base.deliveries array.
   config.action_mailer.delivery_method = :test
+  config.action_mailer.perform_deliveries = true
+  config.action_mailer.raise_delivery_errors = true
+  config.action_mailer.default_url_options = { host: 'test.host' }
 
   # Print deprecation notices to the stderr
   config.active_support.deprecation = :stderr
diff --git a/db/migrate/20250518011250_create_notifications.rb b/db/migrate/20250518011250_create_notifications.rb
new file mode 100644
index 0000000000..0f83267269
--- /dev/null
+++ b/db/migrate/20250518011250_create_notifications.rb
@@ -0,0 +1,10 @@
+class CreateNotifications < ActiveRecord::Migration[7.1]
+  def change
+    create_table :notifications do |t|
+      t.integer :user_id
+      t.string :message
+
+      t.timestamps
+    end
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 6daa71ebf1..be2da1ae53 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,8 +10,8 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.1].define(version: 2024_05_28_223908) do
-  create_table "activity_types", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+ActiveRecord::Schema[7.1].define(version: 2025_05_18_011250) do
+  create_table "activity_types", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.string "name", null: false
     t.string "abbreviation", null: false
     t.datetime "created_at", null: false
@@ -20,21 +20,21 @@
     t.index ["name"], name: "index_activity_types_on_name", unique: true
   end
 
-  create_table "auth_tokens", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "auth_tokens", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.datetime "auth_token_expiry", null: false
     t.bigint "user_id"
     t.string "authentication_token", null: false
     t.index ["user_id"], name: "index_auth_tokens_on_user_id"
   end
 
-  create_table "breaks", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "breaks", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.datetime "start_date", null: false
     t.integer "number_of_weeks", null: false
     t.bigint "teaching_period_id"
     t.index ["teaching_period_id"], name: "index_breaks_on_teaching_period_id"
   end
 
-  create_table "campuses", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "campuses", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.string "name", null: false
     t.integer "mode", null: false
     t.string "abbreviation", null: false
@@ -44,7 +44,7 @@
     t.index ["name"], name: "index_campuses_on_name", unique: true
   end
 
-  create_table "comments_read_receipts", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "comments_read_receipts", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.bigint "task_comment_id", null: false
     t.bigint "user_id", null: false
     t.datetime "created_at", null: false
@@ -54,7 +54,7 @@
     t.index ["user_id"], name: "index_comments_read_receipts_on_user_id"
   end
 
-  create_table "discussion_comments", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "discussion_comments", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.datetime "time_started"
     t.datetime "time_completed"
     t.integer "number_of_prompts"
@@ -62,7 +62,7 @@
     t.datetime "updated_at", null: false
   end
 
-  create_table "group_memberships", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "group_memberships", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.bigint "group_id"
     t.bigint "project_id"
     t.boolean "active", default: true
@@ -72,7 +72,7 @@
     t.index ["project_id"], name: "index_group_memberships_on_project_id"
   end
 
-  create_table "group_sets", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "group_sets", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.bigint "unit_id"
     t.string "name"
     t.boolean "allow_students_to_create_groups", default: true
@@ -85,7 +85,7 @@
     t.index ["unit_id"], name: "index_group_sets_on_unit_id"
   end
 
-  create_table "group_submissions", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "group_submissions", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.bigint "group_id"
     t.string "notes"
     t.bigint "submitted_by_project_id"
@@ -97,7 +97,7 @@
     t.index ["task_definition_id"], name: "index_group_submissions_on_task_definition_id"
   end
 
-  create_table "groups", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "groups", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.bigint "group_set_id"
     t.bigint "tutorial_id"
     t.string "name"
@@ -109,7 +109,7 @@
     t.index ["tutorial_id"], name: "index_groups_on_tutorial_id"
   end
 
-  create_table "learning_outcome_task_links", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "learning_outcome_task_links", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.text "description"
     t.integer "rating"
     t.bigint "task_definition_id"
@@ -122,7 +122,7 @@
     t.index ["task_id"], name: "index_learning_outcome_task_links_on_task_id"
   end
 
-  create_table "learning_outcomes", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "learning_outcomes", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.bigint "unit_id"
     t.integer "ilo_number"
     t.string "name"
@@ -131,7 +131,7 @@
     t.index ["unit_id"], name: "index_learning_outcomes_on_unit_id"
   end
 
-  create_table "logins", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "logins", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.datetime "timestamp"
     t.bigint "user_id"
     t.datetime "created_at", null: false
@@ -139,7 +139,14 @@
     t.index ["user_id"], name: "index_logins_on_user_id"
   end
 
-  create_table "overseer_assessments", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "notifications", charset: "utf8mb4", collation: "utf8mb4_general_ci", force: :cascade do |t|
+    t.integer "user_id"
+    t.string "message"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+  end
+
+  create_table "overseer_assessments", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.bigint "task_id", null: false
     t.string "submission_timestamp", null: false
     t.string "result_task_status"
@@ -150,7 +157,7 @@
     t.index ["task_id"], name: "index_overseer_assessments_on_task_id"
   end
 
-  create_table "overseer_images", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "overseer_images", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.string "name", null: false
     t.string "tag", null: false
     t.datetime "created_at", null: false
@@ -160,7 +167,7 @@
     t.datetime "last_pulled_date"
   end
 
-  create_table "projects", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "projects", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.bigint "unit_id"
     t.string "project_role"
     t.datetime "created_at", null: false
@@ -187,14 +194,14 @@
     t.index ["user_id"], name: "index_projects_on_user_id"
   end
 
-  create_table "roles", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "roles", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.string "name"
     t.text "description"
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
   end
 
-  create_table "task_comments", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "task_comments", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.bigint "task_id", null: false
     t.bigint "user_id", null: false
     t.string "comment", limit: 4096
@@ -225,7 +232,7 @@
     t.index ["user_id"], name: "index_task_comments_on_user_id"
   end
 
-  create_table "task_definitions", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "task_definitions", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.bigint "unit_id"
     t.string "name"
     t.string "description", limit: 4096
@@ -256,7 +263,7 @@
     t.index ["unit_id"], name: "index_task_definitions_on_unit_id"
   end
 
-  create_table "task_engagements", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "task_engagements", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.datetime "engagement_time"
     t.string "engagement"
     t.bigint "task_id"
@@ -265,7 +272,7 @@
     t.index ["task_id"], name: "index_task_engagements_on_task_id"
   end
 
-  create_table "task_pins", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "task_pins", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.bigint "task_id", null: false
     t.bigint "user_id", null: false
     t.datetime "created_at", null: false
@@ -275,7 +282,7 @@
     t.index ["user_id"], name: "fk_rails_915df186ed"
   end
 
-  create_table "task_similarities", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "task_similarities", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.bigint "task_id"
     t.bigint "other_task_id"
     t.integer "pct"
@@ -290,14 +297,14 @@
     t.index ["tii_submission_id"], name: "index_task_similarities_on_tii_submission_id"
   end
 
-  create_table "task_statuses", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "task_statuses", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.string "name"
     t.string "description"
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
   end
 
-  create_table "task_submissions", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "task_submissions", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.datetime "submission_time"
     t.datetime "assessment_time"
     t.string "outcome"
@@ -309,7 +316,7 @@
     t.index ["task_id"], name: "index_task_submissions_on_task_id"
   end
 
-  create_table "tasks", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "tasks", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.bigint "task_definition_id"
     t.bigint "project_id"
     t.bigint "task_status_id"
@@ -335,7 +342,7 @@
     t.index ["task_status_id"], name: "index_tasks_on_task_status_id"
   end
 
-  create_table "teaching_periods", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "teaching_periods", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.string "period", null: false
     t.datetime "start_date", null: false
     t.datetime "end_date", null: false
@@ -394,7 +401,7 @@
     t.index ["tii_task_similarity_id"], name: "index_tii_submissions_on_tii_task_similarity_id"
   end
 
-  create_table "tutorial_enrolments", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "tutorial_enrolments", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.bigint "project_id", null: false
@@ -404,7 +411,7 @@
     t.index ["tutorial_id"], name: "index_tutorial_enrolments_on_tutorial_id"
   end
 
-  create_table "tutorial_streams", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "tutorial_streams", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.string "name", null: false
     t.string "abbreviation", null: false
     t.datetime "created_at", null: false
@@ -418,7 +425,7 @@
     t.index ["unit_id"], name: "index_tutorial_streams_on_unit_id"
   end
 
-  create_table "tutorials", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "tutorials", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.bigint "unit_id"
     t.string "meeting_day"
     t.string "meeting_time"
@@ -437,7 +444,7 @@
     t.index ["unit_role_id"], name: "index_tutorials_on_unit_role_id"
   end
 
-  create_table "unit_roles", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "unit_roles", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.bigint "user_id"
     t.bigint "tutorial_id"
     t.datetime "created_at", null: false
@@ -450,7 +457,7 @@
     t.index ["user_id"], name: "index_unit_roles_on_user_id"
   end
 
-  create_table "units", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "units", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.string "name"
     t.string "description", limit: 4096
     t.datetime "start_date"
@@ -480,7 +487,7 @@
     t.index ["teaching_period_id"], name: "index_units_on_teaching_period_id"
   end
 
-  create_table "users", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "users", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.string "email", default: "", null: false
     t.string "encrypted_password", default: "", null: false
     t.string "reset_password_token"
@@ -513,7 +520,7 @@
     t.index ["role_id"], name: "index_users_on_role_id"
   end
 
-  create_table "webcal_unit_exclusions", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "webcal_unit_exclusions", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.bigint "webcal_id", null: false
     t.bigint "unit_id", null: false
     t.index ["unit_id", "webcal_id"], name: "index_webcal_unit_exclusions_on_unit_id_and_webcal_id", unique: true
@@ -521,7 +528,7 @@
     t.index ["webcal_id"], name: "fk_rails_d5fab02cb7"
   end
 
-  create_table "webcals", charset: "utf8", collation: "utf8_unicode_ci", force: :cascade do |t|
+  create_table "webcals", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.string "guid", limit: 36, null: false
     t.boolean "include_start_dates", default: false, null: false
     t.bigint "user_id"
diff --git a/test/api/staff_grant_extension_test.rb b/test/api/staff_grant_extension_test.rb
new file mode 100644
index 0000000000..a90d74dcd0
--- /dev/null
+++ b/test/api/staff_grant_extension_test.rb
@@ -0,0 +1,256 @@
+require 'test_helper'
+
+class StaffGrantExtensionTest < ActiveSupport::TestCase
+  include Rack::Test::Methods
+  include TestHelpers::AuthHelper
+  include TestHelpers::JsonHelper
+
+  def app
+    Rails.application
+  end
+
+  def test_staff_grant_extension_success
+    unit = FactoryBot.create(:unit)
+    project = unit.projects.first
+    staff = FactoryBot.create(:user, role: Role.tutor)
+    unit.employ_staff(staff, Role.tutor)
+
+    td = TaskDefinition.new({
+      unit_id: unit.id,
+      tutorial_stream: unit.tutorial_streams.first,
+      name: 'Staff Grant Extension Test',
+      description: 'Test task for staff grant extension',
+      weighting: 4,
+      target_grade: 0,
+      start_date: Time.zone.now - 1.week,
+      target_date: Time.zone.now + 1.week,
+      due_date: Time.zone.now + 2.weeks,
+      abbreviation: 'STAFFGRANTTEST',
+      restrict_status_updates: false,
+      upload_requirements: [],
+      plagiarism_warn_pct: 0.8,
+      is_graded: false,
+      max_quality_pts: 0
+    })
+    td.save!
+
+    data_to_post = {
+      student_ids: [project.student.id],
+      task_definition_id: td.id,
+      weeks_requested: 1,
+      comment: 'Staff granted extension'
+    }
+
+    add_auth_header_for user: staff
+    post_json "/api/units/#{unit.id}/staff-grant-extension", data_to_post
+    assert_equal 201, last_response.status
+
+    response = last_response_body
+    assert response["successful"].length == 1, 'Should have one successful extension'
+    assert response["failed"].empty?, 'Should have no failed extensions'
+    assert response["successful"][0]["student_id"] == project.student.id, 'Should match the student ID'
+    assert response["successful"][0]["weeks_requested"] == 1, 'Should have requested 1 week'
+    assert response["successful"][0]["extension_response"].present?, 'Should have extension response'
+    assert response["successful"][0]["task_status"].present?, 'Should have task status'
+
+    notifications = Notification.where(user_id: project.student.id)
+    assert_equal 1, notifications.count, 'Should create one notification for the student'
+    notification = notifications.first
+    assert_match /You were granted an extension for task/, notification.message
+    assert_match /#{td.name}/, notification.message
+    assert_match /#{unit.name}/, notification.message
+
+    td.destroy!
+    unit.destroy!
+  end
+
+  def test_staff_grant_extension_unauthorized
+    unit = FactoryBot.create(:unit)
+    project = unit.projects.first
+    student = project.student # Using student instead of staff
+    td = unit.task_definitions.first
+
+    data_to_post = {
+      student_ids: [project.student.id],
+      task_definition_id: td.id,
+      weeks_requested: 1,
+      comment: 'Unauthorized attempt'
+    }
+
+    add_auth_header_for user: student
+    post_json "/api/units/#{unit.id}/staff-grant-extension", data_to_post
+    assert_equal 403, last_response.status, 'Should not allow non-staff to grant extensions'
+  end
+
+  def test_staff_grant_extension_invalid_weeks
+    unit = FactoryBot.create(:unit)
+    project = unit.projects.first
+    staff = FactoryBot.create(:user, role: Role.tutor)
+    unit.employ_staff(staff, Role.tutor)
+    td = unit.task_definitions.first
+
+    data_to_post = {
+      student_ids: [project.student.id],
+      task_definition_id: td.id,
+      weeks_requested: 0,
+      comment: 'Invalid weeks'
+    }
+
+    add_auth_header_for user: staff
+    post_json "/api/units/#{unit.id}/staff-grant-extension", data_to_post
+    assert_equal 403, last_response.status, 'Should not allow 0 weeks extension'
+  end
+
+  def test_staff_grant_extension_negative_weeks
+    unit = FactoryBot.create(:unit)
+    project = unit.projects.first
+    staff = FactoryBot.create(:user, role: Role.tutor)
+    unit.employ_staff(staff, Role.tutor)
+    td = unit.task_definitions.first
+
+    data_to_post = {
+      student_ids: [project.student.id],
+      task_definition_id: td.id,
+      weeks_requested: -1,
+      comment: 'Negative weeks'
+    }
+
+    add_auth_header_for user: staff
+    post_json "/api/units/#{unit.id}/staff-grant-extension", data_to_post
+    assert_equal 403, last_response.status, 'Should not allow negative weeks extension'
+  end
+
+  def test_staff_grant_extension_missing_params
+    unit = FactoryBot.create(:unit)
+    staff = FactoryBot.create(:user, role: Role.tutor)
+    unit.employ_staff(staff, Role.tutor)
+
+    data_to_post = {
+      student_ids: [1],
+      # Missing task_definition_id and weeks_requested
+      comment: 'Missing params'
+    }
+
+    add_auth_header_for user: staff
+    post_json "/api/units/#{unit.id}/staff-grant-extension", data_to_post
+    assert_equal 400, last_response.status, 'Should require all parameters'
+  end
+
+  def test_staff_grant_extension_transaction_rollback
+    unit = FactoryBot.create(:unit)
+    project = unit.projects.first
+    staff = FactoryBot.create(:user, role: Role.tutor)
+    unit.employ_staff(staff, Role.tutor)
+    td = unit.task_definitions.first
+
+    # Test case 1: One valid student, one skipped student
+    data_to_post = {
+      student_ids: [project.student.id, 999999], # One valid, one invalid
+      task_definition_id: td.id,
+      weeks_requested: 1,
+      comment: 'Transaction test with skipped student'
+    }
+
+    add_auth_header_for user: staff
+    post_json "/api/units/#{unit.id}/staff-grant-extension", data_to_post
+    assert_equal 201, last_response.status, 'Should succeed for valid student'
+
+    response = last_response_body
+    assert response["successful"].length == 1, 'Should have one successful extension'
+    assert response["skipped"].length == 1, 'Should have one skipped student'
+    assert response["failed"].empty?, 'Should have no failed extensions'
+    assert response["skipped"][0]["student_id"] == 999999, 'Should have skipped the invalid student ID'
+    assert response["skipped"][0]["reason"] == 'Student not found in unit', 'Should have correct skip reason'
+
+    # Verify only the valid student got an extension
+    task = project.task_for_task_definition(td)
+    assert task.extensions == 1, 'Should have one extension for the valid student'
+
+    # Test case 2: Test actual transaction rollback
+    # Create a second project to test with
+    project2 = unit.projects.create!(
+      user: FactoryBot.create(:user, role: Role.student),
+      enrolled: true
+    )
+
+    # First, grant extensions to both students
+    data_to_post = {
+      student_ids: [project.student.id, project2.student.id],
+      task_definition_id: td.id,
+      weeks_requested: 1,
+      comment: 'Initial extensions'
+    }
+
+    add_auth_header_for user: staff
+    post_json "/api/units/#{unit.id}/staff-grant-extension", data_to_post
+    assert_equal 201, last_response.status, 'Should succeed for both students'
+
+    # Verify both students got extensions
+    task1 = project.task_for_task_definition(td)
+    task2 = project2.task_for_task_definition(td)
+    assert task1.extensions == 2, 'First student should have two extensions'
+    assert task2.extensions == 1, 'Second student should have one extension'
+
+    # Now try to grant extensions with a task that would cause a failure
+    # Use a task that's past its deadline to force a failure
+    td.due_date = Time.zone.now - 1.day
+    td.save!
+
+    data_to_post = {
+      student_ids: [project.student.id, project2.student.id],
+      task_definition_id: td.id,
+      weeks_requested: 1,
+      comment: 'Transaction rollback test'
+    }
+
+    add_auth_header_for user: staff
+    post_json "/api/units/#{unit.id}/staff-grant-extension", data_to_post
+    assert_equal 403, last_response.status, 'Should fail with 403 when task is past deadline'
+
+    # Verify neither student got a new extension (transaction rolled back)
+    task1.reload
+    task2.reload
+    assert task1.extensions == 2, 'First student should still have two extensions'
+    assert task2.extensions == 1, 'Second student should still have one extension'
+
+    td.destroy!
+    unit.destroy!
+  end
+
+  def test_staff_grant_extension_invalid_unit
+    unit = FactoryBot.create(:unit)
+    project = unit.projects.first
+    staff = FactoryBot.create(:user, role: Role.tutor)
+    unit.employ_staff(staff, Role.tutor)
+    td = unit.task_definitions.first
+
+    data_to_post = {
+      student_ids: [project.student.id],
+      task_definition_id: td.id,
+      weeks_requested: 1,
+      comment: 'Invalid unit'
+    }
+
+    add_auth_header_for user: staff
+    post_json "/api/units/999999/staff-grant-extension", data_to_post
+    assert_equal 404, last_response.status, 'Should return 404 for invalid unit'
+  end
+
+  def test_staff_grant_extension_invalid_task
+    unit = FactoryBot.create(:unit)
+    project = unit.projects.first
+    staff = FactoryBot.create(:user, role: Role.tutor)
+    unit.employ_staff(staff, Role.tutor)
+
+    data_to_post = {
+      student_ids: [project.student.id],
+      task_definition_id: 999999,
+      weeks_requested: 1,
+      comment: 'Invalid task'
+    }
+
+    add_auth_header_for user: staff
+    post_json "/api/units/#{unit.id}/staff-grant-extension", data_to_post
+    assert_equal 404, last_response.status, 'Should return 404 for invalid task definition'
+  end
+end
diff --git a/test/mailers/notifications_mailer_test.rb b/test/mailers/notifications_mailer_test.rb
new file mode 100644
index 0000000000..393b380298
--- /dev/null
+++ b/test/mailers/notifications_mailer_test.rb
@@ -0,0 +1,226 @@
+require 'test_helper'
+
+class NotificationsMailerTest < ActionMailer::TestCase
+  include TestHelpers::AuthHelper
+
+  def setup
+    # Mock Doubtfire configuration
+    Doubtfire::Application.config.institution = {
+      host: 'doubtfire.deakin.edu.au',
+      product_name: 'Doubtfire'
+    }
+
+    # Create unit and staff
+    @unit = FactoryBot.create(:unit)
+    @staff = FactoryBot.create(:user, role: Role.tutor)
+    @unit.employ_staff(@staff, Role.tutor)
+
+    # Create a task definition
+    @task_definition = @unit.task_definitions.create!({
+      tutorial_stream: @unit.tutorial_streams.first,
+      name: 'Test Task',
+      description: 'Test task for notifications',
+      weighting: 4,
+      target_grade: 0,
+      start_date: Time.zone.now - 1.week,
+      target_date: Time.zone.now + 1.week,
+      due_date: Time.zone.now + 2.weeks,
+      abbreviation: 'TESTTASK',
+      restrict_status_updates: false,
+      upload_requirements: [],
+      plagiarism_warn_pct: 0.8,
+      is_graded: false,
+      max_quality_pts: 0
+    })
+
+    # Create students and projects with notification preferences
+    @students = []
+    @projects = []
+
+    # Create one student with notifications enabled
+    student_with_notifications = FactoryBot.create(:user, role: Role.student)
+    student_with_notifications.update(receive_task_notifications: true)
+    project = @unit.projects.create!(user: student_with_notifications, enrolled: true)
+    @students << student_with_notifications
+    @projects << project
+
+    # Create two students without notifications
+    2.times do
+      student = FactoryBot.create(:user, role: Role.student)
+      student.update(receive_task_notifications: false)
+      project = @unit.projects.create!(user: student, enrolled: true)
+      @students << student
+      @projects << project
+    end
+
+    # Clear any existing emails before each test
+    ActionMailer::Base.deliveries.clear
+  end
+
+  def teardown
+    @task_definition.destroy!
+    @unit.destroy!
+    ActionMailer::Base.deliveries.clear
+  end
+
+  test 'creates correct extension summary email' do
+    # Create extensions
+    extensions = []
+    @projects.each do |project|
+      task = project.task_for_task_definition(@task_definition)
+      extension = task.apply_for_extension(@staff, 'Test comment', 1)
+      extension.assess_extension(@staff, true, true)
+      extensions << extension
+    end
+
+    # Get the mail object
+    mail = NotificationsMailer.extension_granted_summary(extensions, @staff, extensions.count)
+
+    # Verify email properties
+    assert_equal [@staff.email], mail.to
+    assert_equal "#{@unit.name}: Staff Grant Extensions", mail.subject
+    assert_match /You have granted extensions for the following students/, mail.html_part.body.to_s
+
+    # Verify from address contains no-reply
+    assert_includes mail.from.first, "no-reply@"
+    assert_includes mail.from.first, NotificationsMailer.doubtfire_host
+  end
+
+  test 'creates correct extension notification email' do
+    # Create extension
+    project = @projects.first
+    task = project.task_for_task_definition(@task_definition)
+    extension = task.apply_for_extension(@staff, 'Test comment', 1)
+    extension.assess_extension(@staff, true, true)
+
+    # Get the mail object
+    mail = NotificationsMailer.extension_granted_notification(extension, @staff)
+
+    # Verify email properties
+    assert_equal [@students.first.email], mail.to
+    assert_equal "#{@unit.name}: Extension granted for #{@task_definition.name}", mail.subject
+    assert_match /Dear #{@students.first.name}/, mail.html_part.body.to_s
+
+    # Verify from address contains staff email
+    assert_includes mail.from.first, @staff.email
+  end
+
+  test 'creates correct extension summary with failed extensions' do
+    # Create successful extensions
+    successful_extensions = []
+    @projects.each do |project|
+      task = project.task_for_task_definition(@task_definition)
+      extension = task.apply_for_extension(@staff, 'Test comment', 1)
+      extension.assess_extension(@staff, true, true)
+      successful_extensions << extension
+    end
+
+    # Create failed extensions
+    failed_extensions = [
+      { student_id: 999, error: 'Student not found in unit' },
+      { student_id: 1000, error: 'Extension cannot be granted beyond task deadline' }
+    ]
+
+    # Get the mail object
+    mail = NotificationsMailer.extension_granted_summary(
+      successful_extensions,
+      @staff,
+      successful_extensions.count,
+      failed_extensions
+    )
+
+    # Verify email includes failed extensions
+    assert_equal [@staff.email], mail.to
+    assert_match /Failed Extensions/, mail.html_part.body.to_s
+    assert_match /999/, mail.html_part.body.to_s
+    assert_match /1000/, mail.html_part.body.to_s
+
+    # Verify from address contains no-reply
+    assert_includes mail.from.first, "no-reply@"
+    assert_includes mail.from.first, NotificationsMailer.doubtfire_host
+  end
+
+  test 'creates correct extension notification with special characters' do
+    # Create task with special characters
+    special_task = @unit.task_definitions.create!({
+      tutorial_stream: @unit.tutorial_streams.first,
+      name: 'Test Task with !@#$%^&*()',
+      description: 'Test task with special characters',
+      weighting: 4,
+      target_grade: 0,
+      start_date: Time.zone.now - 1.week,
+      target_date: Time.zone.now + 1.week,
+      due_date: Time.zone.now + 2.weeks,
+      abbreviation: 'SPECIAL',
+      restrict_status_updates: false,
+      upload_requirements: [],
+      plagiarism_warn_pct: 0.8,
+      is_graded: false,
+      max_quality_pts: 0
+    })
+
+    # Create extension
+    project = @projects.first
+    task = project.task_for_task_definition(special_task)
+    extension = task.apply_for_extension(@staff, 'Special characters test', 1)
+    extension.assess_extension(@staff, true, true)
+
+    # Get the mail object
+    mail = NotificationsMailer.extension_granted_notification(extension, @staff)
+
+    # Verify email handles special characters
+    assert_equal [@students.first.email], mail.to
+    assert_equal "#{@unit.name}: Extension granted for #{special_task.name}", mail.subject
+    assert_match /Dear #{@students.first.name}/, mail.html_part.body.to_s
+
+    # Verify from address contains staff email
+    assert_includes mail.from.first, @staff.email
+
+    # Clean up
+    special_task.destroy!
+  end
+
+  test 'creates correct weekly staff summary email' do
+    # Create data for summary stats
+    summary_stats = {
+      unit: @unit,
+      week_start: Time.zone.now - 1.week,
+      week_end: Time.zone.now,
+      staff: {}
+    }
+
+    unit_role = @unit.unit_roles.find_by(user: @staff)
+    summary_stats[:staff][unit_role] = { data: "test data" }
+
+    # Get the mail object
+    mail = NotificationsMailer.weekly_staff_summary(unit_role, summary_stats)
+
+    # Verify email properties
+    assert_equal [@staff.email], mail.to
+    assert_equal "#{@unit.name}: Weekly Summary", mail.subject
+
+    # Verify from address contains convenor email
+    assert_includes mail.from.first, @unit.main_convenor_user.email
+  end
+
+  test 'creates correct weekly student summary email' do
+    # Create data for summary stats
+    summary_stats = {
+      unit: @unit,
+      week_start: Time.zone.now - 1.week,
+      week_end: Time.zone.now
+    }
+
+    project = @projects.first
+
+    # Get the mail object
+    mail = NotificationsMailer.weekly_student_summary(project, summary_stats, false)
+
+    # Verify email properties
+    assert_equal [@students.first.email], mail.to
+    assert_equal "#{@unit.name}: Weekly Summary", mail.subject
+
+    # Verify from address contains tutor email
+    assert_includes mail.from.first, project.main_convenor_user.email
+  end
+end