⚡ Bolt: Optimized Blockchain Integrity Seal & Issue Retrieval

backend/init_db.py

@@ -1,6 +1,8 @@
 import sys
 import os
 from pathlib import Path
+from sqlalchemy import text
+import logging
 
 # Add project root to path
 current_file = Path(__file__).resolve()
@@ -11,19 +13,13 @@
 from backend.database import engine, Base
 from backend.models import *
 
+logger = logging.getLogger(__name__)
+
 def init_db():
     print("Creating tables...")
     Base.metadata.create_all(bind=engine)
     print("Tables created.")
 
-if __name__ == "__main__":
-    init_db()
-from sqlalchemy import text
-from backend.database import engine
-import logging
-
-logger = logging.getLogger(__name__)
-
 def migrate_db():
     """
     Perform database migrations.
@@ -124,6 +120,13 @@ def migrate_db():
             except Exception:
                 pass
 
+            # Add previous_integrity_hash column for O(1) blockchain verification
+            try:
+                conn.execute(text("ALTER TABLE issues ADD COLUMN previous_integrity_hash VARCHAR"))
+                print("Migrated database: Added previous_integrity_hash column.")
+            except Exception:
+                pass
+
             # Add index on user_email
             try:
                 conn.execute(text("CREATE INDEX ix_issues_user_email ON issues (user_email)"))
@@ -212,3 +215,7 @@ def migrate_db():
             logger.info("Database migration check completed.")
     except Exception as e:
         logger.error(f"Database migration error: {e}")
+
+if __name__ == "__main__":
+    init_db()
+    migrate_db()

backend/models.py

@@ -161,7 +161,8 @@ class Issue(Base):
     longitude = Column(Float, nullable=True, index=True)
     location = Column(String, nullable=True)
     action_plan = Column(JSONEncodedDict, nullable=True)
-    integrity_hash = Column(String, nullable=True)  # Blockchain integrity seal
+    integrity_hash = Column(String, nullable=True)  # Current report hash
+    previous_integrity_hash = Column(String, nullable=True)  # Link to predecessor for O(1) verification
 
 class PushSubscription(Base):
     __tablename__ = "push_subscriptions"

backend/requirements-render.txt

@@ -13,5 +13,7 @@ Pillow
 firebase-functions
 firebase-admin
 a2wsgi
-python-jose[cryptography]
-passlib[bcrypt]
+python-jose
+cryptography
+passlib
+bcrypt

backend/routers/issues.py

@@ -15,7 +15,7 @@
 from backend.models import Issue, PushSubscription
 from backend.schemas import (
     IssueCreateWithDeduplicationResponse, IssueCategory, NearbyIssueResponse,
-    DeduplicationCheckResponse, IssueSummaryResponse, VoteResponse,
+    DeduplicationCheckResponse, IssueSummaryResponse, IssueResponse, VoteResponse,
     IssueStatusUpdateRequest, IssueStatusUpdateResponse, PushSubscriptionRequest,
     PushSubscriptionResponse, BlockchainVerificationResponse
 )
@@ -168,15 +168,22 @@ async def create_issue(
     try:
         # Save to DB only if no nearby issues found or deduplication failed
         if deduplication_info is None or not deduplication_info.has_nearby_issues:
-            # Blockchain feature: calculate integrity hash for the report
-            # Optimization: Fetch only the last hash to maintain the chain with minimal overhead
+            # Robust Blockchain Implementation
+            # 1. Fetch only the last hash to maintain the chain with minimal overhead
             prev_issue = await run_in_threadpool(
                 lambda: db.query(Issue.integrity_hash).order_by(Issue.id.desc()).first()
             )
             prev_hash = prev_issue[0] if prev_issue and prev_issue[0] else ""
 
-# Simple but effective SHA-256 chaining
-            hash_content = f"{description}|{category}|{prev_hash}"
+            # 2. Generate secure reference ID
+            reference_id = str(uuid.uuid4())
+
+            # 3. Calculate robust integrity hash incorporating multiple fields
+            # Chaining logic: hash(ref_id|desc|cat|lat|lon|email|prev_hash)
+            # Use fixed float formatting to ensure consistent hashing across environments
+            lat_str = f"{latitude:.7f}" if latitude is not None else "None"
+            lon_str = f"{longitude:.7f}" if longitude is not None else "None"
+            hash_content = f"{reference_id}|{description}|{category}|{lat_str}|{lon_str}|{user_email}|{prev_hash}"
             integrity_hash = hashlib.sha256(hash_content.encode()).hexdigest()
 
             # RAG Retrieval (New)
@@ -186,7 +193,7 @@ async def create_issue(
                 initial_action_plan = {"relevant_government_rule": relevant_rule}
 
             new_issue = Issue(
-                reference_id=str(uuid.uuid4()),
+                reference_id=reference_id,
                 description=description,
                 category=category,
                 image_path=image_path,
@@ -196,7 +203,8 @@ async def create_issue(
                 longitude=longitude,
                 location=location,
                 action_plan=initial_action_plan,
-                integrity_hash=integrity_hash
+                integrity_hash=integrity_hash,
+                previous_integrity_hash=prev_hash
             )
 
             # Offload blocking DB operations to threadpool
@@ -615,30 +623,44 @@ def get_user_issues(
 async def verify_blockchain_integrity(issue_id: int, db: Session = Depends(get_db)):
     """
     Verify the cryptographic integrity of a report using the blockchain-style chaining.
-    Optimized: Uses column projection to fetch only needed data.
+    Optimized: Uses stored previous_integrity_hash for O(1) chain verification.
     """
-    # Fetch current issue data
+    # Fetch current issue data (Performance Boost: Fetch only needed columns)
     current_issue = await run_in_threadpool(
         lambda: db.query(
-            Issue.id, Issue.description, Issue.category, Issue.integrity_hash
+            Issue.id,
+            Issue.reference_id,
+            Issue.description,
+            Issue.category,
+            Issue.latitude,
+            Issue.longitude,
+            Issue.user_email,
+            Issue.integrity_hash,
+            Issue.previous_integrity_hash
         ).filter(Issue.id == issue_id).first()
     )
 
     if not current_issue:
         raise HTTPException(status_code=404, detail="Issue not found")
 
-    # Fetch previous issue's integrity hash to verify the chain
-    prev_issue_hash = await run_in_threadpool(
-        lambda: db.query(Issue.integrity_hash).filter(Issue.id < issue_id).order_by(Issue.id.desc()).first()
-    )
-
-    prev_hash = prev_issue_hash[0] if prev_issue_hash and prev_issue_hash[0] else ""
+    # Chaining logic depends on when the issue was created (legacy fallback)
+    # Optimized: Use stored previous hash if available, otherwise fallback to subquery (O(N) search)
+    if current_issue.previous_integrity_hash is not None:
+        prev_hash = current_issue.previous_integrity_hash
+        # New robust hash formula with fixed float formatting
+        lat_str = f"{current_issue.latitude:.7f}" if current_issue.latitude is not None else "None"
+        lon_str = f"{current_issue.longitude:.7f}" if current_issue.longitude is not None else "None"
+        hash_content = f"{current_issue.reference_id}|{current_issue.description}|{current_issue.category}|{lat_str}|{lon_str}|{current_issue.user_email}|{prev_hash}"
+    else:
+        # Legacy fallback: Fetch previous issue's hash via subquery
+        prev_issue_hash = await run_in_threadpool(
+            lambda: db.query(Issue.integrity_hash).filter(Issue.id < issue_id).order_by(Issue.id.desc()).first()
+        )
+        prev_hash = prev_issue_hash[0] if prev_issue_hash and prev_issue_hash[0] else ""
+        # Legacy hash formula
+        hash_content = f"{current_issue.description}|{current_issue.category}|{prev_hash}"
 
-    # Recompute hash based on current data and previous hash
-    # Chaining logic: hash(description|category|prev_hash)
-    hash_content = f"{current_issue.description}|{current_issue.category}|{prev_hash}"
     computed_hash = hashlib.sha256(hash_content.encode()).hexdigest()
-
     is_valid = (computed_hash == current_issue.integrity_hash)
 
     if is_valid:
@@ -702,3 +724,43 @@ def get_recent_issues(
     # Thread-safe cache update
     recent_issues_cache.set(data, cache_key)
     return data
+
+@router.get("/api/issues/{issue_id}", response_model=IssueResponse)
+async def get_issue_by_id(issue_id: int, db: Session = Depends(get_db)):
+    """
+    Get a single issue by its ID.
+    Optimized: Uses column projection for efficient retrieval.
+    """
+    # Performance Boost: Use column projection instead of loading full model
+    issue = await run_in_threadpool(
+        lambda: db.query(
+            Issue.id,
+            Issue.category,
+            Issue.description,
+            Issue.created_at,
+            Issue.image_path,
+            Issue.status,
+            Issue.upvotes,
+            Issue.location,
+            Issue.latitude,
+            Issue.longitude,
+            Issue.action_plan
+        ).filter(Issue.id == issue_id).first()
+    )
+
+    if not issue:
+        raise HTTPException(status_code=404, detail="Issue not found")
+
+    return {
+        "id": issue.id,
+        "category": issue.category,
+        "description": issue.description,
+        "created_at": issue.created_at,
+        "image_path": issue.image_path,
+        "status": issue.status,
+        "upvotes": issue.upvotes or 0,
+        "location": issue.location,
+        "latitude": issue.latitude,
+        "longitude": issue.longitude,
+        "action_plan": issue.action_plan
+    }

frontend/src/api/issues.js

@@ -20,5 +20,13 @@ export const issuesApi = {
 
   vote: async (id) => {
     return await apiClient.post(`/api/issues/${id}/vote`, {}); // The backend endpoint might not require a body for upvote
+  },
+
+  getById: async (id) => {
+    return await apiClient.get(`/api/issues/${id}`);
+  },
+
+  verifyBlockchain: async (id) => {
+    return await apiClient.get(`/api/issues/${id}/blockchain-verify`);
   }
 };

frontend/src/views/VerifyView.jsx

@@ -1,6 +1,6 @@
 import React, { useState, useEffect } from 'react';
 import { useParams, useNavigate } from 'react-router-dom';
-import { Camera, Upload, CheckCircle, XCircle, AlertTriangle, ArrowLeft } from 'lucide-react';
+import { Camera, Upload, CheckCircle, XCircle, AlertTriangle, ArrowLeft, ShieldCheck } from 'lucide-react';
 import { issuesApi } from '../api/issues';
 
 const API_URL = import.meta.env.VITE_API_URL || '';
@@ -14,16 +14,18 @@ const VerifyView = () => {
   const [image, setImage] = useState(null);
   const [result, setResult] = useState(null);
   const [error, setError] = useState(null);
+  const [blockchainLoading, setBlockchainLoading] = useState(false);
+  const [blockchainResult, setBlockchainResult] = useState(null);
 
   useEffect(() => {
     const fetchIssue = async () => {
       try {
-        const issues = await issuesApi.getRecent();
-        const found = issues.find(i => i.id === parseInt(id));
-        if (found) {
-          setIssue(found);
+        // Optimization: Fetch issue by ID directly (O(1)) instead of searching recent list (O(N))
+        const data = await issuesApi.getById(id);
+        if (data) {
+          setIssue(data);
         } else {
-          setError("Issue not found in recent list.");
+          setError("Issue not found.");
         }
       } catch (err) {
         console.error("Load failed", err);
@@ -42,6 +44,23 @@ const VerifyView = () => {
     }
   };
 
+  const handleBlockchainVerify = async () => {
+    setBlockchainLoading(true);
+    setBlockchainResult(null);
+    try {
+      const data = await issuesApi.verifyBlockchain(id);
+      setBlockchainResult(data);
+    } catch (err) {
+      console.error("Blockchain verification failed", err);
+      setBlockchainResult({
+        is_valid: false,
+        message: "Failed to connect to the blockchain verification service."
+      });
+    } finally {
+      setBlockchainLoading(false);
+    }
+  };
+
   const handleVerify = async () => {
     if (!image) return;
     setVerifying(true);
@@ -141,6 +160,48 @@ const VerifyView = () => {
             )}
         </div>
       </div>
+
+      {/* Blockchain Integrity Seal Section */}
+      <div className="bg-gradient-to-br from-indigo-50 to-blue-50 rounded-xl shadow-sm border border-indigo-100 p-6 mb-6">
+        <div className="flex items-center gap-3 mb-4">
+          <ShieldCheck className="text-indigo-600" size={28} />
+          <h2 className="text-xl font-bold text-indigo-900">Blockchain Integrity Seal</h2>
+        </div>
+
+        <p className="text-indigo-800 text-sm mb-4">
+          Every report in our system is cryptographically sealed and linked to the previous report, creating an immutable chain of records. Verify that this report hasn't been tampered with.
+        </p>
+
+        <button
+          onClick={handleBlockchainVerify}
+          disabled={blockchainLoading}
+          className="w-full bg-indigo-600 text-white py-2 rounded-lg font-semibold hover:bg-indigo-700 transition disabled:opacity-50"
+        >
+          {blockchainLoading ? 'Verifying Integrity Hash...' : 'Verify Cryptographic Seal'}
+        </button>
+
+        {blockchainResult && (
+          <div className={`mt-4 p-3 rounded border text-sm ${blockchainResult.is_valid ? 'bg-white border-green-200 text-green-800' : 'bg-red-50 border-red-200 text-red-800'}`}>
+            <div className="flex items-start gap-2">
+              {blockchainResult.is_valid ? (
+                <CheckCircle size={18} className="text-green-600 mt-0.5" />
+              ) : (
+                <XCircle size={18} className="text-red-600 mt-0.5" />
+              )}
+              <div>
+                <p className="font-bold">{blockchainResult.is_valid ? 'Integrity Verified' : 'Integrity Compromised'}</p>
+                <p className="opacity-90">{blockchainResult.message}</p>
+                {blockchainResult.current_hash && (
+                  <div className="mt-2 pt-2 border-t border-gray-100 font-mono text-[10px] break-all">
+                    <p className="font-semibold text-gray-500 mb-1 uppercase tracking-tighter">Current Hash:</p>
+                    {blockchainResult.current_hash}
+                  </div>
+                )}
+              </div>
+            </div>
+          </div>
+        )}
+      </div>
     </div>
   );
 };

render.yaml

@@ -14,7 +14,7 @@ services:
           name: vishwaguru-backend
           property: port
       - key: PYTHONPATH
-        value: backend
+        value: .
       # Required API Keys (must be set in Render dashboard)
       - key: GEMINI_API_KEY
         sync: false