Event Ticketing: dynamic pricing and cancelled-event batch refunds

[josephchimebuka]

Summary

This PR implements two ticketing enhancements in the Shade event module:

• Dynamic time-based ticket pricing (early-bird discount vs late markup)
• Automated batch refunds for cancelled events

Issues Closed

Closes #264
Closes #261

What Changed

1) Dynamic Pricing Models (#264)

• Added configurable dynamic pricing controls per event:
  • early_bird_end timestamp
  • early_bird_discount_bps
  • late_markup_bps
• Added new public methods:
  • configure_dynamic_pricing(merchant, event_id, early_bird_end, early_bird_discount_bps, late_markup_bps)
  • get_current_ticket_price(event_id)
• Updated purchase flow to evaluate current time and apply pricing adjustment before Shade payment split:
  • During early-bird window: discounted price
  • After early-bird window: marked-up price
  • If not configured: base price remains unchanged
• Applied the same dynamic unit-price logic to bulk purchase calculations.

2) Batch Refund Logic for Cancelled Events (#261)

• Added cancellation + batch refund flow:
  • cancel_event_and_batch_refund(merchant, event_id)
• Flow behavior:
  • Validates merchant authorization for the event
  • Marks event as cancelled
  • Iterates all ticket IDs in EventTickets(event_id)
  • Refunds each holder based on stored primary purchase price (ticket.purchase_price)
  • Marks refund processing complete to prevent duplicate execution
• Added guardrails:
  • Ticket purchases/resales are blocked for cancelled events
  • Second refund attempt for same event is rejected

Data Model Updates

• Event now tracks:
  • early_bird_end, early_bird_discount_bps, late_markup_bps
  • cancelled, refunds_processed
• Ticket now stores:
  • purchase_price (captured at purchase time and used for cancellation refunds)

Interface / Contract Surface

• Extended Shade trait and implementation with:
  • configure_dynamic_pricing
  • get_current_ticket_price
  • cancel_event_and_batch_refund

Tests

Added/updated event ticket tests to cover:

• Dynamic pricing transition (early-bird discounted buy, late marked-up buy)
• Batch refunds returning funds to all ticket holders after cancellation
• Duplicate batch refund prevention

Executed:

• cargo test -q test_event_tickets in contracts/shade
• Result: passing (17 passed)

Acceptance Criteria Mapping

#264 Create Dynamic Pricing Models

• Time-based price checks implemented
• Cost adjusted before Shade payment processing
• Prices adjust over time between early and late windows

#261 Integrate Shade Batch Refund Logic for Cancelled Events

• Ticket holders iterated via event ticket index
• Refunds executed through Shade event cancellation/refund workflow
• Bulk refunds execute correctly with duplicate-refund prevention

[drips-wave]

@josephchimebuka Great news! 🎉 Based on an automated assessment of this PR, the linked Wave issue(s) no longer count against your application limits.

You can now already apply to more issues while waiting for a review of this PR. Keep up the great work! 🚀

Learn more about application limits