# Epic: Deposit Form & Payment Integration - Brownfield Enhancement

## Epic Goal
Complete the deposit form functionality and integrate secure payment processing to enable online deposits for tattoo appointments, improving customer convenience and reducing manual payment handling.

## Epic Description

**Existing System Context:**
- Current booking system with deposit requirements
- Existing user authentication and appointment management
- Technology stack: Next.js, TypeScript, Tailwind CSS
- Mobile-first user base (70% of bookings from mobile devices)

**Enhancement Details:**
- Implement complete deposit form with client-side validation and error handling
- Integrate Stripe payment processing using Embedded Elements for optimal UX and PCI compliance
- Use inline payment form within booking flow to reduce abandonment
- Implement immediate retry for transient payment failures with fallback to manual processing
- Connect payment success to booking confirmation and email notifications
- Add admin dashboard for payment tracking, reporting, and manual intervention
- Store only payment reference IDs and status (no sensitive card data)
- Success criteria: Reduce deposit processing time from 48hrs to <5min, achieve 95% payment success rate, process 80% of deposits online

## Stories

1. **Story 1:** Complete deposit form UI with validation and error handling
2. **Story 2:** Integrate payment gateway API and handle payment processing
3. **Story 3:** Connect payment success to booking confirmation and email notifications
4. **Story 4:** Add admin payment tracking dashboard and reporting

## Compatibility Requirements
- [ ] Existing booking APIs remain unchanged
- [ ] User authentication system integrates seamlessly
- [ ] Database schema changes are backward compatible
- [ ] UI follows existing design patterns
- [ ] Performance impact is minimal (<200ms response time)

## Risk Mitigation
- **Primary Risk:** Payment security and PCI compliance
- **Mitigation:** Use certified payment gateway, no sensitive data storage
- **Rollback Plan:** Disable payment button, revert to manual deposit handling

## Definition of Done
- [ ] All stories completed with acceptance criteria met
- [ ] Existing functionality verified through testing
- [ ] Payment integration points working correctly
- [ ] Security and compliance requirements met
- [ ] No regression in existing booking features