# Custom Task Status Migration - Task 1 Implementation Summary

## Overview
Successfully implemented database schema changes and migration to support custom task statuses in the VFX Project Management System.

## Changes Made

### 1. Database Schema Updates

#### Project Model (`backend/models/project.py`)
- ✅ Added `custom_task_statuses` JSON column to store project-specific custom statuses
- Column initialized with empty array `[]` for all existing projects

#### Task Model (`backend/models/task.py`)
- ✅ Changed `status` field from `Enum(TaskStatus)` to `String`
- Updated default value from `TaskStatus.NOT_STARTED` to `"not_started"`
- Maintains backward compatibility with existing system statuses

### 2. Schema Updates (`backend/schemas/task.py`)
- ✅ Updated `TaskBase.status` from `TaskStatus` enum to `str` type
- ✅ Updated `TaskUpdate.status` from `Optional[TaskStatus]` to `Optional[str]`
- ✅ Updated `TaskStatusUpdate.status` from `TaskStatus` to `str`
- Changed default value to `"not_started"` (lowercase string)

### 3. Router Updates
Updated all routers to use string values instead of TaskStatus enum:

#### Assets Router (`backend/routers/assets.py`)
- ✅ Changed task creation to use `status="not_started"`
- ✅ Updated status initialization in task status aggregation
- ✅ Updated status filtering to use string comparison
- ✅ Updated status sorting to use string-based status order

#### Reviews Router (`backend/routers/reviews.py`)
- ✅ Updated submission status checks to use `"submitted"` string
- ✅ Changed approval status update to `"approved"` string
- ✅ Changed retake status update to `"retake"` string

#### Shots Router (`backend/routers/shots.py`)
- ✅ Changed task creation to use `status="not_started"`
- ✅ Updated status initialization in task status aggregation
- ✅ Updated status filtering to use string comparison
- ✅ Updated status sorting to use string-based status order

### 4. Migration Script (`backend/migrate_custom_task_statuses.py`)
Created comprehensive migration script that:
- ✅ Adds `custom_task_statuses` column to projects table
- ✅ Initializes column with empty array `[]` for existing projects
- ✅ Converts existing uppercase enum values to lowercase strings:
  - `NOT_STARTED` → `not_started`
  - `IN_PROGRESS` → `in_progress`
  - `SUBMITTED` → `submitted`
  - `APPROVED` → `approved`
  - `RETAKE` → `retake`
- ✅ Provides detailed logging of conversion process
- ✅ Includes verification steps

### 5. Test Script (`backend/test_custom_task_status_migration.py`)
Created verification test that confirms:
- ✅ `custom_task_statuses` column exists in projects table
- ✅ Task status column supports string values
- ✅ All existing task statuses are valid lowercase strings
- ✅ `custom_task_statuses` is initialized as empty array
- ✅ Displays task status distribution

## Migration Results

### Database Changes
```
Projects Table:
- Added column: custom_task_statuses (TEXT/JSON)

Tasks Table:
- Status column: VARCHAR(11) (already TEXT, no change needed)
```

### Data Conversion
Successfully converted 105 tasks:
- 91 tasks: `NOT_STARTED` → `not_started`
- 9 tasks: `IN_PROGRESS` → `in_progress`
- 4 tasks: `RETAKE` → `retake`
- 1 task: `APPROVED` → `approved`

## System Status Values
The following system statuses remain available:
- `not_started` - Task has not been started
- `in_progress` - Task is currently being worked on
- `submitted` - Task work has been submitted for review
- `approved` - Task has been approved
- `retake` - Task requires revisions

## Backward Compatibility
- ✅ All existing tasks continue to work with lowercase string statuses
- ✅ System statuses are always available across all projects
- ✅ No breaking changes to existing API endpoints
- ✅ Frontend can continue using existing status values

## Next Steps
With the database schema and migration complete, the system is ready for:
1. Backend API endpoints for custom status CRUD operations (Task 2-8)
2. Frontend components for custom status management (Task 10-21)
3. Integration with task creation and status update workflows

## Testing
All tests passed successfully:
- ✅ Backend imports without errors
- ✅ Database schema verification
- ✅ Data conversion verification
- ✅ Status value validation

## Requirements Validated
- ✅ Requirement 6.1: System statuses remain available
- ✅ Requirement 6.2: Backward compatibility maintained
- ✅ Requirement 6.3: Existing tasks continue to work
- ✅ Requirement 9.1: Database schema supports custom statuses
