# String ID Migration - Complete Implementation Status

## ✅ Completed Work

### Phase 1: ID Generation Infrastructure (Complete)
- ✅ ID sequence table created
- ✅ ID generator service with thread-safe generation
- ✅ Comprehensive tests including concurrency

### Phase 2: Dual-Write (Complete)
- ✅ Migration 0010 applied - sid columns added to all tables
- ✅ All existing data backfilled with formatted IDs
- ✅ All domain models updated with dual ID fields
- ✅ All repositories updated for dual-write

### Phase 3: String IDs Only (In Progress)

#### ✅ Completed
1. **Migration Created**: `/migrations/0011_switch_to_string_ids/up.sql`
   - Drops integer `id` columns
   - Renames `sid` → `id`
   - Updates all foreign keys to use string IDs
   - ⚠️ **Not yet applied** - ready for deployment

2. **Domain Models Updated**:
   - ✅ `/internal/domain/registry.go` - All types use `string` for IDs
   - ✅ `/internal/domain/tickets.go` - String IDs
   - ✅ `/internal/domain/failure_events.go` - String IDs

3. **Repositories Updated** (5 of 9):
   - ✅ `/internal/repository/registry/customers.go`
   - ✅ `/internal/repository/registry/projects.go`
   - ✅ `/internal/repository/registry/locations.go`
   - ✅ `/internal/repository/registry/lots.go`
   - ⏳ `/internal/repository/registry/assets.go` - **NEEDS UPDATE**
   - ⏳ `/internal/repository/registry/components.go` - **NEEDS UPDATE**
   - ⏳ `/internal/repository/registry/installations.go` - **NEEDS UPDATE**
   - ⏳ `/internal/repository/tickets/tickets.go` - **NEEDS UPDATE**
   - ⏳ `/internal/repository/failures/failures.go` - **NEEDS UPDATE**

#### ⏳ Remaining Work

**Repositories** (4 files to update):
1. `assets.go` - Change `Create()` signature to accept `projectID string`, `locationID *string`, return generated ID directly
2. `components.go` - Change `Create()` to accept `lotID *string`, return generated ID
3. `installations.go` - Update queries to use string IDs
4. `tickets/tickets.go` - Update `Upsert()` and `LinkToAsset()` to use string IDs
5. `failures/failures.go` - Update `Upsert()` to use string IDs

**Pattern for remaining repositories**:
```go
// Change method signatures from int64 to string
func (r *XRepository) Get(ctx context.Context, id string) (domain.X, error)
func (r *XRepository) Create(ctx context.Context, ...) (domain.X, error)

// In Create, generate ID and use it directly:
id, err := r.idgen.Generate(ctx, idgen.X)
_, err = r.db.ExecContext(ctx, `INSERT INTO table (id, ...) VALUES (?, ...)`, id, ...)
return r.Get(ctx, id)  // No more LastInsertId()

// Update all NULL foreign key handling:
var foreignID *string  // instead of *int64
var nullForeignID sql.NullString  // instead of sql.NullInt64
```

**API Layer** (needs review):
- All route handlers that call repository methods
- Path parameter parsing (already strings in most cases)
- Any business logic that works with IDs

**Other Files** (may need updates):
- Ingest service - hardware/software parsing
- Timeline events - if they reference IDs
- Any test files

## Next Steps

### Option 1: Complete Remaining Repositories (Recommended)
Continue updating the remaining 4 repository files following the established pattern, then apply migration.

### Option 2: Test Current State
1. Try to compile with current changes
2. Identify all compilation errors
3. Fix systematically

### Option 3: Apply Migration and Iterate
1. Apply migration 0011
2. Try to run application
3. Fix errors as they appear

## Migration Command (When Ready)

```bash
# Backup database first!
docker exec reanimator-mariadb mariadb-dump -u reanimator -preanimator reanimator > backup_before_string_ids.sql

# Apply migration
docker exec -i reanimator-mariadb mariadb -u reanimator -preanimator reanimator < migrations/0011_switch_to_string_ids/up.sql

# Verify
docker exec -i reanimator-mariadb mariadb -u reanimator -preanimator reanimator -e "DESCRIBE customers"
```

## Rollback Strategy

⚠️ **WARNING**: Migration 0011 is NOT easily reversible. The auto-increment integer IDs will be lost.

**Rollback options**:
1. Restore from database backup (recommended)
2. Manually reconstruct schema (complex, data-dependent)

## Testing After Migration

```bash
# Compile
go build ./...

# Run tests
go test ./...

# Manual verification
go run verify_string_ids.go
```

## Benefits of String IDs

- ✅ Human-readable IDs (CR-0000001 instead of 1)
- ✅ Self-documenting entity types
- ✅ Better for support and debugging
- ✅ Copy-paste friendly in logs and UIs
- ✅ Future-proof for distributed systems
- ✅ No integer overflow concerns