# Multi-State Support

## Overview

Phase 4 implements full multi-state support for CannaiQ, transforming it from an Arizona-only platform to a national cannabis intelligence system. This document covers schema updates, API structure, frontend usage, and operational guidelines.

## Schema Updates

### Core Tables Modified

#### 1. `dispensaries` table
Already has `state` column:
```sql
state CHAR(2) DEFAULT 'AZ'  -- State code (AZ, CA, CO, etc.)
state_id INTEGER REFERENCES states(id)  -- FK to canonical states table
```

#### 2. `raw_payloads` table (Migration 047)
Added state column for query optimization:
```sql
state CHAR(2)  -- Denormalized from dispensary for fast filtering
```

#### 3. `states` table
Canonical reference for all US states:
```sql
CREATE TABLE states (
  id SERIAL PRIMARY KEY,
  code VARCHAR(2) NOT NULL UNIQUE,  -- 'AZ', 'CA', etc.
  name VARCHAR(100) NOT NULL,       -- 'Arizona', 'California', etc.
  created_at TIMESTAMPTZ DEFAULT NOW(),
  updated_at TIMESTAMPTZ DEFAULT NOW()
);
```

### New Indexes (Migration 047)

```sql
-- State-based payload filtering
CREATE INDEX idx_raw_payloads_state ON raw_payloads(state);
CREATE INDEX idx_raw_payloads_state_unprocessed ON raw_payloads(state, processed) WHERE processed = FALSE;

-- Dispensary state queries
CREATE INDEX idx_dispensaries_state_menu_type ON dispensaries(state, menu_type);
CREATE INDEX idx_dispensaries_state_crawl_status ON dispensaries(state, crawl_status);
CREATE INDEX idx_dispensaries_state_active ON dispensaries(state) WHERE crawl_status != 'disabled';
```

### Materialized Views

#### `mv_state_metrics`
Pre-aggregated state-level metrics for fast dashboard queries:
```sql
CREATE MATERIALIZED VIEW mv_state_metrics AS
SELECT
  d.state,
  s.name AS state_name,
  COUNT(DISTINCT d.id) AS store_count,
  COUNT(DISTINCT sp.id) AS total_products,
  COUNT(DISTINCT sp.brand_id) AS unique_brands,
  AVG(sp.price_rec) AS avg_price_rec,
  -- ... more metrics
FROM dispensaries d
LEFT JOIN states s ON d.state = s.code
LEFT JOIN store_products sp ON d.id = sp.dispensary_id
GROUP BY d.state, s.name;
```

Refresh with:
```sql
SELECT refresh_state_metrics();
```

### Views

#### `v_brand_state_presence`
Brand presence and metrics per state:
```sql
SELECT brand_id, brand_name, state, store_count, product_count, avg_price
FROM v_brand_state_presence
WHERE state = 'AZ';
```

#### `v_category_state_distribution`
Category distribution by state:
```sql
SELECT state, category, product_count, store_count, avg_price
FROM v_category_state_distribution
WHERE state = 'CA';
```

### Functions

#### `fn_national_price_comparison(category, brand_id)`
Compare prices across all states:
```sql
SELECT * FROM fn_national_price_comparison('Flower', NULL);
```

#### `fn_brand_state_penetration(brand_id)`
Get brand penetration across states:
```sql
SELECT * FROM fn_brand_state_penetration(123);
```

## API Structure

### State List Endpoints

```
GET /api/states                    # All configured states
GET /api/states?active=true        # Only states with dispensary data
```

Response:
```json
{
  "success": true,
  "data": {
    "states": [
      { "code": "AZ", "name": "Arizona" },
      { "code": "CA", "name": "California" }
    ],
    "count": 2
  }
}
```

### State-Specific Endpoints

```
GET /api/state/:state/summary      # Full state summary with metrics
GET /api/state/:state/brands       # Brands in state (paginated)
GET /api/state/:state/categories   # Categories in state (paginated)
GET /api/state/:state/stores       # Stores in state (paginated)
GET /api/state/:state/analytics/prices  # Price distribution
```

Query parameters:
- `limit` - Results per page (default: 50)
- `offset` - Pagination offset
- `sortBy` - Sort field (e.g., `productCount`, `avgPrice`)
- `sortDir` - Sort direction (`asc` or `desc`)
- `includeInactive` - Include disabled stores

### National Analytics Endpoints

```
GET /api/analytics/national/summary    # National aggregate metrics
GET /api/analytics/national/prices     # Price comparison across states
GET /api/analytics/national/heatmap    # State heatmap data
GET /api/analytics/national/metrics    # All state metrics
```

Heatmap metrics:
- `stores` - Store count per state
- `products` - Product count per state
- `brands` - Brand count per state
- `avgPrice` - Average price per state
- `penetration` - Brand penetration (requires `brandId`)

### Cross-State Comparison Endpoints

```
GET /api/analytics/compare/brand/:brandId        # Compare brand across states
GET /api/analytics/compare/category/:category    # Compare category across states
GET /api/analytics/brand/:brandId/penetration    # Brand penetration by state
GET /api/analytics/brand/:brandId/trend          # Historical penetration trend
```

Query parameters:
- `states` - Comma-separated state codes to include (optional)
- `days` - Days of history for trends (default: 30)

### Admin Endpoints

```
POST /api/admin/states/refresh-metrics  # Refresh materialized views
```

## Frontend Usage

### State Selector

The global state selector is in the sidebar and persists selection via localStorage:

```tsx
import { useStateStore } from '../store/stateStore';

function MyComponent() {
  const { selectedState, setSelectedState, isNationalView } = useStateStore();

  // null = All States / National view
  // 'AZ' = Arizona only

  if (isNationalView()) {
    // Show national data
  } else {
    // Filter by selectedState
  }
}
```

### State Badge Component

Show current state selection:
```tsx
import { StateBadge } from '../components/StateSelector';

<StateBadge />  // Shows "National" or state name
```

### API Calls with State Filter

```tsx
import { api } from '../lib/api';
import { useStateStore } from '../store/stateStore';

function useStateData() {
  const { selectedState } = useStateStore();

  useEffect(() => {
    if (selectedState) {
      // State-specific data
      api.get(`/state/${selectedState}/summary`);
    } else {
      // National data
      api.get('/analytics/national/summary');
    }
  }, [selectedState]);
}
```

### Navigation Routes

| Route | Component | Description |
|-------|-----------|-------------|
| `/national` | NationalDashboard | National overview with all states |
| `/national/heatmap` | StateHeatmap | Interactive state heatmap |
| `/national/compare` | CrossStateCompare | Brand/category cross-state comparison |

## Ingestion Rules

### State Assignment

Every raw payload MUST include state:
1. State is looked up from `dispensaries.state` during payload storage
2. Stored on `raw_payloads.state` for query optimization
3. Inherited by all normalized products/snapshots via `dispensary_id`

### Hydration Pipeline

The hydration worker supports state filtering:
```typescript
// Process only AZ payloads
await getUnprocessedPayloads(pool, { state: 'AZ' });

// Process multiple states
await getUnprocessedPayloads(pool, { states: ['AZ', 'CA', 'NV'] });
```

### Data Isolation

Critical rules:
- **No cross-state contamination** - Product IDs are unique per (dispensary_id, provider_product_id)
- **No SKU merging** - Same SKU in AZ and CA are separate products
- **No store merging** - Same store name in different states are separate records
- Every dispensary maps to exactly ONE state

## Constraints & Best Practices

### Query Performance

1. Use `mv_state_metrics` for dashboard queries (refreshed hourly)
2. Use indexed views for brand/category queries
3. Filter by state early in queries to leverage indexes
4. For cross-state queries, use the dedicated comparison functions

### Cache Strategy

API endpoints should be cached with Redis:
```typescript
// Cache key pattern
`state:${state}:summary` // State summary - 5 min TTL
`national:summary`       // National summary - 5 min TTL
`heatmap:${metric}`      // Heatmap data - 5 min TTL
```

### Adding New States

1. Add state to `states` table (if not already present)
2. Import dispensary data with correct `state` code
3. Run menu detection for new dispensaries
4. Crawl dispensaries with resolved platform IDs
5. Refresh materialized views: `SELECT refresh_state_metrics()`

## Migration Guide

### From Arizona-Only to Multi-State

1. Apply migration 047:
   ```bash
   DATABASE_URL="..." npm run migrate
   ```

2. Existing AZ data requires no changes (already has `state='AZ'`)

3. New states are added via:
   - Manual dispensary import
   - Menu detection crawl
   - Platform ID resolution

4. Frontend automatically shows state selector after update

### Rollback

Migration 047 is additive - no destructive changes:
- New columns have defaults
- Views can be dropped without data loss
- Indexes can be dropped for performance tuning

## Monitoring

### Key Metrics to Watch

1. **Store count by state** - `SELECT state, COUNT(*) FROM dispensaries GROUP BY state`
2. **Product coverage** - `SELECT state, COUNT(DISTINCT sp.id) FROM store_products...`
3. **Crawl health by state** - Check `crawl_runs` by dispensary state
4. **Materialized view freshness** - `SELECT refreshed_at FROM mv_state_metrics`

### Alerts

Set up alerts for:
- Materialized view not refreshed in 2+ hours
- State with 0 products after having products
- Cross-state data appearing (should never happen)

## Future Enhancements

Planned for future phases:
1. **Redis caching** for all state endpoints
2. **Real-time refresh** of materialized views
3. **Geographic heatmaps** with actual US map visualization
4. **State-specific pricing rules** (tax rates, etc.)
5. **Multi-state brand portfolio tracking**