-- Migration 051: Create materialized view for state metrics
-- Used by Analytics V2 state endpoints for fast aggregated queries
-- Canonical tables: states, dispensaries, store_products, store_product_snapshots, brands

-- Drop existing view if it exists (for clean recreation)
DROP MATERIALIZED VIEW IF EXISTS mv_state_metrics;

-- Create materialized view with comprehensive state metrics
-- Schema verified via information_schema on 2025-12-06
-- Real columns used:
--   states: id, code, name, recreational_legal, medical_legal, rec_year, med_year
--   dispensaries: id, state_id (NO is_active column)
--   store_products: id, dispensary_id, brand_id, category_raw, price_rec, price_med, is_in_stock
--   store_product_snapshots: id, store_product_id, captured_at
--   brands: id (joined via sp.brand_id)

CREATE MATERIALIZED VIEW mv_state_metrics AS
SELECT
  s.id AS state_id,
  s.code AS state,
  s.name AS state_name,
  COALESCE(s.recreational_legal, FALSE) AS recreational_legal,
  COALESCE(s.medical_legal, FALSE) AS medical_legal,
  s.rec_year,
  s.med_year,

  -- Dispensary metrics
  COUNT(DISTINCT d.id) AS dispensary_count,

  -- Product metrics
  COUNT(DISTINCT sp.id) AS total_products,
  COUNT(DISTINCT sp.id) FILTER (WHERE sp.is_in_stock = TRUE) AS in_stock_products,
  COUNT(DISTINCT sp.id) FILTER (WHERE sp.is_in_stock = FALSE) AS out_of_stock_products,

  -- Brand metrics (using brand_id FK, not brand_name)
  COUNT(DISTINCT sp.brand_id) FILTER (WHERE sp.brand_id IS NOT NULL) AS unique_brands,

  -- Category metrics (using category_raw, not category)
  COUNT(DISTINCT sp.category_raw) FILTER (WHERE sp.category_raw IS NOT NULL) AS unique_categories,

  -- Pricing metrics (recreational)
  AVG(sp.price_rec) FILTER (WHERE sp.price_rec IS NOT NULL AND sp.is_in_stock = TRUE) AS avg_price_rec,
  PERCENTILE_CONT(0.5) WITHIN GROUP (ORDER BY sp.price_rec)
    FILTER (WHERE sp.price_rec IS NOT NULL AND sp.is_in_stock = TRUE) AS median_price_rec,
  MIN(sp.price_rec) FILTER (WHERE sp.price_rec IS NOT NULL AND sp.is_in_stock = TRUE) AS min_price_rec,
  MAX(sp.price_rec) FILTER (WHERE sp.price_rec IS NOT NULL AND sp.is_in_stock = TRUE) AS max_price_rec,

  -- Pricing metrics (medical)
  AVG(sp.price_med) FILTER (WHERE sp.price_med IS NOT NULL AND sp.is_in_stock = TRUE) AS avg_price_med,
  PERCENTILE_CONT(0.5) WITHIN GROUP (ORDER BY sp.price_med)
    FILTER (WHERE sp.price_med IS NOT NULL AND sp.is_in_stock = TRUE) AS median_price_med,

  -- Snapshot/crawl metrics
  COUNT(sps.id) AS total_snapshots,
  MAX(sps.captured_at) AS last_crawl_at,
  MIN(sps.captured_at) AS first_crawl_at,

  -- Data freshness
  CASE
    WHEN MAX(sps.captured_at) > NOW() - INTERVAL '24 hours' THEN 'fresh'
    WHEN MAX(sps.captured_at) > NOW() - INTERVAL '7 days' THEN 'recent'
    WHEN MAX(sps.captured_at) IS NOT NULL THEN 'stale'
    ELSE 'no_data'
  END AS data_freshness,

  -- Metadata
  NOW() AS refreshed_at

FROM states s
LEFT JOIN dispensaries d ON d.state_id = s.id
LEFT JOIN store_products sp ON sp.dispensary_id = d.id
LEFT JOIN store_product_snapshots sps ON sps.store_product_id = sp.id
GROUP BY s.id, s.code, s.name, s.recreational_legal, s.medical_legal, s.rec_year, s.med_year;

-- Create unique index on state code for fast lookups
CREATE UNIQUE INDEX IF NOT EXISTS mv_state_metrics_state_idx
  ON mv_state_metrics (state);

-- Create index on state_id for joins
CREATE INDEX IF NOT EXISTS mv_state_metrics_state_id_idx
  ON mv_state_metrics (state_id);

-- Create index for legal status filtering
CREATE INDEX IF NOT EXISTS mv_state_metrics_legal_idx
  ON mv_state_metrics (recreational_legal, medical_legal);

-- Create index for data freshness queries
CREATE INDEX IF NOT EXISTS mv_state_metrics_freshness_idx
  ON mv_state_metrics (data_freshness);

-- Comment on the view
COMMENT ON MATERIALIZED VIEW mv_state_metrics IS
  'Aggregated state-level metrics for Analytics V2 endpoints. Refresh periodically with: REFRESH MATERIALIZED VIEW CONCURRENTLY mv_state_metrics;';

-- Record migration
INSERT INTO schema_migrations (version, name, applied_at)
VALUES ('051', 'create_mv_state_metrics', NOW())
ON CONFLICT (version) DO NOTHING;