-- Migration 047: Analytics Infrastructure
-- Phase 3: Analytics Dashboards for CannaiQ
-- Creates views, functions, and tables for price trends, brand penetration, category growth, etc.

-- ============================================================
-- ANALYTICS CACHE TABLE (for expensive query results)
-- ============================================================
CREATE TABLE IF NOT EXISTS analytics_cache (
  id SERIAL PRIMARY KEY,
  cache_key VARCHAR(255) NOT NULL UNIQUE,
  cache_data JSONB NOT NULL,
  computed_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
  expires_at TIMESTAMPTZ NOT NULL,
  query_time_ms INTEGER,
  created_at TIMESTAMPTZ DEFAULT NOW()
);

CREATE INDEX IF NOT EXISTS idx_analytics_cache_key ON analytics_cache(cache_key);
CREATE INDEX IF NOT EXISTS idx_analytics_cache_expires ON analytics_cache(expires_at);

-- ============================================================
-- PRICE EXTRACTION HELPER FUNCTION
-- Extracts pricing from JSONB latest_raw_payload
-- ============================================================
CREATE OR REPLACE FUNCTION extract_min_price(payload JSONB)
RETURNS NUMERIC AS $$
DECLARE
  prices JSONB;
  min_val NUMERIC;
BEGIN
  -- Try recPrices first (retail prices)
  prices := payload->'recPrices';
  IF prices IS NOT NULL AND jsonb_array_length(prices) > 0 THEN
    SELECT MIN(value::NUMERIC) INTO min_val FROM jsonb_array_elements_text(prices) AS value WHERE value ~ '^[0-9.]+$';
    IF min_val IS NOT NULL THEN RETURN min_val; END IF;
  END IF;

  -- Try Prices array
  prices := payload->'Prices';
  IF prices IS NOT NULL AND jsonb_array_length(prices) > 0 THEN
    SELECT MIN(value::NUMERIC) INTO min_val FROM jsonb_array_elements_text(prices) AS value WHERE value ~ '^[0-9.]+$';
    IF min_val IS NOT NULL THEN RETURN min_val; END IF;
  END IF;

  RETURN NULL;
END;
$$ LANGUAGE plpgsql IMMUTABLE;

CREATE OR REPLACE FUNCTION extract_max_price(payload JSONB)
RETURNS NUMERIC AS $$
DECLARE
  prices JSONB;
  max_val NUMERIC;
BEGIN
  prices := payload->'recPrices';
  IF prices IS NOT NULL AND jsonb_array_length(prices) > 0 THEN
    SELECT MAX(value::NUMERIC) INTO max_val FROM jsonb_array_elements_text(prices) AS value WHERE value ~ '^[0-9.]+$';
    IF max_val IS NOT NULL THEN RETURN max_val; END IF;
  END IF;

  prices := payload->'Prices';
  IF prices IS NOT NULL AND jsonb_array_length(prices) > 0 THEN
    SELECT MAX(value::NUMERIC) INTO max_val FROM jsonb_array_elements_text(prices) AS value WHERE value ~ '^[0-9.]+$';
    IF max_val IS NOT NULL THEN RETURN max_val; END IF;
  END IF;

  RETURN NULL;
END;
$$ LANGUAGE plpgsql IMMUTABLE;

CREATE OR REPLACE FUNCTION extract_wholesale_price(payload JSONB)
RETURNS NUMERIC AS $$
DECLARE
  prices JSONB;
  min_val NUMERIC;
BEGIN
  prices := payload->'wholesalePrices';
  IF prices IS NOT NULL AND jsonb_array_length(prices) > 0 THEN
    SELECT MIN(value::NUMERIC) INTO min_val FROM jsonb_array_elements_text(prices) AS value WHERE value ~ '^[0-9.]+$';
    RETURN min_val;
  END IF;
  RETURN NULL;
END;
$$ LANGUAGE plpgsql IMMUTABLE;

-- ============================================================
-- VIEW: v_product_pricing
-- Flattened view of products with extracted pricing
-- ============================================================
CREATE OR REPLACE VIEW v_product_pricing AS
SELECT
  dp.id,
  dp.dispensary_id,
  dp.name,
  dp.brand_name,
  dp.brand_id,
  dp.type as category,
  dp.subcategory,
  dp.strain_type,
  dp.stock_status,
  dp.status,
  d.name as store_name,
  d.city,
  d.state,
  extract_min_price(dp.latest_raw_payload) as min_price,
  extract_max_price(dp.latest_raw_payload) as max_price,
  extract_wholesale_price(dp.latest_raw_payload) as wholesale_price,
  dp.thc,
  dp.cbd,
  dp.updated_at,
  dp.created_at
FROM dutchie_products dp
JOIN dispensaries d ON dp.dispensary_id = d.id;

-- ============================================================
-- VIEW: v_brand_store_presence
-- Which brands are in which stores
-- ============================================================
CREATE OR REPLACE VIEW v_brand_store_presence AS
SELECT
  dp.brand_name,
  dp.brand_id,
  dp.dispensary_id,
  d.name as store_name,
  d.city,
  d.state,
  dp.type as category,
  COUNT(*) as sku_count,
  AVG(extract_min_price(dp.latest_raw_payload)) as avg_price,
  SUM(CASE WHEN dp.stock_status = 'in_stock' THEN 1 ELSE 0 END) as in_stock_count,
  MAX(dp.updated_at) as last_updated
FROM dutchie_products dp
JOIN dispensaries d ON dp.dispensary_id = d.id
WHERE dp.brand_name IS NOT NULL
GROUP BY dp.brand_name, dp.brand_id, dp.dispensary_id, d.name, d.city, d.state, dp.type;

-- ============================================================
-- VIEW: v_category_store_summary
-- Category breakdown per store
-- ============================================================
CREATE OR REPLACE VIEW v_category_store_summary AS
SELECT
  dp.dispensary_id,
  d.name as store_name,
  d.city,
  d.state,
  dp.type as category,
  COUNT(*) as sku_count,
  COUNT(DISTINCT dp.brand_name) as brand_count,
  AVG(extract_min_price(dp.latest_raw_payload)) as avg_price,
  MIN(extract_min_price(dp.latest_raw_payload)) as min_price,
  MAX(extract_max_price(dp.latest_raw_payload)) as max_price,
  SUM(CASE WHEN dp.stock_status = 'in_stock' THEN 1 ELSE 0 END) as in_stock_count
FROM dutchie_products dp
JOIN dispensaries d ON dp.dispensary_id = d.id
WHERE dp.type IS NOT NULL
GROUP BY dp.dispensary_id, d.name, d.city, d.state, dp.type;

-- ============================================================
-- VIEW: v_brand_summary
-- Global brand statistics
-- ============================================================
CREATE OR REPLACE VIEW v_brand_summary AS
SELECT
  dp.brand_name,
  dp.brand_id,
  COUNT(*) as total_skus,
  COUNT(DISTINCT dp.dispensary_id) as store_count,
  COUNT(DISTINCT dp.type) as category_count,
  AVG(extract_min_price(dp.latest_raw_payload)) as avg_price,
  MIN(extract_min_price(dp.latest_raw_payload)) as min_price,
  MAX(extract_max_price(dp.latest_raw_payload)) as max_price,
  SUM(CASE WHEN dp.stock_status = 'in_stock' THEN 1 ELSE 0 END) as in_stock_skus,
  ARRAY_AGG(DISTINCT dp.type) FILTER (WHERE dp.type IS NOT NULL) as categories,
  MAX(dp.updated_at) as last_updated
FROM dutchie_products dp
WHERE dp.brand_name IS NOT NULL
GROUP BY dp.brand_name, dp.brand_id
ORDER BY total_skus DESC;

-- ============================================================
-- VIEW: v_category_summary
-- Global category statistics
-- ============================================================
CREATE OR REPLACE VIEW v_category_summary AS
SELECT
  dp.type as category,
  COUNT(*) as total_skus,
  COUNT(DISTINCT dp.brand_name) as brand_count,
  COUNT(DISTINCT dp.dispensary_id) as store_count,
  AVG(extract_min_price(dp.latest_raw_payload)) as avg_price,
  MIN(extract_min_price(dp.latest_raw_payload)) as min_price,
  MAX(extract_max_price(dp.latest_raw_payload)) as max_price,
  SUM(CASE WHEN dp.stock_status = 'in_stock' THEN 1 ELSE 0 END) as in_stock_skus
FROM dutchie_products dp
WHERE dp.type IS NOT NULL
GROUP BY dp.type
ORDER BY total_skus DESC;

-- ============================================================
-- VIEW: v_store_summary
-- Store-level statistics
-- ============================================================
CREATE OR REPLACE VIEW v_store_summary AS
SELECT
  d.id as store_id,
  d.name as store_name,
  d.city,
  d.state,
  d.chain_id,
  COUNT(dp.id) as total_skus,
  COUNT(DISTINCT dp.brand_name) as brand_count,
  COUNT(DISTINCT dp.type) as category_count,
  AVG(extract_min_price(dp.latest_raw_payload)) as avg_price,
  SUM(CASE WHEN dp.stock_status = 'in_stock' THEN 1 ELSE 0 END) as in_stock_skus,
  d.last_crawl_at,
  d.product_count
FROM dispensaries d
LEFT JOIN dutchie_products dp ON d.id = dp.dispensary_id
GROUP BY d.id, d.name, d.city, d.state, d.chain_id, d.last_crawl_at, d.product_count;

-- ============================================================
-- TABLE: brand_snapshots (for historical brand tracking)
-- ============================================================
CREATE TABLE IF NOT EXISTS brand_snapshots (
  id SERIAL PRIMARY KEY,
  brand_name VARCHAR(255) NOT NULL,
  brand_id VARCHAR(255),
  snapshot_date DATE NOT NULL,
  store_count INTEGER NOT NULL DEFAULT 0,
  total_skus INTEGER NOT NULL DEFAULT 0,
  avg_price NUMERIC(10,2),
  in_stock_skus INTEGER NOT NULL DEFAULT 0,
  categories TEXT[],
  created_at TIMESTAMPTZ DEFAULT NOW(),
  UNIQUE(brand_name, snapshot_date)
);

CREATE INDEX IF NOT EXISTS idx_brand_snapshots_brand ON brand_snapshots(brand_name);
CREATE INDEX IF NOT EXISTS idx_brand_snapshots_date ON brand_snapshots(snapshot_date);

-- ============================================================
-- TABLE: category_snapshots (for historical category tracking)
-- ============================================================
CREATE TABLE IF NOT EXISTS category_snapshots (
  id SERIAL PRIMARY KEY,
  category VARCHAR(255) NOT NULL,
  snapshot_date DATE NOT NULL,
  store_count INTEGER NOT NULL DEFAULT 0,
  brand_count INTEGER NOT NULL DEFAULT 0,
  total_skus INTEGER NOT NULL DEFAULT 0,
  avg_price NUMERIC(10,2),
  in_stock_skus INTEGER NOT NULL DEFAULT 0,
  created_at TIMESTAMPTZ DEFAULT NOW(),
  UNIQUE(category, snapshot_date)
);

CREATE INDEX IF NOT EXISTS idx_category_snapshots_cat ON category_snapshots(category);
CREATE INDEX IF NOT EXISTS idx_category_snapshots_date ON category_snapshots(snapshot_date);

-- ============================================================
-- TABLE: store_change_events (for tracking store changes)
-- ============================================================
CREATE TABLE IF NOT EXISTS store_change_events (
  id SERIAL PRIMARY KEY,
  store_id INTEGER NOT NULL REFERENCES dispensaries(id),
  event_type VARCHAR(50) NOT NULL, -- brand_added, brand_removed, product_added, product_removed, price_change, stock_change
  event_date DATE NOT NULL,
  brand_name VARCHAR(255),
  product_id INTEGER,
  product_name VARCHAR(500),
  category VARCHAR(255),
  old_value TEXT,
  new_value TEXT,
  metadata JSONB,
  created_at TIMESTAMPTZ DEFAULT NOW()
);

CREATE INDEX IF NOT EXISTS idx_store_events_store ON store_change_events(store_id);
CREATE INDEX IF NOT EXISTS idx_store_events_type ON store_change_events(event_type);
CREATE INDEX IF NOT EXISTS idx_store_events_date ON store_change_events(event_date);
CREATE INDEX IF NOT EXISTS idx_store_events_brand ON store_change_events(brand_name);

-- ============================================================
-- TABLE: analytics_alerts
-- ============================================================
CREATE TABLE IF NOT EXISTS analytics_alerts (
  id SERIAL PRIMARY KEY,
  alert_type VARCHAR(50) NOT NULL, -- price_warning, brand_dropped, competitive_intrusion, restock_event
  severity VARCHAR(20) NOT NULL DEFAULT 'info', -- info, warning, critical
  title VARCHAR(255) NOT NULL,
  description TEXT,
  store_id INTEGER REFERENCES dispensaries(id),
  brand_name VARCHAR(255),
  product_id INTEGER,
  category VARCHAR(255),
  metadata JSONB,
  is_read BOOLEAN DEFAULT FALSE,
  created_at TIMESTAMPTZ DEFAULT NOW()
);

CREATE INDEX IF NOT EXISTS idx_analytics_alerts_type ON analytics_alerts(alert_type);
CREATE INDEX IF NOT EXISTS idx_analytics_alerts_read ON analytics_alerts(is_read);
CREATE INDEX IF NOT EXISTS idx_analytics_alerts_created ON analytics_alerts(created_at DESC);

-- ============================================================
-- FUNCTION: Capture daily brand snapshots
-- ============================================================
CREATE OR REPLACE FUNCTION capture_brand_snapshots()
RETURNS INTEGER AS $$
DECLARE
  inserted_count INTEGER;
BEGIN
  INSERT INTO brand_snapshots (brand_name, brand_id, snapshot_date, store_count, total_skus, avg_price, in_stock_skus, categories)
  SELECT
    brand_name,
    brand_id,
    CURRENT_DATE,
    COUNT(DISTINCT dispensary_id),
    COUNT(*),
    AVG(extract_min_price(latest_raw_payload)),
    SUM(CASE WHEN stock_status = 'in_stock' THEN 1 ELSE 0 END),
    ARRAY_AGG(DISTINCT type) FILTER (WHERE type IS NOT NULL)
  FROM dutchie_products
  WHERE brand_name IS NOT NULL
  GROUP BY brand_name, brand_id
  ON CONFLICT (brand_name, snapshot_date)
  DO UPDATE SET
    store_count = EXCLUDED.store_count,
    total_skus = EXCLUDED.total_skus,
    avg_price = EXCLUDED.avg_price,
    in_stock_skus = EXCLUDED.in_stock_skus,
    categories = EXCLUDED.categories;

  GET DIAGNOSTICS inserted_count = ROW_COUNT;
  RETURN inserted_count;
END;
$$ LANGUAGE plpgsql;

-- ============================================================
-- FUNCTION: Capture daily category snapshots
-- ============================================================
CREATE OR REPLACE FUNCTION capture_category_snapshots()
RETURNS INTEGER AS $$
DECLARE
  inserted_count INTEGER;
BEGIN
  INSERT INTO category_snapshots (category, snapshot_date, store_count, brand_count, total_skus, avg_price, in_stock_skus)
  SELECT
    type,
    CURRENT_DATE,
    COUNT(DISTINCT dispensary_id),
    COUNT(DISTINCT brand_name),
    COUNT(*),
    AVG(extract_min_price(latest_raw_payload)),
    SUM(CASE WHEN stock_status = 'in_stock' THEN 1 ELSE 0 END)
  FROM dutchie_products
  WHERE type IS NOT NULL
  GROUP BY type
  ON CONFLICT (category, snapshot_date)
  DO UPDATE SET
    store_count = EXCLUDED.store_count,
    brand_count = EXCLUDED.brand_count,
    total_skus = EXCLUDED.total_skus,
    avg_price = EXCLUDED.avg_price,
    in_stock_skus = EXCLUDED.in_stock_skus;

  GET DIAGNOSTICS inserted_count = ROW_COUNT;
  RETURN inserted_count;
END;
$$ LANGUAGE plpgsql;

-- ============================================================
-- FUNCTION: Calculate price volatility for a product
-- ============================================================
CREATE OR REPLACE FUNCTION calculate_price_volatility(
  p_product_id INTEGER,
  p_days INTEGER DEFAULT 30
)
RETURNS NUMERIC AS $$
DECLARE
  std_dev NUMERIC;
  avg_price NUMERIC;
BEGIN
  -- Using dutchie_product_snapshots if available
  SELECT
    STDDEV(rec_min_price_cents / 100.0),
    AVG(rec_min_price_cents / 100.0)
  INTO std_dev, avg_price
  FROM dutchie_product_snapshots
  WHERE dutchie_product_id = p_product_id
    AND crawled_at >= NOW() - (p_days || ' days')::INTERVAL
    AND rec_min_price_cents IS NOT NULL;

  IF avg_price IS NULL OR avg_price = 0 THEN
    RETURN NULL;
  END IF;

  -- Return coefficient of variation (CV)
  RETURN ROUND((std_dev / avg_price) * 100, 2);
END;
$$ LANGUAGE plpgsql;

-- ============================================================
-- FUNCTION: Get brand penetration stats
-- ============================================================
CREATE OR REPLACE FUNCTION get_brand_penetration(
  p_brand_name VARCHAR,
  p_state VARCHAR DEFAULT NULL
)
RETURNS TABLE (
  total_stores BIGINT,
  stores_carrying BIGINT,
  penetration_pct NUMERIC,
  total_skus BIGINT,
  avg_skus_per_store NUMERIC,
  shelf_share_pct NUMERIC
) AS $$
BEGIN
  RETURN QUERY
  WITH store_counts AS (
    SELECT
      COUNT(DISTINCT d.id) as total,
      COUNT(DISTINCT CASE WHEN dp.brand_name = p_brand_name THEN dp.dispensary_id END) as carrying
    FROM dispensaries d
    LEFT JOIN dutchie_products dp ON d.id = dp.dispensary_id
    WHERE (p_state IS NULL OR d.state = p_state)
  ),
  sku_counts AS (
    SELECT
      COUNT(*) as brand_skus,
      COUNT(DISTINCT dispensary_id) as stores_with_brand
    FROM dutchie_products
    WHERE brand_name = p_brand_name
  ),
  total_skus AS (
    SELECT COUNT(*) as total FROM dutchie_products dp
    JOIN dispensaries d ON dp.dispensary_id = d.id
    WHERE (p_state IS NULL OR d.state = p_state)
  )
  SELECT
    sc.total,
    sc.carrying,
    ROUND((sc.carrying::NUMERIC / NULLIF(sc.total, 0)) * 100, 2),
    skc.brand_skus,
    ROUND(skc.brand_skus::NUMERIC / NULLIF(skc.stores_with_brand, 0), 2),
    ROUND((skc.brand_skus::NUMERIC / NULLIF(ts.total, 0)) * 100, 2)
  FROM store_counts sc, sku_counts skc, total_skus ts;
END;
$$ LANGUAGE plpgsql;

-- ============================================================
-- Initial snapshot capture (run manually if needed)
-- ============================================================
-- Note: Run these after migration to capture initial snapshots:
-- SELECT capture_brand_snapshots();
-- SELECT capture_category_snapshots();

-- ============================================================
-- Grant permissions
-- ============================================================
-- Views are accessible to all roles by default

COMMENT ON VIEW v_product_pricing IS 'Flattened product view with extracted pricing from JSONB';
COMMENT ON VIEW v_brand_store_presence IS 'Brand presence across stores with SKU counts';
COMMENT ON VIEW v_brand_summary IS 'Global brand statistics';
COMMENT ON VIEW v_category_summary IS 'Global category statistics';
COMMENT ON VIEW v_store_summary IS 'Store-level statistics';
COMMENT ON TABLE analytics_cache IS 'Cache for expensive analytics queries';
COMMENT ON TABLE brand_snapshots IS 'Historical daily snapshots of brand metrics';
COMMENT ON TABLE category_snapshots IS 'Historical daily snapshots of category metrics';
COMMENT ON TABLE store_change_events IS 'Log of brand/product changes at stores';
COMMENT ON TABLE analytics_alerts IS 'Analytics-generated alerts and notifications';