-- Migration 028: Snapshot Architecture
-- Implements append-only snapshots for full history tracking
-- Following the principle: "Never delete, only append observations"

-- =====================================================
-- LAYER 1: Raw Append-Only Snapshots (NEVER DELETE)
-- =====================================================

-- Product snapshots - one row per product per crawl
CREATE TABLE IF NOT EXISTS product_snapshots (
  id SERIAL PRIMARY KEY,

  -- Source identification
  crawl_id UUID NOT NULL, -- Groups all products from same crawl run
  dispensary_id INTEGER NOT NULL REFERENCES dispensaries(id),

  -- Product identification
  external_product_id VARCHAR(255), -- Dutchie/provider product ID
  product_slug VARCHAR(500), -- URL slug for matching

  -- Product details (as seen at crawl time)
  name VARCHAR(500) NOT NULL,
  brand VARCHAR(255),
  category VARCHAR(100),
  subcategory VARCHAR(100),

  -- Pricing snapshot
  price NUMERIC(10,2),
  original_price NUMERIC(10,2),
  sale_price NUMERIC(10,2),
  discount_type VARCHAR(50),
  discount_value VARCHAR(100),

  -- Availability snapshot
  availability_status VARCHAR(30) NOT NULL DEFAULT 'unknown',
    -- 'in_stock', 'out_of_stock', 'limited', 'removed_from_menu', 'unknown'
  stock_quantity INTEGER,

  -- Potency snapshot
  thc_percentage NUMERIC(5,2),
  cbd_percentage NUMERIC(5,2),

  -- Product attributes
  strain_type VARCHAR(100),
  weight VARCHAR(100),
  variant VARCHAR(255),

  -- Rich data
  description TEXT,
  image_url TEXT,
  effects TEXT[],
  terpenes TEXT[],

  -- Timestamp
  captured_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),

  -- Raw metadata from provider
  raw_data JSONB
);

-- Indexes for efficient querying
CREATE INDEX IF NOT EXISTS idx_snapshots_dispensary_time ON product_snapshots(dispensary_id, captured_at DESC);
CREATE INDEX IF NOT EXISTS idx_snapshots_crawl ON product_snapshots(crawl_id);
CREATE INDEX IF NOT EXISTS idx_snapshots_brand ON product_snapshots(brand, captured_at DESC);
CREATE INDEX IF NOT EXISTS idx_snapshots_product_slug ON product_snapshots(product_slug, captured_at DESC);
CREATE INDEX IF NOT EXISTS idx_snapshots_external_id ON product_snapshots(external_product_id, captured_at DESC);
CREATE INDEX IF NOT EXISTS idx_snapshots_availability ON product_snapshots(availability_status, captured_at DESC);
CREATE INDEX IF NOT EXISTS idx_snapshots_category ON product_snapshots(category, captured_at DESC);

-- Brand snapshots - summary of brands seen per crawl
CREATE TABLE IF NOT EXISTS brand_snapshots (
  id SERIAL PRIMARY KEY,
  crawl_id UUID NOT NULL,
  dispensary_id INTEGER NOT NULL REFERENCES dispensaries(id),

  brand_name VARCHAR(255) NOT NULL,
  product_count INTEGER NOT NULL DEFAULT 0,
  in_stock_count INTEGER NOT NULL DEFAULT 0,

  -- Price range for this brand at this store at this time
  min_price NUMERIC(10,2),
  max_price NUMERIC(10,2),
  avg_price NUMERIC(10,2),

  -- Categories this brand has products in
  categories TEXT[],

  captured_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

CREATE INDEX IF NOT EXISTS idx_brand_snapshots_dispensary ON brand_snapshots(dispensary_id, captured_at DESC);
CREATE INDEX IF NOT EXISTS idx_brand_snapshots_brand ON brand_snapshots(brand_name, captured_at DESC);
CREATE INDEX IF NOT EXISTS idx_brand_snapshots_crawl ON brand_snapshots(crawl_id);

-- Crawl runs table - metadata about each crawl
CREATE TABLE IF NOT EXISTS crawl_runs (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  dispensary_id INTEGER NOT NULL REFERENCES dispensaries(id),

  started_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
  completed_at TIMESTAMPTZ,

  status VARCHAR(20) NOT NULL DEFAULT 'running', -- 'running', 'completed', 'failed'

  -- Results
  products_found INTEGER DEFAULT 0,
  brands_found INTEGER DEFAULT 0,
  categories_found INTEGER DEFAULT 0,

  -- Errors if any
  error_message TEXT,

  -- Provider info
  provider VARCHAR(50),
  menu_url TEXT
);

CREATE INDEX IF NOT EXISTS idx_crawl_runs_dispensary ON crawl_runs(dispensary_id, started_at DESC);
CREATE INDEX IF NOT EXISTS idx_crawl_runs_status ON crawl_runs(status);

-- =====================================================
-- LAYER 2: Summary/Rollup Tables (can be recalculated)
-- =====================================================

-- Daily brand summary per store
CREATE TABLE IF NOT EXISTS brand_store_day_summary (
  id SERIAL PRIMARY KEY,
  dispensary_id INTEGER NOT NULL REFERENCES dispensaries(id),
  brand_name VARCHAR(255) NOT NULL,
  summary_date DATE NOT NULL,

  -- Presence
  first_seen_at TIMESTAMPTZ,
  last_seen_at TIMESTAMPTZ,
  crawl_count INTEGER DEFAULT 0, -- how many times we saw this brand today

  -- Product counts
  total_skus INTEGER DEFAULT 0,
  in_stock_skus INTEGER DEFAULT 0,
  out_of_stock_events INTEGER DEFAULT 0,

  -- Price stats
  min_price NUMERIC(10,2),
  max_price NUMERIC(10,2),
  avg_price NUMERIC(10,2),

  -- Categories
  categories TEXT[],

  created_at TIMESTAMPTZ DEFAULT NOW(),
  updated_at TIMESTAMPTZ DEFAULT NOW(),

  UNIQUE(dispensary_id, brand_name, summary_date)
);

CREATE INDEX IF NOT EXISTS idx_brand_store_day_dispensary ON brand_store_day_summary(dispensary_id, summary_date DESC);
CREATE INDEX IF NOT EXISTS idx_brand_store_day_brand ON brand_store_day_summary(brand_name, summary_date DESC);

-- Product SKU daily summary
CREATE TABLE IF NOT EXISTS product_sku_day_summary (
  id SERIAL PRIMARY KEY,
  dispensary_id INTEGER NOT NULL REFERENCES dispensaries(id),
  product_slug VARCHAR(500) NOT NULL,
  summary_date DATE NOT NULL,

  -- Latest values
  name VARCHAR(500),
  brand VARCHAR(255),
  category VARCHAR(100),

  -- Price tracking
  opening_price NUMERIC(10,2), -- first price of day
  closing_price NUMERIC(10,2), -- last price of day
  min_price NUMERIC(10,2),
  max_price NUMERIC(10,2),
  price_changes INTEGER DEFAULT 0,

  -- Availability
  times_in_stock INTEGER DEFAULT 0,
  times_out_of_stock INTEGER DEFAULT 0,
  first_seen_at TIMESTAMPTZ,
  last_seen_at TIMESTAMPTZ,

  created_at TIMESTAMPTZ DEFAULT NOW(),
  updated_at TIMESTAMPTZ DEFAULT NOW(),

  UNIQUE(dispensary_id, product_slug, summary_date)
);

CREATE INDEX IF NOT EXISTS idx_sku_day_dispensary ON product_sku_day_summary(dispensary_id, summary_date DESC);
CREATE INDEX IF NOT EXISTS idx_sku_day_slug ON product_sku_day_summary(product_slug, summary_date DESC);

-- =====================================================
-- VIEWS for common queries
-- =====================================================

-- Current products view (latest snapshot per product)
CREATE OR REPLACE VIEW current_products AS
SELECT DISTINCT ON (ps.dispensary_id, ps.product_slug)
  ps.*,
  d.name AS dispensary_name,
  COALESCE(d.dba_name, d.name) AS store_name
FROM product_snapshots ps
JOIN dispensaries d ON d.id = ps.dispensary_id
ORDER BY ps.dispensary_id, ps.product_slug, ps.captured_at DESC;

-- Current brands per store view
CREATE OR REPLACE VIEW current_brands AS
SELECT DISTINCT ON (bs.dispensary_id, bs.brand_name)
  bs.*,
  d.name AS dispensary_name,
  COALESCE(d.dba_name, d.name) AS store_name
FROM brand_snapshots bs
JOIN dispensaries d ON d.id = bs.dispensary_id
WHERE bs.captured_at >= NOW() - INTERVAL '7 days'
ORDER BY bs.dispensary_id, bs.brand_name, bs.captured_at DESC;

-- Brand coverage across stores
CREATE OR REPLACE VIEW brand_store_coverage AS
SELECT
  brand_name,
  COUNT(DISTINCT dispensary_id) AS store_count,
  SUM(product_count) AS total_skus,
  MIN(min_price) AS market_min_price,
  MAX(max_price) AS market_max_price,
  AVG(avg_price) AS market_avg_price,
  MAX(captured_at) AS last_seen_at
FROM brand_snapshots
WHERE captured_at >= NOW() - INTERVAL '7 days'
GROUP BY brand_name;

-- Grant permissions
GRANT SELECT, INSERT ON product_snapshots TO scraper;
GRANT SELECT, INSERT ON brand_snapshots TO scraper;
GRANT SELECT, INSERT, UPDATE ON crawl_runs TO scraper;
GRANT SELECT, INSERT, UPDATE ON brand_store_day_summary TO scraper;
GRANT SELECT, INSERT, UPDATE ON product_sku_day_summary TO scraper;
GRANT SELECT ON current_products TO scraper;
GRANT SELECT ON current_brands TO scraper;
GRANT SELECT ON brand_store_coverage TO scraper;