CREATE TABLE IF NOT EXISTS cs_market_items (
  id serial PRIMARY KEY,
  market_hash_name text NOT NULL,
  name text NOT NULL,
  icon_url text,
  item_type text,
  first_seen_at timestamptz NOT NULL DEFAULT now(),
  last_seen_at timestamptz NOT NULL DEFAULT now()
);
CREATE UNIQUE INDEX IF NOT EXISTS cs_market_items_hash_idx ON cs_market_items (market_hash_name);
CREATE INDEX IF NOT EXISTS cs_market_items_name_idx ON cs_market_items (name);

CREATE TABLE IF NOT EXISTS cs_item_dimensions (
  item_id integer NOT NULL REFERENCES cs_market_items(id) ON DELETE CASCADE,
  key text NOT NULL,
  value text NOT NULL
);
CREATE UNIQUE INDEX IF NOT EXISTS cs_item_dimensions_unique_idx ON cs_item_dimensions (item_id, key);
CREATE INDEX IF NOT EXISTS cs_item_dimensions_filter_idx ON cs_item_dimensions (key, value, item_id);

CREATE TABLE IF NOT EXISTS cs_price_streams (
  source text NOT NULL,
  currency text NOT NULL,
  kind text NOT NULL
);
CREATE UNIQUE INDEX IF NOT EXISTS cs_price_streams_unique_idx
  ON cs_price_streams (source, currency, kind);

CREATE TABLE IF NOT EXISTS cs_price_observations (
  id bigint GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
  item_id integer NOT NULL REFERENCES cs_market_items(id) ON DELETE CASCADE,
  source text NOT NULL,
  currency text NOT NULL,
  observed_at timestamptz NOT NULL,
  price_cents integer NOT NULL CHECK (price_cents >= 0),
  volume integer CHECK (volume IS NULL OR volume >= 0),
  kind text NOT NULL,
  imported_at timestamptz NOT NULL DEFAULT now()
);
CREATE UNIQUE INDEX IF NOT EXISTS cs_price_observations_unique_idx
  ON cs_price_observations (item_id, source, currency, observed_at, kind);
CREATE INDEX IF NOT EXISTS cs_price_observations_lookup_idx
  ON cs_price_observations (item_id, source, currency, observed_at);
CREATE INDEX IF NOT EXISTS cs_price_observations_time_idx
  ON cs_price_observations (observed_at);