-- The Disclosure Bureau — chat schema
-- Apply via Supabase Studio SQL editor OR psql on the production DB.
-- Safe to re-run (uses IF NOT EXISTS guards).

-- 1. profiles — 1:1 with auth.users, holds budget + role
CREATE TABLE IF NOT EXISTS public.profiles (
  id              UUID PRIMARY KEY REFERENCES auth.users(id) ON DELETE CASCADE,
  display_name    TEXT,
  avatar_url      TEXT,
  role            TEXT NOT NULL DEFAULT 'user' CHECK (role IN ('user','admin','suspended')),
  budget_cap_usd  NUMERIC(10,4) NOT NULL DEFAULT 5.0,
  total_cost_usd  NUMERIC(10,4) NOT NULL DEFAULT 0,
  daily_quota     INT NOT NULL DEFAULT 100,
  daily_used      INT NOT NULL DEFAULT 0,
  quota_reset_at  TIMESTAMPTZ NOT NULL DEFAULT (DATE_TRUNC('day', NOW()) + INTERVAL '1 day'),
  preferred_locale TEXT DEFAULT 'pt-BR',
  created_at      TIMESTAMPTZ NOT NULL DEFAULT NOW(),
  updated_at      TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- Auto-create profile on user signup
CREATE OR REPLACE FUNCTION public.handle_new_user()
RETURNS TRIGGER LANGUAGE plpgsql SECURITY DEFINER SET search_path = public AS $$
BEGIN
  INSERT INTO public.profiles (id, display_name)
  VALUES (NEW.id, COALESCE(NEW.raw_user_meta_data->>'full_name', NEW.email));
  RETURN NEW;
END;
$$;
DROP TRIGGER IF EXISTS on_auth_user_created ON auth.users;
CREATE TRIGGER on_auth_user_created
  AFTER INSERT ON auth.users
  FOR EACH ROW EXECUTE FUNCTION public.handle_new_user();

-- 2. chat_sessions — one conversation per row
CREATE TABLE IF NOT EXISTS public.chat_sessions (
  id              UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  user_id         UUID NOT NULL REFERENCES auth.users(id) ON DELETE CASCADE,
  title           TEXT,
  summary         TEXT,
  context_doc_id  TEXT,
  context_page_id TEXT,
  is_public       BOOLEAN NOT NULL DEFAULT FALSE,
  share_token     TEXT UNIQUE,
  archived        BOOLEAN NOT NULL DEFAULT FALSE,
  message_count   INT NOT NULL DEFAULT 0,
  total_tokens    INT NOT NULL DEFAULT 0,
  total_cost_usd  NUMERIC(10,4) NOT NULL DEFAULT 0,
  created_at      TIMESTAMPTZ NOT NULL DEFAULT NOW(),
  updated_at      TIMESTAMPTZ NOT NULL DEFAULT NOW()
);
CREATE INDEX IF NOT EXISTS idx_sessions_user_updated
  ON public.chat_sessions(user_id, updated_at DESC) WHERE NOT archived;
CREATE INDEX IF NOT EXISTS idx_sessions_share
  ON public.chat_sessions(share_token) WHERE share_token IS NOT NULL;

-- 3. messages — one row per turn
CREATE TABLE IF NOT EXISTS public.messages (
  id              UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  session_id      UUID NOT NULL REFERENCES public.chat_sessions(id) ON DELETE CASCADE,
  role            TEXT NOT NULL CHECK (role IN ('user','assistant','tool','system')),
  content         TEXT NOT NULL,
  tool_calls      JSONB,
  tool_results    JSONB,
  citations       JSONB,
  model           TEXT,
  tokens_in       INT,
  tokens_out      INT,
  cost_usd        NUMERIC(10,6),
  duration_ms     INT,
  created_at      TIMESTAMPTZ NOT NULL DEFAULT NOW()
);
CREATE INDEX IF NOT EXISTS idx_messages_session
  ON public.messages(session_id, created_at);

-- 4. usage_events — audit log of every billable action (optional but cheap)
CREATE TABLE IF NOT EXISTS public.usage_events (
  id              BIGSERIAL PRIMARY KEY,
  user_id         UUID NOT NULL REFERENCES auth.users(id) ON DELETE CASCADE,
  session_id      UUID REFERENCES public.chat_sessions(id) ON DELETE SET NULL,
  event_type      TEXT NOT NULL,          -- 'message','tool_call','enrichment',...
  cost_usd        NUMERIC(10,6) NOT NULL DEFAULT 0,
  metadata        JSONB,
  created_at      TIMESTAMPTZ NOT NULL DEFAULT NOW()
);
CREATE INDEX IF NOT EXISTS idx_usage_user_created
  ON public.usage_events(user_id, created_at DESC);

-- 5. updated_at trigger
CREATE OR REPLACE FUNCTION public.touch_updated_at()
RETURNS TRIGGER LANGUAGE plpgsql AS $$
BEGIN
  NEW.updated_at = NOW();
  RETURN NEW;
END;
$$;

DROP TRIGGER IF EXISTS profiles_touch ON public.profiles;
CREATE TRIGGER profiles_touch BEFORE UPDATE ON public.profiles
  FOR EACH ROW EXECUTE FUNCTION public.touch_updated_at();

DROP TRIGGER IF EXISTS sessions_touch ON public.chat_sessions;
CREATE TRIGGER sessions_touch BEFORE UPDATE ON public.chat_sessions
  FOR EACH ROW EXECUTE FUNCTION public.touch_updated_at();

-- 6. message-count + cost rollup trigger
CREATE OR REPLACE FUNCTION public.rollup_session_stats()
RETURNS TRIGGER LANGUAGE plpgsql AS $$
BEGIN
  UPDATE public.chat_sessions
  SET
    message_count = message_count + 1,
    total_tokens  = total_tokens + COALESCE(NEW.tokens_in, 0) + COALESCE(NEW.tokens_out, 0),
    total_cost_usd = total_cost_usd + COALESCE(NEW.cost_usd, 0),
    updated_at    = NOW()
  WHERE id = NEW.session_id;

  -- Also bump the user's total
  UPDATE public.profiles p
  SET total_cost_usd = total_cost_usd + COALESCE(NEW.cost_usd, 0),
      daily_used     = daily_used + 1
  FROM public.chat_sessions s
  WHERE s.id = NEW.session_id AND p.id = s.user_id;

  RETURN NEW;
END;
$$;
DROP TRIGGER IF EXISTS messages_rollup ON public.messages;
CREATE TRIGGER messages_rollup AFTER INSERT ON public.messages
  FOR EACH ROW EXECUTE FUNCTION public.rollup_session_stats();

-- 7. ROW LEVEL SECURITY — defense in depth
ALTER TABLE public.profiles ENABLE ROW LEVEL SECURITY;
ALTER TABLE public.chat_sessions ENABLE ROW LEVEL SECURITY;
ALTER TABLE public.messages ENABLE ROW LEVEL SECURITY;
ALTER TABLE public.usage_events ENABLE ROW LEVEL SECURITY;

-- profiles: user sees/updates only their own
DROP POLICY IF EXISTS "own_profile_select" ON public.profiles;
CREATE POLICY "own_profile_select" ON public.profiles
  FOR SELECT USING (auth.uid() = id);
DROP POLICY IF EXISTS "own_profile_update" ON public.profiles;
CREATE POLICY "own_profile_update" ON public.profiles
  FOR UPDATE USING (auth.uid() = id);

-- chat_sessions: user's own + anyone can read public-shared ones
DROP POLICY IF EXISTS "own_sessions_select" ON public.chat_sessions;
CREATE POLICY "own_sessions_select" ON public.chat_sessions
  FOR SELECT USING (auth.uid() = user_id OR is_public = TRUE);
DROP POLICY IF EXISTS "own_sessions_modify" ON public.chat_sessions;
CREATE POLICY "own_sessions_modify" ON public.chat_sessions
  FOR ALL USING (auth.uid() = user_id) WITH CHECK (auth.uid() = user_id);

-- messages: only owners of the parent session (or public if session is_public)
DROP POLICY IF EXISTS "session_messages_select" ON public.messages;
CREATE POLICY "session_messages_select" ON public.messages
  FOR SELECT USING (
    EXISTS (SELECT 1 FROM public.chat_sessions s
            WHERE s.id = messages.session_id
              AND (s.user_id = auth.uid() OR s.is_public = TRUE))
  );
DROP POLICY IF EXISTS "session_messages_insert" ON public.messages;
CREATE POLICY "session_messages_insert" ON public.messages
  FOR INSERT WITH CHECK (
    EXISTS (SELECT 1 FROM public.chat_sessions s
            WHERE s.id = messages.session_id AND s.user_id = auth.uid())
  );
DROP POLICY IF EXISTS "session_messages_delete" ON public.messages;
CREATE POLICY "session_messages_delete" ON public.messages
  FOR DELETE USING (
    EXISTS (SELECT 1 FROM public.chat_sessions s
            WHERE s.id = messages.session_id AND s.user_id = auth.uid())
  );

-- usage_events: insert by service role only; user can read their own
DROP POLICY IF EXISTS "own_usage_select" ON public.usage_events;
CREATE POLICY "own_usage_select" ON public.usage_events
  FOR SELECT USING (auth.uid() = user_id);

-- 8. Helper RPC: get_or_create_session
CREATE OR REPLACE FUNCTION public.get_or_create_session(
  p_context_doc_id  TEXT DEFAULT NULL,
  p_context_page_id TEXT DEFAULT NULL,
  p_title           TEXT DEFAULT NULL
) RETURNS UUID LANGUAGE plpgsql SECURITY INVOKER SET search_path = public AS $$
DECLARE
  new_id UUID;
BEGIN
  IF auth.uid() IS NULL THEN
    RAISE EXCEPTION 'unauthenticated';
  END IF;
  new_id := gen_random_uuid();
  INSERT INTO chat_sessions (id, user_id, title, context_doc_id, context_page_id)
  VALUES (new_id, auth.uid(), p_title, p_context_doc_id, p_context_page_id);
  RETURN new_id;
END;
$$;
GRANT EXECUTE ON FUNCTION public.get_or_create_session TO authenticated;

-- 9. Helper RPC: enforce budget cap
CREATE OR REPLACE FUNCTION public.check_budget(p_user_id UUID)
RETURNS BOOLEAN LANGUAGE plpgsql SECURITY DEFINER SET search_path = public AS $$
DECLARE
  prof RECORD;
BEGIN
  SELECT * INTO prof FROM profiles WHERE id = p_user_id;
  IF prof.role = 'suspended' THEN RETURN FALSE; END IF;
  IF prof.total_cost_usd >= prof.budget_cap_usd THEN RETURN FALSE; END IF;
  -- Reset daily counter if past midnight
  IF prof.quota_reset_at <= NOW() THEN
    UPDATE profiles
    SET daily_used = 0,
        quota_reset_at = DATE_TRUNC('day', NOW()) + INTERVAL '1 day'
    WHERE id = p_user_id;
    RETURN TRUE;
  END IF;
  IF prof.daily_used >= prof.daily_quota THEN RETURN FALSE; END IF;
  RETURN TRUE;
END;
$$;
GRANT EXECUTE ON FUNCTION public.check_budget TO authenticated;