-- Ensure ak_users has a primary key and chat tables reference it consistently
-- This script can be executed on Supabase/PostgreSQL to harden chat user relations
--
-- Steps:
-- 1. Add a primary key on public.ak_users(id) if it is missing.
-- 2. Backfill missing ak_users rows from auth.users so foreign keys can validate.
-- 3. Recreate chat_* foreign keys that point to ak_users.

begin;

-- 1) Guard against duplicate or null ids before creating the primary key.
DO
$$
DECLARE
  duplicate_ids integer;
  null_ids integer;
BEGIN
  SELECT count(*) INTO duplicate_ids
  FROM (
    SELECT id
    FROM public.ak_users
    GROUP BY id
    HAVING count(*) > 1
  ) dup;

  SELECT count(*) INTO null_ids
  FROM public.ak_users
  WHERE id IS NULL;

  IF duplicate_ids > 0 THEN
    RAISE EXCEPTION 'Cannot add primary key on public.ak_users(id): % duplicate id(s) detected', duplicate_ids;
  ELSIF null_ids > 0 THEN
    RAISE EXCEPTION 'Cannot add primary key on public.ak_users(id): % row(s) have NULL id', null_ids;
  END IF;

  IF NOT EXISTS (
    SELECT 1
    FROM pg_constraint
    WHERE conname = 'ak_users_pkey'
      AND conrelid = 'public.ak_users'::regclass
  ) THEN
    ALTER TABLE public.ak_users
      ADD CONSTRAINT ak_users_pkey PRIMARY KEY (id);
  END IF;
END;
$$;

-- 2) Backfill basic ak_users profiles from auth.users for any missing ids.
INSERT INTO public.ak_users (
    id,
    username,
    email,
    password_hash,
    gender,
    birthday,
    height_cm,
    weight_kg,
    bio,
    phone,
    avatar_url,
    region_id,
    school_id,
    grade_id,
    class_id,
    role,
    created_at,
    updated_at,
    auth_id,
    preferred_language
)
SELECT
    au.id,
    COALESCE(NULLIF(trim(au.raw_user_meta_data ->> 'nickname'), ''),
             NULLIF(trim(au.raw_user_meta_data ->> 'username'), ''),
             split_part(au.email, '@', 1)),
    COALESCE(au.email, 'user_' || substr(au.id::text, 1, 8) || '@akmon.local'),
    'auth-managed:' || au.id::text,
    COALESCE(NULLIF(trim(au.raw_user_meta_data ->> 'gender'), ''), 'other'),
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    NULLIF(trim(au.raw_user_meta_data ->> 'avatar_url'), ''),
    NULL,
    NULL,
    NULL,
    NULL,
    COALESCE(NULLIF(trim(au.raw_user_meta_data ->> 'role'), ''), 'student'),
    COALESCE(au.created_at, now()),
    COALESCE(au.updated_at, now()),
    au.id,
    NULLIF(trim(au.raw_user_meta_data ->> 'preferred_language'), '')
FROM auth.users au
LEFT JOIN public.ak_users ak ON ak.id = au.id
WHERE ak.id IS NULL;

-- 3) Recreate chat foreign keys to reference ak_users.
ALTER TABLE public.chat_conversations
  DROP CONSTRAINT IF EXISTS chat_conversations_owner_id_fkey;
ALTER TABLE public.chat_conversations
  ADD CONSTRAINT chat_conversations_owner_id_fkey
  FOREIGN KEY (owner_id) REFERENCES public.ak_users(id) ON DELETE SET NULL;

ALTER TABLE public.chat_participants
  DROP CONSTRAINT IF EXISTS chat_participants_user_id_fkey;
ALTER TABLE public.chat_participants
  ADD CONSTRAINT chat_participants_user_id_fkey
  FOREIGN KEY (user_id) REFERENCES public.ak_users(id) ON DELETE CASCADE;

ALTER TABLE public.chat_messages
  DROP CONSTRAINT IF EXISTS chat_messages_sender_id_fkey;
ALTER TABLE public.chat_messages
  ADD CONSTRAINT chat_messages_sender_id_fkey
  FOREIGN KEY (sender_id) REFERENCES public.ak_users(id) ON DELETE CASCADE;

ALTER TABLE public.chat_notifications
  DROP CONSTRAINT IF EXISTS chat_notifications_user_id_fkey;
ALTER TABLE public.chat_notifications
  ADD CONSTRAINT chat_notifications_user_id_fkey
  FOREIGN KEY (user_id) REFERENCES public.ak_users(id) ON DELETE CASCADE;

ALTER TABLE public.chat_mqtt_downlinks
  DROP CONSTRAINT IF EXISTS chat_mqtt_downlinks_target_user_id_fkey;
ALTER TABLE public.chat_mqtt_downlinks
  ADD CONSTRAINT chat_mqtt_downlinks_target_user_id_fkey
  FOREIGN KEY (target_user_id) REFERENCES public.ak_users(id) ON DELETE SET NULL;

ALTER TABLE public.chat_mqtt_downlinks
  DROP CONSTRAINT IF EXISTS chat_mqtt_downlinks_created_by_fkey;
ALTER TABLE public.chat_mqtt_downlinks
  ADD CONSTRAINT chat_mqtt_downlinks_created_by_fkey
  FOREIGN KEY (created_by) REFERENCES public.ak_users(id) ON DELETE CASCADE;

commit;