-- Tables de messagerie interne (V1)

CREATE TABLE IF NOT EXISTS public.messagerie_threads (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
  updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

CREATE TABLE IF NOT EXISTS public.messagerie_participants (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  thread_id UUID NOT NULL REFERENCES public.messagerie_threads(id) ON DELETE CASCADE,
  user_id UUID NOT NULL REFERENCES public.utilisateurs(id) ON DELETE CASCADE,
  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
  UNIQUE(thread_id, user_id)
);

CREATE TABLE IF NOT EXISTS public.messagerie_messages (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  thread_id UUID NOT NULL REFERENCES public.messagerie_threads(id) ON DELETE CASCADE,
  sender_id UUID NOT NULL REFERENCES public.utilisateurs(id) ON DELETE CASCADE,
  contenu TEXT NOT NULL,
  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

CREATE INDEX IF NOT EXISTS idx_messagerie_participants_user_id ON public.messagerie_participants(user_id);
CREATE INDEX IF NOT EXISTS idx_messagerie_messages_thread_id ON public.messagerie_messages(thread_id);
CREATE INDEX IF NOT EXISTS idx_messagerie_messages_created_at ON public.messagerie_messages(created_at DESC);

-- RLS simple: participant du thread uniquement
ALTER TABLE public.messagerie_threads ENABLE ROW LEVEL SECURITY;
ALTER TABLE public.messagerie_participants ENABLE ROW LEVEL SECURITY;
ALTER TABLE public.messagerie_messages ENABLE ROW LEVEL SECURITY;

DROP POLICY IF EXISTS messagerie_threads_select ON public.messagerie_threads;
CREATE POLICY messagerie_threads_select ON public.messagerie_threads
FOR SELECT TO anon
USING (
  EXISTS (
    SELECT 1 FROM public.messagerie_participants p
    WHERE p.thread_id = messagerie_threads.id
  )
);

DROP POLICY IF EXISTS messagerie_threads_insert ON public.messagerie_threads;
CREATE POLICY messagerie_threads_insert ON public.messagerie_threads
FOR INSERT TO anon
WITH CHECK (true);

DROP POLICY IF EXISTS messagerie_threads_update ON public.messagerie_threads;
CREATE POLICY messagerie_threads_update ON public.messagerie_threads
FOR UPDATE TO anon
USING (
  EXISTS (
    SELECT 1 FROM public.messagerie_participants p
    WHERE p.thread_id = messagerie_threads.id
  )
)
WITH CHECK (true);

DROP POLICY IF EXISTS messagerie_participants_select ON public.messagerie_participants;
CREATE POLICY messagerie_participants_select ON public.messagerie_participants
FOR SELECT TO anon
USING (true);

DROP POLICY IF EXISTS messagerie_participants_insert ON public.messagerie_participants;
CREATE POLICY messagerie_participants_insert ON public.messagerie_participants
FOR INSERT TO anon
WITH CHECK (true);

DROP POLICY IF EXISTS messagerie_messages_select ON public.messagerie_messages;
CREATE POLICY messagerie_messages_select ON public.messagerie_messages
FOR SELECT TO anon
USING (
  EXISTS (
    SELECT 1 FROM public.messagerie_participants p
    WHERE p.thread_id = messagerie_messages.thread_id
  )
);

DROP POLICY IF EXISTS messagerie_messages_insert ON public.messagerie_messages;
CREATE POLICY messagerie_messages_insert ON public.messagerie_messages
FOR INSERT TO anon
WITH CHECK (
  EXISTS (
    SELECT 1 FROM public.messagerie_participants p
    WHERE p.thread_id = messagerie_messages.thread_id
      AND p.user_id = messagerie_messages.sender_id
  )
);