-- ============================================
-- Sistema de Mensagens - MediConnect
-- ============================================

-- Tabela de conversas entre médicos e pacientes
-- Usa external_doctor_id e external_patient_id para referenciar dados do Supabase externo
CREATE TABLE IF NOT EXISTS conversations (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  external_doctor_id UUID NOT NULL,  -- ID do médico no Supabase externo
  external_patient_id UUID NOT NULL, -- ID do paciente no Supabase externo
  created_at TIMESTAMPTZ DEFAULT NOW(),
  updated_at TIMESTAMPTZ DEFAULT NOW(),
  UNIQUE(external_doctor_id, external_patient_id)
);

-- Índices para performance
CREATE INDEX IF NOT EXISTS idx_conversations_doctor ON conversations(external_doctor_id);
CREATE INDEX IF NOT EXISTS idx_conversations_patient ON conversations(external_patient_id);

-- Tabela de mensagens
CREATE TABLE IF NOT EXISTS messages (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  conversation_id UUID NOT NULL REFERENCES conversations(id) ON DELETE CASCADE,
  sender_id UUID NOT NULL,  -- ID do usuário (médico ou paciente) no Supabase externo
  sender_type VARCHAR(10) NOT NULL CHECK (sender_type IN ('doctor', 'patient')),
  content TEXT,
  message_type VARCHAR(20) NOT NULL DEFAULT 'text' CHECK (message_type IN ('text', 'file', 'image', 'video', 'audio', 'report', 'appointment')),
  read_at TIMESTAMPTZ,
  created_at TIMESTAMPTZ DEFAULT NOW(),
  updated_at TIMESTAMPTZ DEFAULT NOW(),
  
  -- Campos para anexos
  attachment_name VARCHAR(255),
  attachment_url TEXT,
  attachment_type VARCHAR(100),
  attachment_size INTEGER,
  
  -- Metadados
  metadata JSONB DEFAULT '{}'::jsonb
);

-- Índices para performance
CREATE INDEX IF NOT EXISTS idx_messages_conversation ON messages(conversation_id);
CREATE INDEX IF NOT EXISTS idx_messages_sender ON messages(sender_id);
CREATE INDEX IF NOT EXISTS idx_messages_created_at ON messages(created_at DESC);
CREATE INDEX IF NOT EXISTS idx_messages_read_at ON messages(read_at);

-- Tabela de status online (usando Supabase Realtime)
CREATE TABLE IF NOT EXISTS user_presence (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  user_id UUID NOT NULL,  -- ID do usuário no Supabase externo
  user_type VARCHAR(10) NOT NULL CHECK (user_type IN ('doctor', 'patient', 'admin', 'secretaria')),
  online BOOLEAN DEFAULT false,
  last_seen TIMESTAMPTZ DEFAULT NOW(),
  metadata JSONB DEFAULT '{}'::jsonb,
  UNIQUE(user_id, user_type)
);

-- Índice para verificação rápida de status
CREATE INDEX IF NOT EXISTS idx_user_presence_user ON user_presence(user_id, user_type);
CREATE INDEX IF NOT EXISTS idx_user_presence_online ON user_presence(online);

-- Tabela de anexos compartilhados
CREATE TABLE IF NOT EXISTS message_attachments (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  message_id UUID NOT NULL REFERENCES messages(id) ON DELETE CASCADE,
  file_name VARCHAR(255) NOT NULL,
  file_url TEXT NOT NULL,
  file_type VARCHAR(100) NOT NULL,
  file_size INTEGER NOT NULL,
  mime_type VARCHAR(100),
  thumbnail_url TEXT,
  uploaded_by UUID NOT NULL,  -- ID do usuário no Supabase externo
  created_at TIMESTAMPTZ DEFAULT NOW(),
  metadata JSONB DEFAULT '{}'::jsonb
);

-- Índices
CREATE INDEX IF NOT EXISTS idx_attachments_message ON message_attachments(message_id);
CREATE INDEX IF NOT EXISTS idx_attachments_uploader ON message_attachments(uploaded_by);

-- Tabela de notificações de mensagens
CREATE TABLE IF NOT EXISTS message_notifications (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  user_id UUID NOT NULL,
  user_type VARCHAR(10) NOT NULL,
  message_id UUID NOT NULL REFERENCES messages(id) ON DELETE CASCADE,
  read BOOLEAN DEFAULT false,
  sent_at TIMESTAMPTZ DEFAULT NOW(),
  read_at TIMESTAMPTZ
);

-- Índices
CREATE INDEX IF NOT EXISTS idx_notifications_user ON message_notifications(user_id, user_type);
CREATE INDEX IF NOT EXISTS idx_notifications_read ON message_notifications(read);

-- ============================================
-- Triggers para atualização automática
-- ============================================

-- Trigger para atualizar updated_at em conversations
CREATE OR REPLACE FUNCTION update_conversation_timestamp()
RETURNS TRIGGER AS $$
BEGIN
  UPDATE conversations 
  SET updated_at = NOW() 
  WHERE id = NEW.conversation_id;
  RETURN NEW;
END;
$$ LANGUAGE plpgsql;

CREATE TRIGGER update_conversation_on_message
AFTER INSERT ON messages
FOR EACH ROW
EXECUTE FUNCTION update_conversation_timestamp();

-- Trigger para atualizar last_seen em user_presence
CREATE OR REPLACE FUNCTION update_last_seen()
RETURNS TRIGGER AS $$
BEGIN
  NEW.last_seen = NOW();
  RETURN NEW;
END;
$$ LANGUAGE plpgsql;

CREATE TRIGGER update_user_presence_last_seen
BEFORE UPDATE ON user_presence
FOR EACH ROW
EXECUTE FUNCTION update_last_seen();

-- ============================================
-- Funções auxiliares
-- ============================================

-- Função para obter conversas de um usuário
-- Retorna apenas IDs - frontend busca nomes do Supabase externo
CREATE OR REPLACE FUNCTION get_user_conversations(
  p_user_id UUID,
  p_user_type VARCHAR
)
RETURNS TABLE (
  conversation_id UUID,
  other_user_id UUID,
  other_user_name TEXT,
  other_user_specialty TEXT,
  other_user_avatar TEXT,
  last_message TEXT,
  last_message_time TIMESTAMPTZ,
  unread_count BIGINT,
  is_online BOOLEAN
) AS $$
BEGIN
  IF p_user_type = 'patient' THEN
    RETURN QUERY
    SELECT 
      c.id as conversation_id,
      c.external_doctor_id as other_user_id,
      NULL::TEXT as other_user_name,  -- Frontend busca do Supabase externo
      NULL::TEXT as other_user_specialty,  -- Frontend busca do Supabase externo
      NULL::TEXT as other_user_avatar,
      (SELECT content FROM messages WHERE conversation_id = c.id ORDER BY created_at DESC LIMIT 1) as last_message,
      (SELECT created_at FROM messages WHERE conversation_id = c.id ORDER BY created_at DESC LIMIT 1) as last_message_time,
      (SELECT COUNT(*) FROM messages m WHERE m.conversation_id = c.id AND m.sender_type = 'doctor' AND m.read_at IS NULL) as unread_count,
      COALESCE((SELECT online FROM user_presence WHERE user_id = c.external_doctor_id AND user_type = 'doctor'), false) as is_online
    FROM conversations c
    WHERE c.external_patient_id = p_user_id
    ORDER BY last_message_time DESC NULLS LAST;
  ELSE
    RETURN QUERY
    SELECT 
      c.id as conversation_id,
      c.external_patient_id as other_user_id,
      NULL::TEXT as other_user_name,  -- Frontend busca do Supabase externo
      NULL::TEXT as other_user_specialty,
      NULL::TEXT as other_user_avatar,
      (SELECT content FROM messages WHERE conversation_id = c.id ORDER BY created_at DESC LIMIT 1) as last_message,
      (SELECT created_at FROM messages WHERE conversation_id = c.id ORDER BY created_at DESC LIMIT 1) as last_message_time,
      (SELECT COUNT(*) FROM messages m WHERE m.conversation_id = c.id AND m.sender_type = 'patient' AND m.read_at IS NULL) as unread_count,
      COALESCE((SELECT online FROM user_presence WHERE user_id = c.external_patient_id AND user_type = 'patient'), false) as is_online
    FROM conversations c
    WHERE c.external_doctor_id = p_user_id
    ORDER BY last_message_time DESC NULLS LAST;
  END IF;
END;
$$ LANGUAGE plpgsql;

-- Função para criar ou obter conversa
CREATE OR REPLACE FUNCTION get_or_create_conversation(
  p_doctor_id UUID,
  p_patient_id UUID
)
RETURNS UUID AS $$
DECLARE
  v_conversation_id UUID;
BEGIN
  SELECT id INTO v_conversation_id
  FROM conversations
  WHERE external_doctor_id = p_doctor_id AND external_patient_id = p_patient_id;
  
  IF v_conversation_id IS NULL THEN
    INSERT INTO conversations (external_doctor_id, external_patient_id)
    VALUES (p_doctor_id, p_patient_id)
    RETURNING id INTO v_conversation_id;
  END IF;
  
  RETURN v_conversation_id;
END;
$$ LANGUAGE plpgsql;

-- Função para marcar mensagens como lidas
CREATE OR REPLACE FUNCTION mark_messages_as_read(
  p_conversation_id UUID,
  p_user_id UUID,
  p_user_type VARCHAR
)
RETURNS INTEGER AS $$
DECLARE
  v_updated_count INTEGER;
BEGIN
  UPDATE messages
  SET read_at = NOW()
  WHERE conversation_id = p_conversation_id
    AND sender_id != p_user_id
    AND sender_type != p_user_type
    AND read_at IS NULL;
  
  GET DIAGNOSTICS v_updated_count = ROW_COUNT;
  RETURN v_updated_count;
END;
$$ LANGUAGE plpgsql;

-- ============================================
-- Políticas RLS (Row Level Security)
-- ============================================

-- Habilitar RLS
ALTER TABLE conversations ENABLE ROW LEVEL SECURITY;
ALTER TABLE messages ENABLE ROW LEVEL SECURITY;
ALTER TABLE user_presence ENABLE ROW LEVEL SECURITY;
ALTER TABLE message_attachments ENABLE ROW LEVEL SECURITY;
ALTER TABLE message_notifications ENABLE ROW LEVEL SECURITY;

-- Políticas para conversations
CREATE POLICY "Users can view their own conversations"
  ON conversations FOR SELECT
  USING (
    external_doctor_id = auth.uid()
    OR external_patient_id = auth.uid()
  );

CREATE POLICY "Users can create conversations"
  ON conversations FOR INSERT
  WITH CHECK (
    external_doctor_id = auth.uid()
    OR external_patient_id = auth.uid()
  );

-- Políticas para messages
CREATE POLICY "Users can view messages in their conversations"
  ON messages FOR SELECT
  USING (
    conversation_id IN (
      SELECT id FROM conversations 
      WHERE external_doctor_id = auth.uid()
         OR external_patient_id = auth.uid()
    )
  );

CREATE POLICY "Users can send messages in their conversations"
  ON messages FOR INSERT
  WITH CHECK (
    conversation_id IN (
      SELECT id FROM conversations 
      WHERE external_doctor_id = auth.uid()
         OR external_patient_id = auth.uid()
    )
  );

CREATE POLICY "Users can update their own messages"
  ON messages FOR UPDATE
  USING (
    sender_id = auth.uid()
    OR conversation_id IN (
      SELECT id FROM conversations 
      WHERE external_doctor_id = auth.uid()
         OR external_patient_id = auth.uid()
    )
  );

-- Políticas para user_presence
CREATE POLICY "Everyone can view presence"
  ON user_presence FOR SELECT
  USING (true);

CREATE POLICY "Users can update their own presence"
  ON user_presence FOR ALL
  USING (user_id = auth.uid());

-- Políticas para attachments
CREATE POLICY "Users can view attachments in their conversations"
  ON message_attachments FOR SELECT
  USING (
    message_id IN (
      SELECT m.id FROM messages m
      JOIN conversations c ON m.conversation_id = c.id
      WHERE c.external_doctor_id = auth.uid()
         OR c.external_patient_id = auth.uid()
    )
  );

CREATE POLICY "Users can upload attachments"
  ON message_attachments FOR INSERT
  WITH CHECK (uploaded_by = auth.uid());

-- ============================================
-- Comentários
-- ============================================

COMMENT ON TABLE conversations IS 'Conversas entre médicos e pacientes';
COMMENT ON TABLE messages IS 'Mensagens trocadas em conversas';
COMMENT ON TABLE user_presence IS 'Status online/offline de usuários em tempo real';
COMMENT ON TABLE message_attachments IS 'Anexos compartilhados em mensagens';
COMMENT ON TABLE message_notifications IS 'Notificações de novas mensagens';