-- Migration: Create messages table
-- Description: Chat messages in rooms

CREATE TABLE IF NOT EXISTS messages (
    id BIGSERIAL PRIMARY KEY,
    room_id BIGINT NOT NULL,
    user_id BIGINT NOT NULL,
    content TEXT NOT NULL,
    message_type VARCHAR(50) NOT NULL DEFAULT 'text', -- 'text', 'image', 'audio', 'file', 'system'
    parent_id BIGINT, -- For threaded replies
    is_edited BOOLEAN DEFAULT false,
    is_deleted BOOLEAN DEFAULT false,
    metadata JSONB, -- For additional data (file info, mentions, etc.)
    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    deleted_at TIMESTAMP WITH TIME ZONE,
    
    CONSTRAINT fk_messages_room_id FOREIGN KEY (room_id) REFERENCES rooms(id) ON DELETE CASCADE,
    CONSTRAINT fk_messages_user_id FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE,
    CONSTRAINT fk_messages_parent_id FOREIGN KEY (parent_id) REFERENCES messages(id) ON DELETE SET NULL
);

-- Indexes
CREATE INDEX IF NOT EXISTS idx_messages_room_id_created_at ON messages(room_id, created_at DESC);
CREATE INDEX IF NOT EXISTS idx_messages_user_id ON messages(user_id);
CREATE INDEX IF NOT EXISTS idx_messages_parent_id ON messages(parent_id) WHERE parent_id IS NOT NULL;
CREATE INDEX IF NOT EXISTS idx_messages_message_type ON messages(message_type);
CREATE INDEX IF NOT EXISTS idx_messages_deleted_at ON messages(deleted_at);
CREATE INDEX IF NOT EXISTS idx_messages_is_deleted ON messages(is_deleted) WHERE is_deleted = false;

-- Full-text search index for message content
CREATE INDEX IF NOT EXISTS idx_messages_content_search ON messages USING gin(to_tsvector('english', content));

-- Comments
COMMENT ON TABLE messages IS 'Chat messages in rooms with support for threading and different types';
COMMENT ON COLUMN messages.message_type IS 'Type of message: text, image, audio, file, or system';
COMMENT ON COLUMN messages.parent_id IS 'Parent message ID for threaded replies';
COMMENT ON COLUMN messages.metadata IS 'JSON metadata for file info, mentions, reactions, etc.';