-- Conversations table
CREATE TABLE IF NOT EXISTS conversations (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
    metadata JSONB DEFAULT '{}'::jsonb
);

-- Messages table
CREATE TABLE IF NOT EXISTS messages (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    conversation_id UUID REFERENCES conversations(id) ON DELETE CASCADE,
    role VARCHAR(20) NOT NULL CHECK (role IN ('user', 'assistant')),
    content TEXT NOT NULL,
    context_used TEXT[],
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
    metadata JSONB DEFAULT '{}'::jsonb
);

-- Indexes for performance
CREATE INDEX IF NOT EXISTS idx_messages_conversation_id ON messages(conversation_id);
CREATE INDEX IF NOT EXISTS idx_messages_created_at ON messages(created_at DESC);
CREATE INDEX IF NOT EXISTS idx_conversations_created_at ON conversations(created_at DESC);