-- Create users table for WhatsApp AI Agent
CREATE TABLE IF NOT EXISTS users (
    wa_id TEXT PRIMARY KEY,
    name TEXT NOT NULL DEFAULT 'Unknown',
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

-- Create chat_sessions table
CREATE TABLE IF NOT EXISTS chat_sessions (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    wa_id TEXT NOT NULL REFERENCES users(wa_id) ON DELETE CASCADE,
    started_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
    last_activity TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
    ended BOOLEAN DEFAULT FALSE
);

-- Create messages table
CREATE TABLE IF NOT EXISTS messages (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    session_id UUID NOT NULL REFERENCES chat_sessions(id) ON DELETE CASCADE,
    wa_id TEXT NOT NULL REFERENCES users(wa_id) ON DELETE CASCADE,
    wamid TEXT NOT NULL, -- Meta message ID
    role TEXT NOT NULL CHECK (role IN ('user', 'assistant')),
    content TEXT NOT NULL,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

-- Create personas table for user preferences and context
CREATE TABLE IF NOT EXISTS personas (
    wa_id TEXT PRIMARY KEY REFERENCES users(wa_id) ON DELETE CASCADE,
    language TEXT,
    tone TEXT,
    intent TEXT,
    budget TEXT,
    size_preference_sqm TEXT,
    location_preference TEXT,
    must_have TEXT[],
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

-- Create indexes for better query performance
CREATE INDEX IF NOT EXISTS idx_users_created_at ON users(created_at DESC);
CREATE INDEX IF NOT EXISTS idx_users_updated_at ON users(updated_at DESC);
CREATE INDEX IF NOT EXISTS idx_chat_sessions_wa_id ON chat_sessions(wa_id);
CREATE INDEX IF NOT EXISTS idx_chat_sessions_last_activity ON chat_sessions(last_activity DESC);
CREATE INDEX IF NOT EXISTS idx_chat_sessions_ended ON chat_sessions(ended);
CREATE INDEX IF NOT EXISTS idx_messages_session_id ON messages(session_id);
CREATE INDEX IF NOT EXISTS idx_messages_wa_id ON messages(wa_id);
CREATE INDEX IF NOT EXISTS idx_messages_created_at ON messages(created_at DESC);
CREATE INDEX IF NOT EXISTS idx_messages_wamid ON messages(wamid);
CREATE INDEX IF NOT EXISTS idx_personas_wa_id ON personas(wa_id);
CREATE INDEX IF NOT EXISTS idx_personas_updated_at ON personas(updated_at DESC);

-- Enable Row Level Security (RLS) - optional but recommended
ALTER TABLE users ENABLE ROW LEVEL SECURITY;
ALTER TABLE chat_sessions ENABLE ROW LEVEL SECURITY;
ALTER TABLE messages ENABLE ROW LEVEL SECURITY;
ALTER TABLE personas ENABLE ROW LEVEL SECURITY;

-- Create policies to allow all operations (you can restrict this based on your needs)
CREATE POLICY "Allow all operations on users" ON users
    FOR ALL USING (true);

CREATE POLICY "Allow all operations on chat_sessions" ON chat_sessions
    FOR ALL USING (true);

CREATE POLICY "Allow all operations on messages" ON messages
    FOR ALL USING (true);

CREATE POLICY "Allow all operations on personas" ON personas
    FOR ALL USING (true);

-- Optional: Create a function to automatically update the updated_at timestamp
CREATE OR REPLACE FUNCTION update_updated_at_column()
RETURNS TRIGGER AS $$
BEGIN
    NEW.updated_at = NOW();
    RETURN NEW;
END;
$$ language 'plpgsql';

-- Create trigger to automatically update updated_at for users
CREATE TRIGGER update_users_updated_at 
    BEFORE UPDATE ON users 
    FOR EACH ROW 
    EXECUTE FUNCTION update_updated_at_column();

-- Create trigger to automatically update last_activity for chat_sessions
CREATE OR REPLACE FUNCTION update_last_activity_column()
RETURNS TRIGGER AS $$
BEGIN
    NEW.last_activity = NOW();
    RETURN NEW;
END;
$$ language 'plpgsql';

CREATE TRIGGER update_chat_sessions_last_activity 
    BEFORE UPDATE ON chat_sessions 
    FOR EACH ROW 
    EXECUTE FUNCTION update_last_activity_column();

-- Create trigger to automatically update updated_at for personas
CREATE TRIGGER update_personas_updated_at 
    BEFORE UPDATE ON personas 
    FOR EACH ROW 
    EXECUTE FUNCTION update_updated_at_column();