-- Migration: Add users and sessions tables for authentication
-- Run this before 002_add_document_shares.sql

-- Enable UUID extension
CREATE EXTENSION IF NOT EXISTS "uuid-ossp";

-- Users table
CREATE TABLE IF NOT EXISTS users (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    email VARCHAR(255) NOT NULL,
    name VARCHAR(255) NOT NULL,
    avatar_url TEXT,
    provider VARCHAR(50) NOT NULL CHECK (provider IN ('google', 'github')),
    provider_user_id VARCHAR(255) NOT NULL,
    created_at TIMESTAMPTZ DEFAULT NOW(),
    updated_at TIMESTAMPTZ DEFAULT NOW(),
    last_login_at TIMESTAMPTZ,
    UNIQUE(provider, provider_user_id)
);

CREATE INDEX idx_users_email ON users(email);
CREATE INDEX idx_users_provider ON users(provider, provider_user_id);

COMMENT ON TABLE users IS 'Stores user accounts from OAuth providers';
COMMENT ON COLUMN users.provider IS 'OAuth provider: google or github';
COMMENT ON COLUMN users.provider_user_id IS 'User ID from OAuth provider';

-- Sessions table
CREATE TABLE IF NOT EXISTS sessions (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    token_hash VARCHAR(64) NOT NULL,
    expires_at TIMESTAMPTZ NOT NULL,
    created_at TIMESTAMPTZ DEFAULT NOW(),
    user_agent TEXT,
    ip_address VARCHAR(45),
    UNIQUE(token_hash)
);

CREATE INDEX idx_sessions_user_id ON sessions(user_id);
CREATE INDEX idx_sessions_token_hash ON sessions(token_hash);
CREATE INDEX idx_sessions_expires_at ON sessions(expires_at);

COMMENT ON TABLE sessions IS 'Stores active JWT sessions for revocation support';
COMMENT ON COLUMN sessions.token_hash IS 'SHA-256 hash of JWT token';
COMMENT ON COLUMN sessions.user_agent IS 'User agent string for device tracking';

-- Add owner_id to documents table if it doesn't exist
ALTER TABLE documents ADD COLUMN IF NOT EXISTS owner_id UUID REFERENCES users(id) ON DELETE SET NULL;
CREATE INDEX IF NOT EXISTS idx_documents_owner_id ON documents(owner_id);

COMMENT ON COLUMN documents.owner_id IS 'User who created the document';