-- Create timers table
CREATE TABLE IF NOT EXISTS timers (
    id INT AUTO_INCREMENT PRIMARY KEY,
    task_id INT NULL,
    user_id INT NOT NULL,
    start_time DATETIME NOT NULL,
    end_time DATETIME NULL,
    duration VARCHAR(20) NULL,
    description TEXT,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
    FOREIGN KEY (task_id) REFERENCES tasks(id) ON DELETE SET NULL,
    FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE,
    INDEX idx_user_start (user_id, start_time),
    INDEX idx_task_id (task_id),
    INDEX idx_end_time (end_time)
);
