-- Create patient_queue table
CREATE TABLE IF NOT EXISTS patient_queue (
    id INT AUTO_INCREMENT PRIMARY KEY,
    patient_id INT NOT NULL,
    department_id INT NOT NULL,
    doctor_id INT NULL,
    visit_id INT NULL,
    token_number INT NOT NULL,
    status ENUM('waiting', 'serving', 'completed', 'cancelled') DEFAULT 'waiting',
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
    FOREIGN KEY (patient_id) REFERENCES patients(id) ON DELETE CASCADE,
    FOREIGN KEY (department_id) REFERENCES departments(id) ON DELETE CASCADE,
    FOREIGN KEY (doctor_id) REFERENCES doctors(id) ON DELETE SET NULL,
    FOREIGN KEY (visit_id) REFERENCES visits(id) ON DELETE SET NULL
);

-- Index for faster searching of today's queue
CREATE INDEX idx_queue_date_dept ON patient_queue(created_at, department_id);