-- Work Allocation System Database Schema
-- MySQL 8.0

-- Create departments table
CREATE TABLE IF NOT EXISTS departments (
    id INT AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(100) NOT NULL UNIQUE,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

-- Create sub_departments table
CREATE TABLE IF NOT EXISTS sub_departments (
    id INT AUTO_INCREMENT PRIMARY KEY,
    department_id INT NOT NULL,
    name VARCHAR(100) NOT NULL,
    primary_activity VARCHAR(255),
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (department_id) REFERENCES departments(id) ON DELETE CASCADE,
    UNIQUE KEY unique_subdept (department_id, name)
);

-- Create users table
CREATE TABLE IF NOT EXISTS users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(50) NOT NULL UNIQUE,
    name VARCHAR(100) NOT NULL,
    email VARCHAR(100) NOT NULL UNIQUE,
    password VARCHAR(255) NOT NULL,
    role ENUM('SuperAdmin', 'Supervisor', 'Contractor', 'Employee') NOT NULL,
    department_id INT,
    contractor_id INT,
    is_active BOOLEAN DEFAULT TRUE,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (department_id) REFERENCES departments(id) ON DELETE SET NULL,
    FOREIGN KEY (contractor_id) REFERENCES users(id) ON DELETE SET NULL
);

-- Create work_allocations table
CREATE TABLE IF NOT EXISTS work_allocations (
    id INT AUTO_INCREMENT PRIMARY KEY,
    employee_id INT NOT NULL,
    supervisor_id INT NOT NULL,
    contractor_id INT NOT NULL,
    sub_department_id INT,
    activity VARCHAR(255),
    description TEXT,
    assigned_date DATE NOT NULL,
    completion_date DATE,
    status ENUM('Pending', 'InProgress', 'Completed', 'Cancelled') DEFAULT 'Pending',
    rate DECIMAL(10, 2),
    units DECIMAL(10, 2),
    total_amount DECIMAL(10, 2),
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (employee_id) REFERENCES users(id) ON DELETE CASCADE,
    FOREIGN KEY (supervisor_id) REFERENCES users(id) ON DELETE CASCADE,
    FOREIGN KEY (contractor_id) REFERENCES users(id) ON DELETE CASCADE,
    FOREIGN KEY (sub_department_id) REFERENCES sub_departments(id) ON DELETE SET NULL
);

-- Create attendance table
CREATE TABLE IF NOT EXISTS attendance (
    id INT AUTO_INCREMENT PRIMARY KEY,
    employee_id INT NOT NULL,
    supervisor_id INT NOT NULL,
    check_in_time DATETIME,
    check_out_time DATETIME,
    work_date DATE NOT NULL,
    status ENUM('CheckedIn', 'CheckedOut', 'Absent') DEFAULT 'CheckedIn',
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (employee_id) REFERENCES users(id) ON DELETE CASCADE,
    FOREIGN KEY (supervisor_id) REFERENCES users(id) ON DELETE CASCADE,
    UNIQUE KEY unique_attendance (employee_id, work_date)
);

-- Create contractor_rates table
CREATE TABLE IF NOT EXISTS contractor_rates (
    id INT AUTO_INCREMENT PRIMARY KEY,
    contractor_id INT NOT NULL,
    sub_department_id INT,
    activity VARCHAR(255),
    rate DECIMAL(10, 2) NOT NULL,
    effective_date DATE NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (contractor_id) REFERENCES users(id) ON DELETE CASCADE,
    FOREIGN KEY (sub_department_id) REFERENCES sub_departments(id) ON DELETE SET NULL
);

-- Create indexes for better query performance
CREATE INDEX idx_users_role ON users(role);
CREATE INDEX idx_users_department ON users(department_id);
CREATE INDEX idx_users_contractor ON users(contractor_id);
CREATE INDEX idx_work_allocations_employee ON work_allocations(employee_id);
CREATE INDEX idx_work_allocations_supervisor ON work_allocations(supervisor_id);
CREATE INDEX idx_work_allocations_contractor ON work_allocations(contractor_id);
CREATE INDEX idx_work_allocations_date ON work_allocations(assigned_date);
CREATE INDEX idx_work_allocations_status ON work_allocations(status);
CREATE INDEX idx_attendance_employee ON attendance(employee_id);
CREATE INDEX idx_attendance_date ON attendance(work_date);
CREATE INDEX idx_attendance_status ON attendance(status);
CREATE INDEX idx_contractor_rates_contractor ON contractor_rates(contractor_id);
CREATE INDEX idx_contractor_rates_date ON contractor_rates(effective_date);