#!/usr/bin/env python3
"""
Minimal Tablet Lending and Return Management System
Using only built-in Python modules
"""

import sqlite3
from datetime import datetime

def init_db():
    """Initialize database with required tables"""
    conn = sqlite3.connect('tablets.db')
    cursor = conn.cursor()
    
    # Create tables
    cursor.execute('''
        CREATE TABLE IF NOT EXISTS tablets (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            brand TEXT NOT NULL,
            model TEXT NOT NULL,
            serial_number TEXT UNIQUE NOT NULL,
            status TEXT DEFAULT 'available'
        )
    ''')
    
    cursor.execute('''
        CREATE TABLE IF NOT EXISTS users (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            name TEXT NOT NULL,
            identification TEXT UNIQUE
        )
    ''')
    
    cursor.execute('''
        CREATE TABLE IF NOT EXISTS loans (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            tablet_id INTEGER NOT NULL,
            user_id INTEGER NOT NULL,
            loan_date TEXT NOT NULL,
            return_date TEXT,
            status TEXT DEFAULT 'active',
            FOREIGN KEY (tablet_id) REFERENCES tablets (id),
            FOREIGN KEY (user_id) REFERENCES users (id)
        )
    ''')
    
    # Create non_loanable_devices table
    cursor.execute('''
        CREATE TABLE IF NOT EXISTS non_loanable_devices (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            brand TEXT NOT NULL,
            model TEXT NOT NULL,
            serial_number TEXT UNIQUE NOT NULL,
            device_type TEXT NOT NULL,
            location TEXT,
            status TEXT DEFAULT 'available',
            notes TEXT,
            purchase_date TEXT,
            purchase_cost REAL
        )
    ''')
    
    conn.commit()
    conn.close()

def add_tablet(brand, model, serial_number):
    """Add a new tablet to inventory"""
    conn = sqlite3.connect('tablets.db')
    cursor = conn.cursor()
    
    try:
        cursor.execute('''
            INSERT INTO tablets (brand, model, serial_number, status)
            VALUES (?, ?, ?, 'available')
        ''', (brand, model, serial_number))
        conn.commit()
        print(f"✓ Added tablet: {brand} {model} ({serial_number})")
    except sqlite3.IntegrityError:
        print(f"✗ Error: Serial number {serial_number} already exists")
    finally:
        conn.close()

def add_user(name, identification):
    """Add a new user"""
    conn = sqlite3.connect('tablets.db')
    cursor = conn.cursor()
    
    try:
        cursor.execute('''
            INSERT INTO users (name, identification)
            VALUES (?, ?)
        ''', (name, identification))
        conn.commit()
        print(f"✓ Added user: {name} ({identification})")
    except sqlite3.IntegrityError:
        print(f"✗ Error: Identification {identification} already exists")
    finally:
        conn.close()

def loan_tablet(tablet_id, user_id):
    """Loan a tablet to a user"""
    conn = sqlite3.connect('tablets.db')
    cursor = conn.cursor()
    
    # Check if tablet is available
    cursor.execute("SELECT status FROM tablets WHERE id = ?", (tablet_id,))
    result = cursor.fetchone()
    
    if result and result[0] == 'available':
        # Update tablet status
        cursor.execute("UPDATE tablets SET status = 'loaned' WHERE id = ?", (tablet_id,))
        
        # Create loan record
        loan_date = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
        cursor.execute('''
            INSERT INTO loans (tablet_id, user_id, loan_date, status)
            VALUES (?, ?, ?, 'active')
        ''', (tablet_id, user_id, loan_date))
        
        conn.commit()
        print(f"✓ Tablet {tablet_id} loaned to user {user_id}")
    else:
        print(f"✗ Error: Tablet {tablet_id} is not available for loan")
    
    conn.close()

def return_tablet(loan_id):
    """Return a loaned tablet"""
    conn = sqlite3.connect('tablets.db')
    cursor = conn.cursor()
    
    # Get loan information
    cursor.execute("SELECT tablet_id FROM loans WHERE id = ? AND status = 'active'", (loan_id,))
    loan = cursor.fetchone()
    
    if loan:
        tablet_id = loan[0]
        
        # Update loan status and return date
        return_date = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
        cursor.execute('''
            UPDATE loans SET status = 'returned', return_date = ? WHERE id = ?
        ''', (return_date, loan_id))
        
        # Update tablet status
        cursor.execute("UPDATE tablets SET status = 'available' WHERE id = ?", (tablet_id,))
        
        conn.commit()
        print(f"✓ Tablet returned for loan {loan_id}")
    else:
        print(f"✗ Error: Loan {loan_id} not found or already returned")
    
    conn.close()

def show_available_tablets():
    """Show available tablets"""
    conn = sqlite3.connect('tablets.db')
    cursor = conn.cursor()
    
    cursor.execute("SELECT id, brand, model, serial_number FROM tablets WHERE status = 'available'")
    tablets = cursor.fetchall()
    
    print("\n=== Available Tablets ===")
    if tablets:
        for tablet in tablets:
            print(f"ID: {tablet[0]}, {tablet[1]} {tablet[2]} ({tablet[3]})")
    else:
        print("No available tablets")
    
    conn.close()

def show_active_loans():
    """Show active loans"""
    conn = sqlite3.connect('tablets.db')
    cursor = conn.cursor()
    
    cursor.execute('''
        SELECT l.id, t.brand, t.model, t.serial_number, u.name, l.loan_date
        FROM loans l
        JOIN tablets t ON l.tablet_id = t.id
        JOIN users u ON l.user_id = u.id
        WHERE l.status = 'active'
    ''')
    loans = cursor.fetchall()
    
    print("\n=== Active Loans ===")
    if loans:
        for loan in loans:
            print(f"Loan ID: {loan[0]}, Tablet: {loan[1]} {loan[2]} ({loan[3]}), Borrower: {loan[4]}, Loan Date: {loan[5]}")
    else:
        print("No active loans")
    
    conn.close()

def show_loan_history():
    """Show complete loan history"""
    conn = sqlite3.connect('tablets.db')
    cursor = conn.cursor()
    
    cursor.execute('''
        SELECT l.id, t.brand, t.model, t.serial_number, u.name, 
               l.loan_date, l.return_date, l.status
        FROM loans l
        JOIN tablets t ON l.tablet_id = t.id
        JOIN users u ON l.user_id = u.id
        ORDER BY l.loan_date DESC
    ''')
    loans = cursor.fetchall()
    
    print("\n=== Loan History ===")
    if loans:
        for loan in loans:
            return_date = loan[6] or 'Not returned'
            print(f"Loan ID: {loan[0]}, Tablet: {loan[1]} {loan[2]} ({loan[3]}), Borrower: {loan[4]}")
            print(f"  Loan Date: {loan[5]}, Return Date: {return_date}, Status: {loan[7]}")
    else:
        print("No loan history")
    
    conn.close()


def add_non_loanable_device(brand, model, serial_number, device_type, location='', notes='', purchase_date='', purchase_cost=None):
    """Add a new non-loanable device to inventory"""
    conn = sqlite3.connect('tablets.db')
    cursor = conn.cursor()
    
    try:
        cursor.execute('''
            INSERT INTO non_loanable_devices 
            (brand, model, serial_number, device_type, location, status, notes, purchase_date, purchase_cost)
            VALUES (?, ?, ?, ?, ?, 'available', ?, ?, ?)
        ''', (brand, model, serial_number, device_type, location, notes, purchase_date, purchase_cost))
        conn.commit()
        print(f"✓ Added non-loanable device: {brand} {model} ({serial_number}) - Type: {device_type}")
    except sqlite3.IntegrityError:
        print(f"✗ Error: Serial number {serial_number} already exists")
    finally:
        conn.close()


def show_non_loanable_devices():
    """Show all non-loanable devices"""
    conn = sqlite3.connect('tablets.db')
    cursor = conn.cursor()
    
    cursor.execute("SELECT id, brand, model, serial_number, device_type, location, status FROM non_loanable_devices")
    devices = cursor.fetchall()
    
    print("\n=== Non-Loanable Devices ===")
    if devices:
        for device in devices:
            print(f"ID: {device[0]}, Type: {device[4]}, {device[1]} {device[2]} ({device[3]}), Location: {device[5] or 'N/A'}, Status: {device[6]}")
    else:
        print("No non-loanable devices")
    
    conn.close()


def delete_non_loanable_device(device_id):
    """Delete a non-loanable device"""
    conn = sqlite3.connect('tablets.db')
    cursor = conn.cursor()
    
    cursor.execute("DELETE FROM non_loanable_devices WHERE id = ?", (device_id,))
    conn.commit()
    
    if cursor.rowcount > 0:
        print(f"✓ Non-loanable device {device_id} deleted")
    else:
        print(f"✗ Error: Device {device_id} not found")
    
    conn.close()

def main():
    """Main menu"""
    init_db()
    
    print("=== Tablet Lending and Return Management System ===")
    print("Using SQLite database: tablets.db")
    
    while True:
        print("\nMenu:")
        print("1. Add Tablet")
        print("2. Add User")
        print("3. Loan Tablet")
        print("4. Return Tablet")
        print("5. Show Available Tablets")
        print("6. Show Active Loans")
        print("7. Show Loan History")
        print("8. Add Non-Loanable Device")
        print("9. Show Non-Loanable Devices")
        print("10. Delete Non-Loanable Device")
        print("11. Exit")
        
        choice = input("Enter your choice (1-11): ")
        
        if choice == '1':
            print("\n=== Add Tablet ===")
            brand = input("Brand: ")
            model = input("Model: ")
            serial_number = input("Serial Number: ")
            add_tablet(brand, model, serial_number)
        
        elif choice == '2':
            print("\n=== Add User ===")
            name = input("Name: ")
            identification = input("Identification: ")
            add_user(name, identification)
        
        elif choice == '3':
            print("\n=== Loan Tablet ===")
            show_available_tablets()
            show_users()
            
            tablet_id = input("Enter Tablet ID to loan: ")
            user_id = input("Enter User ID: ")
            
            try:
                loan_tablet(int(tablet_id), int(user_id))
            except ValueError:
                print("✗ Error: Invalid ID format")
        
        elif choice == '4':
            print("\n=== Return Tablet ===")
            show_active_loans()
            
            loan_id = input("Enter Loan ID to return: ")
            
            try:
                return_tablet(int(loan_id))
            except ValueError:
                print("✗ Error: Invalid Loan ID format")
        
        elif choice == '5':
            show_available_tablets()
        
        elif choice == '6':
            show_active_loans()
        
        elif choice == '7':
            show_loan_history()
        
        elif choice == '8':
            print("\n=== Add Non-Loanable Device ===")
            brand = input("Brand: ")
            model = input("Model: ")
            serial_number = input("Serial Number: ")
            device_type = input("Device Type (e.g., projector, monitor): ")
            location = input("Location (optional): ")
            notes = input("Notes (optional): ")
            add_non_loanable_device(brand, model, serial_number, device_type, location, notes)
        
        elif choice == '9':
            show_non_loanable_devices()
        
        elif choice == '10':
            print("\n=== Delete Non-Loanable Device ===")
            show_non_loanable_devices()
            device_id = input("Enter Device ID to delete: ")
            try:
                delete_non_loanable_device(int(device_id))
            except ValueError:
                print("✗ Error: Invalid ID format")
        
        elif choice == '11':
            print("Goodbye!")
            break
        
        else:
            print("✗ Invalid choice. Please try again.")

def show_users():
    """Show available users"""
    conn = sqlite3.connect('tablets.db')
    cursor = conn.cursor()
    
    cursor.execute("SELECT id, name, identification FROM users")
    users = cursor.fetchall()
    
    print("\n=== Available Users ===")
    if users:
        for user in users:
            print(f"ID: {user[0]}, {user[1]} ({user[2]})")
    else:
        print("No users available")
    
    conn.close()

if __name__ == '__main__':
    main()