import os
import uuid
import json
import uvicorn
from flask import Flask, render_template_string, request, redirect, url_for, session, flash
# --- CONFIGURATION ---
app = Flask(__name__)
app.secret_key = 'azad_university_secret_key'
USERS_FILE = 'users/users.json'

TEMPLATE = open('ui/main.html', 'r').read()

# --- DATA PERSISTENCE HELPER FUNCTIONS ---

def load_users():
    """Loads users from the JSON file. Returns an empty list if file doesn't exist."""
    if not os.path.exists(USERS_FILE):
        return []
    try:
        with open(USERS_FILE, 'r', encoding='utf-8') as f:
            return json.load(f)
    except (json.JSONDecodeError, IOError):
        return []

def save_users(users_list):
    """Saves the current list of users to the JSON file."""
    try:
        with open(USERS_FILE, 'w', encoding='utf-8') as f:
            json.dump(users_list, f, ensure_ascii=False, indent=4)
    except IOError as e:
        print(f"Error saving data: {e}")

def get_user_courses(username):
    """Loads courses for a specific user from their JSON file."""
    user_file = f'users_courses/{username}.json'
    if not os.path.exists(user_file):
        return []
    try:
        with open(user_file, 'r', encoding='utf-8') as f:
            return json.load(f)
    except (json.JSONDecodeError, IOError):
        return []

def save_user_courses(username, courses_list):
    """Saves courses for a specific user to their JSON file."""
    # Ensure directory exists
    os.makedirs('users_courses', exist_ok=True)
    user_file = f'users_courses/{username}.json'
    try:
        with open(user_file, 'w', encoding='utf-8') as f:
            json.dump(courses_list, f, ensure_ascii=False, indent=4)
    except IOError as e:
        print(f"Error saving data: {e}")

# --- AUTHENTICATION ROUTES ---

@app.route('/register', methods=['GET', 'POST'])
def register():
    if request.method == 'POST':
        username = request.form.get('username')
        password = request.form.get('password')
        
        users = load_users()
        
        # Check if username already exists
        for user in users:
            if user['username'] == username:
                flash('نام کاربری قبلاً ثبت شده است', 'error')
                return redirect(url_for('register'))
        
        # Create new user
        new_user = {
            'id': str(uuid.uuid4()),
            'username': username,
            'password': password  # In production, use password hashing!
        }
        users.append(new_user)
        save_users(users)
        
        flash('ثبت نام موفقیت‌آمیز بود! حالا وارد شوید', 'success')
        return redirect(url_for('login'))
    
    return render_template_string(TEMPLATE, page='register')

@app.route('/login', methods=['GET', 'POST'])
def login():
    if request.method == 'POST':
        username = request.form.get('username')
        password = request.form.get('password')
        
        users = load_users()
        
        # Check credentials
        for user in users:
            if user['username'] == username and user['password'] == password:
                session['user_id'] = user['id']
                session['username'] = user['username']
                flash(f'خوش آمدید، {username}!', 'success')
                return redirect(url_for('index'))
        
        flash('نام کاربری یا رمز عبور اشتباه است', 'error')
        return redirect(url_for('login'))
    
    return render_template_string(TEMPLATE, page='login')

@app.route('/logout')
def logout():
    session.pop('user_id', None)
    session.pop('username', None)
    flash('با موفقیت خارج شدید', 'success')
    return redirect(url_for('login'))

# --- MAIN ROUTES ---

@app.route('/')
def index():
    if 'user_id' not in session:
        return redirect(url_for('login'))
    
    courses = get_user_courses(session['username'])
    # Sort courses: High priority first
    priority_order = {"high": 0, "normal": 1, "low": 2}
    sorted_courses = sorted(courses, key=lambda x: priority_order.get(x["priority"], 1))
    return render_template_string(TEMPLATE, courses=sorted_courses, username=session['username'])

@app.route('/add', methods=['POST'])
def add_course():
    if 'user_id' not in session:
        return redirect(url_for('login'))
    
    courses = get_user_courses(session['username'])
    new_course = {
        "id": str(uuid.uuid4()),
        "name": request.form.get('name'),
        "code": request.form.get('code'),
        "group": request.form.get('group'),
        "day": request.form.get('day'),
        "prof": request.form.get('prof'),
        "priority": request.form.get('priority')
    }
    courses.append(new_course)
    save_user_courses(session['username'], courses)
    return redirect(url_for('index'))

@app.route('/delete/<course_id>')
def delete_course(course_id):
    if 'user_id' not in session:
        return redirect(url_for('login'))
    
    courses = get_user_courses(session['username'])
    # Filter out the course with the matching ID
    updated_courses = [c for c in courses if c['id'] != course_id]
    save_user_courses(session['username'], updated_courses)
    return redirect(url_for('index'))

@app.route('/edit/<course_id>', methods=['GET', 'POST'])
def edit_course(course_id):
    if 'user_id' not in session:
        return redirect(url_for('login'))
    
    courses = get_user_courses(session['username'])
    course = next((c for c in courses if c['id'] == course_id), None)
    
    if not course:
        flash('درس مورد نظر یافت نشد', 'error')
        return redirect(url_for('index'))
    
    if request.method == 'POST':
        course['name'] = request.form.get('name')
        course['code'] = request.form.get('code')
        course['group'] = request.form.get('group')
        course['day'] = request.form.get('day')
        course['prof'] = request.form.get('prof')
        course['priority'] = request.form.get('priority')
        save_user_courses(session['username'], courses)
        flash('درس با موفقیت ویرایش شد', 'success')
        return redirect(url_for('index'))
    
    return render_template_string(TEMPLATE, page='edit_course', course=course, username=session['username'])