import streamlit as st
import pandas as pd
from datetime import datetime, timedelta
from persiantools.jdatetime import JalaliDate

# Load schedule data from CSV
def load_schedule():
    try:
        schedule_data = pd.read_csv('schedule.csv')
    except FileNotFoundError:
        schedule_data = pd.DataFrame(columns=['Class', 'Day', 'Start Time', 'Username', 'System'])
    return schedule_data

# Save schedule data to CSV
def save_schedule(schedule_data):
    schedule_data.to_csv('schedule.csv', index=False)

# Load user details from CSV
def load_user_details():
    try:
        user_details = pd.read_csv('details.csv')
    except FileNotFoundError:
        user_details = pd.DataFrame(columns=['username', 'password'])
    return user_details

# Check for system availability
def has_system_availability(schedule_data, class_selected, day_selected, start_time_selected, system_selected):
    bookings = schedule_data[
        (schedule_data['Class'] == class_selected) & 
        (schedule_data['Day'] == day_selected) & 
        (schedule_data['Start Time'] == start_time_selected)
    ]
    if len(bookings) >= 3:
        return False
    elif system_selected in bookings['System'].values:
        return False
    else:
        return True

# Convert string day and time to datetime
def get_class_datetime(day_selected, start_time_selected):
    days_of_week = ["شنبه", "یکشنبه", "دوشنبه", "سه‌شنبه", "چهارشنبه", "پنج‌شنبه"]
    today = JalaliDate.today().to_gregorian()
    current_day_index = today.weekday()  # This returns the current day of the week as an integer (0=Monday, 6=Sunday)

    # Adjusting days of the week to start from Saturday to match the Persian calendar
    target_day_index = days_of_week.index(day_selected)
    adjusted_day_index = (target_day_index + 1) % 7  # Mapping Saturday to 0, ..., Friday to 6

    delta_days = (adjusted_day_index - current_day_index) % 7

    # If the class day is today but time has passed, move to the next week
    class_time = datetime.strptime(start_time_selected, "%H:%M").time()
    if delta_days == 0 and class_time < datetime.now().time():
        delta_days = 7

    class_date = today + timedelta(days=delta_days)
    class_datetime = datetime.combine(class_date, class_time)

    return class_datetime

# Initialize session state variables
if 'username' not in st.session_state:
    st.session_state.username = ""
if 'password' not in st.session_state:
    st.session_state.password = ""
if 'schedule_data' not in st.session_state:
    st.session_state.schedule_data = load_schedule()
if 'authenticated' not in st.session_state:
    st.session_state.authenticated = False
if 'is_admin' not in st.session_state:
    st.session_state.is_admin = False

# Login Page
def login_page():
    st.title("ورود")
    st.session_state.username = st.text_input("نام کاربری")
    st.session_state.password = st.text_input("رمز عبور", type='password')

    user_details = load_user_details()

    if st.button("ورود"):
        if (
            (st.session_state.username in user_details['username'].values) and 
            (st.session_state.password in user_details[user_details['username'] == st.session_state.username]['password'].values)
        ) or (st.session_state.username == "armin" and st.session_state.password == "12345679"):
            st.session_state.authenticated = True
            st.session_state.is_admin = (st.session_state.username == "armin")
            # Load schedule data again after login
            st.session_state.schedule_data = load_schedule()
            st.experimental_rerun()
        else:
            st.error("نام کاربری یا رمز عبور اشتباه است. لطفا دوباره تلاش کنید.")

# Class Schedule Page
def schedule_page():
    st.title("برنامه کلاسی")

    classes = ["تعمیرات موبایل"]
    days = ["شنبه", "یکشنبه", "دوشنبه", "سه‌شنبه", "چهارشنبه", "پنج‌شنبه"]
    start_times = ["10:30","12:00","13:30","15:00","16:30","18:00","19:30"]
    systems = ["ست ۱", "ست ۲", "ست ۳", "ست ۴", "ست ۵", "ست ۶"]

    st.header("مدیریت کلاس‌ها")

    col1, col2 = st.columns(2)
    
    with col1:
        st.subheader("اضافه کردن کلاس")
        class_selected = st.selectbox("کلاس", classes, key='add_class_select')
        day_selected = st.selectbox("روز", days, key='add_day_select')
        start_time_selected = st.selectbox("زمان شروع", start_times, key='add_time_select')
        system_selected = st.selectbox("سیستم", systems, key='add_system_select')
        
        if st.button("اضافه کردن کلاس"):
            class_datetime = get_class_datetime(day_selected, start_time_selected)
            if class_datetime - datetime.now() < timedelta(hours=90):
                st.error("کلاس‌ها باید حداقل ۳۰ ساعت قبل رزرو شوند.")
            elif not has_system_availability(st.session_state.schedule_data, class_selected, day_selected, start_time_selected, system_selected):
                st.error(f"سیستم '{system_selected}' در زمان '{start_time_selected}' در روز '{day_selected}' برای '{class_selected}' موجود نیست.")
            else:
                new_row = pd.DataFrame([[class_selected, day_selected, start_time_selected, st.session_state.username, system_selected]], columns=['Class', 'Day', 'Start Time', 'Username', 'System'])
                st.session_state.schedule_data = pd.concat([st.session_state.schedule_data, new_row], ignore_index=True)
                save_schedule(st.session_state.schedule_data)
                st.success(f"کلاس {class_selected} با موفقیت اضافه شد به {system_selected}.")
    
    with col2:
        st.subheader("حذف کلاس")
        if not st.session_state.schedule_data.empty and 'Username' in st.session_state.schedule_data.columns:
            user_classes = st.session_state.schedule_data[
                (st.session_state.schedule_data['Username'] == st.session_state.username) |
                st.session_state.is_admin
            ]
            if not user_classes.empty:
                class_to_remove = st.selectbox("کلاس", user_classes['Class'].unique(), key='remove_class_select')
                day_to_remove = st.selectbox("روز", user_classes[user_classes['Class'] == class_to_remove]['Day'].unique(), key='remove_day_select')
                time_to_remove = st.selectbox("زمان شروع", user_classes[
                    (user_classes['Class'] == class_to_remove) & 
                    (user_classes['Day'] == day_to_remove)
                ]['Start Time'].unique(), key='remove_time_select')
                system_to_remove = st.selectbox("سیستم", user_classes[
                    (user_classes['Class'] == class_to_remove) & 
                    (user_classes['Day'] == day_to_remove) & 
                    (user_classes['Start Time'] == time_to_remove)
                ]['System'].unique(), key='remove_system_select')

                if st.button("حذف کلاس"):
                    st.session_state.schedule_data = st.session_state.schedule_data[~(
                        (st.session_state.schedule_data['Class'] == class_to_remove) &
                        (st.session_state.schedule_data['Day'] == day_to_remove) &
                        (st.session_state.schedule_data['Start Time'] == time_to_remove) &
                        (st.session_state.schedule_data['System'] == system_to_remove) &
                        ((st.session_state.is_admin) or (st.session_state.schedule_data['Username'] == st.session_state.username))
                    )]
                    save_schedule(st.session_state.schedule_data)
                    st.success(f"کلاس {class_to_remove} در روز {day_to_remove} ساعت {time_to_remove} با موفقیت حذف شد.")
            else:
                st.error("شما هیچ کلاسی برای حذف ندارید.")
        else:
            st.error("هیچ کلاسی برای حذف وجود ندارد یا ستون 'Username' موجود نیست.")
    
    st.header("برنامه شما")
    st.table(st.session_state.schedule_data)

    if st.button("خروج"):
        st.session_state['authenticated'] = False
        st.session_state['username'] = ""
        st.session_state['password'] = ""
        st.session_state['is_admin'] = False
        st.experimental_rerun()

# Authentication check
if not st.session_state['authenticated']:
    login_page()
else:
    schedule_page()