module Main where

import Database.PostgreSQL.Simple
import Control.Monad (forever, forM_)
import Control.Monad.IO.Class (liftIO)
import Control.Monad.Trans.Class (lift)
import Control.Monad.Trans.Reader (runReaderT, ask)
import Control.Exception (catch, SomeException)
import Data.Maybe (isJust, fromJust)
import Data.Time (Day)
import Data.Time.Format (parseTimeM, defaultTimeLocale)
import Data.Time.Calendar (Day)

import User
import Reservation
import Session
import Types
import Database

main :: IO ()
main = do
    conn <- catch connectDB handleSqlError
    initializeDB conn
    addAdminUser conn

    putStrLn "Welcome to the Ticket Booking System!"
    user <- loginOrRegister conn
    runSession user $ appLoop conn user
    
loginOrRegister :: Connection -> IO User
loginOrRegister conn = do
    putStrLn "1) Register 2) Login"
    choice <- getLine
    case choice of
        "1" -> do
            putStrLn "Enter your name:"
            name <- getLine
            putStrLn "Enter your password:"
            password <- getLine
            registerUser conn name password
            loginOrRegister conn
        "2" -> do
            putStrLn "Enter your name:"
            name <- getLine
            putStrLn "Enter your password:"
            password <- getLine
            mUser <- loginUser conn name password
            if isJust mUser
                then return (fromJust mUser)
                else do
                    putStrLn "Invalid credentials, please try again."
                    loginOrRegister conn
        _ -> do
            putStrLn "Invalid option, please try again."
            loginOrRegister conn

appLoop :: Connection -> User -> Session ()
appLoop conn user = forever $ do
    lift $ putStrLn $ "Logged in as " ++ userName user ++ ". "
    isAdminResult <- liftIO $ User.isAdmin conn (userName user)

    if isAdminResult == Just True
        then adminMenu
        else userMenu

  where
    adminMenu = do
        lift $ putStrLn "Admin Menu:"
        lift $ putStrLn "1) Add event 2) View events 3) Exit"
        choice <- lift getLine
        case choice of
            "1" -> do
                lift $ putStrLn "Enter event name:"
                eventName <- lift getLine
                lift $ putStrLn "Enter event date (YYYY-MM-DD):"
                eventDateStr <- lift getLine
                case parseEventDate eventDateStr of
                    Just eventDate ->
                        if isValidEventDate eventDate
                            then do
                                lift $ addEvent conn user eventName eventDate
                            else lift $ putStrLn "Invalid event date. Please enter a date between 2024-05-27 and 2026-01-01, with a valid month (01-12) and day (01-31)."
                    Nothing -> lift $ putStrLn "Invalid date format. Please enter the date in the format YYYY-MM-DD."
            "2" -> do
                events <- lift $ getEvents conn
                lift $ printEvents events
            "3" -> liftIO $ putStrLn "Exiting..." >> error "Program terminated by user"
            _   -> lift $ putStrLn "Invalid option. Please try again."

    userMenu = do
        lift $ putStrLn "User Menu:"
        lift $ putStrLn "1) Add reservation 2) View reservations 3) View events 4) Check event attendees 5) Exit"
        choice <- lift getLine
        case choice of
            "1" -> do
                events <- lift $ getEvents conn
                lift $ printEvents events
                lift $ putStrLn "Enter event ID:"
                eventIdStr <- lift getLine
                let eventId = read eventIdStr :: Int
                lift $ addReservation conn (userId user) eventId
            "2" -> do
                reservations <- lift $ getReservations conn (userId user)
                lift $ putStrLn "Your reservations:"
                lift $ forM_ reservations (printReservation conn)
            "3" -> do
                events <- lift $ getEvents conn
                lift $ printEvents events
            "4" -> do
                events <- lift $ getEvents conn
                lift $ printEvents events
                lift $ putStrLn "Enter event ID to check attendees:"
                eventIdStr <- lift getLine
                let eventId = read eventIdStr :: Int
                attendees <- lift $ getUsersForEvent conn eventId
                lift $ putStrLn $ "Attendees for event " ++ show eventId ++ ":"
                lift $ forM_ attendees $ \(userId, userName) -> putStrLn $ show userName
            "5" -> liftIO $ putStrLn "Exiting..." >> error "Program terminated by user"
            _   -> lift $ putStrLn "Invalid option. Please try again."

handleSqlError :: SomeException -> IO Connection
handleSqlError e = do
    putStrLn $ "Database connection error: " ++ show e
    error "Failed to connect to the database"

printEvents :: [Event] -> IO ()
printEvents events = do
    putStrLn "Available events:"
    forM_ events $ \event ->
        putStrLn $ "Event ID: " ++ show (eventId event) ++ ", Name: " ++ eventName event ++ ", Date: " ++ show (eventDate event)

printReservation :: Connection -> Reservation -> IO ()
printReservation conn reservation = do
    event <- getEvent conn (reservationEventId reservation)
    putStrLn $ "Event Name: " ++ eventName event ++ ", Event Date: " ++ show (eventDate event)