/*
 * This file is part of sdbclient
 * Copyright (C) 2022 Jonni Liljamo <jonni@liljamo.com>
 *
 * Licensed under GPL-3.0-only.
 * See LICENSE for licensing information.
 */

use bevy::{app::AppExit, prelude::*};

use crate::cfg::CfgUser;

use crate::{despawn_screen, GameState};

mod mainmenuscreen;
use mainmenuscreen::*;

mod settingsmenuscreen;
use settingsmenuscreen::*;

mod settingsdisplayscreen;
use settingsdisplayscreen::*;

mod settingsaudioscreen;
use settingsaudioscreen::*;

mod settingsmiscscreen;
use settingsmiscscreen::*;

mod accountscreenloggedout;
use accountscreenloggedout::*;

mod accountscreenloggedin;
use accountscreenloggedin::*;

mod playscreen;
use playscreen::*;

use super::config::{SaveEvent, SaveEventValue};

mod accountlogin;
mod accountregister;

pub struct MenuPlugin;

impl Plugin for MenuPlugin {
    fn build(&self, app: &mut App) {
        app.
            // Start with no menu. The menu is loaded when the GameState::MainMenu is entered.
            add_state(MenuState::None)
            .add_system_set(SystemSet::on_enter(GameState::MainMenu).with_system(menu_setup))
            // Systems for main menu screen
            .add_system_set(SystemSet::on_enter(MenuState::Main).with_system(main_menu_setup))
            .add_system_set(SystemSet::on_exit(MenuState::Main).with_system(despawn_screen::<OnMainMenuScreen>))
            // Systems for settings menu screen
            .add_system_set(SystemSet::on_enter(MenuState::Settings).with_system(settings_menu_setup))
            .add_system_set(SystemSet::on_exit(MenuState::Settings).with_system(despawn_screen::<OnSettingsMenuScreen>))
            // Systems for settings display screen
            .add_system_set(SystemSet::on_enter(MenuState::SettingsDisplay).with_system(settings_display_setup))
            .add_system_set(SystemSet::on_exit(MenuState::SettingsDisplay).with_system(despawn_screen::<OnSettingsDisplayScreen>))
            // Systems for settings audio screen
            .add_system_set(SystemSet::on_enter(MenuState::SettingsAudio).with_system(settings_audio_setup))
            .add_system_set(SystemSet::on_exit(MenuState::SettingsAudio).with_system(despawn_screen::<OnSettingsAudioScreen>))
            // Systems for settings misc screen
            .add_system_set(SystemSet::on_enter(MenuState::SettingsMisc).with_system(settings_misc_setup))
            .add_system_set(SystemSet::on_exit(MenuState::SettingsMisc).with_system(despawn_screen::<OnSettingsMiscScreen>))
            // Systems for account loggedout screen
            .add_system_set(SystemSet::on_enter(MenuState::AccountLoggedOut).with_system(account_loggedout_setup))
            .add_system_set(SystemSet::on_exit(MenuState::AccountLoggedOut).with_system(despawn_screen::<OnAccountLoggedOutScreen>))
            // Systems for account loggedin screen
            .add_system_set(SystemSet::on_enter(MenuState::AccountLoggedIn).with_system(account_loggedin_setup))
            .add_system_set(SystemSet::on_exit(MenuState::AccountLoggedIn).with_system(despawn_screen::<OnAccountLoggedInScreen>))
            // Systems for play screen
            .add_system_set(SystemSet::on_enter(MenuState::Play).with_system(play_setup))
            .add_system_set(SystemSet::on_exit(MenuState::Play).with_system(despawn_screen::<OnPlayScreen>))
            // Common systems
            .add_system_set(SystemSet::on_update(GameState::MainMenu).with_system(menu_action).with_system(button_system));

        app.add_plugin(accountregister::AccountRegisterPlugin)
            .add_plugin(accountlogin::AccountLoginPlugin);
    }
}

/// Menu State
#[derive(Clone, Eq, PartialEq, Debug, Hash)]
pub enum MenuState {
    None,
    Main,
    Play,
    Settings,
    SettingsDisplay,
    SettingsAudio,
    SettingsMisc,
    AccountLoggedIn,
    AccountLoggedOut,
    AccountLogin,
    AccountRegister,
}

/// Tag component for tagging entities on account screen
#[derive(Component)]
struct OnAccountScreen;

const NORMAL_BUTTON: Color = Color::rgb(0.15, 0.15, 0.15);
const HOVERED_BUTTON: Color = Color::rgb(0.25, 0.25, 0.25);
const HOVERED_PRESSED_BUTTON: Color = Color::rgb(0.25, 0.65, 0.25);
const PRESSED_BUTTON: Color = Color::rgb(0.35, 0.75, 0.35);

/// Tag component for tagging currently selected settings tab
#[derive(Component)]
struct SelectedSettingsTab;

/// All button actions
#[derive(Component)]
enum MenuButtonAction {
    Play,
    Settings,
    SettingsDisplay,
    SettingsAudio,
    SettingsMisc,
    Account,
    AccountLogin,
    AccountRegister,
    AccountLogout,
    BackToMainMenu,
    BackToSettings,
    Exit,
}

fn menu_action(
    interaction_query: Query<
        (&Interaction, &MenuButtonAction),
        (Changed<Interaction>, With<Button>),
    >,
    mut app_exit_events: EventWriter<AppExit>,
    mut menu_state: ResMut<State<MenuState>>,
    mut register_state: ResMut<State<accountregister::RegisterState>>,
    mut login_state: ResMut<State<accountlogin::LoginState>>,
    mut cfg_user: ResMut<CfgUser>,
    mut save_event_writer: EventWriter<SaveEvent>,
    //mut game_state: ResMut<State<GameState>>,
) {
    for (interaction, menu_button_action) in &interaction_query {
        if *interaction == Interaction::Clicked {
            match menu_button_action {
                MenuButtonAction::Exit => app_exit_events.send(AppExit),
                MenuButtonAction::Play => menu_state.set(MenuState::Play).unwrap(),
                MenuButtonAction::Settings => menu_state.set(MenuState::Settings).unwrap(),
                MenuButtonAction::SettingsDisplay => {
                    menu_state.set(MenuState::SettingsDisplay).unwrap()
                }
                MenuButtonAction::SettingsAudio => {
                    menu_state.set(MenuState::SettingsAudio).unwrap()
                }
                MenuButtonAction::SettingsMisc => menu_state.set(MenuState::SettingsMisc).unwrap(),
                MenuButtonAction::Account => {
                    if cfg_user.logged_in {
                        menu_state.set(MenuState::AccountLoggedIn).unwrap()
                    } else {
                        menu_state.set(MenuState::AccountLoggedOut).unwrap()
                    }
                }
                MenuButtonAction::AccountLogin => {
                    menu_state.set(MenuState::AccountLogin).unwrap();
                    login_state.set(accountlogin::LoginState::Input).unwrap();
                }
                MenuButtonAction::AccountRegister => {
                    menu_state.set(MenuState::AccountRegister).unwrap();
                    register_state
                        .set(accountregister::RegisterState::Input)
                        .unwrap();
                }
                MenuButtonAction::AccountLogout => {
                    // Reset CfgUser to default.
                    *cfg_user = CfgUser::default();

                    save_event_writer.send(SaveEvent {
                        value: SaveEventValue::User(cfg_user.clone()),
                    });

                    menu_state.set(MenuState::AccountLoggedOut).unwrap()
                }
                MenuButtonAction::BackToSettings => menu_state.set(MenuState::Settings).unwrap(),
                MenuButtonAction::BackToMainMenu => menu_state.set(MenuState::Main).unwrap(),
            }
        }
    }
}

/// System for handling button hovering
fn button_system(
    mut interaction_query: Query<
        (
            &Interaction,
            &mut BackgroundColor,
            Option<&SelectedSettingsTab>,
        ),
        (Changed<Interaction>, With<Button>),
    >,
) {
    for (interaction, mut color, selected) in &mut interaction_query {
        *color = match (*interaction, selected) {
            (Interaction::Clicked, _) | (Interaction::None, Some(_)) => PRESSED_BUTTON.into(),
            (Interaction::Hovered, Some(_)) => HOVERED_PRESSED_BUTTON.into(),
            (Interaction::Hovered, None) => HOVERED_BUTTON.into(),
            (Interaction::None, None) => NORMAL_BUTTON.into(),
        }
    }
}

fn menu_setup(mut menu_state: ResMut<State<MenuState>>) {
    let _ = menu_state.set(MenuState::Main);
}