/*
 * This file is part of sdbclient
 * Copyright (C) 2023 Jonni Liljamo <jonni@liljamo.com>
 *
 * Licensed under GPL-3.0-only.
 * See LICENSE for licensing information.
 */

use bevy::prelude::*;
use iyes_loopless::prelude::*;

use crate::cfg::CfgUser;

use crate::{despawn_screen, remove_ui, GameState};

mod mainmenuscreen;
use mainmenuscreen::*;

mod settingsscreen;
use settingsscreen::*;

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_loopless_state(MenuState::None)
            .add_enter_system(GameState::MainMenu, menu_setup)
            // Systems for main menu screen
            .add_enter_system(MenuState::Main, main_menu_setup)
            .add_exit_system(MenuState::Main, remove_ui)
            .add_event::<ToAccountEvent>()
            .add_event::<ExitEvent>()
            .add_system_set(
                ConditionSet::new()
                    .run_in_state(MenuState::Main)
                    .with_system(handle_to_account_event.run_on_event::<ToAccountEvent>())
                    .with_system(handle_exit_event.run_on_event::<ExitEvent>())
                    .into()
            )
            // Systems for the settings screen
            .add_enter_system(MenuState::Settings, settings_setup)
            .add_exit_system(MenuState::Settings, remove_ui)
            // Systems for account loggedout screen
            .add_enter_system(MenuState::AccountLoggedOut, account_loggedout_setup)
            .add_exit_system(MenuState::AccountLoggedOut, despawn_screen::<OnAccountLoggedOutScreen>)
            // Systems for account loggedin screen
            .add_enter_system(MenuState::AccountLoggedIn, account_loggedin_setup)
            .add_exit_system(MenuState::AccountLoggedIn, despawn_screen::<OnAccountLoggedInScreen>)
            // Systems for play screen
            .add_enter_system(MenuState::Play, play_setup)
            .add_exit_system(MenuState::Play, remove_ui)
            // Common systems
            .add_system_set(
                ConditionSet::new()
                    .run_in_state(GameState::MainMenu)
                    .with_system(menu_action)
                    .with_system(button_system)
                    .into()
            );

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

/// Menu State
#[derive(Clone, Eq, PartialEq, Debug, Hash)]
pub enum MenuState {
    None,
    Main,
    Play,
    Lobby,
    CreateGame,
    JoinGame,
    Settings,
    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 {
    AccountLogin,
    AccountRegister,
    AccountLogout,
    BackToMainMenu,
}

fn menu_action(
    mut commands: Commands,
    interaction_query: Query<
        (&Interaction, &MenuButtonAction),
        (Changed<Interaction>, With<Button>),
    >,
    mut cfg_user: ResMut<CfgUser>,
    mut save_event_writer: EventWriter<SaveEvent>,
) {
    for (interaction, menu_button_action) in &interaction_query {
        if *interaction == Interaction::Clicked {
            match menu_button_action {
                MenuButtonAction::AccountLogin => {
                    commands.insert_resource(NextState(MenuState::AccountLogin));
                    commands.insert_resource(NextState(accountlogin::LoginState::Input));
                }
                MenuButtonAction::AccountRegister => {
                    commands.insert_resource(NextState(MenuState::AccountRegister));
                    commands.insert_resource(NextState(accountregister::RegisterState::Input));
                }
                MenuButtonAction::AccountLogout => {
                    // Reset CfgUser to default.
                    *cfg_user = CfgUser::default();

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

                    commands.insert_resource(NextState(MenuState::AccountLoggedOut))
                }
                MenuButtonAction::BackToMainMenu => {
                    commands.insert_resource(NextState(MenuState::Main))
                }
            }
        }
    }
}

/// 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 commands: Commands) {
    commands.insert_resource(NextState(MenuState::Main))
}