use crate::{settings, actor, audio};
use bevy::prelude::*;
use bevy::diagnostic::{DiagnosticsStore, FrameTimeDiagnosticsPlugin};
use std::collections::VecDeque;
use std::time::SystemTime;

const HUD_REFRESH_TIME: f32 = 0.5;
const FONT: &str = "tmp/fonts/NotoSansSC-Thin.ttf";
const LOG_MAX: usize = 5;
const LOG_MAX_TIME_S: u64 = 10;

pub struct HudPlugin;
impl Plugin for HudPlugin {
    fn build(&self, app: &mut App) {
        app.add_systems(Startup, setup);
        app.add_systems(Update, (update, handle_input));
        app.insert_resource(Log { logs: VecDeque::with_capacity(LOG_MAX) });
        app.insert_resource(FPSUpdateTimer(
                Timer::from_seconds(HUD_REFRESH_TIME, TimerMode::Repeating)));
    }
}

#[derive(Component)]
struct GaugesText;

#[derive(Resource)]
struct FPSUpdateTimer(Timer);

struct Message {
    text: String,
    time: u64,
}

#[derive(Resource)]
struct Log {
    logs: VecDeque<Message>,
}

impl Log {
    pub fn add(&mut self, message: String) {
        if self.logs.len() == LOG_MAX {
            self.logs.pop_front();
        }
        if let Ok(epoch) = SystemTime::now().duration_since(SystemTime::UNIX_EPOCH) {
            self.logs.push_back(Message {
                text: message,
                time: epoch.as_secs(),
            });
        }
    }

    pub fn remove_old(&mut self) {
        if let Some(message) = self.logs.front() {
            if let Ok(epoch) = SystemTime::now().duration_since(SystemTime::UNIX_EPOCH) {
                if epoch.as_secs() - message.time > LOG_MAX_TIME_S {
                    self.logs.pop_front();
                }
            }
        }
    }
}

fn setup(
    mut commands: Commands,
    settings: Res<settings::Settings>,
    asset_server: Res<AssetServer>,
    mut log: ResMut<Log>,
) {
    log.add("Customer wake-up registered.".to_string());
    log.add("Systems reactivated.".to_string());
    let visibility = if settings.hud_active {
        Visibility::Inherited
    } else {
        Visibility::Hidden
    };
    let mut bundle_fps = TextBundle::from_sections([
        TextSection::new(
            "帧率 ",
            TextStyle {
                font: asset_server.load(FONT),
                font_size: settings.font_size_hud,
                color: Color::GRAY,
                ..default()
            },
        ),
        TextSection::new(
            "",
            TextStyle {
                font: asset_server.load(FONT),
                font_size: settings.font_size_hud,
                color: Color::GRAY,
                ..default()
            }
        ),
        TextSection::new(
            "\n电量 ",
            TextStyle {
                font: asset_server.load(FONT),
                font_size: settings.font_size_hud,
                color: Color::GRAY,
                ..default()
            },
        ),
        TextSection::new(
            "",
            TextStyle {
                font: asset_server.load(FONT),
                font_size: settings.font_size_hud,
                color: Color::GRAY,
                ..default()
            }
        ),
        TextSection::new(
            "\n氧 OXYGEN ",
            TextStyle {
                font: asset_server.load(FONT),
                font_size: settings.font_size_hud,
                color: Color::GRAY,
                ..default()
            },
        ),
        TextSection::new(
            "",
            TextStyle {
                font: asset_server.load(FONT),
                font_size: settings.font_size_hud,
                color: Color::GRAY,
                ..default()
            }
        ),
        TextSection::new(
            "\nAdren水平 ",
            TextStyle {
                font: asset_server.load(FONT),
                font_size: settings.font_size_hud,
                color: Color::GRAY,
                ..default()
            },
        ),
        TextSection::new(
            "",
            TextStyle {
                font: asset_server.load(FONT),
                font_size: settings.font_size_hud,
                color: Color::GRAY,
                ..default()
            }
        ),
        TextSection::new(
            "\n\n",
            TextStyle {
                font: asset_server.load(FONT),
                font_size: settings.font_size_hud,
                color: Color::GRAY,
                ..default()
            }
        ),
        TextSection::from_style(
            TextStyle {
                font: asset_server.load(FONT),
                font_size: settings.font_size_hud,
                color: Color::GRAY,
                ..default()
            }
        ),
    ]).with_style(Style {
        top: Val::VMin(2.0),
        left: Val::VMin(3.0),
        ..default()
    });
    bundle_fps.visibility = visibility;
    commands.spawn((
        bundle_fps,
        GaugesText,
    ));
}

fn update(
    diagnostics: Res<DiagnosticsStore>,
    time: Res<Time>,
    mut log: ResMut<Log>,
    player: Query<(&actor::Suit, &actor::LifeForm), With<actor::Player>>,
    mut timer: ResMut<FPSUpdateTimer>,
    mut query: Query<&mut Text, With<GaugesText>>,
) {
    if timer.0.tick(time.delta()).just_finished() {
        let player = player.get_single();
        if player.is_ok() {
            let (suit, lifeform) = player.unwrap();
            for mut text in &mut query {
                if let Some(fps) = diagnostics.get(&FrameTimeDiagnosticsPlugin::FPS) {
                    if let Some(value) = fps.smoothed() {
                        // Update the value of the second section
                        text.sections[1].value = format!("{value:.0}");
                    }
                }
                let power = suit.power;
                text.sections[3].value = format!("{power:}Wh");
                let oxy_percent = suit.oxygen / suit.oxygen_max * 100.0;
                let oxy_total = suit.oxygen * 1e6;
                text.sections[5].value = format!("{oxy_percent:.1}% [{oxy_total:.0}mg]");
                let adrenaline = lifeform.adrenaline * 990.0 + 10.0;
                text.sections[7].value = format!("{adrenaline:.0}pg/mL");
            }
        }
        for mut text in &mut query {
            let logs_vec: Vec<&str> = log.logs.iter().map(|s| s.text.as_str()).collect();
            text.sections[9].value = logs_vec.join("\n");
        }
        log.remove_old();
    }
}

fn handle_input(
    keyboard_input: Res<ButtonInput<KeyCode>>,
    settings: Res<settings::Settings>,
    mut query: Query<&mut Visibility, With<GaugesText>>,
    mut ev_click: EventWriter<audio::AudioClickEvent>,
) {
    if keyboard_input.just_pressed(settings.key_togglehud) {
        for mut vis in &mut query {
            if *vis == Visibility::Inherited {
                *vis = Visibility::Hidden;
            } else {
                *vis = Visibility::Inherited;
            }
            ev_click.send(audio::AudioClickEvent());
        }
    }
}