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

pub const HUD_REFRESH_TIME: f32 = 0.5;
pub const FONT: &str = "fonts/Yupiter-Regular.ttf";
pub const LOG_MAX: usize = 20;
pub const LOG_MAX_TIME_S: u64 = 20;
pub const CHOICE_NONE: &str = "";
pub const AMBIENT_LIGHT: f32 = 0.0; // Space is DARK
pub const AMBIENT_LIGHT_AR: f32 = 15.0;
//pub const REPLY_NUMBERS: [char; 10] = ['❶', '❷', '❸', '❹', '❺', '❻', '❼', '❽', '❾', '⓿'];
//pub const REPLY_NUMBERS: [char; 10] = ['①', '②', '③', '④', '⑤', '⑥', '⑦', '⑧', '⑨', '⑩'];
pub const REPLY_NUMBERS: [char; 10] = ['➀', '➁', '➂', '➃', '➄', '➅', '➆', '➇', '➈', '➉'];

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.add_systems(PostUpdate, despawn_old_choices);
        app.insert_resource(Log {
            logs: VecDeque::with_capacity(LOG_MAX),
            needs_rerendering: true,
        });
        app.insert_resource(FPSUpdateTimer(
                Timer::from_seconds(HUD_REFRESH_TIME, TimerMode::Repeating)));
    }
}

#[derive(Component)] struct GaugesText;
#[derive(Component)] struct ChatText;
#[derive(Component)] struct Reticule;
#[derive(Component)] struct ToggleableHudElement;

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

#[derive(Component)]
pub struct ChoiceAvailable {
    pub conv_id: String,
    pub conv_label: String,
    pub recipient: String,
    pub text: String,
}

pub enum LogLevel {
    Warning,
    //Error,
    Info,
    //Debug,
    Chat,
    //Ping,
}

struct Message {
    text: String,
    sender: String,
    level: LogLevel,
    time: u64,
}

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

impl Log {
    pub fn info(&mut self, message: String) {
        self.add(message, "System".to_string(), LogLevel::Info);
    }

    pub fn chat(&mut self, message: String, sender: String) {
        self.add(message, sender, LogLevel::Chat);
    }

    pub fn warning(&mut self, message: String) {
        self.add(message, "WARNING".to_string(), LogLevel::Warning);
    }

    pub fn add(&mut self, message: String, sender: String, level: LogLevel) {
        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,
                sender: sender,
                level: level,
                time: epoch.as_secs(),
            });
            self.needs_rerendering = true;
        }
    }

    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>,
    mut ambient_light: ResMut<AmbientLight>,
) {
    log.info("Resuming from suspend".to_string());
    log.warning("Oxygen Low".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::MAROON,
                ..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雌激素水平 172pg/mL",
            TextStyle {
                font: asset_server.load(FONT),
                font_size: settings.font_size_hud,
                color: Color::GRAY,
                ..default()
            },
        ),
        TextSection::new(
            "\nProximity 警告 ",
            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(
            "\nSuit Integrity ",
            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相对的v ",
            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((
        GaugesText,
        ToggleableHudElement,
        bundle_fps,
    ));

    // Add Chat Box
    let bundle_chatbox = TextBundle::from_sections([
        TextSection::new(
            "Warning: System Log Uninitialized",
            TextStyle {
                font: asset_server.load(FONT),
                font_size: settings.font_size_hud,
                color: Color::rgb(0.7, 0.7, 0.7),
                ..default()
            }
        ),
        TextSection::new(
            "\n",
            TextStyle {
                font: asset_server.load(FONT),
                font_size: settings.font_size_hud,
                color: Color::WHITE,
                ..default()
            }
        ),
        TextSection::new(
            "\n\n\n",
            TextStyle {
                font: asset_server.load(FONT),
                font_size: settings.font_size_hud,
                color: Color::WHITE,
                ..default()
            }
        ),
    ]).with_style(Style {
        position_type: PositionType::Absolute,
        bottom: Val::VMin(0.0),
        left: Val::VMin(0.0),
        ..default()
    }).with_text_justify(JustifyText::Left);
    commands.spawn((
        NodeBundle {
            style: Style {
                width: Val::Percent(50.),
                align_items: AlignItems::Start,
                position_type: PositionType::Absolute,
                bottom: Val::Vh(10.0),
                left: Val::Vw(25.0),
                ..default()
            },
            ..default()
        },
    )).with_children(|parent| {
         parent.spawn((
             bundle_chatbox,
             ChatText,
         ));
    });

    commands.spawn((
        Reticule,
        ToggleableHudElement,
        NodeBundle {
            style: Style {
                width: Val::Px(2.0),
                height: Val::Px(2.0),
                position_type: PositionType::Absolute,
                top: Val::Vh(50.0),
                left: Val::Vw(50.0),
                ..default()
            },
            visibility: visibility,
            background_color: Color::rgb(0.4, 0.4, 0.6).into(),
            ..default()
        },
    ));

    // AR-related things
    ambient_light.brightness = if settings.hud_active {
        AMBIENT_LIGHT_AR
    } else {
        AMBIENT_LIGHT
    };
}

fn update(
    diagnostics: Res<DiagnosticsStore>,
    time: Res<Time>,
    mut log: ResMut<Log>,
    player: Query<(&actor::Suit, &actor::LifeForm, &actor::Actor), With<actor::Player>>,
    mut timer: ResMut<FPSUpdateTimer>,
    mut query: Query<&mut Text, With<GaugesText>>,
    q_choices: Query<&ChoiceAvailable>,
    mut query_chat: Query<&mut Text, (With<ChatText>, Without<GaugesText>)>,
    query_all_actors: Query<&actor::Actor>,
    settings: Res<settings::Settings>,
) {
    // TODO only when hud is actually on
    if timer.0.tick(time.delta()).just_finished() || log.needs_rerendering {
        let player = player.get_single();
        if player.is_ok() {
            let (suit, lifeform, actor) = 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;

                // the remaining oxygen hud info ignores leaking suits from low integrity
                if suit.oxygen > nature::OXY_H {
                    let oxy_hour = suit.oxygen / nature::OXY_H;
                    text.sections[5].value = format!("{oxy_percent:.1}% [{oxy_total:.0}mg] [lasts {oxy_hour:.1} hours]");
                } else {
                    let oxy_min = suit.oxygen / nature::OXY_M;
                    text.sections[5].value = format!("{oxy_percent:.1}% [{oxy_total:.0}mg] [lasts {oxy_min:.1} min]");
                }
                let adrenaline = lifeform.adrenaline * 990.0 + 10.0;
                text.sections[7].value = format!("{adrenaline:.0}pg/mL");
                let all_actors = query_all_actors.iter().len();
                text.sections[10].value = format!("{all_actors:.0}");
                let integrity = suit.integrity * 100.0;
                text.sections[12].value = format!("{integrity:.0}%");
                let speed = actor.v.length();
                let kmh = speed * 60.0 * 60.0 / 1000.0;
                text.sections[14].value = format!("{speed:.0}m/s | {kmh:.0}km/h");
            }
        }

        if let Ok(mut chat) = query_chat.get_single_mut() {
            // Choices
            let mut choices: Vec<String> = Vec::new();
            let mut count = 0;
            for choice in &q_choices {
                if count > 9 {
                    break;
                }
                let press_this = REPLY_NUMBERS[count];
                let reply = &choice.text;
                //let recipient = &choice.recipient;
                // TODO: indicate recipients if there's more than one
                choices.push(format!("{press_this}  {reply}"));
                count += 1;
            }
            if count < 4 {
                for _padding in 0..(4-count) {
                    choices.push(" ".to_string());
                }
                chat.sections[2].value = choices.join("\n");
            }

            // Chat Log and System Log
            let logfilter = if settings.hud_active {
                |_msg: &&Message| { true }
            } else {
                |msg: &&Message| { match msg.level {
                    LogLevel::Chat => true,
                    LogLevel::Warning => true,
                    LogLevel::Info => true,
                    //_ => false
                }}
            };
            let logs_vec: Vec<String> = log.logs.iter()
                .filter(logfilter)
                .map(|s| format!("{}: {}", s.sender, s.text)).collect();
            chat.sections[0].value = logs_vec.join("\n");
        }
        log.needs_rerendering = false;
        log.remove_old();
    }
}

fn handle_input(
    keyboard_input: Res<ButtonInput<KeyCode>>,
    mut settings: ResMut<settings::Settings>,
    mut q_hud: Query<&mut Visibility, With<ToggleableHudElement>>,
    q_choices: Query<&ChoiceAvailable>,
    mut evwriter_sendmsg: EventWriter<actor::SendMessageEvent>,
    mut evwriter_sfx: EventWriter<audio::PlaySfxEvent>,
    mut evwriter_togglemusic: EventWriter<audio::ToggleMusicEvent>,
    mut ambient_light: ResMut<AmbientLight>,
) {
    if keyboard_input.just_pressed(settings.key_togglehud) {
        if settings.hud_active {
            for mut hudelement_visibility in q_hud.iter_mut() {
                *hudelement_visibility = Visibility::Hidden;
            }
            settings.hud_active = false;
            ambient_light.brightness = AMBIENT_LIGHT;
        }
        else {
            for mut hudelement_visibility in q_hud.iter_mut() {
                *hudelement_visibility = Visibility::Inherited;
            }
            settings.hud_active = true;
            ambient_light.brightness = AMBIENT_LIGHT_AR;
        }
        evwriter_sfx.send(audio::PlaySfxEvent(audio::Sfx::Switch));
        evwriter_togglemusic.send(audio::ToggleMusicEvent());
    }

    let mut selected_choice = 1;
    'outer: for key in settings.get_reply_keys() {
        if keyboard_input.just_pressed(key) {
            let mut count = 1;
            for choice in &q_choices {
                if count == selected_choice {
                    evwriter_sfx.send(audio::PlaySfxEvent(audio::Sfx::Click));
                    evwriter_sendmsg.send(actor::SendMessageEvent {
                        conv_id: choice.conv_id.clone(),
                        conv_label: choice.conv_label.clone(),
                        text: choice.text.clone(),
                    });
                    break 'outer;
                }
                count += 1;
            }
        }
        selected_choice += 1;
    }
}

fn despawn_old_choices(
    mut commands: Commands,
    q_conv: Query<&actor::Chat>,
    q_choices: Query<(Entity, &ChoiceAvailable)>,
) {
    let chats: Vec<&actor::Chat> = q_conv.iter().collect();
    'outer: for (entity, choice) in &q_choices {
        // Let's see if this choice still has a chat in the appropriate state
        for chat in &chats {
            if choice.conv_id == chat.id && choice.conv_label == chat.label {
                continue 'outer;
            }
        }

        // Despawn the choice, since no matching chat was found
        commands.entity(entity).despawn();
    }
}