use cosmic::iced::wayland::popup::{destroy_popup, get_popup};
use cosmic::iced::Limits;
use cosmic::iced::{
    time,
    wayland::InitialSurface,
    widget::{button, column, text, vertical_space},
    window, Alignment, Application, Color, Command, Length, Rectangle, Subscription,
};
use cosmic::iced_style::application::{self, Appearance};
use cosmic::theme;
use cosmic::{
    widget::{icon, rectangle_tracker::*},
    Element, Theme,
};
use cosmic_applet::{cosmic_panel_config::PanelAnchor, CosmicAppletHelper};

use chrono::{DateTime, Local, Timelike};
use std::time::Duration;

pub fn main() -> cosmic::iced::Result {
    let helper = CosmicAppletHelper::default();
    let mut settings = helper.window_settings();
    match &mut settings.initial_surface {
        InitialSurface::XdgWindow(s) => {
            s.autosize = true;
            s.size_limits = Limits::NONE.min_height(1.0).min_width(1.0);
        }
        _ => {}
    };
    Time::run(settings)
}

struct Time {
    applet_helper: CosmicAppletHelper,
    theme: Theme,
    popup: Option<window::Id>,
    id_ctr: u128,
    update_at: Every,
    now: DateTime<Local>,
    msg: String,
    rectangle_tracker: Option<RectangleTracker<u32>>,
    rectangle: Rectangle,
}

impl Default for Time {
    fn default() -> Self {
        Time {
            applet_helper: CosmicAppletHelper::default(),
            theme: Theme::default(),
            popup: None,
            id_ctr: 0,
            update_at: Every::Minute,
            now: Local::now(),
            msg: String::new(),
            rectangle_tracker: None,
            rectangle: Rectangle::default(),
        }
    }
}

#[derive(Debug, Clone)]
#[allow(dead_code)]
enum Every {
    Minute,
    Second,
}

#[derive(Debug, Clone)]
enum Message {
    TogglePopup,
    Tick,
    Ignore,
    Rectangle(RectangleUpdate<u32>),
}

impl Application for Time {
    type Message = Message;
    type Theme = Theme;
    type Executor = cosmic::SingleThreadExecutor;
    type Flags = ();

    fn new(_flags: ()) -> (Time, Command<Message>) {
        (Time::default(), Command::none())
    }

    fn title(&self) -> String {
        String::from("Time")
    }

    fn theme(&self) -> Theme {
        self.theme.clone()
    }

    fn close_requested(&self, _id: window::Id) -> Self::Message {
        Message::Ignore
    }

    fn style(&self) -> <Self::Theme as application::StyleSheet>::Style {
        <Self::Theme as application::StyleSheet>::Style::Custom(Box::new(|theme| Appearance {
            background_color: Color::from_rgba(0.0, 0.0, 0.0, 0.0),
            text_color: theme.cosmic().on_bg_color().into(),
        }))
    }

    fn subscription(&self) -> Subscription<Message> {
        const FALLBACK_DELAY: u64 = 500;
        let update_delay = match self.update_at {
            Every::Minute => chrono::Duration::minutes(1),
            Every::Second => chrono::Duration::seconds(1),
        };

        // Calculate the time until next second/minute so we can sleep the thread until then.
        let now = Local::now().time();
        let next = (now + update_delay)
            .with_second(0)
            .expect("Setting seconds to 0 should always be possible")
            .with_nanosecond(0)
            .expect("Setting nanoseconds to 0 should always be possible.");
        let wait = 1.max((next - now).num_milliseconds());
        Subscription::batch(vec![
            rectangle_tracker_subscription(0).map(|e| Message::Rectangle(e.1)),
            time::every(Duration::from_millis(
                wait.try_into().unwrap_or(FALLBACK_DELAY),
            ))
            .map(|_| Message::Tick),
        ])
    }

    fn update(&mut self, message: Message) -> Command<Message> {
        match message {
            Message::TogglePopup => {
                if let Some(p) = self.popup.take() {
                    destroy_popup(p)
                } else {
                    use std::os::unix::process::ExitStatusExt;
                    let calendar = std::str::from_utf8(
                        &std::process::Command::new("happiness")
                            .output()
                            .unwrap_or(std::process::Output {
                                stdout: "`sudo apt install happiness`".as_bytes().to_vec(),
                                stderr: Vec::new(),
                                status: std::process::ExitStatus::from_raw(0),
                            })
                            .stdout,
                    )
                    .unwrap()
                    .to_string();
                    self.msg = calendar;
                    self.id_ctr += 1;
                    let new_id = window::Id(self.id_ctr);
                    self.popup.replace(new_id);

                    let mut popup_settings = self.applet_helper.get_popup_settings(
                        window::Id(0),
                        new_id,
                        None,
                        None,
                        None,
                    );
                    let Rectangle {
                        x,
                        y,
                        width,
                        height,
                    } = self.rectangle;
                    popup_settings.positioner.anchor_rect = Rectangle::<i32> {
                        x: x as i32,
                        y: y as i32,
                        width: width as i32,
                        height: height as i32,
                    };
                    get_popup(popup_settings)
                }
            }
            Message::Tick => {
                self.now = Local::now();
                Command::none()
            }
            Message::Ignore => Command::none(),
            Message::Rectangle(u) => {
                match u {
                    RectangleUpdate::Rectangle(r) => {
                        self.rectangle = r.1;
                    }
                    RectangleUpdate::Init(tracker) => {
                        self.rectangle_tracker = Some(tracker);
                    }
                }
                Command::none()
            }
        }
    }

    fn view(&self, id: window::Id) -> Element<Message> {
        if id == window::Id(0) {
            let button = button(
                if matches!(
                    self.applet_helper.anchor,
                    PanelAnchor::Top | PanelAnchor::Bottom
                ) {
                    column![text(self.now.format("%b %-d %-I:%M %p").to_string()).size(14)]
                } else {
                    let mut date_time_col = column![
                        icon(
                            "emoji-recent-symbolic",
                            self.applet_helper.suggested_size().0
                        )
                        .style(theme::Svg::Symbolic),
                        text(self.now.format("%I").to_string()).size(14),
                        text(self.now.format("%M").to_string()).size(14),
                        text(self.now.format("%p").to_string()).size(14),
                        vertical_space(Length::Fixed(4.0)),
                        // TODO better calendar icon?
                        icon(
                            "calendar-go-today-symbolic",
                            self.applet_helper.suggested_size().0
                        )
                        .style(theme::Svg::Symbolic),
                    ]
                    .align_items(Alignment::Center)
                    .spacing(4);
                    for d in self.now.format("%x").to_string().split("/") {
                        date_time_col = date_time_col.push(text(d.to_string()).size(14));
                    }
                    date_time_col
                },
            )
            .on_press(Message::TogglePopup)
            .style(theme::Button::Text);

            if let Some(tracker) = self.rectangle_tracker.as_ref() {
                tracker.container(0, button).into()
            } else {
                button.into()
            }
        } else {
            let content = column![]
                .align_items(Alignment::Start)
                .spacing(12)
                .padding([24, 0])
                .push(text(&self.msg).size(14))
                .padding(8);

            self.applet_helper.popup_container(content).into()
        }
    }
}