use abstutil::prettyprint_usize;
use geom::{Circle, Distance, Duration, Polygon, Pt2D, Time};
use map_gui::tools::PopupMsg;
use map_gui::ID;
use sim::AlertLocation;
use widgetry::{
    Choice, Color, ControlState, EdgeInsets, EventCtx, GeomBatch, GfxCtx, HorizontalAlignment, Key,
    Line, Outcome, Panel, PersistentSplit, ScreenDims, Text, TextExt, VerticalAlignment, Widget,
};

use crate::app::{App, Transition};
use crate::common::Warping;
use crate::sandbox::time_warp::JumpToTime;
use crate::sandbox::{GameplayMode, SandboxMode, TimeWarpScreen};

pub struct TimePanel {
    pub panel: Panel,
    pub override_height: Option<f64>,

    time: Time,
    paused: bool,
    setting: SpeedSetting,
}

#[derive(Clone, Copy, PartialEq, PartialOrd)]
pub enum SpeedSetting {
    /// 1 sim second per real second
    Realtime,
    /// 5 sim seconds per real second
    Fast,
    /// 30 sim seconds per real second
    Faster,
    /// 1 sim hour per real second
    Fastest,
}

impl TimePanel {
    pub fn new(ctx: &mut EventCtx, app: &App) -> TimePanel {
        let mut time = TimePanel {
            panel: Panel::empty(ctx),
            override_height: None,
            time: app.primary.sim.time(),
            paused: false,
            setting: SpeedSetting::Realtime,
        };
        time.recreate_panel(ctx, app);
        time
    }

    pub fn recreate_panel(&mut self, ctx: &mut EventCtx, app: &App) {
        let mut row = Vec::new();
        row.push({
            let button = ctx
                .style()
                .btn_plain
                .icon("system/assets/speed/triangle.svg")
                .hotkey(Key::Space);

            Widget::custom_row(vec![if self.paused {
                button.build_widget(ctx, "play")
            } else {
                button
                    .image_path("system/assets/speed/pause.svg")
                    .build_widget(ctx, "pause")
            }])
            .margin_right(16)
        });

        row.push(
            Widget::custom_row(
                vec![
                    (SpeedSetting::Realtime, "real-time speed"),
                    (SpeedSetting::Fast, "5x speed"),
                    (SpeedSetting::Faster, "30x speed"),
                    (SpeedSetting::Fastest, "3600x speed"),
                ]
                .into_iter()
                .map(|(s, label)| {
                    let mut txt = Text::from(Line(label).small());
                    txt.extend(Text::tooltip(ctx, Key::LeftArrow, "slow down"));
                    txt.extend(Text::tooltip(ctx, Key::RightArrow, "speed up"));

                    let mut triangle_btn = ctx
                        .style()
                        .btn_plain
                        .btn()
                        .image_path("system/assets/speed/triangle.svg")
                        .image_dims(ScreenDims::new(16.0, 26.0))
                        .tooltip(txt)
                        .padding(EdgeInsets {
                            top: 8.0,
                            bottom: 8.0,
                            left: 3.0,
                            right: 3.0,
                        });

                    if s == SpeedSetting::Realtime {
                        triangle_btn = triangle_btn.padding_left(10.0);
                    }
                    if s == SpeedSetting::Fastest {
                        triangle_btn = triangle_btn.padding_right(10.0);
                    }

                    if self.setting < s {
                        triangle_btn = triangle_btn
                            .image_color(ctx.style().btn_outline.fg_disabled, ControlState::Default)
                    }

                    triangle_btn.build_widget(ctx, label)
                })
                .collect(),
            )
            .margin_right(16),
        );

        row.push(
            PersistentSplit::widget(
                ctx,
                "step forwards",
                app.opts.time_increment,
                Key::M,
                vec![
                    Choice::new("+1h", Duration::hours(1)),
                    Choice::new("+30m", Duration::minutes(30)),
                    Choice::new("+10m", Duration::minutes(10)),
                    Choice::new("+0.1s", Duration::seconds(0.1)),
                ],
            )
            .margin_right(16),
        );

        row.push(
            ctx.style()
                .btn_plain
                .icon("system/assets/speed/jump_to_time.svg")
                .hotkey(Key::B)
                .build_widget(ctx, "jump to specific time"),
        );

        row.push(
            ctx.style()
                .btn_plain
                .icon("system/assets/speed/reset.svg")
                .hotkey(Key::X)
                .build_widget(ctx, "reset to midnight"),
        );

        let mut panel = Panel::new(Widget::col(vec![
            self.create_time_panel(ctx, app).named("time"),
            Widget::custom_row(row),
        ]))
        .aligned(HorizontalAlignment::Left, VerticalAlignment::Top);
        if let Some(h) = self.override_height {
            panel = panel.exact_height(h);
        }
        self.panel = panel.build(ctx);
    }

    fn create_time_panel(&mut self, ctx: &EventCtx, app: &App) -> Widget {
        let (finished, unfinished) = app.primary.sim.num_trips();
        let trip_results = Widget::row(vec![
            {
                let mut txt = Text::new();
                let pct = if unfinished == 0 {
                    100.0
                } else {
                    100.0 * (finished as f64) / ((finished + unfinished) as f64)
                };
                txt.add(Line(format!(
                    "Finished trips: {} ({}%)",
                    prettyprint_usize(finished),
                    pct as usize
                )));
                txt.into_widget(ctx).centered_vert()
            },
            if app.primary.dirty_from_edits {
                ctx.style()
                    .btn_plain
                    .icon("system/assets/tools/warning.svg")
                    .build_widget(ctx, "see why results are tentative")
                    .centered_vert()
                    .align_right()
            } else {
                Widget::nothing()
            },
        ]);
        // TODO This likely fits better in the top center panel, but no easy way to squeeze it
        // into the panel for all gameplay modes
        let record_trips = if let Some(n) = app.primary.sim.num_recorded_trips() {
            Widget::row(vec![
                GeomBatch::from(vec![(
                    Color::RED,
                    Circle::new(Pt2D::new(0.0, 0.0), Distance::meters(10.0)).to_polygon(),
                )])
                .into_widget(ctx)
                .centered_vert(),
                format!("{} trips captured", prettyprint_usize(n)).text_widget(ctx),
                ctx.style()
                    .btn_solid_primary
                    .text("Finish Capture")
                    .build_def(ctx)
                    .align_right(),
            ])
        } else {
            Widget::nothing()
        };

        let time_bar = {
            let mut batch = GeomBatch::new();
            // This is manually tuned
            let width = 400.0;
            let height = 15.0;
            // Just clamp if we simulate past the expected end
            let percent = self
                .time
                .to_percent(app.primary.sim.get_end_of_day())
                .min(1.0);

            // TODO Why is the rounding so hard? The white background is always rounded
            // at both ends. The moving bar should always be rounded on the left, flat
            // on the right, except at the very end (for the last 'radius' pixels). And
            // when the width is too small for the radius, this messes up.

            batch.push(Color::WHITE, Polygon::rectangle(width, height));

            if percent != 0.0 {
                batch.push(
                    if percent < 0.25 || percent > 0.75 {
                        app.cs.night_time_slider
                    } else {
                        app.cs.day_time_slider
                    },
                    Polygon::rectangle(percent * width, height),
                );
            }

            batch.into_widget(ctx)
        };

        Widget::col(vec![
            Text::from(Line(self.time.ampm_tostring()).big_monospaced()).into_widget(ctx),
            time_bar,
            trip_results,
            record_trips,
        ])
    }

    pub fn event(
        &mut self,
        ctx: &mut EventCtx,
        app: &mut App,
        maybe_mode: Option<&GameplayMode>,
    ) -> Option<Transition> {
        if self.time != app.primary.sim.time() {
            self.time = app.primary.sim.time();
            let time = self.create_time_panel(ctx, app);
            self.panel.replace(ctx, "time", time);
        }

        match self.panel.event(ctx) {
            Outcome::Clicked(x) => match x.as_ref() {
                "real-time speed" => {
                    self.setting = SpeedSetting::Realtime;
                    self.recreate_panel(ctx, app);
                    return None;
                }
                "5x speed" => {
                    self.setting = SpeedSetting::Fast;
                    self.recreate_panel(ctx, app);
                    return None;
                }
                "30x speed" => {
                    self.setting = SpeedSetting::Faster;
                    self.recreate_panel(ctx, app);
                    return None;
                }
                "3600x speed" => {
                    self.setting = SpeedSetting::Fastest;
                    self.recreate_panel(ctx, app);
                    return None;
                }
                "play" => {
                    self.paused = false;
                    self.recreate_panel(ctx, app);
                    return None;
                }
                "pause" => {
                    self.pause(ctx, app);
                }
                "reset to midnight" => {
                    if let Some(mode) = maybe_mode {
                        return Some(Transition::Replace(SandboxMode::simple_new(
                            app,
                            mode.clone(),
                        )));
                    } else {
                        return Some(Transition::Push(PopupMsg::new(
                            ctx,
                            "Error",
                            vec!["Sorry, you can't go rewind time from this mode."],
                        )));
                    }
                }
                "jump to specific time" => {
                    return Some(Transition::Push(JumpToTime::new(
                        ctx,
                        app,
                        maybe_mode.cloned(),
                    )));
                }
                "step forwards" => {
                    let dt = self.panel.persistent_split_value("step forwards");
                    if dt == Duration::seconds(0.1) {
                        app.primary
                            .sim
                            .tiny_step(&app.primary.map, &mut app.primary.sim_cb);
                        app.recalculate_current_selection(ctx);
                        return Some(Transition::KeepWithMouseover);
                    }
                    return Some(Transition::Push(TimeWarpScreen::new(
                        ctx,
                        app,
                        app.primary.sim.time() + dt,
                        None,
                    )));
                }
                "see why results are tentative" => {
                    return Some(Transition::Push(PopupMsg::new(
                        ctx,
                        "Simulation results not finalized",
                        vec![
                            "You edited the map in the middle of the day.",
                            "Some trips may have been interrupted, and others might have made \
                             different decisions if they saw the new map from the start.",
                            "To get final results, reset to midnight and test your proposal over \
                             a full day.",
                        ],
                    )));
                }
                "Finish Capture" => {
                    app.primary.sim.save_recorded_traffic(&app.primary.map);
                }
                _ => unreachable!(),
            },
            _ => {}
        }
        // Just kind of constantly scrape this
        app.opts.time_increment = self.panel.persistent_split_value("step forwards");

        if ctx.input.pressed(Key::LeftArrow) {
            match self.setting {
                SpeedSetting::Realtime => self.pause(ctx, app),
                SpeedSetting::Fast => {
                    self.setting = SpeedSetting::Realtime;
                    self.recreate_panel(ctx, app);
                }
                SpeedSetting::Faster => {
                    self.setting = SpeedSetting::Fast;
                    self.recreate_panel(ctx, app);
                }
                SpeedSetting::Fastest => {
                    self.setting = SpeedSetting::Faster;
                    self.recreate_panel(ctx, app);
                }
            }
        }
        if ctx.input.pressed(Key::RightArrow) {
            match self.setting {
                SpeedSetting::Realtime => {
                    if self.paused {
                        self.paused = false;
                        self.recreate_panel(ctx, app);
                    } else {
                        self.setting = SpeedSetting::Fast;
                        self.recreate_panel(ctx, app);
                    }
                }
                SpeedSetting::Fast => {
                    self.setting = SpeedSetting::Faster;
                    self.recreate_panel(ctx, app);
                }
                SpeedSetting::Faster => {
                    self.setting = SpeedSetting::Fastest;
                    self.recreate_panel(ctx, app);
                }
                SpeedSetting::Fastest => {}
            }
        }

        if !self.paused {
            if let Some(real_dt) = ctx.input.nonblocking_is_update_event() {
                ctx.input.use_update_event();
                let multiplier = match self.setting {
                    SpeedSetting::Realtime => 1.0,
                    SpeedSetting::Fast => 5.0,
                    SpeedSetting::Faster => 30.0,
                    SpeedSetting::Fastest => 3600.0,
                };
                let dt = multiplier * real_dt;
                // TODO This should match the update frequency in widgetry. Plumb along the deadline
                // or frequency to here.
                app.primary.sim.time_limited_step(
                    &app.primary.map,
                    dt,
                    Duration::seconds(0.033),
                    &mut app.primary.sim_cb,
                );
                app.recalculate_current_selection(ctx);
            }
        }

        // TODO Need to do this anywhere that steps the sim, like TimeWarpScreen.
        let alerts = app.primary.sim.clear_alerts();
        if !alerts.is_empty() {
            let popup = PopupMsg::new(
                ctx,
                "Alerts",
                alerts.iter().map(|(_, _, msg)| msg).collect(),
            );
            let maybe_id = match alerts[0].1 {
                AlertLocation::Nil => None,
                AlertLocation::Intersection(i) => Some(ID::Intersection(i)),
                // TODO Open info panel and warp to them
                AlertLocation::Person(_) => None,
                AlertLocation::Building(b) => Some(ID::Building(b)),
            };
            // TODO Can filter for particular alerts places like this:
            /*if !alerts[0].2.contains("Turn conflict cycle") {
                return None;
            }*/
            /*if maybe_id != Some(ID::Building(map_model::BuildingID(91))) {
                return None;
            }*/
            self.pause(ctx, app);
            if let Some(id) = maybe_id {
                // Just go to the first one, but print all messages
                return Some(Transition::Multi(vec![
                    Transition::Push(popup),
                    Transition::Push(Warping::new(
                        ctx,
                        app.primary.canonical_point(id).unwrap(),
                        Some(10.0),
                        None,
                        &mut app.primary,
                    )),
                ]));
            } else {
                return Some(Transition::Push(popup));
            }
        }

        None
    }

    pub fn draw(&self, g: &mut GfxCtx) {
        self.panel.draw(g);
    }

    pub fn pause(&mut self, ctx: &mut EventCtx, app: &App) {
        if !self.paused {
            self.paused = true;
            self.recreate_panel(ctx, app);
        }
    }

    pub fn resume(&mut self, ctx: &mut EventCtx, app: &App, setting: SpeedSetting) {
        if self.paused || self.setting != setting {
            self.paused = false;
            self.setting = setting;
            self.recreate_panel(ctx, app);
        }
    }

    pub fn is_paused(&self) -> bool {
        self.paused
    }
}