pub use gameplay::{spawn_agents_around, GameplayMode, TutorialPointer, TutorialState};
use maplit::btreeset;
pub use speed::{SpeedControls, TimePanel};
pub use time_warp::TimeWarpScreen;

use geom::Time;
use sim::{AgentType, Analytics, Scenario};
use widgetry::{
    lctrl, Btn, Choice, EventCtx, GfxCtx, HorizontalAlignment, Key, Line, Outcome, Panel, Text,
    TextExt, UpdateType, VerticalAlignment, Widget,
};

use self::misc_tools::{RoutePreview, TurnExplorer};
use crate::app::App;
use crate::common::{tool_panel, CommonState, ContextualActions, IsochroneViewer, Minimap};
use crate::debug::DebugMode;
use crate::edit::{
    apply_map_edits, can_edit_lane, EditMode, LaneEditor, SaveEdits, StopSignEditor,
    TrafficSignalEditor,
};
use crate::game::{ChooseSomething, State, Transition};
use crate::helpers::ID;
use crate::layer::PickLayer;
use crate::load::{FileLoader, MapLoader};
use crate::options::OptionsPanel;
use crate::pregame::MainMenu;
use crate::render::UnzoomedAgents;

pub mod dashboards;
pub mod gameplay;
mod misc_tools;
mod speed;
mod time_warp;
mod uber_turns;

pub struct SandboxMode {
    gameplay: Box<dyn gameplay::GameplayState>,
    pub gameplay_mode: GameplayMode,

    pub controls: SandboxControls,
}

pub struct SandboxControls {
    pub common: Option<CommonState>,
    route_preview: Option<RoutePreview>,
    tool_panel: Option<Panel>,
    time_panel: Option<TimePanel>,
    speed: Option<SpeedControls>,
    pub agent_meter: Option<AgentMeter>,
    minimap: Option<Minimap>,
}

impl SandboxMode {
    // TODO Audit all callers
    pub fn new(ctx: &mut EventCtx, app: &mut App, mode: GameplayMode) -> Box<dyn State> {
        SandboxMode::async_new(ctx, app, mode, Box::new(|_, _| Vec::new()))
    }

    /// This does not immediately initialize anything (like loading the correct map, instantiating
    /// the scenario, etc). That means if you're chaining this call with other transitions, you
    /// probably need to defer running them using `finalize`.
    pub fn async_new(
        _: &mut EventCtx,
        app: &mut App,
        mode: GameplayMode,
        finalize: Box<dyn FnOnce(&mut EventCtx, &mut App) -> Vec<Transition>>,
    ) -> Box<dyn State> {
        app.primary.clear_sim();
        Box::new(SandboxLoader {
            stage: Some(LoadStage::LoadingMap),
            mode,
            finalize: Some(finalize),
        })
    }

    // Just for Warping
    pub fn contextual_actions(&self) -> Actions {
        Actions {
            is_paused: self
                .controls
                .speed
                .as_ref()
                .map(|s| s.is_paused())
                .unwrap_or(true),
            can_interact: self.gameplay.can_examine_objects(),
            gameplay: self.gameplay_mode.clone(),
        }
    }
}

impl State for SandboxMode {
    fn event(&mut self, ctx: &mut EventCtx, app: &mut App) -> Transition {
        // Do this before gameplay
        if self.gameplay.can_move_canvas() {
            ctx.canvas_movement();
        }

        let mut actions = self.contextual_actions();
        if let Some(t) = self
            .gameplay
            .event(ctx, app, &mut self.controls, &mut actions)
        {
            return t;
        }

        if ctx.redo_mouseover() {
            app.recalculate_current_selection(ctx);
        }

        // Order here is pretty arbitrary
        if app.opts.dev && ctx.input.pressed(lctrl(Key::D)) {
            return Transition::Push(DebugMode::new(ctx));
        }

        if let Some(ref mut m) = self.controls.minimap {
            if let Some(t) = m.event(ctx, app) {
                return t;
            }
            if let Some(t) = PickLayer::update(ctx, app, &m.panel) {
                return t;
            }
        }

        if let Some(ref mut s) = self.controls.speed {
            if let Some(t) = s.event(ctx, app, Some(&self.gameplay_mode)) {
                return t;
            }
        }

        if let Some(ref mut r) = self.controls.route_preview {
            if let Some(t) = r.event(ctx, app) {
                return t;
            }
        }

        // Fragile ordering. Let this work before tool_panel, so Key::Escape from the info panel
        // beats the one to quit. And let speed update the sim before we update the info panel.
        if let Some(ref mut c) = self.controls.common {
            if let Some(t) = c.event(ctx, app, &mut actions) {
                return t;
            }
        }

        if let Some(ref mut tp) = self.controls.time_panel {
            tp.event(ctx, app);
        }

        if let Some(ref mut tp) = self.controls.tool_panel {
            match tp.event(ctx) {
                Outcome::Clicked(x) => match x.as_ref() {
                    "back" => {
                        return maybe_exit_sandbox(ctx);
                    }
                    "settings" => {
                        return Transition::Push(OptionsPanel::new(ctx, app));
                    }
                    _ => unreachable!(),
                },
                _ => {}
            }
        }
        if let Some(ref mut am) = self.controls.agent_meter {
            if let Some(t) = am.event(ctx, app) {
                return t;
            }
        }

        if self
            .controls
            .speed
            .as_ref()
            .map(|s| s.is_paused())
            .unwrap_or(true)
        {
            Transition::Keep
        } else {
            ctx.request_update(UpdateType::Game);
            Transition::Keep
        }
    }

    fn draw(&self, g: &mut GfxCtx, app: &App) {
        if let Some(ref l) = app.primary.layer {
            l.draw(g, app);
        }

        if let Some(ref c) = self.controls.common {
            c.draw(g, app);
        } else {
            CommonState::draw_osd(g, app);
        }
        if let Some(ref tp) = self.controls.tool_panel {
            tp.draw(g);
        }
        if let Some(ref s) = self.controls.speed {
            s.draw(g);
        }
        if let Some(ref tp) = self.controls.time_panel {
            tp.draw(g);
        }
        if let Some(ref am) = self.controls.agent_meter {
            am.draw(g);
        }
        if let Some(ref m) = self.controls.minimap {
            m.draw(g, app);
        }
        if let Some(ref r) = self.controls.route_preview {
            r.draw(g);
        }

        self.gameplay.draw(g, app);
    }

    fn on_destroy(&mut self, _: &mut EventCtx, app: &mut App) {
        app.primary.layer = None;
        app.unzoomed_agents = UnzoomedAgents::new(&app.cs);
        self.gameplay.on_destroy(app);
    }
}

pub fn maybe_exit_sandbox(ctx: &mut EventCtx) -> Transition {
    Transition::Push(ChooseSomething::new(
        ctx,
        "Are you ready to leave this mode?",
        vec![
            Choice::string("keep playing"),
            Choice::string("quit to main screen").key(Key::Q),
        ],
        Box::new(|resp, ctx, app| {
            if resp == "keep playing" {
                return Transition::Pop;
            }

            ctx.canvas.save_camera_state(app.primary.map.get_name());
            if app.primary.map.unsaved_edits() {
                return Transition::Multi(vec![
                    Transition::Push(Box::new(BackToMainMenu)),
                    Transition::Push(SaveEdits::new(
                        ctx,
                        app,
                        "Do you want to save your proposal first?",
                        true,
                        None,
                        Box::new(|_, _| {}),
                    )),
                ]);
            }
            Transition::Replace(Box::new(BackToMainMenu))
        }),
    ))
}

struct BackToMainMenu;

impl State for BackToMainMenu {
    fn event(&mut self, ctx: &mut EventCtx, app: &mut App) -> Transition {
        ctx.loading_screen("reset map and sim", |ctx, mut timer| {
            // Always safe to do this
            apply_map_edits(ctx, app, app.primary.map.new_edits());
            app.primary
                .map
                .recalculate_pathfinding_after_edits(&mut timer);

            app.primary.clear_sim();
            app.set_prebaked(None);
        });
        Transition::Clear(vec![MainMenu::new(ctx, app)])
    }

    fn draw(&self, _: &mut GfxCtx, _: &App) {}
}

pub struct AgentMeter {
    time: Time,
    pub panel: Panel,
}

impl AgentMeter {
    pub fn new(ctx: &mut EventCtx, app: &App) -> AgentMeter {
        use abstutil::prettyprint_usize;

        let (finished, unfinished) = app.primary.sim.num_trips();
        let by_type = app.primary.sim.num_agents();

        let mut row = Vec::new();
        for (agent_type, name) in vec![
            (AgentType::Pedestrian, "pedestrian"),
            (AgentType::Bike, "bike"),
            (AgentType::Car, "car"),
        ] {
            let n = prettyprint_usize(by_type.get(agent_type));
            row.push(Widget::custom_row(vec![
                Widget::draw_svg_with_tooltip(
                    ctx,
                    format!("system/assets/meters/{}.svg", name),
                    Text::from(Line(format!("{} {}", n, agent_type.plural_noun()))),
                )
                .margin_right(5),
                n.draw_text(ctx),
            ]));
        }
        row.push(Widget::custom_row(vec![
            Widget::draw_svg_with_tooltip(
                ctx,
                "system/assets/meters/bus.svg",
                Text::from_multiline(vec![
                    Line(format!(
                        "{} public transit passengers",
                        prettyprint_usize(by_type.get(AgentType::TransitRider))
                    )),
                    Line(format!(
                        "{} buses",
                        prettyprint_usize(by_type.get(AgentType::Bus))
                    )),
                    Line(format!(
                        "{} trains",
                        prettyprint_usize(by_type.get(AgentType::Train))
                    )),
                ]),
            )
            .margin_right(5),
            prettyprint_usize(by_type.get(AgentType::TransitRider)).draw_text(ctx),
        ]));

        let rows = vec![
            "Active trips".draw_text(ctx),
            Widget::custom_row(row).centered(),
            Widget::horiz_separator(ctx, 0.2),
            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.draw(ctx)
                },
                Btn::svg_def("system/assets/meters/trip_histogram.svg")
                    .build(ctx, "more data", Key::Q)
                    .align_right(),
            ]),
        ];

        let panel = Panel::new(Widget::col(rows))
            .aligned(HorizontalAlignment::Right, VerticalAlignment::Top)
            .build(ctx);

        AgentMeter {
            time: app.primary.sim.time(),
            panel,
        }
    }

    pub fn event(&mut self, ctx: &mut EventCtx, app: &mut App) -> Option<Transition> {
        if self.time != app.primary.sim.time() {
            *self = AgentMeter::new(ctx, app);
            return self.event(ctx, app);
        }
        match self.panel.event(ctx) {
            Outcome::Clicked(x) => match x.as_ref() {
                "more data" => {
                    return Some(Transition::Push(dashboards::FinishedTripTable::new(
                        ctx, app,
                    )));
                }
                _ => unreachable!(),
            },
            _ => {}
        }

        None
    }

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

// pub for Warping
pub struct Actions {
    is_paused: bool,
    can_interact: bool,
    gameplay: GameplayMode,
}
impl ContextualActions for Actions {
    fn actions(&self, app: &App, id: ID) -> Vec<(Key, String)> {
        let mut actions = Vec::new();
        if self.can_interact {
            match id.clone() {
                ID::Intersection(i) => {
                    if app.primary.map.get_i(i).is_traffic_signal() {
                        actions.push((Key::E, "edit traffic signal".to_string()));
                    }
                    if app.primary.map.get_i(i).is_stop_sign()
                        && self.gameplay.can_edit_stop_signs()
                    {
                        actions.push((Key::E, "edit stop sign".to_string()));
                    }
                    if app.opts.dev {
                        actions.push((Key::U, "explore uber-turns".to_string()));
                    }
                }
                ID::Lane(l) => {
                    if !app.primary.map.get_turns_from_lane(l).is_empty() {
                        actions.push((Key::Z, "explore turns from this lane".to_string()));
                    }
                    if can_edit_lane(&self.gameplay, l, app) {
                        actions.push((Key::E, "edit lane".to_string()));
                    }
                }
                ID::Building(_) => {
                    if app.opts.dev {
                        actions.push((Key::I, "explore isochrone from here".to_string()));
                    }
                }
                _ => {}
            }
        }
        actions.extend(match self.gameplay {
            GameplayMode::Freeform(_) => gameplay::freeform::actions(app, id),
            GameplayMode::Tutorial(_) => gameplay::tutorial::actions(app, id),
            _ => Vec::new(),
        });
        actions
    }
    fn execute(
        &mut self,
        ctx: &mut EventCtx,
        app: &mut App,
        id: ID,
        action: String,
        close_panel: &mut bool,
    ) -> Transition {
        match (id, action.as_ref()) {
            (ID::Intersection(i), "edit traffic signal") => Transition::Multi(vec![
                Transition::Push(EditMode::new(ctx, app, self.gameplay.clone())),
                Transition::Push(TrafficSignalEditor::new(
                    ctx,
                    app,
                    btreeset! {i},
                    self.gameplay.clone(),
                )),
            ]),
            (ID::Intersection(i), "edit stop sign") => Transition::Multi(vec![
                Transition::Push(EditMode::new(ctx, app, self.gameplay.clone())),
                Transition::Push(StopSignEditor::new(ctx, app, i, self.gameplay.clone())),
            ]),
            (ID::Intersection(i), "explore uber-turns") => {
                Transition::Push(uber_turns::UberTurnPicker::new(ctx, app, i))
            }
            (ID::Lane(l), "explore turns from this lane") => {
                Transition::Push(TurnExplorer::new(ctx, app, l))
            }
            (ID::Lane(l), "edit lane") => Transition::Multi(vec![
                Transition::Push(EditMode::new(ctx, app, self.gameplay.clone())),
                Transition::Push(LaneEditor::new(ctx, app, l, self.gameplay.clone())),
            ]),
            (ID::Building(b), "explore isochrone from here") => {
                Transition::Push(IsochroneViewer::new(ctx, app, b))
            }
            (_, "follow (run the simulation)") => {
                *close_panel = false;
                Transition::ModifyState(Box::new(|state, ctx, app| {
                    let mode = state.downcast_mut::<SandboxMode>().unwrap();
                    let speed = mode.controls.speed.as_mut().unwrap();
                    assert!(speed.is_paused());
                    speed.resume_realtime(ctx, app);
                }))
            }
            (_, "unfollow (pause the simulation)") => {
                *close_panel = false;
                Transition::ModifyState(Box::new(|state, ctx, app| {
                    let mode = state.downcast_mut::<SandboxMode>().unwrap();
                    let speed = mode.controls.speed.as_mut().unwrap();
                    assert!(!speed.is_paused());
                    speed.pause(ctx, app);
                }))
            }
            (id, action) => match self.gameplay {
                GameplayMode::Freeform(_) => gameplay::freeform::execute(ctx, app, id, action),
                GameplayMode::Tutorial(_) => gameplay::tutorial::execute(ctx, app, id, action),
                _ => unreachable!(),
            },
        }
    }
    fn is_paused(&self) -> bool {
        self.is_paused
    }
    fn gameplay_mode(&self) -> GameplayMode {
        self.gameplay.clone()
    }
}

// TODO Setting SandboxMode up is quite convoluted, all in order to support asynchronously loading
// files on the web. Each LoadStage is followed in order, with some optional short-circuiting.
//
// Ideally there'd be a much simpler way to express this using Rust's async, to let the compiler
// express this state machine for us.

enum LoadStage {
    LoadingMap,
    LoadingScenario,
    GotScenario(Scenario),
    // Scenario name
    LoadingPrebaked(String),
    // Scenario name, maybe prebaked data
    GotPrebaked(String, Option<Analytics>),
    Finalizing,
}

struct SandboxLoader {
    // Always exists, just a way to avoid clones
    stage: Option<LoadStage>,
    mode: GameplayMode,
    finalize: Option<Box<dyn FnOnce(&mut EventCtx, &mut App) -> Vec<Transition>>>,
}

impl State for SandboxLoader {
    fn event(&mut self, ctx: &mut EventCtx, app: &mut App) -> Transition {
        loop {
            match self.stage.take().unwrap() {
                LoadStage::LoadingMap => {
                    return Transition::Push(MapLoader::new(
                        ctx,
                        app,
                        self.mode.map_name().to_string(),
                        Box::new(|_, _| {
                            Transition::Multi(vec![
                                Transition::Pop,
                                Transition::ModifyState(Box::new(|state, _, _| {
                                    let loader = state.downcast_mut::<SandboxLoader>().unwrap();
                                    loader.stage = Some(LoadStage::LoadingScenario);
                                })),
                            ])
                        }),
                    ));
                }
                LoadStage::LoadingScenario => {
                    match ctx.loading_screen("load scenario", |_, mut timer| {
                        self.mode.scenario(
                            &app.primary.map,
                            app.primary.current_flags.num_agents,
                            app.primary.current_flags.sim_flags.make_rng(),
                            &mut timer,
                        )
                    }) {
                        gameplay::LoadScenario::Nothing => {
                            app.set_prebaked(None);
                            self.stage = Some(LoadStage::Finalizing);
                            continue;
                        }
                        gameplay::LoadScenario::Scenario(scenario) => {
                            self.stage = Some(LoadStage::GotScenario(scenario));
                            continue;
                        }
                        gameplay::LoadScenario::Path(path) => {
                            return Transition::Push(FileLoader::<Scenario>::new(
                                ctx,
                                path,
                                Box::new(|_, _, scenario| {
                                    // TODO Handle corrupt files
                                    let scenario = scenario.unwrap();
                                    Transition::Multi(vec![
                                        Transition::Pop,
                                        Transition::ModifyState(Box::new(|state, _, _| {
                                            let loader =
                                                state.downcast_mut::<SandboxLoader>().unwrap();
                                            loader.stage = Some(LoadStage::GotScenario(scenario));
                                        })),
                                    ])
                                }),
                            ));
                        }
                    }
                }
                LoadStage::GotScenario(mut scenario) => {
                    let scenario_name = scenario.scenario_name.clone();
                    ctx.loading_screen("instantiate scenario", |_, mut timer| {
                        if let GameplayMode::PlayScenario(_, _, ref modifiers) = self.mode {
                            let mut rng = app.primary.current_flags.sim_flags.make_rng();
                            for m in modifiers {
                                scenario = m.apply(&app.primary.map, scenario, &mut rng);
                            }
                        }

                        scenario.instantiate(
                            &mut app.primary.sim,
                            &app.primary.map,
                            &mut app.primary.current_flags.sim_flags.make_rng(),
                            &mut timer,
                        );
                        app.primary
                            .sim
                            .tiny_step(&app.primary.map, &mut app.primary.sim_cb);
                    });

                    self.stage = Some(LoadStage::LoadingPrebaked(scenario_name));
                    continue;
                }
                LoadStage::LoadingPrebaked(scenario_name) => {
                    // Maybe we've already got prebaked data for this map+scenario.
                    if app
                        .has_prebaked()
                        .map(|(m, s)| m == app.primary.map.get_name() && s == &scenario_name)
                        .unwrap_or(false)
                    {
                        self.stage = Some(LoadStage::Finalizing);
                        continue;
                    }

                    return Transition::Push(FileLoader::<Analytics>::new(
                        ctx,
                        abstutil::path_prebaked_results(app.primary.map.get_name(), &scenario_name),
                        Box::new(move |_, _, prebaked| {
                            Transition::Multi(vec![
                                Transition::Pop,
                                Transition::ModifyState(Box::new(move |state, _, _| {
                                    let loader = state.downcast_mut::<SandboxLoader>().unwrap();
                                    loader.stage =
                                        Some(LoadStage::GotPrebaked(scenario_name, prebaked));
                                })),
                            ])
                        }),
                    ));
                }
                LoadStage::GotPrebaked(scenario_name, prebaked) => {
                    if let Some(prebaked) = prebaked {
                        app.set_prebaked(Some((
                            app.primary.map.get_name().clone(),
                            scenario_name,
                            prebaked,
                        )));
                    } else {
                        warn!(
                            "No prebaked simulation results for \"{}\" scenario on {} map. This \
                             means trip dashboards can't compare current times to any kind of \
                             baseline.",
                            scenario_name,
                            app.primary.map.get_name()
                        );
                        app.set_prebaked(None);
                    }
                    self.stage = Some(LoadStage::Finalizing);
                    continue;
                }
                LoadStage::Finalizing => {
                    let gameplay = self.mode.initialize(ctx, app);
                    let sandbox = Box::new(SandboxMode {
                        controls: SandboxControls {
                            common: if gameplay.has_common() {
                                Some(CommonState::new())
                            } else {
                                None
                            },
                            route_preview: if gameplay.can_examine_objects() {
                                Some(RoutePreview::new())
                            } else {
                                None
                            },
                            tool_panel: if gameplay.has_tool_panel() {
                                Some(tool_panel(ctx))
                            } else {
                                None
                            },
                            time_panel: if gameplay.has_time_panel() {
                                Some(TimePanel::new(ctx, app))
                            } else {
                                None
                            },
                            speed: if gameplay.has_speed() {
                                Some(SpeedControls::new(ctx, app))
                            } else {
                                None
                            },
                            agent_meter: if gameplay.has_agent_meter() {
                                Some(AgentMeter::new(ctx, app))
                            } else {
                                None
                            },
                            minimap: if gameplay.has_minimap() {
                                Some(Minimap::new(ctx, app))
                            } else {
                                None
                            },
                        },
                        gameplay,
                        gameplay_mode: self.mode.clone(),
                    });

                    let mut transitions = vec![Transition::Replace(sandbox)];
                    transitions.extend((self.finalize.take().unwrap())(ctx, app));
                    return Transition::Multi(transitions);
                }
            }
        }
    }

    fn draw(&self, _: &mut GfxCtx, _: &App) {}
}