use crate::helpers::{ColorScheme, ID};
use crate::render::{
    draw_vehicle, AgentCache, DrawCtx, DrawMap, DrawOptions, DrawPedestrian, Renderable,
    MIN_ZOOM_FOR_DETAIL,
};
use abstutil;
use abstutil::MeasureMemory;
use ezgui::{Color, EventCtx, GfxCtx, Prerender};
use geom::{Bounds, Circle, Distance, Duration};
use map_model::{Map, Traversable};
use serde_derive::{Deserialize, Serialize};
use sim::{GetDrawAgents, Sim, SimFlags};
use structopt::StructOpt;

// TODO Collapse stuff!
pub struct UI {
    pub primary: PerMapUI,
    pub cs: ColorScheme,
}

impl UI {
    pub fn new(flags: Flags, ctx: &mut EventCtx) -> UI {
        let cs = ColorScheme::load().unwrap();
        UI {
            primary: PerMapUI::new(flags, &cs, ctx),
            cs,
        }
    }

    pub fn draw(
        &self,
        g: &mut GfxCtx,
        opts: DrawOptions,
        source: &GetDrawAgents,
        show_objs: &ShowObject,
    ) {
        let ctx = DrawCtx {
            cs: &self.cs,
            map: &self.primary.map,
            draw_map: &self.primary.draw_map,
            sim: &self.primary.sim,
        };
        let mut sample_intersection: Option<String> = None;

        g.clear(self.cs.get_def("true background", Color::BLACK));
        g.redraw(&self.primary.draw_map.boundary_polygon);

        if g.canvas.cam_zoom < MIN_ZOOM_FOR_DETAIL && !g.is_screencap() {
            // Unzoomed mode
            let layers = show_objs.layers();
            if layers.show_areas {
                g.redraw(&self.primary.draw_map.draw_all_areas);
            }
            if layers.show_lanes {
                g.redraw(&self.primary.draw_map.draw_all_thick_roads);
            }
            if layers.show_intersections {
                g.redraw(&self.primary.draw_map.draw_all_unzoomed_intersections);
            }
            if layers.show_buildings {
                g.redraw(&self.primary.draw_map.draw_all_buildings);
            }

            if layers.show_extra_shapes {
                for es in &self.primary.draw_map.extra_shapes {
                    if show_objs.show(es.get_id()) {
                        es.draw(g, &opts, &ctx);
                    }
                }
            }

            // Still show area/extra shape selection when zoomed out.
            if let Some(ID::Area(id)) = self.primary.current_selection {
                g.draw_polygon(
                    self.cs.get("selected"),
                    &ctx.draw_map.get_a(id).get_outline(&ctx.map),
                );
            } else if let Some(ID::ExtraShape(id)) = self.primary.current_selection {
                g.draw_polygon(
                    self.cs.get("selected"),
                    &ctx.draw_map.get_es(id).get_outline(&ctx.map),
                );
            }

            let (moving, waiting) = self.primary.sim.get_unzoomed_polygons(&self.primary.map);
            g.draw_polygons(self.cs.get_def("moving blob of cars", Color::CYAN), &moving);
            g.draw_polygons(
                self.cs.get_def("waiting blob of cars", Color::RED),
                &waiting,
            );
        } else {
            let mut cache = self.primary.draw_map.agents.borrow_mut();
            let objects = self.get_renderables_back_to_front(
                g.get_screen_bounds(),
                &g.prerender,
                &mut cache,
                source,
                show_objs,
            );

            let mut drawn_all_buildings = false;
            let mut drawn_all_areas = false;

            for obj in objects {
                match obj.get_id() {
                    ID::Building(_) => {
                        if !drawn_all_buildings {
                            g.redraw(&self.primary.draw_map.draw_all_buildings);
                            drawn_all_buildings = true;
                        }
                    }
                    ID::Area(_) => {
                        if !drawn_all_areas {
                            g.redraw(&self.primary.draw_map.draw_all_areas);
                            drawn_all_areas = true;
                        }
                    }
                    _ => {}
                };
                obj.draw(g, &opts, &ctx);

                if self.primary.current_selection == Some(obj.get_id()) {
                    g.draw_polygon(
                        self.cs.get_def("selected", Color::RED.alpha(0.7)),
                        &obj.get_outline(&ctx.map),
                    );
                }

                if g.is_screencap() && sample_intersection.is_none() {
                    if let ID::Intersection(id) = obj.get_id() {
                        sample_intersection = Some(format!("_i{}", id.0));
                    }
                }
            }
        }

        if let Some(i) = sample_intersection {
            g.set_screencap_naming_hint(i);
        }
    }

    // Because we have to sometimes borrow part of self for GetDrawAgents, this just returns the
    // Option<ID> that the caller should assign. When this monolithic UI nonsense is dismantled,
    // this weirdness goes away.
    pub fn handle_mouseover(
        &self,
        ctx: &mut EventCtx,
        source: &GetDrawAgents,
        show_objs: &ShowObject,
        debug_areas: bool,
    ) -> Option<ID> {
        if !ctx.canvas.is_dragging() && ctx.input.get_moved_mouse().is_some() {
            // Unzoomed mode. Ignore when debugging areas.
            if ctx.canvas.cam_zoom < MIN_ZOOM_FOR_DETAIL && !debug_areas {
                return None;
            }

            let pt = ctx.canvas.get_cursor_in_map_space()?;

            let mut cache = self.primary.draw_map.agents.borrow_mut();
            let mut objects = self.get_renderables_back_to_front(
                Circle::new(pt, Distance::meters(3.0)).get_bounds(),
                ctx.prerender,
                &mut cache,
                source,
                show_objs,
            );
            objects.reverse();

            for obj in objects {
                // In unzoomed mode, can only mouseover areas
                match obj.get_id() {
                    ID::Area(_) => {
                        if !debug_areas {
                            continue;
                        }
                    }
                    // Never mouseover these
                    ID::Road(_) => {
                        continue;
                    }
                    _ => {
                        if ctx.canvas.cam_zoom < MIN_ZOOM_FOR_DETAIL {
                            continue;
                        }
                    }
                }
                if obj.contains_pt(pt, &self.primary.map) {
                    return Some(obj.get_id());
                }
            }
            return None;
        }
        if ctx.input.window_lost_cursor() {
            return None;
        }
        self.primary.current_selection
    }

    // TODO This could probably belong to DrawMap again, but it's annoying to plumb things that
    // State does, like show_icons_for() and show().
    fn get_renderables_back_to_front<'a>(
        &'a self,
        bounds: Bounds,
        prerender: &Prerender,
        agents: &'a mut AgentCache,
        source: &GetDrawAgents,
        show_objs: &ShowObject,
    ) -> Vec<Box<&'a Renderable>> {
        let map = &self.primary.map;
        let draw_map = &self.primary.draw_map;

        let mut areas: Vec<Box<&Renderable>> = Vec::new();
        let mut lanes: Vec<Box<&Renderable>> = Vec::new();
        let mut roads: Vec<Box<&Renderable>> = Vec::new();
        let mut intersections: Vec<Box<&Renderable>> = Vec::new();
        let mut buildings: Vec<Box<&Renderable>> = Vec::new();
        let mut extra_shapes: Vec<Box<&Renderable>> = Vec::new();
        let mut bus_stops: Vec<Box<&Renderable>> = Vec::new();
        let mut agents_on: Vec<Traversable> = Vec::new();

        for id in draw_map.get_matching_objects(bounds) {
            if !show_objs.show(id) {
                continue;
            }
            match id {
                ID::Area(id) => areas.push(Box::new(draw_map.get_a(id))),
                ID::Lane(id) => {
                    lanes.push(Box::new(draw_map.get_l(id)));
                    agents_on.push(Traversable::Lane(id));
                    for bs in &map.get_l(id).bus_stops {
                        bus_stops.push(Box::new(draw_map.get_bs(*bs)));
                    }
                }
                ID::Road(id) => {
                    roads.push(Box::new(draw_map.get_r(id)));
                }
                ID::Intersection(id) => {
                    intersections.push(Box::new(draw_map.get_i(id)));
                    for t in &map.get_i(id).turns {
                        agents_on.push(Traversable::Turn(*t));
                    }
                }
                // TODO front paths will get drawn over buildings, depending on quadtree order.
                // probably just need to make them go around other buildings instead of having
                // two passes through buildings.
                ID::Building(id) => buildings.push(Box::new(draw_map.get_b(id))),
                ID::ExtraShape(id) => extra_shapes.push(Box::new(draw_map.get_es(id))),

                ID::BusStop(_) | ID::Turn(_) | ID::Car(_) | ID::Pedestrian(_) | ID::Trip(_) => {
                    panic!("{:?} shouldn't be in the quadtree", id)
                }
            }
        }

        // From background to foreground Z-order
        let mut borrows: Vec<Box<&Renderable>> = Vec::new();
        borrows.extend(areas);
        borrows.extend(lanes);
        borrows.extend(roads);
        borrows.extend(intersections);
        borrows.extend(buildings);
        borrows.extend(extra_shapes);
        borrows.extend(bus_stops);

        // Expand all of the Traversables into agents, populating the cache if needed.
        {
            let time = source.time();
            let step_count = source.step_count();

            for on in &agents_on {
                if !agents.has(time, *on) {
                    let mut list: Vec<Box<Renderable>> = Vec::new();
                    for c in source.get_draw_cars(*on, map).into_iter() {
                        list.push(draw_vehicle(c, map, prerender, &self.cs));
                    }
                    for p in source.get_draw_peds(*on, map).into_iter() {
                        list.push(Box::new(DrawPedestrian::new(
                            p, step_count, map, prerender, &self.cs,
                        )));
                    }
                    agents.put(time, *on, list);
                }
            }
        }

        for on in agents_on {
            for obj in agents.get(on) {
                borrows.push(obj);
            }
        }

        // This is a stable sort.
        borrows.sort_by_key(|r| r.get_zorder());

        borrows
    }
}

#[derive(Serialize, Deserialize, Debug)]
pub struct EditorState {
    pub map_name: String,
    pub cam_x: f64,
    pub cam_y: f64,
    pub cam_zoom: f64,
}

pub struct ShowLayers {
    pub show_buildings: bool,
    pub show_intersections: bool,
    pub show_lanes: bool,
    pub show_areas: bool,
    pub show_extra_shapes: bool,
    pub geom_debug_mode: bool,
}

impl ShowLayers {
    pub fn new() -> ShowLayers {
        ShowLayers {
            show_buildings: true,
            show_intersections: true,
            show_lanes: true,
            show_areas: true,
            show_extra_shapes: true,
            geom_debug_mode: false,
        }
    }
}

pub trait ShowObject {
    fn show(&self, obj: ID) -> bool;
    fn layers(&self) -> &ShowLayers;
}

pub struct ShowEverything {
    layers: ShowLayers,
}

impl ShowEverything {
    pub fn new() -> ShowEverything {
        ShowEverything {
            layers: ShowLayers::new(),
        }
    }
}

impl ShowObject for ShowEverything {
    fn show(&self, _: ID) -> bool {
        true
    }

    fn layers(&self) -> &ShowLayers {
        &self.layers
    }
}

#[derive(StructOpt, Debug, Clone)]
#[structopt(name = "editor")]
pub struct Flags {
    #[structopt(flatten)]
    pub sim_flags: SimFlags,

    /// Extra KML or ExtraShapes to display
    #[structopt(long = "kml")]
    pub kml: Option<String>,

    // TODO Ideally these'd be phrased positively, but can't easily make them default to true.
    /// Should lane markings be drawn? Sometimes they eat too much GPU memory.
    #[structopt(long = "dont_draw_lane_markings")]
    pub dont_draw_lane_markings: bool,

    /// Enable cpuprofiler?
    #[structopt(long = "enable_profiler")]
    pub enable_profiler: bool,

    /// Number of agents to generate when requested. If unspecified, trips to/from borders will be
    /// included.
    #[structopt(long = "num_agents")]
    pub num_agents: Option<usize>,

    /// Don't start with the splash screen and menu
    #[structopt(long = "no_splash")]
    pub no_splash: bool,
}

// All of the state that's bound to a specific map+edit has to live here.
pub struct PerMapUI {
    pub map: Map,
    pub draw_map: DrawMap,
    pub sim: Sim,

    pub current_selection: Option<ID>,
    pub current_flags: Flags,
}

impl PerMapUI {
    pub fn new(flags: Flags, cs: &ColorScheme, ctx: &mut EventCtx) -> PerMapUI {
        let (map, sim, draw_map) = ctx.loading_screen(|ctx, timer| {
            let mut mem = MeasureMemory::new();
            let (map, sim, _) = flags.sim_flags.load(Some(Duration::seconds(30.0)), timer);
            mem.reset("Map and Sim", timer);

            timer.start("draw_map");
            let draw_map = DrawMap::new(&map, &flags, cs, ctx.prerender, timer);
            timer.stop("draw_map");
            mem.reset("DrawMap", timer);

            (map, sim, draw_map)
        });

        PerMapUI {
            map,
            draw_map,
            sim,
            current_selection: None,
            current_flags: flags.clone(),
        }
    }

    pub fn reset_sim(&mut self) {
        // TODO savestate_every gets lost
        self.sim = Sim::new(
            &self.map,
            self.current_flags.sim_flags.run_name.clone(),
            None,
        );
    }
}