//! Top editor toolbar (below menu bar): spawn/file left, transport center.

use bevy::prelude::*;
use bevy_egui::egui;
use egui_phosphor_icons::icons;

use crate::history::spawn_with_history;
use crate::scene_io::{SceneIo, SceneIoRequest};
use crate::state::{EditorMode, PlayPaused, PlayPossession};
use crate::ui::UiState;
use crate::viewport::brush_tool::start_draw_brush_tool;
use crate::viewport::{editor_spawn_ground_position, snap_translation, ViewportSettings};
use shared::PrimitiveShape;

use super::helpers::{
    light_snapshot, primitive_snapshot, toggle_play_mode, toggle_play_paused, toggle_possession,
};
use super::widgets::{icon_button, panel_toolbar_row, toolbar_separator, transport_button_large};

/// Toolbar strip height (menu bar is separate).
const TOOLBAR_HEIGHT: f32 = 56.0;
const TRANSPORT_WIDTH: f32 = 152.0;
const TRANSPORT_SLOT_STEP: f32 = 54.0;

pub fn editor_toolbar_panel(world: &mut World, root_ui: &mut egui::Ui) {
    egui::Panel::top("editor_toolbar")
        .exact_size(TOOLBAR_HEIGHT)
        .show_inside(root_ui, |ui| {
            toolbar_ui(world, ui);
        });
}

pub fn toolbar_ui(world: &mut World, ui: &mut egui::Ui) {
    let (toolbar_rect, _) = ui.allocate_exact_size(
        egui::vec2(ui.available_width(), TOOLBAR_HEIGHT - 4.0),
        egui::Sense::hover(),
    );

    let center_y = toolbar_rect.center().y;
    let left_rect = egui::Rect::from_min_max(
        egui::pos2(toolbar_rect.left() + 8.0, center_y - 18.0),
        egui::pos2(toolbar_rect.right(), center_y + 18.0),
    );
    let transport_rect = egui::Rect::from_center_size(
        egui::pos2(toolbar_rect.center().x, center_y),
        egui::vec2(TRANSPORT_WIDTH, 44.0),
    );

    let mut left_ui = ui.new_child(
        egui::UiBuilder::new()
            .id_salt("toolbar_left")
            .max_rect(left_rect)
            .layout(egui::Layout::left_to_right(egui::Align::Center)),
    );
    left_ui.spacing_mut().item_spacing.x = 6.0;
    left_toolbar(world, &mut left_ui);

    let mut transport_ui = ui.new_child(
        egui::UiBuilder::new()
            .id_salt("toolbar_transport")
            .max_rect(transport_rect)
            .layout(egui::Layout::left_to_right(egui::Align::Center)),
    );
    transport_ui.spacing_mut().item_spacing.x = 10.0;
    transport_controls(world, &mut transport_ui);
}

fn left_toolbar(world: &mut World, ui: &mut egui::Ui) {
    panel_toolbar_row(ui, |ui| {
        if icon_button(ui, icons::CUBE, "Spawn cube").clicked() {
            spawn_primitive_at_camera(world, PrimitiveShape::Box, "Cube");
        }
        if icon_button(ui, icons::MOUNTAINS, "Spawn ramp").clicked() {
            spawn_primitive_at_camera(world, PrimitiveShape::Ramp, "Ramp");
        }
        if icon_button(ui, icons::SPHERE, "Spawn sphere").clicked() {
            spawn_primitive_at_camera(world, PrimitiveShape::Sphere, "Sphere");
        }
        if icon_button(ui, icons::LIGHTBULB, "Spawn point light").clicked() {
            let pos = camera_ground_spawn(world);
            spawn_with_history(world, light_snapshot("Point Light", pos));
        }
        if icon_button(ui, icons::PENCIL_SIMPLE_LINE, "Draw brush (B)").clicked() {
            start_draw_brush_tool(world);
        }

        toolbar_separator(ui);

        if icon_button(ui, icons::FILE, "New scene").clicked() {
            world.resource_mut::<SceneIo>().request = Some(SceneIoRequest::New);
        }
        if icon_button(ui, icons::FOLDER_OPEN, "Open scene").clicked() {
            world.resource_mut::<SceneIo>().request = Some(SceneIoRequest::Open);
        }
        if icon_button(ui, icons::FLOPPY_DISK, "Save scene").clicked() {
            world.resource_mut::<SceneIo>().request = Some(SceneIoRequest::Save);
        }
        if icon_button(ui, icons::COPY, "Save scene as").clicked() {
            world.resource_mut::<SceneIo>().request = Some(SceneIoRequest::SaveAs);
        }
    });
}

fn transport_controls(world: &mut World, ui: &mut egui::Ui) {
    let mode = *world.resource::<State<EditorMode>>().get();
    match mode {
        EditorMode::Editing => {
            ui.add_space(TRANSPORT_SLOT_STEP);
            let play_clicked = ui
                .push_id("transport_center", |ui| {
                    transport_button_large(ui, icons::PLAY, "Play (F5)", true).clicked()
                })
                .inner;
            if play_clicked {
                toggle_play_mode(world);
            }
        }
        EditorMode::Playing => {
            let paused = world.resource::<PlayPaused>().0;
            let pause_icon = if paused { icons::PLAY } else { icons::PAUSE };
            let pause_tip = if paused {
                "Resume simulation (F6)"
            } else {
                "Pause simulation (F6)"
            };
            let pause_clicked = ui
                .push_id("transport_left", |ui| {
                    transport_button_large(ui, pause_icon, pause_tip, false).clicked()
                })
                .inner;
            if pause_clicked {
                toggle_play_paused(world);
            }
            let stop_clicked = ui
                .push_id("transport_center", |ui| {
                    transport_button_large(ui, icons::STOP, "Stop and return to Edit (F5)", false)
                        .clicked()
                })
                .inner;
            if stop_clicked {
                toggle_play_mode(world);
            }

            let possession = *world.resource::<PlayPossession>();
            let (eject_icon, eject_tip) = match possession {
                PlayPossession::Possessed => (icons::SIGN_OUT, "Eject from player (F8)"),
                PlayPossession::Ejected => (icons::USER, "Possess player (F8)"),
            };
            let possession_clicked = ui
                .push_id("transport_right", |ui| {
                    transport_button_large(ui, eject_icon, eject_tip, false).clicked()
                })
                .inner;
            if possession_clicked {
                toggle_possession(world);
            }
        }
    }
}

fn camera_ground_spawn(world: &mut World) -> Vec3 {
    let rect = world.resource::<UiState>().viewport_rect;
    let settings = world.resource::<ViewportSettings>().clone();
    let pos = editor_spawn_ground_position(world, rect);
    snap_translation(pos, &settings)
}

fn spawn_primitive_at_camera(world: &mut World, shape: PrimitiveShape, name: &str) {
    let pos = camera_ground_spawn(world);
    spawn_with_history(world, primitive_snapshot(name, shape, pos));
}