use super::{H7CAD, Message};
use super::document::DocumentTab;
use super::history::history_dropdown_labels;
use super::helpers::grid_plane_from_camera;
use crate::scene::{VIEWCUBE_DRAW_PX, VIEWCUBE_PAD};
use crate::scene::grip::grips_to_screen;
use crate::ui::overlay;
use iced::widget::{button, column, container, mouse_area, row, shader, stack, text, Row};
use iced::window;
use iced::{keyboard, Background, Border, Color, Element, Fill, Subscription, Task, Theme};

const VIEWCUBE_HIT_SIZE: f32 = VIEWCUBE_DRAW_PX;

impl H7CAD {
    pub fn view(&self, window_id: window::Id) -> Element<'_, Message> {
        // ── Layer Properties Manager window ───────────────────────────────
        if Some(window_id) == self.layer_window {
            let tab = &self.tabs[self.active_tab];
            return tab.layers.view_window();
        }

        let i = self.active_tab;
        let tab = &self.tabs[i];
        let is_paper = tab.scene.current_layout != "Model";
        let viewport_3d = shader(&tab.scene).width(Fill).height(Fill);

        let selection_overlay = {
            let sel = tab.scene.selection.borrow().clone();
            let snap_info = tab.snap_result.map(|s| (s.screen, s.snap_type));

            let grips: Vec<overlay::GripMarker> =
                if tab.active_cmd.is_none() && !tab.selected_grips.is_empty() {
                    let (vw, vh) = tab.scene.selection.borrow().vp_size;
                    let bounds = iced::Rectangle {
                        x: 0.0, y: 0.0, width: vw, height: vh,
                    };
                    let vp_mat = tab.scene.camera.borrow().view_proj(bounds);
                    let sel_h = tab.selected_handle;
                    grips_to_screen(&tab.selected_grips, vp_mat, bounds)
                        .into_iter()
                        .filter(|(_, screen, _, _)| {
                            screen.x.is_finite()
                                && screen.y.is_finite()
                                && screen.x >= -bounds.width
                                && screen.x <= bounds.width * 2.0
                                && screen.y >= -bounds.height
                                && screen.y <= bounds.height * 2.0
                        })
                        .map(|(grip_id, screen, _is_midpoint, shape)| {
                            let is_hot = tab
                                .active_grip
                                .as_ref()
                                .map_or(false, |g| Some(g.handle) == sel_h && g.grip_id == grip_id);
                            overlay::GripMarker { pos: screen, shape, is_hot }
                        })
                        .collect()
                } else {
                    vec![]
                };

            let grid = if self.show_grid {
                let (vw, vh) = tab.scene.selection.borrow().vp_size;
                let bounds = iced::Rectangle { x: 0.0, y: 0.0, width: vw, height: vh };
                let cam = tab.scene.camera.borrow();
                let plane = grid_plane_from_camera(cam.pitch, cam.yaw);
                Some(overlay::GridParams {
                    view_proj: cam.view_proj(bounds),
                    bounds,
                    plane,
                })
            } else {
                None
            };
            overlay::selection_overlay(sel, snap_info, grips, grid)
        };

        let nav = container(overlay::nav_toolbar())
            .align_right(Fill)
            .align_top(Fill)
            .padding(iced::Padding { top: 148.0, right: 8.0, bottom: 0.0, left: 0.0 });

        let info = container(overlay::info_bar(
            if is_paper { &tab.scene.current_layout } else { "Custom View" },
            &tab.visual_style,
        ))
        .padding([4, 6]);

        let viewport_mouse = mouse_area(container(
            iced::widget::Space::new().width(Fill).height(Fill),
        ))
        .on_move(Message::ViewportMove)
        .on_press(Message::ViewportLeftPress)
        .on_release(Message::ViewportLeftRelease)
        .on_right_press(Message::ViewportRightPress)
        .on_right_release(Message::ViewportRightRelease)
        .on_middle_press(Message::ViewportMiddlePress)
        .on_middle_release(Message::ViewportMiddleRelease)
        .on_scroll(Message::ViewportScroll)
        .on_exit(Message::ViewportExit);

        let cube_click = mouse_area(container(
            iced::widget::Space::new()
                .width(iced::Length::Fixed(VIEWCUBE_HIT_SIZE))
                .height(iced::Length::Fixed(VIEWCUBE_HIT_SIZE)),
        ))
        .on_move(Message::CursorMoved)
        .on_press(Message::ViewportClick);

        let cube_click = container(cube_click)
            .align_right(Fill)
            .align_top(Fill)
            .padding(iced::Padding { top: VIEWCUBE_PAD, right: VIEWCUBE_PAD, bottom: 0.0, left: 0.0 })
            .width(Fill)
            .height(Fill);

        let bg_color = if is_paper {
            Color { r: 0.22, g: 0.24, b: 0.28, a: 1.0 }
        } else {
            Color { r: 0.11, g: 0.11, b: 0.11, a: 1.0 }
        };

        let viewport_stack = stack![
            container(viewport_3d)
                .style(move |_: &Theme| container::Style {
                    background: Some(Background::Color(bg_color)),
                    ..Default::default()
                })
                .width(Fill)
                .height(Fill),
            container(info).width(Fill).height(Fill),
            selection_overlay,
            viewport_mouse,
            nav,
            cube_click,
        ]
        .width(Fill)
        .height(Fill);

        let center_stack = iced::widget::stack![
            row![tab.properties.view(), viewport_stack]
                .width(Fill)
                .height(Fill),
        ]
        .width(Fill)
        .height(Fill);

        let tab_bar = doc_tab_bar(&self.tabs, self.active_tab);

        let main_ui = container(
            column![
                self.ribbon.view(
                    is_paper,
                    self.tabs[self.active_tab].history.undo_stack.len(),
                    self.tabs[self.active_tab].history.redo_stack.len(),
                ),
                tab_bar,
                center_stack,
                self.command_line.view(),
                self.status_bar.view(
                    &self.snapper,
                    self.snap_popup_open,
                    self.ortho_mode,
                    self.polar_mode,
                    self.show_grid,
                    tab.scene.layout_names(),
                    tab.scene.current_layout.clone()
                )
            ]
            .width(Fill)
            .height(Fill),
        )
        .style(|_: &Theme| container::Style {
            background: Some(Background::Color(Color { r: 0.11, g: 0.11, b: 0.11, a: 1.0 })),
            ..Default::default()
        })
        .width(Fill)
        .height(Fill);

        let snap_layer: Element<'_, Message> = if self.snap_popup_open {
            crate::ui::snap_popup::snap_popup_overlay(&self.snapper, 4.0)
        } else {
            iced::widget::Space::new().width(0).height(0).into()
        };

        let dropdown_layer: Element<'_, Message> = self
            .ribbon
            .dropdown_overlay(
                &history_dropdown_labels(&self.tabs[self.active_tab].history.undo_stack),
                &history_dropdown_labels(&self.tabs[self.active_tab].history.redo_stack),
            )
            .unwrap_or_else(|| iced::widget::Space::new().width(0).height(0).into());

        stack![main_ui, self.app_menu.view(), snap_layer, dropdown_layer].into()
    }

    pub fn subscription(&self) -> Subscription<Message> {
        use iced::event;
        iced::Subscription::batch([
            window::frames().map(Message::Tick),
            event::listen_with(|ev, status, win_id| {
                use iced::event::Status;
                match ev {
                    iced::Event::Window(window::Event::Closed) => {
                        Some(Message::OsWindowClosed(win_id))
                    }
                    iced::Event::Window(window::Event::Resized(sz)) => {
                        Some(Message::WindowResized(sz.width as f32, sz.height as f32))
                    }
                    iced::Event::Keyboard(keyboard::Event::KeyPressed {
                        key, modifiers, ..
                    }) => {
                        let ctrl = modifiers.control();
                        let shift = modifiers.shift();
                        match key {
                            keyboard::Key::Named(keyboard::key::Named::Enter)
                            | keyboard::Key::Named(keyboard::key::Named::Space)
                                if status == Status::Ignored =>
                            {
                                Some(Message::CommandFinalize)
                            }
                            keyboard::Key::Named(keyboard::key::Named::Escape) => {
                                Some(Message::CommandEscape)
                            }
                            keyboard::Key::Named(keyboard::key::Named::Delete)
                                if status == Status::Ignored =>
                            {
                                Some(Message::DeleteSelected)
                            }
                            keyboard::Key::Named(keyboard::key::Named::F3) => {
                                Some(Message::ToggleSnapEnabled)
                            }
                            keyboard::Key::Named(keyboard::key::Named::F7) => {
                                Some(Message::ToggleGrid)
                            }
                            keyboard::Key::Named(keyboard::key::Named::F8) => {
                                Some(Message::ToggleOrtho)
                            }
                            keyboard::Key::Named(keyboard::key::Named::F9) => {
                                Some(Message::ToggleGridSnap)
                            }
                            keyboard::Key::Named(keyboard::key::Named::F10) => {
                                Some(Message::TogglePolar)
                            }
                            keyboard::Key::Character(c) if ctrl => match c.as_str() {
                                "n" => Some(Message::ClearScene),
                                "o" => Some(Message::OpenFile),
                                "s" if !shift => Some(Message::SaveFile),
                                "s" if shift => Some(Message::SaveAs),
                                "z" if !shift => Some(Message::Undo),
                                "z" if shift => Some(Message::Redo),
                                "y" => Some(Message::Redo),
                                "c" => Some(Message::Command("COPYCLIP".to_string())),
                                "x" => Some(Message::Command("CUTCLIP".to_string())),
                                "v" => Some(Message::Command("PASTECLIP".to_string())),
                                _ => None,
                            },
                            _ => None,
                        }
                    }
                    _ => None,
                }
            }),
        ])
    }

    pub(super) fn focus_cmd_input(&self) -> Task<Message> {
        iced::widget::operation::focus(iced::widget::Id::new(crate::ui::command_line::CMD_INPUT_ID))
    }

    pub(super) fn blur_cmd_input(&self) -> Task<Message> {
        let op = iced::advanced::widget::operation::focusable::unfocus::<Message>();
        iced::advanced::widget::operate(op)
    }
}

// ── Document tab bar ───────────────────────────────────────────────────────

pub(super) fn doc_tab_bar<'a>(tabs: &'a [DocumentTab], active_tab: usize) -> Element<'a, Message> {
    const BAR_BG: Color = Color { r: 0.13, g: 0.13, b: 0.13, a: 1.0 };
    const TAB_ACTIVE: Color = Color { r: 0.22, g: 0.22, b: 0.22, a: 1.0 };
    const TAB_HOVER: Color = Color { r: 0.18, g: 0.18, b: 0.18, a: 1.0 };
    const TAB_INACTIVE: Color = Color { r: 0.13, g: 0.13, b: 0.13, a: 1.0 };
    const ACCENT: Color = Color { r: 0.20, g: 0.55, b: 0.90, a: 1.0 };
    const TEXT_ACTIVE: Color = Color::WHITE;
    const TEXT_INACTIVE: Color = Color { r: 0.60, g: 0.60, b: 0.60, a: 1.0 };
    const CLOSE_HOVER: Color = Color { r: 0.70, g: 0.22, b: 0.22, a: 1.0 };
    const BORDER_COLOR: Color = Color { r: 0.25, g: 0.25, b: 0.25, a: 1.0 };

    let mut bar = Row::new().spacing(0).align_y(iced::Center);

    for (idx, tab) in tabs.iter().enumerate() {
        let is_active = idx == active_tab;
        let name = tab.tab_display_name();
        let label = if tab.dirty { format!("● {}", name) } else { name };

        let title_btn = button(text(label).size(12))
            .on_press(Message::TabSwitch(idx))
            .padding([5, 12])
            .style(move |_: &Theme, status| button::Style {
                background: Some(Background::Color(match (is_active, status) {
                    (true, _) => TAB_ACTIVE,
                    (false, button::Status::Hovered) => TAB_HOVER,
                    _ => TAB_INACTIVE,
                })),
                text_color: if is_active { TEXT_ACTIVE } else { TEXT_INACTIVE },
                border: Border {
                    color: if is_active { ACCENT } else { Color::TRANSPARENT },
                    width: if is_active { 1.0 } else { 0.0 },
                    radius: 0.0.into(),
                },
                shadow: iced::Shadow::default(),
                snap: false,
            });

        let close_btn = button(text("×").size(11).color(Color { r: 0.55, g: 0.55, b: 0.55, a: 1.0 }))
            .on_press(Message::TabClose(idx))
            .padding([3, 5])
            .style(move |_: &Theme, status| button::Style {
                background: Some(Background::Color(match status {
                    button::Status::Hovered => CLOSE_HOVER,
                    _ => if is_active { TAB_ACTIVE } else { TAB_INACTIVE },
                })),
                border: Border { radius: 3.0.into(), ..Default::default() },
                ..Default::default()
            });

        bar = bar.push(
            container(row![title_btn, close_btn].spacing(0).align_y(iced::Center))
                .style(move |_: &Theme| container::Style {
                    border: Border {
                        color: if is_active { BORDER_COLOR } else { Color::TRANSPARENT },
                        width: if is_active { 1.0 } else { 0.0 },
                        radius: 0.0.into(),
                    },
                    ..Default::default()
                }),
        );
    }

    let new_btn = button(text("+").size(14).color(Color { r: 0.65, g: 0.65, b: 0.65, a: 1.0 }))
        .on_press(Message::TabNew)
        .padding([4, 10])
        .style(|_: &Theme, status| button::Style {
            background: Some(Background::Color(match status {
                button::Status::Hovered => TAB_HOVER,
                _ => Color::TRANSPARENT,
            })),
            border: Border { radius: 0.0.into(), ..Default::default() },
            ..Default::default()
        });

    bar = bar.push(new_btn);
    bar = bar.push(iced::widget::Space::new().width(Fill));

    container(bar)
        .style(|_: &Theme| container::Style {
            background: Some(Background::Color(BAR_BG)),
            border: Border {
                color: BORDER_COLOR,
                width: 1.0,
                radius: 0.0.into(),
            },
            ..Default::default()
        })
        .height(30)
        .width(Fill)
        .padding([0, 2])
        .into()
}