mod actions;
mod constants;
mod dialogs;
mod file_registry;
mod stages;

mod icon_names {
    include!(concat!(env!("OUT_DIR"), "/icon_names.rs"));
}

use std::cell::RefCell;
use std::path::PathBuf;

use crate::actions::Action;
use crate::icon_names::shipped::{
    IMAGE_REGULAR, MENU_LARGE, SPLIT_HORIZONTAL_REGULAR, SPLIT_VERTICAL_REGULAR, ZOOM_IN_REGULAR,
    ZOOM_OUT_REGULAR,
};
use cairo::ImageSurface;
use gtk::prelude::*;
use gtk::glib;
use relm4::{
    Component, ComponentController, ComponentParts, ComponentSender, RelmApp, RelmWidgetExt,
    SimpleComponent,
    actions::{AccelsPlus, ActionablePlus, RelmAction, RelmActionGroup},
    gtk,
};
use sourceview5::LanguageManager;
use sourceview5::prelude::{BufferExt, TextBufferExt, TextViewExt};
use stages::all_stages;
use wmap_parser::{Map, parse};
use wmap_renderer::{Configuration, StageType, render_to_surface};

// Action group and action type declarations
relm4::new_action_group!(WindowActionGroup, "window");
relm4::new_stateless_action!(NewAction, WindowActionGroup, "new");
relm4::new_stateless_action!(OpenAction, WindowActionGroup, "open");
relm4::new_stateless_action!(SaveAction, WindowActionGroup, "save");
relm4::new_stateless_action!(SaveAsAction, WindowActionGroup, "save-as");
relm4::new_stateless_action!(CloseAction, WindowActionGroup, "close");
relm4::new_stateless_action!(ExportImageAction, WindowActionGroup, "export-image");
relm4::new_stateless_action!(ChangeOrientationAction, WindowActionGroup, "change-orientation");
relm4::new_stateless_action!(ZoomInAction, WindowActionGroup, "zoom-in");
relm4::new_stateless_action!(ZoomOutAction, WindowActionGroup, "zoom-out");

/// Macro to reduce boilerplate when registering actions with accelerators.
macro_rules! register_action {
    ($group:expr, $app:expr, $sender:expr, $action_type:ty, $message:expr, $accelerators:expr) => {{
        let sender = $sender.clone();
        let action: RelmAction<$action_type> = RelmAction::new_stateless(move |_| {
            sender.input($message);
        });
        $group.add_action(action);
        $app.set_accelerators_for_action::<$action_type>($accelerators);
    }};
}

fn setup_actions(window: gtk::Window, sender: ComponentSender<AppModel>) {
    let application = relm4::main_application();
    let mut action_group = RelmActionGroup::<WindowActionGroup>::new();

    register_action!(action_group, application, sender, ZoomInAction, Action::ZoomIn, &["<Primary>equal", "<Primary>plus"]);
    register_action!(action_group, application, sender, ZoomOutAction, Action::ZoomOut, &["<Primary>minus"]);
    register_action!(action_group, application, sender, ChangeOrientationAction, Action::ChangeOrientation, &["<Primary>l"]);
    register_action!(action_group, application, sender, ExportImageAction, Action::ExportImage, &["<Primary>e"]);
    register_action!(action_group, application, sender, NewAction, Action::New, &["<Primary>n"]);
    register_action!(action_group, application, sender, SaveAction, Action::Save { close_after: false }, &["<Primary>s"]);
    register_action!(action_group, application, sender, SaveAsAction, Action::SaveAs { close_after: false }, &["<Primary><Shift>s"]);
    register_action!(action_group, application, sender, OpenAction, Action::Open, &["<Primary>o"]);
    register_action!(action_group, application, sender, CloseAction, Action::CloseWindow, &["<Primary>w"]);

    action_group.register_for_widget(&window);
}

struct AppInit {
    zoom: f64,
    file_path: Option<PathBuf>,
}

struct AppModel {
    orientation: gtk::Orientation,
    stage_type_list: gtk::StringList,
    stage_type: StageType,
    source: sourceview5::Buffer,
    map: Map,
    zoom: f64,
    render_configuration: Configuration,
    surface: ImageSurface,
    surface_width: i32,
    surface_height: i32,
    drawing_area: gtk::DrawingArea,
    current_file: Option<PathBuf>,
    modified: bool,
    pending_load_events: RefCell<u32>,
    initialized: bool,
    window: gtk::Window,
}

impl AppModel {
    fn update_image(&mut self) {
        if let Ok(surface) =
            render_to_surface(&self.map, self.stage_type, &self.render_configuration)
        {
            self.surface_width = (surface.width() as f64 * self.zoom).round() as i32;
            self.surface_height = (surface.height() as f64 * self.zoom).round() as i32;
            self.surface = surface;

            let zoom = self.zoom;
            let surface_clone = self.surface.clone();
            self.drawing_area
                .set_draw_func(move |_, cr, _width, _height| {
                    cr.scale(zoom, zoom);
                    cr.set_source_surface(&surface_clone, 0.0, 0.0).ok();
                    cr.paint().ok();
                });

            self.drawing_area.set_content_width(self.surface_width);
            self.drawing_area.set_content_height(self.surface_height);
            self.drawing_area.queue_draw();
        }
    }

    fn window_title(&self) -> String {
        let filename = self
            .current_file
            .as_ref()
            .and_then(|path| path.file_name())
            .and_then(|name| name.to_str())
            .unwrap_or("Untitled");

        if self.modified {
            format!("{}* - {}", filename, constants::APP_NAME)
        } else {
            format!("{} - {}", filename, constants::APP_NAME)
        }
    }

    fn is_empty_document(&self) -> bool {
        self.current_file.is_none() && !self.modified && self.source_text().is_empty()
    }

    fn source_text(&self) -> glib::GString {
        self.source
            .text(&self.source.start_iter(), &self.source.end_iter(), false)
    }

    fn set_source_text(&self, content: &str) {
        *self.pending_load_events.borrow_mut() += 1;
        self.source.set_text(content);
    }

    pub fn open_new_window(file_path: Option<PathBuf>) {
        let controller = AppModel::builder()
            .launch(AppInit {
                zoom: 1.0,
                file_path,
            })
            .detach();

        let application = relm4::main_application();
        let window = controller.widget();
        application.add_window(window);
        window.present();

        file_registry::store_controller(controller);
    }
}

#[relm4::component]
impl SimpleComponent for AppModel {
    type Input = Action;
    type Output = ();
    type Init = AppInit;

    view! {
        #[root]
        gtk::Window {
            #[watch]
            set_title: Some(&model.window_title()),
            set_default_width: 300,
            set_default_height: 100,

            gtk::Box {
                set_orientation: gtk::Orientation::Vertical,
                set_spacing: 0,

                gtk::HeaderBar {
                    pack_start = &gtk::Box {
                        set_orientation: gtk::Orientation::Horizontal,

                        gtk::Button::with_label("Change Orientation") {
                            #[watch]
                            set_icon_name: match model.orientation {
                                gtk::Orientation::Horizontal => SPLIT_VERTICAL_REGULAR,
                                _ => SPLIT_HORIZONTAL_REGULAR
                            },
                            ActionablePlus::set_stateless_action::<ChangeOrientationAction>: &(),
                        }
                    },
                    pack_end = &gtk::Box {
                        set_orientation: gtk::Orientation::Horizontal,

                        gtk::Button::with_label("Export as Image") {
                            set_icon_name: IMAGE_REGULAR,
                            ActionablePlus::set_stateless_action::<ExportImageAction>: &(),
                        },

                        gtk::DropDown {
                            set_model: Some(&model.stage_type_list),
                            set_show_arrow: true,
                            set_selected: 0,
                            connect_selected_notify[sender] => move |dropdown| {
                                let selected = dropdown.selected();
                                sender.input(Action::StageTypeSelected(selected as usize));
                            },
                        },
                        gtk::MenuButton {
                            set_icon_name: MENU_LARGE,
                            #[wrap(Some)]
                            set_popover = &gtk::PopoverMenu::from_model(Some(&main_menu)) {}
                        }
                    }
                },

                gtk::Paned {
                    #[watch]
                    set_orientation: model.orientation,
                    set_expand: true,

                    #[wrap(Some)]
                    set_start_child = &gtk::ScrolledWindow {
                        sourceview5::View {
                            set_expand: true,
                            set_monospace: true,
                            set_buffer: Some(&model.source)
                        }
                    },

                    #[wrap(Some)]
                    set_end_child = &gtk::ScrolledWindow {
                        #[local_ref]
                        drawing_area -> gtk::DrawingArea {
                            #[watch]
                            set_content_width: model.surface_width,
                            #[watch]
                            set_content_height: model.surface_height
                        }
                    }
                },

                gtk::ActionBar {
                    pack_end = &gtk::Box {
                        set_orientation: gtk::Orientation::Horizontal,

                        gtk::Label {
                            #[watch]
                            set_label: &format!("{:.1}x", model.zoom),
                            set_margin_end: 5
                        },

                        gtk::Button::with_label("Zoom Out") {
                            set_icon_name: ZOOM_OUT_REGULAR,
                            set_margin_end: 5,
                            add_css_class: "flat",
                            add_css_class: "zoom",
                            add_css_class: "zoom-out",
                            ActionablePlus::set_stateless_action::<ZoomOutAction>: &(),
                        },

                        gtk::Scale {
                            set_orientation: gtk::Orientation::Horizontal,
                            #[watch]
                            set_value: model.zoom,
                            set_draw_value: false,
                            set_range: (constants::MIN_ZOOM, constants::MAX_ZOOM),
                            set_increments: (constants::ZOOM_STEP, constants::ZOOM_STEP),
                            set_value_pos: gtk::PositionType::Left,
                            set_width_request: 100,
                            connect_value_changed[sender] => move |scale| {
                                sender.input(Action::Zoom(scale.value()));
                            }
                        },

                        gtk::Button::with_label("Zoom In") {
                            set_icon_name: ZOOM_IN_REGULAR,
                            add_css_class: "flat",
                            add_css_class: "zoom",
                            add_css_class: "zoom-in",
                            ActionablePlus::set_stateless_action::<ZoomInAction>: &(),
                        },
                    }
                }
            }
        }
    }

    menu! {
        main_menu: {
            "New Map" => NewAction,
            "Open..." => OpenAction,
            "Save" => SaveAction,
            "Save As..." => SaveAsAction,
            "Close" => CloseAction,
            "Export Map as Image" => ExportImageAction,
            section!{
                match model.orientation {
                    gtk::Orientation::Horizontal => "Use Vertical Layout",
                    _ => "Use Horizontal Layout"
                } => ChangeOrientationAction,
            },
            section! {
                "Zoom In" => ZoomInAction,
                "Zoom Out" => ZoomOutAction,
            },
        }
    }

    fn init(
        init: Self::Init,
        root: Self::Root,
        sender: ComponentSender<Self>,
    ) -> ComponentParts<Self> {
        let stage_types: Vec<&str> = all_stages()
            .iter()
            .map(|stage_type| stage_type.name())
            .collect();
        let stage_type_list = gtk::StringList::new(&stage_types);

        let source = sourceview5::Buffer::new(None);
        source.set_highlight_syntax(true);

        let language_manager = LanguageManager::default();
        if let Some(language) = language_manager.language("wmap") {
            source.set_language(Some(&language));
        }

        let (initial_content, current_file) = if let Some(ref path) = init.file_path {
            match std::fs::read_to_string(path) {
                Ok(content) => (content, Some(path.clone())),
                Err(_) => (String::new(), None),
            }
        } else {
            (String::new(), None)
        };

        source.set_text(&initial_content);

        let sender_for_source = sender.clone();
        source.connect_changed(move |_| {
            sender_for_source.input(Action::SourceChanged);
        });

        setup_actions(root.clone(), sender.clone());

        let drawing_area = gtk::DrawingArea::new();
        let map = parse(&initial_content);
        let mut render_configuration = Configuration::default();
        let stage_type = StageType::Activities;
        render_configuration.options.smart_label_positioning = true;
        let surface =
            render_to_surface(&map, stage_type, &render_configuration).unwrap_or_else(|_| {
                ImageSurface::create(cairo::Format::ARgb32, 1, 1)
                    .expect("Failed to create fallback surface")
            });

        if let Some(ref path) = current_file {
            file_registry::register_file(path, &root);
        }

        let mut model = AppModel {
            orientation: gtk::Orientation::Horizontal,
            stage_type_list,
            stage_type,
            source,
            map,
            zoom: init.zoom,
            render_configuration,
            surface,
            surface_width: 0,
            surface_height: 0,
            drawing_area: drawing_area.clone(),
            current_file,
            modified: false,
            pending_load_events: RefCell::new(0),
            initialized: false,
            window: root.clone(),
        };
        model.update_image();

        let sender_for_init = sender.clone();
        glib::idle_add_local_once(move || {
            sender_for_init.input(Action::MarkInitialized);
        });

        let sender_for_close = sender.clone();
        root.connect_close_request(move |_| {
            sender_for_close.input(Action::CloseWindow);
            glib::Propagation::Stop
        });

        let widgets = view_output!();

        ComponentParts { model, widgets }
    }

    fn update(&mut self, message: Self::Input, sender: ComponentSender<Self>) {
        match message {
            Action::ChangeOrientation => {
                self.orientation = match self.orientation {
                    gtk::Orientation::Horizontal => gtk::Orientation::Vertical,
                    _ => gtk::Orientation::Horizontal,
                }
            }
            Action::StageTypeSelected(index) => {
                let all_stages = all_stages();
                if index < all_stages.len() {
                    self.stage_type = all_stages[index];
                }
                self.update_image();
            }
            Action::SourceChanged => {
                let pending = *self.pending_load_events.borrow();
                if pending > 0 {
                    *self.pending_load_events.borrow_mut() -= 1;
                } else if self.initialized {
                    self.modified = true;
                }
                self.map = parse(&self.source_text());
                self.update_image();
            }
            Action::Zoom(new_zoom) => {
                self.zoom = new_zoom;
                self.update_image();
            }
            Action::ZoomOut => {
                if self.zoom - constants::ZOOM_STEP >= constants::MIN_ZOOM {
                    self.zoom -= constants::ZOOM_STEP;
                    self.update_image();
                }
            }
            Action::ZoomIn => {
                if self.zoom < constants::MAX_ZOOM {
                    self.zoom += constants::ZOOM_STEP;
                    self.update_image();
                }
            }
            Action::ExportImage => {}
            Action::New => {
                Self::open_new_window(None);
            }
            Action::Open => {
                dialogs::show_open_dialog(&self.window, self.is_empty_document(), sender);
            }
            Action::Save { close_after } => {
                if let Some(path) = self.current_file.clone() {
                    sender.input(Action::SaveToFile { path, close_after });
                } else {
                    sender.input(Action::SaveAs { close_after });
                }
            }
            Action::SaveAs { close_after } => {
                dialogs::show_save_dialog(
                    &self.window,
                    self.current_file.clone(),
                    close_after,
                    sender,
                );
            }
            Action::LoadFile(path) => {
                match std::fs::read_to_string(&path) {
                    Ok(content) => {
                        if let Some(ref old_path) = self.current_file {
                            file_registry::unregister_file(old_path);
                        }
                        self.set_source_text(&content);
                        file_registry::register_file(&path, &self.window);
                        self.current_file = Some(path);
                        self.modified = false;
                    }
                    Err(error) => {
                        dialogs::show_error(&self.window, "Error Opening File", &error.to_string());
                    }
                }
            }
            Action::SaveToFile { path, close_after } => {
                let content = self.source_text();

                let path = if path.extension().is_none()
                    || path.extension().unwrap_or_default() != constants::FILE_EXTENSION
                {
                    path.with_extension(constants::FILE_EXTENSION)
                } else {
                    path
                };

                match std::fs::write(&path, content.as_str()) {
                    Ok(()) => {
                        if close_after {
                            file_registry::unregister_file(&path);
                            self.modified = false;
                            self.window.close();
                        } else {
                            if self.current_file.as_ref() != Some(&path) {
                                if let Some(ref old_path) = self.current_file {
                                    file_registry::unregister_file(old_path);
                                }
                                file_registry::register_file(&path, &self.window);
                            }
                            self.current_file = Some(path);
                            self.modified = false;
                        }
                    }
                    Err(error) => {
                        dialogs::show_error(&self.window, "Error Saving File", &error.to_string());
                    }
                }
            }
            Action::MarkInitialized => {
                self.initialized = true;
            }
            Action::CloseWindow => {
                if self.modified {
                    dialogs::show_unsaved_changes_dialog(
                        &self.window,
                        self.current_file.clone(),
                        sender,
                    );
                } else {
                    if let Some(ref path) = self.current_file {
                        file_registry::unregister_file(path);
                    }
                    self.window.destroy();
                }
            }
        }
    }
}

fn main() {
    relm4_icons::initialize_icons(icon_names::GRESOURCE_BYTES, icon_names::RESOURCE_PREFIX);
    let application = RelmApp::new("systems.tranquil.map");
    application.run::<AppModel>(AppInit {
        zoom: 1.0,
        file_path: None,
    });
}