// Map, wardley map editor for linux
// Copyright (C) 2026 Rubén Beltrán del Río

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.

// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

// Suppress warnings from relm4 view! macro internals
#![allow(unused_assignments)]

mod actions;
mod constants;
mod dialogs;
mod file_registry;
mod handlers;
mod preferences;
mod stages;
mod ui_helpers;

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::gio;
use gtk::glib;
use gtk::prelude::*;
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_STAGE_TYPES;
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");
relm4::new_stateless_action!(PreferencesAction, WindowActionGroup, "preferences");

/// 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"]
    );
    register_action!(
        action_group,
        application,
        sender,
        PreferencesAction,
        Action::ShowPreferences,
        &["<Primary>comma"]
    );

    action_group.register_for_widget(&window);

    // Register new-from-template action with string parameter (template ID)
    let template_action =
        gio::SimpleAction::new("new-from-template", Some(glib::VariantTy::STRING));
    {
        let sender = sender.clone();
        template_action.connect_activate(move |_, param| {
            if let Some(variant) = param
                && let Some(template_id) = variant.get::<String>()
            {
                sender.input(Action::NewFromTemplateById(template_id));
            }
        });
    }
    window.insert_action_group(
        "win",
        Some(&{
            let group = gio::SimpleActionGroup::new();
            group.add_action(&template_action);
            group
        }),
    );
}

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

struct AppModel {
    orientation: gtk::Orientation,
    stage_type_list: gtk::StringList,
    available_stage_types: Vec<StageType>,
    stage_type: StageType,
    source: sourceview5::Buffer,
    source_view: sourceview5::View,
    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,
    preferences: preferences::UserPreferences,
    preferences_window: Option<relm4::Controller<preferences::PreferencesWindow>>,
    editor_css_provider: gtk::CssProvider,
    templates_menu: gio::Menu,
    main_menu: gio::Menu,
}

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);
    }

    fn apply_preferences(&mut self) {
        // Apply editor preferences
        self.source_view
            .set_wrap_mode(if self.preferences.soft_wrap_lines {
                gtk::WrapMode::Word
            } else {
                gtk::WrapMode::None
            });

        // Build CSS for editor font
        let css = if self.preferences.use_custom_editor_font {
            self.source_view.set_monospace(false);
            format!(
                "textview {{ font-family: \"{}\"; font-size: {}pt; }}",
                self.preferences.custom_editor_font_name, self.preferences.editor_font_size as i32
            )
        } else {
            // Use monospace but still apply font size
            self.source_view.set_monospace(true);
            format!(
                "textview {{ font-size: {}pt; }}",
                self.preferences.editor_font_size as i32
            )
        };

        // Update the CSS provider (reusing the same one avoids accumulation)
        self.editor_css_provider.load_from_data(&css);

        // Apply render configuration
        self.render_configuration.options.smart_label_positioning =
            self.preferences.use_smart_label_positioning;
        self.render_configuration.options.show_background = self.preferences.show_map_background;

        // Apply map font
        if self.preferences.use_custom_font {
            self.render_configuration.theme.fonts.face = self.preferences.custom_font_name.clone();
        } else {
            // Reset to default font
            self.render_configuration.theme.fonts.face = String::from("sans-serif");
        }
    }

    fn rebuild_stage_type_list(&mut self) {
        // Build list: built-in stage types + custom stages from preferences
        let mut stage_types: Vec<StageType> = ALL_STAGE_TYPES.to_vec();

        // Add custom stages from preferences
        for custom in &self.preferences.custom_stages {
            stage_types.push(StageType::Custom {
                name: custom.name.clone(),
                i: custom.stage.i.clone(),
                ii: custom.stage.ii.clone(),
                iii: custom.stage.iii.clone(),
                iv: custom.stage.iv.clone(),
            });
        }

        // Update the StringList for the dropdown
        // Clear existing items
        while self.stage_type_list.n_items() > 0 {
            self.stage_type_list.remove(0);
        }

        // Add all stage type names
        for stage_type in &stage_types {
            self.stage_type_list.append(stage_type.name());
        }

        self.available_stage_types = stage_types;
    }

    fn rebuild_templates_menu(&self) {
        self.templates_menu.remove_all();
        for template in &self.preferences.map_templates {
            let item = gio::MenuItem::new(
                Some(&template.name),
                Some(&format!("win.new-from-template::{}", template.id)),
            );
            self.templates_menu.append_item(&item);
        }
    }

    pub fn open_new_window(file_path: Option<PathBuf>, initial_content: Option<String>) {
        let controller = AppModel::builder()
            .launch(AppInit {
                zoom: 1.0,
                file_path,
                initial_content,
            })
            .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: constants::DEFAULT_WINDOW_WIDTH,
            set_default_height: constants::DEFAULT_WINDOW_HEIGHT,

            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(&model.main_menu)) {}
                        }
                    }
                },

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

                    #[wrap(Some)]
                    set_start_child = &gtk::ScrolledWindow {
                        #[local_ref]
                        source_view -> sourceview5::View {
                            set_expand: 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>: &(),
                        },
                    }
                }
            }
        }
    }

    fn init(
        init: Self::Init,
        root: Self::Root,
        sender: ComponentSender<Self>,
    ) -> ComponentParts<Self> {
        let stage_types: Vec<&str> = ALL_STAGE_TYPES
            .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 {
            (init.initial_content.unwrap_or_default(), None)
        };

        source.set_text(&initial_content);

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

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

        // Create source view
        let source_view = sourceview5::View::with_buffer(&source);
        source_view.set_monospace(true);

        // Create CSS provider for editor font styling
        let editor_css_provider = gtk::CssProvider::new();
        source_view.style_context().add_provider(
            &editor_css_provider,
            gtk::STYLE_PROVIDER_PRIORITY_APPLICATION,
        );

        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);
        }

        // Load preferences
        let prefs = preferences::storage::load();

        let templates_menu = gio::Menu::new();

        // Populate templates menu from preferences
        for template in &prefs.map_templates {
            let item = gio::MenuItem::new(
                Some(&template.name),
                Some(&format!("win.new-from-template::{}", template.id)),
            );
            templates_menu.append_item(&item);
        }

        // Build main menu
        let main_menu = gio::Menu::new();
        main_menu.append(Some("New Map"), Some("window.new"));
        main_menu.append_submenu(Some("New from Template"), &templates_menu);
        main_menu.append(Some("Open..."), Some("window.open"));
        main_menu.append(Some("Save"), Some("window.save"));
        main_menu.append(Some("Save As..."), Some("window.save-as"));
        main_menu.append(Some("Close"), Some("window.close"));
        main_menu.append(Some("Export Map as Image"), Some("window.export-image"));

        let layout_section = gio::Menu::new();
        layout_section.append(
            Some("Use Vertical Layout"),
            Some("window.change-orientation"),
        );
        main_menu.append_section(None, &layout_section);

        let zoom_section = gio::Menu::new();
        zoom_section.append(Some("Zoom In"), Some("window.zoom-in"));
        zoom_section.append(Some("Zoom Out"), Some("window.zoom-out"));
        main_menu.append_section(None, &zoom_section);

        let prefs_section = gio::Menu::new();
        prefs_section.append(Some("Preferences"), Some("window.preferences"));
        main_menu.append_section(None, &prefs_section);

        let mut model = AppModel {
            orientation: gtk::Orientation::Horizontal,
            stage_type_list,
            available_stage_types: ALL_STAGE_TYPES.to_vec(),
            stage_type,
            source,
            source_view: source_view.clone(),
            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(),
            preferences: prefs,
            preferences_window: None,
            editor_css_provider,
            templates_menu,
            main_menu,
        };

        // Apply preferences and rebuild stage type list
        model.apply_preferences();
        model.rebuild_stage_type_list();
        model.update_image();

        // Register this window's sender for broadcasting
        file_registry::register_sender(sender.input_sender().clone());

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

        {
            let sender = sender.clone();
            root.connect_close_request(move |_| {
                sender.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 {
            // View actions
            Action::ChangeOrientation => handlers::view::change_orientation(self),
            Action::StageTypeSelected(index) => handlers::view::stage_type_selected(self, index),

            // Source changes
            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();
            }

            // Zoom actions
            Action::Zoom(level) => handlers::zoom::zoom(self, level),
            Action::ZoomIn => handlers::zoom::zoom_in(self),
            Action::ZoomOut => handlers::zoom::zoom_out(self),

            // Export
            Action::ExportImage => {
                dialogs::show_export_dialog(&self.window, self.current_file.clone(), sender)
            }
            Action::ExportToFile { path, format } => {
                handlers::export::export_to_file(self, path, format)
            }

            // File actions
            Action::New => {
                // Use default template if one exists
                let content = self
                    .preferences
                    .map_templates
                    .iter()
                    .find(|t| t.is_default)
                    .map(|t| t.content.clone());
                Self::open_new_window(None, content);
            }
            Action::NewFromTemplateById(template_id) => {
                if let Ok(id) = uuid::Uuid::parse_str(&template_id)
                    && let Some(template) =
                        self.preferences.map_templates.iter().find(|t| t.id == id)
                {
                    Self::open_new_window(None, Some(template.content.clone()));
                }
            }
            Action::Open => {
                dialogs::show_open_dialog(&self.window, self.is_empty_document(), sender)
            }
            Action::Save { close_after } => handlers::file::save(self, close_after, &sender),
            Action::SaveAs { close_after } => dialogs::show_save_dialog(
                &self.window,
                self.current_file.clone(),
                close_after,
                sender,
            ),
            Action::LoadFile(path) => handlers::file::load_file(self, path),
            Action::SaveToFile { path, close_after } => {
                handlers::file::save_to_file(self, path, close_after)
            }
            Action::CloseWindow => handlers::file::close_window(self, &sender),

            // Internal actions
            Action::MarkInitialized => self.initialized = true,

            // Preferences
            Action::ShowPreferences => {
                if self.preferences_window.is_none() {
                    let controller = preferences::PreferencesWindow::builder()
                        .transient_for(&self.window)
                        .launch(self.preferences.clone())
                        .forward(sender.input_sender(), |output| match output {
                            preferences::window::PreferencesOutput::PreferencesChanged(prefs) => {
                                Action::PreferencesChanged(prefs)
                            }
                            preferences::window::PreferencesOutput::Closed => {
                                Action::PreferencesWindowClosed
                            }
                        });
                    self.preferences_window = Some(controller);
                }
                if let Some(ref controller) = self.preferences_window {
                    controller.widget().present();
                }
            }
            Action::PreferencesChanged(prefs) => {
                self.preferences = prefs;
                self.apply_preferences();
                self.rebuild_stage_type_list();
                self.rebuild_templates_menu();
                self.update_image();
                // Broadcast to all other windows to reload preferences
                file_registry::broadcast_to_all_windows(Action::ReloadPreferences);
            }
            Action::PreferencesWindowClosed => {
                self.preferences_window = None;
            }
            Action::ReloadPreferences => {
                // Reload preferences from disk (another window changed them)
                self.preferences = preferences::storage::load();
                self.apply_preferences();
                self.rebuild_stage_type_list();
                self.rebuild_templates_menu();
                self.update_image();
            }
        }
    }
}

fn main() {
    relm4_icons::initialize_icons(icon_names::GRESOURCE_BYTES, icon_names::RESOURCE_PREFIX);

    // Load preferences to get default template for initial window
    let prefs = preferences::storage::load();
    let initial_content = prefs
        .map_templates
        .iter()
        .find(|t| t.is_default)
        .map(|t| t.content.clone());

    let application = RelmApp::new(constants::APP_ID);
    application.run::<AppModel>(AppInit {
        zoom: 1.0,
        file_path: None,
        initial_content,
    });
}