//! Dialog helper functions for file operations and error display.

use std::path::PathBuf;

use gtk::prelude::*;
use relm4::{ComponentSender, gtk};

use crate::AppModel;
use crate::actions::{Action, ImageFormat};
use crate::constants;
use crate::file_registry;

/// Creates a file filter for .wmap files in file pickers.
pub fn create_file_filter() -> gtk::FileFilter {
    let filter = gtk::FileFilter::new();
    filter.add_pattern(&format!("*.{}", constants::FILE_EXTENSION));
    filter.add_mime_type(constants::MIME_TYPE);
    filter.set_name(Some("Wardley Map Files"));
    filter
}

/// Shows an error dialog with the given title and message.
pub fn show_error(window: &gtk::Window, title: &str, message: &str) {
    let dialog = gtk::MessageDialog::new(
        Some(window),
        gtk::DialogFlags::MODAL | gtk::DialogFlags::DESTROY_WITH_PARENT,
        gtk::MessageType::Error,
        gtk::ButtonsType::Ok,
        message,
    );
    dialog.set_title(Some(title));
    dialog.connect_response(|dialog, _| {
        dialog.close();
    });
    dialog.show();
}

/// Shows a file open dialog and handles the response.
pub fn show_open_dialog(
    window: &gtk::Window,
    is_empty_document: bool,
    sender: ComponentSender<AppModel>,
) {
    let dialog = gtk::FileChooserDialog::new(
        Some("Open Map"),
        Some(window),
        gtk::FileChooserAction::Open,
        &[
            ("Cancel", gtk::ResponseType::Cancel),
            ("Open", gtk::ResponseType::Accept),
        ],
    );
    dialog.add_filter(&create_file_filter());

    dialog.connect_response(move |dialog, response| {
        dialog.close();
        if response == gtk::ResponseType::Accept
            && let Some(file) = dialog.file()
            && let Some(path) = file.path()
        {
            // Check if file is already open - if so, focus that window
            if let Some(existing_window) = file_registry::find_window_for_file(&path) {
                existing_window.present();
                return;
            }

            if is_empty_document {
                sender.input(Action::LoadFile(path));
            } else {
                AppModel::open_new_window(Some(path));
            }
        }
    });
    dialog.present();
}

/// Shows a file save dialog and handles the response.
pub fn show_save_dialog(
    window: &gtk::Window,
    current_file: Option<PathBuf>,
    close_after: bool,
    sender: ComponentSender<AppModel>,
) {
    let dialog = gtk::FileChooserDialog::new(
        Some("Save Map As"),
        Some(window),
        gtk::FileChooserAction::Save,
        &[
            ("Cancel", gtk::ResponseType::Cancel),
            ("Save", gtk::ResponseType::Accept),
        ],
    );
    dialog.add_filter(&create_file_filter());

    if let Some(ref current_path) = current_file {
        if let Some(parent) = current_path.parent() {
            let folder = gtk::gio::File::for_path(parent);
            dialog.set_current_folder(Some(&folder)).ok();
        }
        if let Some(filename) = current_path.file_name() {
            dialog.set_current_name(filename.to_str().unwrap_or("map.wmap"));
        }
    } else {
        dialog.set_current_name("map.wmap");
    }

    dialog.connect_response(move |dialog, response| {
        dialog.close();
        if response == gtk::ResponseType::Accept
            && let Some(file) = dialog.file()
            && let Some(path) = file.path()
        {
            sender.input(Action::SaveToFile { path, close_after });
        }
    });
    dialog.present();
}

/// Shows a dialog asking whether to save unsaved changes before closing.
pub fn show_unsaved_changes_dialog(
    window: &gtk::Window,
    current_file: Option<PathBuf>,
    sender: ComponentSender<AppModel>,
) {
    let dialog = gtk::MessageDialog::new(
        Some(window),
        gtk::DialogFlags::MODAL | gtk::DialogFlags::DESTROY_WITH_PARENT,
        gtk::MessageType::Warning,
        gtk::ButtonsType::None,
        "Save changes before closing?",
    );
    dialog.set_title(Some("Unsaved Changes"));
    dialog.add_button("Don't Save", gtk::ResponseType::Reject);
    dialog.add_button("Cancel", gtk::ResponseType::Cancel);
    dialog.add_button("Save", gtk::ResponseType::Accept);

    let window = window.clone();
    dialog.connect_response(move |dialog, response| {
        dialog.close();
        match response {
            gtk::ResponseType::Accept => {
                if current_file.is_some() {
                    sender.input(Action::Save { close_after: true });
                } else {
                    sender.input(Action::SaveAs { close_after: true });
                }
            }
            gtk::ResponseType::Reject => {
                if let Some(ref path) = current_file {
                    file_registry::unregister_file(path);
                }
                window.destroy();
            }
            _ => {}
        }
    });
    dialog.show();
}

/// Creates a file filter for an image format.
fn create_image_filter(format: ImageFormat) -> gtk::FileFilter {
    let filter = gtk::FileFilter::new();
    filter.add_pattern(&format!("*.{}", format.extension()));
    filter.add_mime_type(format.mime_type());
    let name = match format {
        ImageFormat::Png => "PNG Image",
        ImageFormat::Svg => "SVG Image",
    };
    filter.set_name(Some(name));
    filter
}

/// Shows an export image dialog and handles the response.
pub fn show_export_dialog(
    window: &gtk::Window,
    current_file: Option<PathBuf>,
    sender: ComponentSender<AppModel>,
) {
    let dialog = gtk::FileChooserDialog::new(
        Some("Export Map as Image"),
        Some(window),
        gtk::FileChooserAction::Save,
        &[
            ("Cancel", gtk::ResponseType::Cancel),
            ("Export", gtk::ResponseType::Accept),
        ],
    );

    let png_filter = create_image_filter(ImageFormat::Png);
    let svg_filter = create_image_filter(ImageFormat::Svg);
    dialog.add_filter(&png_filter);
    dialog.add_filter(&svg_filter);

    // Set default filename based on current file
    let base_name = current_file
        .as_ref()
        .and_then(|p| p.file_stem())
        .and_then(|s| s.to_str())
        .unwrap_or("map")
        .to_string();

    if let Some(ref current_path) = current_file
        && let Some(parent) = current_path.parent()
    {
        let folder = gtk::gio::File::for_path(parent);
        dialog.set_current_folder(Some(&folder)).ok();
    }
    dialog.set_current_name(&format!("{}.png", base_name));

    // Update extension when filter changes
    {
        let png_filter_ref = png_filter.clone();
        let base_name_clone = base_name.clone();
        dialog.connect_notify_local(Some("filter"), move |dialog, _| {
            let ext = if dialog.filter().as_ref() == Some(&png_filter_ref) {
                "png"
            } else {
                "svg"
            };
            dialog.set_current_name(&format!("{}.{}", base_name_clone, ext));
        });
    }

    let png_filter_clone = png_filter.clone();
    dialog.connect_response(move |dialog, response| {
        dialog.close();
        if response == gtk::ResponseType::Accept
            && let Some(file) = dialog.file()
            && let Some(path) = file.path()
        {
            // Determine format from selected filter or file extension
            let format = if dialog.filter().as_ref() == Some(&png_filter_clone) {
                ImageFormat::Png
            } else if let Some(ext) = path.extension().and_then(|e| e.to_str()) {
                match ext.to_lowercase().as_str() {
                    "svg" => ImageFormat::Svg,
                    _ => ImageFormat::Png,
                }
            } else {
                ImageFormat::Png
            };

            // Ensure correct extension
            let path = if path.extension().is_none() {
                path.with_extension(format.extension())
            } else {
                path
            };

            sender.input(Action::ExportToFile { path, format });
        }
    });
    dialog.present();
}