use crate::shell::tray::{reload_main_window, show_main_window};
use tauri::menu::{Menu, MenuItem, PredefinedMenuItem, Submenu};
use tauri::Manager;

pub(crate) const DESKTOP_APP_MENU_SHOW: &str = "app-menu-show-main-window";
pub(crate) const DESKTOP_APP_MENU_BACK: &str = "app-menu-history-back";
pub(crate) const DESKTOP_APP_MENU_FORWARD: &str = "app-menu-history-forward";
pub(crate) const DESKTOP_APP_MENU_RELOAD: &str = "app-menu-reload-main-window";
pub(crate) const DESKTOP_APP_MENU_QUIT: &str = "app-menu-quit-desktop-shell";
pub(crate) const DESKTOP_HISTORY_BACK_SCRIPT: &str = "window.history.back(); true;";
pub(crate) const DESKTOP_HISTORY_FORWARD_SCRIPT: &str = "window.history.forward(); true;";

#[derive(Debug, PartialEq, Eq)]
pub(crate) enum DesktopAppMenuAction {
    ShowMainWindow,
    GoBack,
    GoForward,
    ReloadMainWindow,
    QuitApp,
    Ignore,
}

pub(crate) fn resolve_desktop_app_menu_action(menu_id: &str) -> DesktopAppMenuAction {
    match menu_id {
        DESKTOP_APP_MENU_SHOW => DesktopAppMenuAction::ShowMainWindow,
        DESKTOP_APP_MENU_BACK => DesktopAppMenuAction::GoBack,
        DESKTOP_APP_MENU_FORWARD => DesktopAppMenuAction::GoForward,
        DESKTOP_APP_MENU_RELOAD => DesktopAppMenuAction::ReloadMainWindow,
        DESKTOP_APP_MENU_QUIT => DesktopAppMenuAction::QuitApp,
        _ => DesktopAppMenuAction::Ignore,
    }
}

fn eval_main_window_history_back(app: &tauri::AppHandle) -> tauri::Result<()> {
    if let Some(window) = app.get_webview_window("main") {
        window.eval(DESKTOP_HISTORY_BACK_SCRIPT)?;
    }

    Ok(())
}

fn eval_main_window_history_forward(app: &tauri::AppHandle) -> tauri::Result<()> {
    if let Some(window) = app.get_webview_window("main") {
        window.eval(DESKTOP_HISTORY_FORWARD_SCRIPT)?;
    }

    Ok(())
}

fn handle_desktop_app_menu_action(app: &tauri::AppHandle, action: DesktopAppMenuAction) {
    match action {
        DesktopAppMenuAction::ShowMainWindow => {
            let _ = show_main_window(app);
        }
        DesktopAppMenuAction::GoBack => {
            let _ = eval_main_window_history_back(app);
        }
        DesktopAppMenuAction::GoForward => {
            let _ = eval_main_window_history_forward(app);
        }
        DesktopAppMenuAction::ReloadMainWindow => {
            let _ = reload_main_window(app);
        }
        DesktopAppMenuAction::QuitApp => app.exit(0),
        DesktopAppMenuAction::Ignore => {}
    }
}

pub(crate) fn register_desktop_app_menu(app: &tauri::App) -> tauri::Result<()> {
    let show_item =
        MenuItem::with_id(app, DESKTOP_APP_MENU_SHOW, "显示主窗口", true, None::<&str>)?;
    let back_item = MenuItem::with_id(app, DESKTOP_APP_MENU_BACK, "后退", true, Some("Alt+Left"))?;
    let forward_item = MenuItem::with_id(
        app,
        DESKTOP_APP_MENU_FORWARD,
        "前进",
        true,
        Some("Alt+Right"),
    )?;
    let reload_item = MenuItem::with_id(
        app,
        DESKTOP_APP_MENU_RELOAD,
        "刷新",
        true,
        Some("CmdOrCtrl+R"),
    )?;
    let quit_item = MenuItem::with_id(
        app,
        DESKTOP_APP_MENU_QUIT,
        "退出",
        true,
        Some("CmdOrCtrl+Q"),
    )?;
    let app_separator = PredefinedMenuItem::separator(app)?;
    let app_menu = Submenu::with_items(
        app,
        "Genarrative",
        true,
        &[
            &show_item,
            &back_item,
            &forward_item,
            &reload_item,
            &app_separator,
            &quit_item,
        ],
    )?;

    let undo_item = PredefinedMenuItem::undo(app, Some("撤销"))?;
    let redo_item = PredefinedMenuItem::redo(app, Some("重做"))?;
    let edit_separator = PredefinedMenuItem::separator(app)?;
    let cut_item = PredefinedMenuItem::cut(app, Some("剪切"))?;
    let copy_item = PredefinedMenuItem::copy(app, Some("复制"))?;
    let paste_item = PredefinedMenuItem::paste(app, Some("粘贴"))?;
    let select_all_item = PredefinedMenuItem::select_all(app, Some("全选"))?;
    let edit_menu = Submenu::with_items(
        app,
        "编辑",
        true,
        &[
            &undo_item,
            &redo_item,
            &edit_separator,
            &cut_item,
            &copy_item,
            &paste_item,
            &select_all_item,
        ],
    )?;

    let minimize_item = PredefinedMenuItem::minimize(app, Some("最小化"))?;
    let maximize_item = PredefinedMenuItem::maximize(app, Some("最大化"))?;
    let window_separator = PredefinedMenuItem::separator(app)?;
    let close_item = PredefinedMenuItem::close_window(app, Some("关闭窗口"))?;
    let window_menu = Submenu::with_items(
        app,
        "窗口",
        true,
        &[
            &minimize_item,
            &maximize_item,
            &window_separator,
            &close_item,
        ],
    )?;

    app.set_menu(Menu::with_items(
        app,
        &[&app_menu, &edit_menu, &window_menu],
    )?)?;
    app.on_menu_event(|app, event| {
        let menu_id = event.id().0.as_str();
        handle_desktop_app_menu_action(app, resolve_desktop_app_menu_action(menu_id));
    });

    Ok(())
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn desktop_app_menu_ids_map_to_window_actions() {
        assert_eq!(
            resolve_desktop_app_menu_action(DESKTOP_APP_MENU_SHOW),
            DesktopAppMenuAction::ShowMainWindow
        );
        assert_eq!(
            resolve_desktop_app_menu_action(DESKTOP_APP_MENU_BACK),
            DesktopAppMenuAction::GoBack
        );
        assert_eq!(
            resolve_desktop_app_menu_action(DESKTOP_APP_MENU_FORWARD),
            DesktopAppMenuAction::GoForward
        );
        assert_eq!(
            resolve_desktop_app_menu_action(DESKTOP_APP_MENU_RELOAD),
            DesktopAppMenuAction::ReloadMainWindow
        );
        assert_eq!(
            resolve_desktop_app_menu_action(DESKTOP_APP_MENU_QUIT),
            DesktopAppMenuAction::QuitApp
        );
        assert_eq!(
            resolve_desktop_app_menu_action("unknown"),
            DesktopAppMenuAction::Ignore
        );
    }

    #[test]
    fn desktop_app_menu_history_scripts_are_fixed_browser_history_calls() {
        assert_eq!(DESKTOP_HISTORY_BACK_SCRIPT, "window.history.back(); true;");
        assert_eq!(
            DESKTOP_HISTORY_FORWARD_SCRIPT,
            "window.history.forward(); true;"
        );
    }
}