use crate::host_bridge::{DesktopShareState, HostBridgeReplayState};
use crate::shell::deep_link::{
    register_desktop_deep_link_events, register_desktop_deep_link_schemes,
};
use crate::shell::tray::{
    register_desktop_tray, register_desktop_window_close_events,
    resolve_desktop_single_instance_action, show_main_window, DesktopSingleInstanceAction,
};
use crate::shell::webview::{
    desktop_external_navigation_url, desktop_window_config_with_runtime_platform,
    emit_current_desktop_lifecycle_event, handle_desktop_webview_download,
    log_desktop_host_event_result, open_desktop_external_navigation,
    open_normalized_desktop_external_url, register_desktop_file_drop_events,
    register_desktop_lifecycle_events, register_desktop_navigation_events,
    replay_desktop_webview_state, should_allow_desktop_webview_navigation,
    should_replay_desktop_webview_state_on_page_load,
};
use crate::shell::window_state::desktop_window_state_plugin;
use tauri::webview::NewWindowResponse;

const DESKTOP_MAIN_WINDOW_LABEL: &str = "main";

fn desktop_main_window_config_from_windows(
    windows: &[tauri::utils::config::WindowConfig],
) -> tauri::Result<tauri::utils::config::WindowConfig> {
    windows
        .iter()
        .find(|window| window.label == DESKTOP_MAIN_WINDOW_LABEL)
        .cloned()
        .map(desktop_window_config_with_runtime_platform)
        .ok_or(tauri::Error::WindowNotFound)
}

#[cfg(dev)]
fn apply_desktop_dev_url_to_main_window_config(
    mut config: tauri::utils::config::WindowConfig,
    dev_url: &tauri::Url,
) -> tauri::utils::config::WindowConfig {
    config.url = tauri::WebviewUrl::External(dev_url.clone());
    desktop_window_config_with_runtime_platform(config)
}

fn desktop_main_window_config(
    app: &tauri::App,
) -> tauri::Result<tauri::utils::config::WindowConfig> {
    let config = desktop_main_window_config_from_windows(&app.config().app.windows)?;
    #[cfg(dev)]
    if let Some(dev_url) = app.config().build.dev_url.as_ref() {
        return Ok(apply_desktop_dev_url_to_main_window_config(config, dev_url));
    }
    Ok(config)
}

fn desktop_new_window_external_url(url: &tauri::Url) -> Option<String> {
    desktop_external_navigation_url(url)
}

fn desktop_new_window_response<R: tauri::Runtime>() -> NewWindowResponse<R> {
    NewWindowResponse::Deny
}

pub(crate) fn run() {
    tauri::Builder::default()
        .manage(DesktopShareState::default())
        .manage(HostBridgeReplayState::default())
        .plugin(tauri_plugin_single_instance::init(|app, _argv, _cwd| {
            match resolve_desktop_single_instance_action() {
                DesktopSingleInstanceAction::ShowMainWindow => {
                    log_desktop_host_event_result("single_instance.show", show_main_window(app));
                }
            }
        }))
        .plugin(desktop_window_state_plugin())
        .plugin(tauri_plugin_deep_link::init())
        .plugin(tauri_plugin_clipboard_manager::init())
        .plugin(tauri_plugin_dialog::init())
        .plugin(tauri_plugin_notification::init())
        .plugin(tauri_plugin_opener::init())
        .setup(|app| {
            let tray_registered = match register_desktop_tray(app) {
                Ok(()) => true,
                Err(_error) => {
                    eprintln!("desktop tray registration failed");
                    false
                }
            };
            let config = desktop_main_window_config(app)?;
            let app_handle = app.handle().clone();
            let new_window_app_handle = app.handle().clone();
            let window = tauri::WebviewWindowBuilder::from_config(app.handle(), &config)?
                .on_navigation(move |url| {
                    if should_allow_desktop_webview_navigation(url) {
                        true
                    } else {
                        open_desktop_external_navigation(&app_handle, url);
                        false
                    }
                })
                .on_new_window(move |url, _features| {
                    if let Some(external_url) = desktop_new_window_external_url(&url) {
                        log_desktop_host_event_result(
                            "webview.new_window.external",
                            open_normalized_desktop_external_url(
                                &new_window_app_handle,
                                external_url,
                            ),
                        );
                    }
                    desktop_new_window_response::<tauri::Wry>()
                })
                .on_page_load(|window, payload| {
                    if should_replay_desktop_webview_state_on_page_load(payload.event()) {
                        replay_desktop_webview_state(&window);
                    }
                })
                .on_download(|_webview, event| handle_desktop_webview_download(&event))
                .build()?;
            register_desktop_window_close_events(&window, tray_registered);
            register_desktop_lifecycle_events(&window);
            log_desktop_host_event_result(
                "app.lifecycle",
                emit_current_desktop_lifecycle_event(&window),
            );
            register_desktop_navigation_events(&window)?;
            register_desktop_file_drop_events(&window);
            register_desktop_deep_link_events(app)?;
            register_desktop_deep_link_schemes(app);
            Ok(())
        })
        .invoke_handler(tauri::generate_handler![
            crate::host_bridge::host_bridge_request
        ])
        .run(tauri::generate_context!())
        .expect("failed to run Genarrative desktop shell");
}

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

    #[test]
    fn desktop_main_window_config_uses_labeled_main_window() {
        let mut secondary_window = tauri::utils::config::WindowConfig::default();
        secondary_window.label = "secondary".to_string();
        secondary_window.url = tauri::WebviewUrl::App(PathBuf::from("secondary.html"));

        let mut main_window = tauri::utils::config::WindowConfig::default();
        main_window.label = "main".to_string();
        main_window.url = tauri::WebviewUrl::App(PathBuf::from("index.html"));

        let config = desktop_main_window_config_from_windows(&[secondary_window, main_window])
            .expect("main window config");

        assert_eq!(config.label, "main");
        match config.url {
            tauri::WebviewUrl::App(path) => {
                let path = path.to_string_lossy();
                assert!(path.starts_with("index.html?"));
                assert!(path.contains("clientRuntime=native_app"));
                assert!(path.contains("clientType=native_app"));
                assert!(path.contains("hostShell=tauri_desktop"));
                assert!(path.contains("hostPlatform="));
                assert!(path.contains(&format!("hostVersion={}", env!("CARGO_PKG_VERSION"))));
                assert!(path.contains("bridgeVersion="));
                assert!(path.contains("hostCapabilities="));
            }
            other => panic!("unexpected main window url {other:?}"),
        }
    }

    #[cfg(dev)]
    #[test]
    fn desktop_main_window_config_uses_dev_url_in_dev_builds() {
        let mut main_window = tauri::utils::config::WindowConfig::default();
        main_window.label = "main".to_string();
        main_window.url = tauri::WebviewUrl::App(PathBuf::from("index.html"));

        let mut config = tauri::utils::config::Config::default();
        config.app.windows = vec![main_window];
        config.build.dev_url =
            Some(tauri::Url::parse("http://127.0.0.1:3000/").expect("desktop dev url"));

        let mut resolved = desktop_main_window_config_from_windows(&config.app.windows)
            .expect("main window config");
        if let Some(dev_url) = config.build.dev_url.as_ref() {
            resolved = apply_desktop_dev_url_to_main_window_config(resolved, dev_url);
        }

        match resolved.url {
            tauri::WebviewUrl::External(url) => {
                assert_eq!(url.origin().ascii_serialization(), "http://127.0.0.1:3000");
                assert_eq!(url.path(), "/");
                assert_eq!(
                    url.query_pairs()
                        .find(|(key, _)| key == "hostShell")
                        .map(|(_, value)| value.into_owned()),
                    Some("tauri_desktop".to_string())
                );
            }
            other => panic!("unexpected dev main window url {other:?}"),
        }
    }

    #[test]
    fn desktop_main_window_config_rejects_missing_main_window() {
        let mut secondary_window = tauri::utils::config::WindowConfig::default();
        secondary_window.label = "secondary".to_string();

        let error = desktop_main_window_config_from_windows(&[secondary_window])
            .expect_err("missing main window should fail startup");

        assert!(matches!(error, tauri::Error::WindowNotFound));
    }

    #[test]
    fn desktop_new_window_policy_denies_embedded_windows() {
        assert!(matches!(
            desktop_new_window_response::<tauri::Wry>(),
            NewWindowResponse::Deny
        ));
    }

    #[test]
    fn desktop_new_window_policy_opens_only_safe_external_urls() {
        let external_url = tauri::Url::parse("https://example.com/share")
            .expect("external desktop new window url");
        assert_eq!(
            desktop_new_window_external_url(&external_url),
            Some("https://example.com/share".to_string())
        );

        let same_origin_url = tauri::Url::parse("https://www.genarrative.world/works/detail")
            .expect("same-origin desktop new window url");
        assert_eq!(desktop_new_window_external_url(&same_origin_url), None);

        let unsafe_url =
            tauri::Url::parse("javascript:alert(1)").expect("unsafe desktop new window url");
        assert_eq!(desktop_new_window_external_url(&unsafe_url), None);
    }
}