use crate::locale::en;
use crate::server::{validate_url, Server, DEFAULT_SERVER};
use std::{path::PathBuf, sync::Mutex, time::Duration};
use tauri::{
    menu::{AboutMetadata, MenuBuilder, MenuItem, SubmenuBuilder},
    webview::{NewWindowResponse, PageLoadEvent},
    AppHandle, Manager, Url, WebviewUrl, WebviewWindowBuilder, WindowEvent,
};

#[derive(Default)]
struct Connection {
    server: Option<Server>,
    label: Option<String>,
    revision: u64,
    ready: bool,
    phase: &'static str,
}

impl Connection {
    fn begin_navigation(&mut self) -> u64 {
        self.revision += 1;
        self.phase = "connecting";
        self.revision
    }

    fn timeout(&mut self, revision: u64) -> bool {
        if self.revision != revision || self.phase != "connecting" {
            return false;
        }
        self.phase = "connectionError";
        true
    }
}

fn allows_server_navigation(server: &Url, destination: &Url) -> bool {
    destination.scheme() == "https"
        && destination.origin() == server.origin()
        && destination.username().is_empty()
        && destination.password().is_none()
}

fn allows_external_navigation(destination: &Url) -> bool {
    matches!(destination.scheme(), "https" | "http")
        && destination.host_str().is_some()
        && destination.username().is_empty()
        && destination.password().is_none()
}

fn open_external(destination: &Url) {
    if allows_external_navigation(destination) {
        // Arguments are passed directly to Launch Services, never through a shell.
        let destination = destination.to_string();
        std::thread::spawn(move || {
            let _ = std::process::Command::new("/usr/bin/open")
                .arg("--")
                .arg(destination)
                .status();
        });
    }
}

fn allows_launcher_navigation(destination: &Url) -> bool {
    destination.scheme() == "tauri"
        && destination.host_str() == Some("localhost")
        && destination.port().is_none()
        && destination.username().is_empty()
        && destination.password().is_none()
}

fn configuration_path(app: &AppHandle) -> tauri::Result<PathBuf> {
    Ok(app.path().app_config_dir()?.join("active-server"))
}

fn update_launcher(app: &AppHandle) {
    let state = app.state::<Mutex<Connection>>();
    let state = state.lock().unwrap();
    let mut message = Url::parse("tauri://localhost/").unwrap();
    message
        .query_pairs_mut()
        .append_pair(
            "server",
            state
                .server
                .as_ref()
                .map_or(DEFAULT_SERVER, |server| server.url.as_str()),
        )
        .append_pair("phase", state.phase)
        .append_pair("ready", if state.ready { "true" } else { "false" });
    if let Some(window) = app.get_webview_window("launcher") {
        let _ = window.eval(format!(
            "window.updateLauncher?.('{}')",
            message.query().unwrap()
        ));
    }
}

fn show_launcher(app: &AppHandle) {
    update_launcher(app);
    if let Some(window) = app.get_webview_window("launcher") {
        let _ = window.show();
        let _ = window.set_focus();
    }
}

fn begin_navigation(app: &AppHandle, label: &str) {
    let state = app.state::<Mutex<Connection>>();
    let revision = {
        let mut state = state.lock().unwrap();
        if state.label.as_deref() != Some(label) {
            return;
        }
        state.begin_navigation()
    };
    update_launcher(app);
    let handle = app.clone();
    std::thread::spawn(move || {
        std::thread::sleep(Duration::from_secs(15));
        let state = handle.state::<Mutex<Connection>>();
        let timed_out = state.lock().unwrap().timeout(revision);
        if timed_out {
            show_launcher(&handle);
        }
    });
}

fn open_workspace(app: &AppHandle, input: &str) -> Result<(), &'static str> {
    let url = validate_url(input)?;
    let state = app.state::<Mutex<Connection>>();
    let (server, old_label, label) = {
        let mut state = state.lock().unwrap();
        let same_server = state
            .server
            .as_ref()
            .is_some_and(|server| server.url == url);
        if same_server && state.ready {
            if let Some(window) = state
                .label
                .as_ref()
                .and_then(|label| app.get_webview_window(label))
            {
                window.show().map_err(|_| "connectionError")?;
                window.set_focus().map_err(|_| "connectionError")?;
                return Ok(());
            }
        }
        let server = if same_server {
            state.server.clone().unwrap()
        } else {
            Server::new(url).map_err(|_| "storageError")?
        };
        server
            .save(&configuration_path(app).map_err(|_| "storageError")?)
            .map_err(|_| "storageError")?;
        let old_label = state.label.take();
        state.server = Some(server.clone());
        state.ready = false;
        state.revision += 1;
        let label = format!("workspace-{}", state.revision);
        state.label = Some(label.clone());
        (server, old_label, label)
    };
    if let Some(window) = old_label.and_then(|label| app.get_webview_window(&label)) {
        window.close().map_err(|_| "connectionError")?;
    }
    begin_navigation(app, &label);
    let handle = app.clone();
    let navigation_label = label.clone();
    let server_url = server.url.clone();
    let popup_server = server_url.clone();
    let popup_handle = app.clone();
    let popup_label = label.clone();
    let window =
        WebviewWindowBuilder::new(app, &label, WebviewUrl::External(server.dashboard_url()))
            .title(en::APP_NAME)
            .inner_size(1280.0, 850.0)
            .min_inner_size(375.0, 600.0)
            .center()
            .visible(false)
            .data_store_identifier(server.profile)
            .initialization_script(include_str!("../../ui/workspace-navigation.js"))
            .on_navigation(move |destination| {
                if !allows_server_navigation(&server_url, destination) {
                    open_external(destination);
                    return false;
                }
                begin_navigation(&handle, &navigation_label);
                true
            })
            .on_new_window(move |destination, _| {
                if allows_server_navigation(&popup_server, &destination) {
                    if let Some(window) = popup_handle.get_webview_window(&popup_label) {
                        let _ = window.navigate(destination);
                    }
                } else {
                    open_external(&destination);
                }
                NewWindowResponse::Deny
            })
            .on_page_load(|window, payload| {
                if payload.event() != PageLoadEvent::Finished {
                    return;
                }
                let app = window.app_handle();
                let state = app.state::<Mutex<Connection>>();
                let should_show = {
                    let mut state = state.lock().unwrap();
                    if state.label.as_deref() != Some(window.label())
                        || state.phase != "connecting"
                        || !state.server.as_ref().is_some_and(|server| {
                            allows_server_navigation(&server.url, payload.url())
                        })
                    {
                        return;
                    }
                    let first_load = !state.ready;
                    state.ready = true;
                    state.phase = "connected";
                    first_load
                };
                if should_show {
                    let _ = window.show();
                    let _ = window.set_focus();
                    if let Some(launcher) = app.get_webview_window("launcher") {
                        let _ = launcher.hide();
                    }
                }
                update_launcher(app);
            })
            .build()
            .map_err(|_| "connectionError")?;
    #[cfg(target_os = "macos")]
    window
        .with_webview(|webview| unsafe {
            unsafe extern "C" {
                fn install_workspace_navigation(webview: *mut std::ffi::c_void);
            }
            install_workspace_navigation(webview.inner().cast());
        })
        .map_err(|_| "connectionError")?;
    let handle = app.clone();
    window.on_window_event(move |event| {
        if let WindowEvent::CloseRequested { api, .. } = event {
            let current = handle
                .state::<Mutex<Connection>>()
                .lock()
                .unwrap()
                .label
                .as_deref()
                == Some(&label);
            if current {
                api.prevent_close();
                handle.exit(0);
            }
        }
    });
    Ok(())
}

fn handle_launcher_action(app: &AppHandle, destination: &Url) {
    let result = match destination.path() {
        "/action/updates" => {
            #[cfg(target_os = "macos")]
            crate::updates::show(app);
            Ok(())
        }
        "/action/open" => {
            let input = destination
                .query_pairs()
                .find(|(key, _)| key == "server")
                .map(|(_, value)| value.into_owned())
                .unwrap_or_default();
            open_workspace(app, &input)
        }
        "/action/resume" => {
            let label = app
                .state::<Mutex<Connection>>()
                .lock()
                .unwrap()
                .label
                .clone();
            if let Some(window) = label.and_then(|label| app.get_webview_window(&label)) {
                let _ = window.show();
                let _ = window.set_focus();
            }
            Ok(())
        }
        _ => Ok(()),
    };
    if let Err(error) = result {
        app.state::<Mutex<Connection>>().lock().unwrap().phase = error;
        show_launcher(app);
    }
}

pub fn context<R: tauri::Runtime>() -> tauri::Context<R> {
    tauri::generate_context!()
}

fn about_metadata(version: String) -> AboutMetadata<'static> {
    AboutMetadata {
        name: Some(en::APP_NAME.into()),
        version: Some(version),
        #[cfg(target_os = "macos")]
        short_version: Some(crate::metadata::build_number().into()),
        ..Default::default()
    }
}

pub fn builder() -> tauri::Builder<tauri::Wry> {
    tauri::Builder::default().setup(|app| {
        let (server, phase) = match Server::load(&configuration_path(app.handle())?) {
            Ok(Some(server)) => (Some(server), "connecting"),
            Ok(None) => (None, "idle"),
            Err(_) => (None, "storageError"),
        };
        let startup_server = server.clone();
        app.manage(Mutex::new(Connection {
            server,
            phase,
            ..Default::default()
        }));
        let menu = MenuBuilder::new(app)
            .item(
                &SubmenuBuilder::with_id(app, "app-menu", en::APP_NAME)
                    .about_with_text(
                        en::ABOUT,
                        Some(about_metadata(app.package_info().version.to_string())),
                    )
                    .text("check-updates", en::CHECK_UPDATES)
                    .item(&MenuItem::with_id(
                        app,
                        "install-update",
                        en::INSTALL_UPDATE,
                        false,
                        None::<&str>,
                    )?)
                    .separator()
                    .text("server-settings", en::SERVER_SETTINGS)
                    .separator()
                    .quit()
                    .build()?,
            )
            .item(
                &SubmenuBuilder::new(app, en::EDIT)
                    .undo()
                    .redo()
                    .separator()
                    .cut()
                    .copy()
                    .paste()
                    .select_all()
                    .build()?,
            )
            .item(
                &SubmenuBuilder::new(app, en::NAVIGATION)
                    .text("workspace-back", en::BACK)
                    .text("workspace-forward", en::FORWARD)
                    .build()?,
            )
            .build()?;
        app.set_menu(menu)?;
        #[cfg(target_os = "macos")]
        crate::updates::setup(app.handle())?;
        app.on_menu_event(|app, event| {
            #[cfg(target_os = "macos")]
            match event.id().as_ref() {
                "check-updates" => {
                    crate::updates::check(app, true);
                    return;
                }
                "install-update" => {
                    crate::updates::show(app);
                    return;
                }
                _ => {}
            }
            if event.id().as_ref() == "server-settings" {
                show_launcher(app);
            } else if let Some(script) = match event.id().as_ref() {
                "workspace-back" => Some("window.history.back()"),
                "workspace-forward" => Some("window.history.forward()"),
                _ => None,
            } {
                let label = app
                    .state::<Mutex<Connection>>()
                    .lock()
                    .unwrap()
                    .label
                    .clone();
                if let Some(window) = label.and_then(|label| app.get_webview_window(&label)) {
                    let _ = window.eval(script);
                }
            }
        });
        let handle = app.handle().clone();
        let launcher =
            WebviewWindowBuilder::new(app, "launcher", WebviewUrl::App("index.html".into()))
                .title(en::APP_NAME)
                .inner_size(560.0, 720.0)
                .min_inner_size(375.0, 640.0)
                .visible(false)
                .center()
                .on_navigation(move |destination| {
                    if !allows_launcher_navigation(destination) {
                        return false;
                    }
                    if destination.path().starts_with("/action/") {
                        let handle = handle.clone();
                        let destination = destination.clone();
                        let _ = handle.clone().run_on_main_thread(move || {
                            handle_launcher_action(&handle, &destination)
                        });
                        return false;
                    }
                    matches!(destination.path(), "" | "/" | "/index.html")
                })
                .on_new_window(|_, _| NewWindowResponse::Deny)
                .on_page_load(|window, payload| {
                    if payload.event() == PageLoadEvent::Finished {
                        let app = window.app_handle().clone();
                        update_launcher(&app);
                        #[cfg(target_os = "macos")]
                        crate::updates::refresh(&app);
                        let needs_setup = app
                            .state::<Mutex<Connection>>()
                            .lock()
                            .unwrap()
                            .server
                            .is_none();
                        if needs_setup {
                            show_launcher(&app);
                        }
                    }
                })
                .build()?;
        let window = launcher.clone();
        launcher.on_window_event(move |event| {
            if let WindowEvent::CloseRequested { api, .. } = event {
                api.prevent_close();
                let has_workspace = window
                    .app_handle()
                    .state::<Mutex<Connection>>()
                    .lock()
                    .unwrap()
                    .ready;
                if has_workspace {
                    let _ = window.hide();
                } else {
                    window.app_handle().exit(0);
                }
            }
        });
        if let Some(server) = startup_server {
            if let Err(error) = open_workspace(app.handle(), server.url.as_str()) {
                app.state::<Mutex<Connection>>().lock().unwrap().phase = error;
                show_launcher(app.handle());
            }
        }
        Ok(())
    })
}

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

    #[cfg(target_os = "macos")]
    #[test]
    fn about_shows_app_version_followed_by_the_actual_build_number() {
        let metadata = about_metadata("9.8.7".into());
        assert_eq!(metadata.version.as_deref(), Some("9.8.7"));
        assert_eq!(
            metadata.short_version.as_deref(),
            Some(crate::metadata::build_number())
        );
        assert_ne!(metadata.version, metadata.short_version);
    }

    #[test]
    fn external_links_accept_only_web_urls_without_credentials() {
        for input in [
            "https://git.example.com/org/repo/pulls/1#diff",
            "http://git.example.com/repo",
        ] {
            assert!(allows_external_navigation(&Url::parse(input).unwrap()));
        }
        for input in [
            "https://user:secret@git.example.com/",
            "file:///etc/passwd",
            "javascript:alert(1)",
            "tauri://localhost/action/open",
            "mailto:user@example.com",
            "data:text/html,test",
        ] {
            assert!(!allows_external_navigation(&Url::parse(input).unwrap()));
        }
    }

    #[test]
    fn navigation_is_limited_to_the_selected_https_origin() {
        let server = validate_url("https://example.com:8443/app/").unwrap();
        for path in [
            "/login",
            "/two-factor-challenge",
            "/projects/1?ticket=52#details",
        ] {
            assert!(allows_server_navigation(
                &server,
                &server.join(path).unwrap()
            ));
        }
        for destination in [
            "http://example.com:8443/",
            "https://example.com/",
            "https://other.example.com:8443/",
            "https://user:secret@example.com:8443/",
            "tauri://localhost/action/open?server=https://evil.test",
            "file:///etc/passwd",
            "data:text/html,hello",
            "javascript:alert(1)",
        ] {
            assert!(!allows_server_navigation(
                &server,
                &Url::parse(destination).unwrap()
            ));
        }
    }

    #[test]
    fn launcher_actions_are_restricted_to_the_bundled_origin() {
        assert!(allows_launcher_navigation(
            &Url::parse("tauri://localhost/action/open").unwrap()
        ));
        for input in [
            DEFAULT_SERVER,
            "https://localhost/",
            "tauri://other/index.html",
            "tauri://user@localhost/index.html",
        ] {
            assert!(!allows_launcher_navigation(&Url::parse(input).unwrap()));
        }
    }

    #[test]
    fn stale_timeouts_do_not_replace_newer_connections_or_loaded_forms() {
        let mut state = Connection::default();
        let first = state.begin_navigation();
        let second = state.begin_navigation();
        assert!(!state.timeout(first));
        state.ready = true;
        assert!(state.timeout(second));
        assert!(state.ready);
        assert!(!state.timeout(second));
        let third = state.begin_navigation();
        state.phase = "connected";
        assert!(!state.timeout(third));
    }

    #[test]
    fn remote_pages_cannot_invoke_native_commands() {
        let builder = tauri::test::mock_builder();
        #[cfg(target_os = "macos")]
        let builder = builder.plugin(tauri_plugin_updater::Builder::new().build());
        let app = builder.build(context()).unwrap();
        let window = WebviewWindowBuilder::new(
            &app,
            "workspace-1",
            WebviewUrl::External(Url::parse(DEFAULT_SERVER).unwrap()),
        )
        .build()
        .unwrap();
        for command in [
            "plugin:updater|check",
            "plugin:updater|download_and_install",
            "plugin:window|close",
            "plugin:webview|create_webview_window",
            "plugin:path|resolve_directory",
        ] {
            let response = tauri::test::get_ipc_response(
                &window,
                tauri::webview::InvokeRequest {
                    cmd: command.into(),
                    callback: tauri::ipc::CallbackFn(0),
                    error: tauri::ipc::CallbackFn(1),
                    url: Url::parse(DEFAULT_SERVER).unwrap(),
                    body: tauri::ipc::InvokeBody::default(),
                    headers: Default::default(),
                    invoke_key: tauri::test::INVOKE_KEY.into(),
                },
            );
            assert!(response
                .unwrap_err()
                .as_str()
                .unwrap()
                .contains("not allowed"));
        }
    }

    #[test]
    fn packaged_app_exposes_no_native_capabilities_or_global_api() {
        let config: serde_json::Value =
            serde_json::from_str(include_str!("../tauri.conf.json")).unwrap();
        assert_eq!(config["bundle"]["macOS"]["minimumSystemVersion"], "14.0");
        assert_eq!(config["app"]["withGlobalTauri"], false);
        assert_eq!(
            config["app"]["security"]["capabilities"],
            serde_json::json!([])
        );
    }
}