use serde_json;
use std::env;
use std::sync::{Arc, Mutex};
use tauri::{
    Emitter, Listener, Manager, PhysicalPosition, Position, TitleBarStyle, WebviewUrl,
    WebviewWindowBuilder,
};
use tauri_plugin_deep_link::DeepLinkExt;
use tauri_plugin_updater;
use tauri_plugin_dialog;
use tauri_plugin_process;
use tauri::menu::{Menu, MenuItem};
use tauri::image::Image;
use tauri::tray::{MouseButton, MouseButtonState, TrayIconBuilder, TrayIconEvent};
use image;

// Global state for search window availability
type SearchWindowState = Arc<Mutex<bool>>;

#[tauri::command]
fn show_window(window: tauri::Window) -> Result<(), String> {
    // Always target the main window specifically, not the calling window
    let app_handle = window.app_handle();
    let main_window = match app_handle.get_webview_window("main") {
        Some(window) => window,
        None => {
            return Err("Main window not found".to_string());
        }
    };

    main_window
        .show()
        .map_err(|e| format!("Failed to show window: {}", e))?;
    main_window
        .set_focus()
        .map_err(|e| format!("Failed to set focus: {}", e))?;

    Ok(())
}

/// Prompt the user to download and install an update.
/// Shared by both manual and silent update flows.
#[cfg(desktop)]
async fn prompt_and_install_update(app: &tauri::AppHandle, update: tauri_plugin_updater::Update) {
    use tauri_plugin_dialog::{DialogExt, MessageDialogKind, MessageDialogButtons};

    let answer = app.dialog()
        .message(format!("A new version {} is available. Would you like to update now?", update.version))
        .title("Update Available")
        .kind(MessageDialogKind::Info)
        .buttons(MessageDialogButtons::OkCancel)
        .blocking_show();

    if answer {
        let _ = update.download_and_install(
            |_chunk_length, _content_length| {},
            || {
                println!("Update download finished");
            }
        ).await;
    }
}

/// Silent update check — only shows a dialog when an update is available.
/// Used on startup and by the periodic background timer.
#[cfg(desktop)]
async fn silent_update_check(app: tauri::AppHandle) {
    use tauri_plugin_updater::UpdaterExt;

    if let Ok(updater) = app.updater() {
        match updater.check().await {
            Ok(Some(update)) => {
                println!("Update available: {}", update.version);
                prompt_and_install_update(&app, update).await;
            }
            Ok(None) => {
                println!("No updates available");
            }
            Err(e) => {
                println!("Silent update check failed: {}", e);
            }
        }
    }
}

/// Manual update check (triggered from tray menu).
/// Shows dialogs for all outcomes: update available, up-to-date, and errors.
#[tauri::command]
async fn check_for_updates(app: tauri::AppHandle) -> Result<(), String> {
    use tauri_plugin_dialog::{DialogExt, MessageDialogKind, MessageDialogButtons};
    use tauri_plugin_updater::UpdaterExt;
    
    #[cfg(desktop)]
    {
        if let Ok(updater) = app.updater() {
            match updater.check().await {
                Ok(Some(update)) => {
                    prompt_and_install_update(&app, update).await;
                }
                Ok(None) => {
                    let version = app.package_info().version.to_string();
                    app.dialog()
                        .message(format!("Midday\nversion {}\n\nYou're up to date!", version))
                        .title("No Updates Available")
                        .kind(MessageDialogKind::Info)
                        .buttons(MessageDialogButtons::Ok)
                        .blocking_show();
                }
                Err(e) => {
                    app.dialog()
                        .message(format!("Failed to check for updates: {}", e))
                        .title("Update Check Failed")
                        .kind(MessageDialogKind::Error)
                        .buttons(MessageDialogButtons::Ok)
                        .blocking_show();
                }
            }
        } else {
            app.dialog()
                .message("Update checking is not available in this build.")
                .title("Updates Not Available")
                .kind(MessageDialogKind::Warning)
                .buttons(MessageDialogButtons::Ok)
                .blocking_show();
        }
    }
    
    #[cfg(not(desktop))]
    {
        app.dialog()
            .message("Updates are managed through your app store.")
            .title("Check App Store")
            .kind(MessageDialogKind::Info)
            .buttons(MessageDialogButtons::Ok)
            .blocking_show();
    }
    
    Ok(())
}

fn toggle_search_window(
    app: &tauri::AppHandle,
    search_state: &SearchWindowState,
) -> Result<(), Box<dyn std::error::Error>> {
    println!("🔍 === TOGGLE_SEARCH_WINDOW CALLED ===");

    let is_search_enabled = {
        let guard = search_state.lock().unwrap();
        let value = *guard;
        println!("🔍 Current search window state from lock: {}", value);
        value
    };

    if !is_search_enabled {
        println!("❌ Search window disabled, showing main window instead");
        // Search is disabled, show main window
        if let Some(main_window) = app.get_webview_window("main") {
            main_window.show()?;
            main_window.set_focus()?;
        }
        return Ok(());
    }

    println!("✅ Search window enabled, proceeding with search toggle");
    // Search is enabled, proceed with search toggle
    let search_window_label = "search";

    println!("🔍 Looking for existing search window...");
    if let Some(window) = app.get_webview_window(search_window_label) {
        println!("🔍 Found existing search window");
        if window.is_visible()? {
            println!("🔍 Search window is visible, hiding it");
            // Emit close event to search window
            let _ = window.emit("search-window-open", false);
            window.hide()?;
        } else {
            println!("🔍 Search window is hidden, showing it");
            // Set always on top when showing
            window.set_always_on_top(true)?;
            position_window_on_current_monitor(app, &window)?;
            window.show()?;
            window.set_focus()?; // Focus the window so it can detect focus loss

            // Emit open event to search window
            let _ = window.emit("search-window-open", true);
        }
    } else {
        println!("🔍 Search window doesn't exist, creating it now...");
        // Create search window on-demand
        let app_url = get_app_url();
        let app_clone = app.clone();

        // Use blocking approach for shortcut/tray handlers to ensure window is created
        tauri::async_runtime::block_on(async move {
            if let Ok(_) = create_preloaded_search_window(&app_clone, &app_url).await {
                println!("✅ Search window created successfully via block_on");
                // After creation, show it immediately
                if let Some(window) = app_clone.get_webview_window("search") {
                    let _ = window.set_always_on_top(true);
                    let _ = position_window_on_current_monitor(&app_clone, &window);
                    let _ = window.show();
                    let _ = window.set_focus();
                    let _ = window.emit("search-window-open", true);
                    println!("✅ Search window shown successfully");
                } else {
                    println!("❌ Search window not found after creation");
                }
            } else {
                println!("❌ Failed to create search window");
            }
        });
    }

    Ok(())
}

fn position_window_on_current_monitor(
    app: &tauri::AppHandle,
    window: &tauri::WebviewWindow,
) -> Result<(), Box<dyn std::error::Error>> {
    // Get cursor position to determine current monitor
    if let Ok(cursor_position) = app.cursor_position() {
        // Get all monitors
        if let Ok(monitors) = app.available_monitors() {
            // Find which monitor contains the cursor
            let current_monitor = monitors.iter().find(|monitor| {
                let pos = monitor.position();
                let size = monitor.size();
                cursor_position.x >= pos.x as f64
                    && cursor_position.x < (pos.x + size.width as i32) as f64
                    && cursor_position.y >= pos.y as f64
                    && cursor_position.y < (pos.y + size.height as i32) as f64
            });

            if let Some(monitor) = current_monitor {
                let monitor_size = monitor.size();
                let monitor_position = monitor.position();

                // Get the actual window size to ensure accurate centering
                let window_size = window.outer_size().unwrap_or(tauri::PhysicalSize {
                    width: 720,
                    height: 450,
                });

                // Calculate center position on the monitor with slight offset for system UI
                let center_x = monitor_position.x + (monitor_size.width as i32 / 2)
                    - (window_size.width as i32 / 2);
                let center_y = monitor_position.y + (monitor_size.height as i32 / 2)
                    - (window_size.height as i32 / 2);

                // Adjust for macOS menu bar (typically 25-30px) and other system UI
                let center_y = center_y + 15; // Slight downward adjustment for menu bar

                window.set_position(Position::Physical(PhysicalPosition {
                    x: center_x,
                    y: center_y,
                }))?;

                return Ok(());
            }
        }
    }

    // Fallback to default center if monitor detection fails
    window.center()?;
    Ok(())
}

async fn create_preloaded_search_window(
    app: &tauri::AppHandle,
    app_url: &str,
) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    let search_window_label = "search";
    let search_url = format!("{}/desktop/search", app_url);

    let mut search_builder = WebviewWindowBuilder::new(
        app,
        search_window_label,
        WebviewUrl::External(tauri::Url::parse(&search_url)?),
    )
    .title("Midday Search")
    .inner_size(720.0, 450.0)
    .min_inner_size(720.0, 450.0)
    .resizable(false)
    .user_agent("Mozilla/5.0 (compatible; Midday Desktop App)")
    .transparent(true)
    .decorations(false)
    .visible(false) // Start hidden for preloading
    .on_download(|_window, _event| {
        println!("Search window download triggered!");
        // Allow downloads from search window too
        true
    });

    // Platform-specific styling
    search_builder = search_builder
        .hidden_title(true)
        .title_bar_style(TitleBarStyle::Overlay);

    let search_window = search_builder.shadow(false).build()?;

    // Position window on primary monitor (will be repositioned when shown)
    search_window.center()?;

    // Close requests are now handled via auth state changes and direct window management

    // Handle window events - comprehensive auto-hide behavior
    let window_clone = search_window.clone();
    search_window.on_window_event(move |event| {
        match event {
            // Main case: window loses focus (click outside anywhere)
            tauri::WindowEvent::Focused(false) => {
                // Emit close event to search window
                let _ = window_clone.emit("search-window-open", false);
                // Turn off always on top and hide
                let _ = window_clone.set_always_on_top(false);
                let _ = window_clone.hide();
            }
            // Additional safety: if window somehow becomes invisible but should be hidden
            tauri::WindowEvent::Resized(_) | tauri::WindowEvent::Moved(_) => {
                // Check if still focused after these events, if not, hide
                if let Ok(false) = window_clone.is_focused() {
                    let _ = window_clone.emit("search-window-open", false);
                    let _ = window_clone.set_always_on_top(false);
                    let _ = window_clone.hide();
                }
            }
            _ => {}
        }
    });

    Ok(())
}

fn get_app_url() -> String {
    // Try runtime environment variable first, then fall back to compile-time
    let env = env::var("MIDDAY_ENV")
        .unwrap_or_else(|_| {
            option_env!("MIDDAY_ENV")
                .unwrap_or("development")
                .to_string()
        });

    println!("🌍 Environment detected: {}", env);

    match env.as_str() {
        "development" | "dev" => {
            let url = "http://localhost:3001".to_string();
            println!("🌍 Using development URL: {}", url);
            url
        },
        "staging" => {
            let url = "https://beta.midday.ai".to_string();
            println!("🌍 Using staging URL: {}", url);
            url
        },
        "production" | "prod" => {
            let url = "https://app.midday.ai".to_string();
            println!("🌍 Using production URL: {}", url);
            url
        },
        _ => {
            eprintln!("Unknown environment: {}, defaulting to development", env);
            let url = "http://localhost:3001".to_string();
            println!("🌍 Using fallback development URL: {}", url);
            url
        }
    }
}

fn is_external_url(url: &str, app_url: &str) -> bool {
    // Parse both URLs to compare domains
    if let (Ok(target_url), Ok(base_url)) = (tauri::Url::parse(url), tauri::Url::parse(app_url)) {
        // Check if schemes are http/https
        let is_http_scheme = target_url.scheme() == "http" || target_url.scheme() == "https";

        // Check if it's a different domain/host
        let is_different_host = target_url.host() != base_url.host();

        return is_http_scheme && is_different_host;
    }
    false
}

fn handle_deep_link_event(app_handle: &tauri::AppHandle, urls: Vec<String>) {
    for url in &urls {
        // Only handle midday schemes (midday://, midday-dev://, midday-staging://)
        if let Some(idx) = url.find("://") {
            let scheme = &url[..idx];
            if !scheme.contains("midday") {
                continue;
            }
            let path = &url[idx + 3..];

            // Remove any leading slashes
            let clean_path = path.trim_start_matches('/');

            // Get the main window and emit navigation event to frontend
            if let Some(window) = app_handle.get_webview_window("main") {
                // Emit event to frontend with just the path - frontend handles the full URL construction
                if let Ok(_) = window.emit("deep-link-navigate", clean_path) {
                    // Always show the window first, then bring it to front
                    let _ = window.show();
                    let _ = window.set_focus();
                }
            }
        }
    }
}

#[cfg_attr(mobile, tauri::mobile_entry_point)]
pub fn run() {
    let app_url = get_app_url();

    tauri::Builder::default()
        .plugin(tauri_plugin_opener::init())
        .plugin(tauri_plugin_deep_link::init())
        .plugin(tauri_plugin_dialog::init())
        .plugin(tauri_plugin_process::init())
        .plugin(tauri_plugin_upload::init())
        .plugin(tauri_plugin_fs::init())
        .invoke_handler(tauri::generate_handler![show_window, check_for_updates])
        .setup(move |app| {
            // Add updater plugin conditionally for desktop
            #[cfg(desktop)]
            app.handle().plugin(tauri_plugin_updater::Builder::new().build())?;

            // Check for updates on startup (after a short delay) and every 4 hours
            #[cfg(desktop)]
            {
                let app_handle_for_updates = app.handle().clone();
                tauri::async_runtime::spawn(async move {
                    // Wait 5 seconds after startup before first check
                    tokio::time::sleep(std::time::Duration::from_secs(5)).await;
                    println!("Running startup update check...");
                    silent_update_check(app_handle_for_updates.clone()).await;

                    // Then check every 4 hours
                    let mut interval = tokio::time::interval(std::time::Duration::from_secs(4 * 60 * 60));
                    interval.tick().await; // skip the immediate first tick
                    loop {
                        interval.tick().await;
                        println!("Running periodic update check...");
                        silent_update_check(app_handle_for_updates.clone()).await;
                    }
                });
            }

            let app_url_clone = app_url.clone();
            let app_handle = app.handle().clone();

            // Create shared search window state
            let search_state: SearchWindowState = Arc::new(Mutex::new(false));
            
            // Add search state to managed state so commands can access it
            app.manage(search_state.clone());

            // Clone app_handle before it gets moved into closures
            let app_handle_for_deep_links = app_handle.clone();
            let app_handle_for_navigation = app_handle.clone();
            
            // Auth state is now accessed via managed state for consistency

            // Initialize global shortcuts
            {
                use tauri_plugin_global_shortcut::{
                    Code, GlobalShortcutExt, Modifiers, Shortcut, ShortcutState,
                };

                let search_shortcut =
                    Shortcut::new(Some(Modifiers::SHIFT | Modifiers::ALT), Code::KeyK);

                if let Ok(_) = app.handle().plugin(
                    tauri_plugin_global_shortcut::Builder::new()
                        .with_handler(move |app_handle, shortcut, event| {
                            if shortcut == &search_shortcut
                                && event.state() == ShortcutState::Pressed
                            {
                                println!("🔍 Global shortcut triggered - checking search state via managed state");
                                // Get search state from managed state (same as commands use)
                                if let Some(managed_search_state) = app_handle.try_state::<SearchWindowState>() {
                                    let current_search_state = *managed_search_state.lock().unwrap();
                                    println!("🔍 Shortcut: Search state from managed state: {}", current_search_state);
                                    
                                    // Use the same app_handle for both search state and toggle function
                                    let result = toggle_search_window(app_handle, &managed_search_state);
                                    match result {
                                        Ok(_) => println!("🔍 Shortcut: toggle_search_window returned Ok"),
                                        Err(e) => println!("🔍 Shortcut: toggle_search_window returned Err: {}", e)
                                    }
                                } else {
                                    println!("❌ Failed to get managed search state for shortcut");
                                }
                            }
                        })
                        .build(),
                ) {
                    let _ = app.global_shortcut().register(search_shortcut);
                }
            }

            // Register deep links at runtime for development (Linux/Windows only).
            // macOS does not support runtime registration — the scheme is registered
            // via Info.plist when the .app bundle is installed in /Applications.
            #[cfg(any(target_os = "linux", all(debug_assertions, windows)))]
            {
                match app_handle.deep_link().register_all() {
                    Ok(_) => println!("🔗 Deep link schemes registered successfully"),
                    Err(e) => eprintln!("🔗 Failed to register deep link schemes: {}", e),
                }
            }

            // Log deep link URLs if the app was launched via a deep link
            if let Ok(urls) = app_handle.deep_link().get_current() {
                println!("🔗 Current deep link URLs on launch: {:?}", urls);
            }

            // Handle deep link events
            app_handle.deep_link().on_open_url(move |event| {
                let url_strings: Vec<String> =
                    event.urls().iter().map(|url| url.to_string()).collect();
                println!("🔗 Deep link received: {:?}", url_strings);
                handle_deep_link_event(&app_handle_for_deep_links, url_strings);
            });

            let win_builder = WebviewWindowBuilder::new(
                app,
                "main",
                WebviewUrl::External(tauri::Url::parse(&app_url).unwrap()),
            )
            .title("Midday")
            .inner_size(1450.0, 910.0)
            .min_inner_size(1450.0, 910.0)
            .user_agent("Mozilla/5.0 (compatible; Midday Desktop App)")
            .decorations(false)
            .visible(false)
            .transparent(true)
            .shadow(true)
            .hidden_title(true)
            .title_bar_style(TitleBarStyle::Overlay)
            .disable_drag_drop_handler()
            .on_download(|_window, _event| {
                println!("Download triggered!");
                // Allow all downloads - they will go to default Downloads folder
                true
            })
            .on_navigation(move |url| {
                let url_str = url.as_str();

                // Check if this is an external URL
                if is_external_url(url_str, &app_url_clone) {
                    // Clone the URL string to avoid lifetime issues
                    let url_string = url_str.to_string();
                    let app_handle_clone = app_handle_for_navigation.clone();

                    // Open in system browser using the opener plugin
                    tauri::async_runtime::spawn(async move {
                        let _ = tauri_plugin_opener::OpenerExt::opener(&app_handle_clone)
                                .open_url(url_string, None::<String>);
                    });

                    // Prevent navigation in webview
                    return false;
                }

                // Allow internal navigation
                true
            });

            let window = win_builder.build().unwrap();

            // Listen for search window state events from the frontend
            let search_state_for_events = search_state.clone();
            let app_handle_for_events = app_handle.clone();
            window.listen("search-window-enabled", move |event| {
                if let Ok(enabled) = serde_json::from_str::<bool>(&event.payload()) {
                    println!("🔍 Event received: search-window-enabled = {}", enabled);
                    *search_state_for_events.lock().unwrap() = enabled;
                    println!("🔍 Search window state updated to {}", enabled);
                    
                    // If search is disabled, clean up search window to prevent interference
                    if !enabled {
                        println!("🔍 Search disabled, cleaning up search window");
                        if let Some(search_window) = app_handle_for_events.get_webview_window("search") {
                            let _ = search_window.close();
                            println!("🔍 Search window closed and cleaned up");
                        }
                    }
                }
            });

            // Listen for search window close requests from the frontend
            let app_handle_for_close = app_handle.clone();
            window.listen("search-window-close-requested", move |_event| {
                println!("🔍 Event received: search-window-close-requested");
                if let Some(search_window) = app_handle_for_close.get_webview_window("search") {
                    let _ = search_window.emit("search-window-open", false);
                    let _ = search_window.set_always_on_top(false);
                    let _ = search_window.hide();
                    println!("🔍 Search window closed via close request");
                }
            });

            // Fallback timer to ensure main window shows on first launch
            let window_clone = window.clone();
            tauri::async_runtime::spawn(async move {
                std::thread::sleep(std::time::Duration::from_secs(2));

                // Check if window is still hidden after 2 seconds
                if let Ok(is_visible) = window_clone.is_visible() {
                    if !is_visible {
                        let _ = window_clone.show();
                        let _ = window_clone.set_focus();
                    }
                }
            });

            // Don't preload search window immediately - create it on first use instead
            // This prevents interference with the login flow

            // Set the default app menu to restore the Midday menu
            let app_menu = Menu::default(app.handle())?;
            app.set_menu(app_menu)?;

            // Setup simple system tray for search toggle only
            // Load custom tray icon
            let tray_icon = {
                let icon_bytes = include_bytes!("../icons/tray-icon.png");
                let img = image::load_from_memory(icon_bytes).map_err(|e| format!("Failed to load tray icon: {}", e))?;
                let rgba = img.to_rgba8();
                let (width, height) = rgba.dimensions();
                Image::new_owned(rgba.into_raw(), width, height)
            };

            // Create tray menu
            let check_updates_item = MenuItem::with_id(app, "check_updates", "Check for Updates...", true, None::<&str>)?;
            let tray_menu = Menu::with_items(app, &[&check_updates_item])?;

            let _tray = TrayIconBuilder::new()
                .icon(tray_icon)
                .menu(&tray_menu)
                .show_menu_on_left_click(false)
                .on_menu_event(|app, event| {
                    println!("🔧 Tray menu event triggered: {:?}", event.id);
                    if event.id == "check_updates" {
                        println!("🔧 Calling check_for_updates...");
                        let app_handle = app.clone();
                        tauri::async_runtime::spawn(async move {
                            let _ = check_for_updates(app_handle).await;
                        });
                    }
                })
                .on_tray_icon_event(move |tray, event| {
                    match event {
                        // Handle left clicks to toggle search window (keep existing behavior)
                        TrayIconEvent::Click {
                            button: MouseButton::Left,
                            button_state: MouseButtonState::Up,
                            ..
                        } => {
                            let app_handle = tray.app_handle();
                            if let Some(managed_search_state) = app_handle.try_state::<SearchWindowState>() {
                                let _ = toggle_search_window(app_handle, &managed_search_state);
                            }
                        },
                        _ => {}
                    }
                })
                .build(app)?;

            Ok(())
        })
        .build(tauri::generate_context!())
        .expect("error while building tauri app")
        .run(|app_handle, event| match event {
            tauri::RunEvent::Reopen { .. } => {
                if let Some(main_window) = app_handle.get_webview_window("main") {
                    let _ = main_window.show();
                    let _ = main_window.set_focus();
                }
            }
            tauri::RunEvent::ExitRequested { api, .. } => {
                // Prevent app from quitting to keep global shortcuts working
                api.prevent_exit();
                
                // Hide all windows instead of quitting
                if let Some(main_window) = app_handle.get_webview_window("main") {
                    let _ = main_window.hide();
                }
                if let Some(search_window) = app_handle.get_webview_window("search") {
                    let _ = search_window.hide();
                }
            }
            _ => {}
        });
}