package org.openautonomousconnection.webclient.ui;

import javafx.application.Platform;
import javafx.concurrent.Worker;
import javafx.embed.swing.JFXPanel;
import javafx.scene.Scene;
import javafx.scene.control.ContextMenu;
import javafx.scene.control.MenuItem;
import javafx.scene.input.Clipboard;
import javafx.scene.input.ClipboardContent;
import javafx.scene.input.ContextMenuEvent;
import javafx.scene.web.WebEngine;
import javafx.scene.web.WebHistory;
import javafx.scene.web.WebView;
import org.openautonomousconnection.luascript.security.LuaExecutionPolicy;
import org.openautonomousconnection.oacswing.component.OACPanel;
import org.openautonomousconnection.webclient.ClientImpl;
import org.openautonomousconnection.webclient.lua.WebLogger;
import org.openautonomousconnection.webclient.settings.FxEngine;
import org.w3c.dom.Document;

import javax.swing.*;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import java.awt.*;
import java.io.StringWriter;
import java.util.Objects;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.function.Consumer;

/**
 * Logical browser tab: stable UI key + embedded JavaFX WebView.
 *
 * <p>This class merges the previous {@code BrowserTab} + {@code TabView} into one component.</p>
 */
public final class BrowserTab extends OACPanel {

    private final String key;

    private final AtomicBoolean initialized = new AtomicBoolean(false);
    private final Consumer<String> onLocationChanged;
    private final WebLogger webLogger;
    private final ClientImpl protocolClient;

    private final boolean luaEnabled;
    private final LuaExecutionPolicy luaPolicy;

    private volatile Runnable openInNewTab;

    private JFXPanel fxPanel;
    private WebView webView;
    private WebEngine engine;
    private volatile FxEngine luaEngine;

    /**
     * Creates a browser tab.
     *
     * @param key              stable UI key (must match CardLayout key and titlebar tab title)
     * @param initialUrl       initial URL (used for logger context)
     * @param onLocationChange callback invoked on URL changes
     * @param luaEnabled       whether Lua is enabled for this tab
     * @param luaPolicy        execution policy for Lua
     */
    public BrowserTab(String key, String initialUrl, Consumer<String> onLocationChange, boolean luaEnabled, LuaExecutionPolicy luaPolicy, ClientImpl protocolClient) {
        super();
        this.key = Objects.requireNonNull(key, "key");
        this.onLocationChanged = Objects.requireNonNull(onLocationChange, "onLocationChange");
        this.protocolClient = Objects.requireNonNull(protocolClient, "protocolClient");
        this.webLogger = new WebLogger(Objects.requireNonNull(initialUrl, "initialUrl"), protocolClient);
        this.luaEnabled = luaEnabled;
        this.luaPolicy = Objects.requireNonNull(luaPolicy, "luaPolicy");
        setLayout(new BorderLayout());
    }

    private static String serializeDom(Document doc) throws Exception {
        TransformerFactory tf = TransformerFactory.newInstance();
        Transformer t = tf.newTransformer();
        t.setOutputProperty(OutputKeys.METHOD, "html");
        t.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
        t.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
        t.setOutputProperty(OutputKeys.INDENT, "yes");

        StringWriter sw = new StringWriter(64 * 1024);
        t.transform(new DOMSource(doc), new StreamResult(sw));
        return sw.toString();
    }

    /**
     * Returns the stable tab key.
     *
     * @return key
     */
    public String getKey() {
        return key;
    }

    public ClientImpl getProtocolClient() {
        return protocolClient;
    }

    /**
     * Sets callback for opening current page in a new tab.
     *
     * @param callback callback
     */
    public void setOpenInNewTabCallback(Runnable callback) {
        this.openInNewTab = callback;
    }

    @Override
    public void addNotify() {
        super.addNotify();

        if (!initialized.compareAndSet(false, true)) {
            return;
        }

        fxPanel = new JFXPanel();
        add(fxPanel, BorderLayout.CENTER);

        Platform.runLater(() -> {
            webView = new WebView();
            webView.setContextMenuEnabled(false);

            engine = webView.getEngine();
            engine.setJavaScriptEnabled(false);

            engine.locationProperty().addListener((obs, oldV, newV) -> fireLocationChanged(newV));
            engine.getLoadWorker().stateProperty().addListener((obs, oldS, newS) -> {
                if (newS == Worker.State.RUNNING || newS == Worker.State.SUCCEEDED) {
                    fireLocationChanged(engine.getLocation());
                }
            });

            installCustomContextMenu();

            if (luaEnabled) {
                luaEngine = new FxEngine(engine, webView, luaPolicy, webLogger);
                luaEngine.install();
            } else {
                luaEngine = null;
            }

            fxPanel.setScene(new Scene(webView));
        });
    }

    /**
     * Loads a URL.
     *
     * @param url URL
     */
    public void loadUrl(String url) {
        String target = Objects.requireNonNull(url, "url").trim();
        if (target.isEmpty()) return;

        Platform.runLater(() -> {
            WebEngine e = engine;
            if (e != null) e.load(target);
        });
    }

    /**
     * Reloads the current page.
     */
    public void reload() {
        String current = getEngineLocation();
        if (current == null || current.isBlank()) return;

        Platform.runLater(() -> {
            WebEngine e = engine;
            if (e != null) e.reload();
        });
    }

    /**
     * Goes back in history if possible.
     */
    public void goBack() {
        if (peekHistoryTarget(-1) == null) return;

        Platform.runLater(() -> {
            WebEngine e = engine;
            if (e == null) return;
            WebHistory h = e.getHistory();
            if (h.getCurrentIndex() > 0) h.go(-1);
        });
    }

    /**
     * Goes forward in history if possible.
     */
    public void goForward() {
        if (peekHistoryTarget(+1) == null) return;

        Platform.runLater(() -> {
            WebEngine e = engine;
            if (e == null) return;
            WebHistory h = e.getHistory();
            if (h.getCurrentIndex() < h.getEntries().size() - 1) h.go(1);
        });
    }

    /**
     * Returns current location if known.
     *
     * @return URL or null
     */
    public String getLocationUrl() {
        return getEngineLocation();
    }

    /**
     * Returns current engine location.
     *
     * @return url or null
     */
    public String getEngineLocation() {
        WebEngine e = engine;
        return e != null ? e.getLocation() : null;
    }

    /**
     * Applies HTML live to the current tab (no saving).
     *
     * @param html html text
     */
    public void applyHtml(String html) {
        String content = html == null ? "" : html;

        Platform.runLater(() -> {
            WebEngine e = engine;
            if (e != null) e.loadContent(content, "text/html");
        });
    }

    /**
     * Returns the current rendered HTML (DOM serialization).
     *
     * @return current html (never null)
     */
    public String getCurrentHtml() {
        CompletableFuture<String> fut = new CompletableFuture<>();
        Platform.runLater(() -> {
            try {
                WebEngine e = engine;
                if (e == null) {
                    fut.complete("");
                    return;
                }
                Document doc = e.getDocument();
                if (doc == null) {
                    fut.complete("");
                    return;
                }
                fut.complete(serializeDom(doc));
            } catch (Throwable t) {
                fut.completeExceptionally(t);
            }
        });

        try {
            return fut.join();
        } catch (Throwable t) {
            return "";
        }
    }

    /**
     * Releases resources.
     */
    public void dispose() {
        FxEngine le = luaEngine;
        luaEngine = null;
        if (le != null) {
            try {
                le.close();
            } catch (Exception ignored) {
                // Intentionally ignored
            }
        }

        Platform.runLater(() -> {
            WebEngine e = engine;
            if (e != null) {
                try {
                    e.load(null);
                } catch (Exception ignored) {
                    // Intentionally ignored
                }
            }
            engine = null;
            webView = null;
            if (fxPanel != null) {
                fxPanel.setScene(null);
            }
        });

        disconnectProtocolQuietly();
    }

    private void fireLocationChanged(String location) {
        if (location == null) return;
        String s = location.trim();
        if (s.isEmpty()) return;

        try {
            onLocationChanged.accept(s);
        } catch (Exception ignored) {
            // Must not break FX thread
        }
    }

    private void installCustomContextMenu() {
        final ContextMenu menu = new ContextMenu();

        MenuItem back = new MenuItem("Back");
        back.setOnAction(e -> SwingUtilities.invokeLater(this::goBack));

        MenuItem forward = new MenuItem("Forward");
        forward.setOnAction(e -> SwingUtilities.invokeLater(this::goForward));

        MenuItem reload = new MenuItem("Reload");
        reload.setOnAction(e -> SwingUtilities.invokeLater(this::reload));

        MenuItem copyLink = new MenuItem("Copy Link");
        copyLink.setOnAction(e -> {
            WebEngine e2 = engine;
            String loc = e2 != null ? e2.getLocation() : null;
            if (loc == null) return;
            ClipboardContent cc = new ClipboardContent();
            cc.putString(loc);
            Clipboard.getSystemClipboard().setContent(cc);
        });

        MenuItem openNewTab = new MenuItem("Open in New Tab");
        openNewTab.setOnAction(e -> {
            Runnable r = this.openInNewTab;
            if (r != null) SwingUtilities.invokeLater(r);
        });

        menu.getItems().addAll(back, forward, reload, copyLink, openNewTab);

        webView.addEventHandler(ContextMenuEvent.CONTEXT_MENU_REQUESTED, ev -> {
            menu.hide();
            menu.show(webView, ev.getScreenX(), ev.getScreenY());
            ev.consume();
        });
    }

    private String peekHistoryTarget(int delta) {
        WebEngine e = engine;
        if (e == null) return null;
        WebHistory h = e.getHistory();
        int idx = h.getCurrentIndex() + delta;
        if (idx < 0 || idx >= h.getEntries().size()) return null;
        return h.getEntries().get(idx).getUrl();
    }

    private void disconnectProtocolQuietly() {
        try {
            if (protocolClient.getClientServerConnection() != null) {
                protocolClient.getClientServerConnection().disconnect();
            }
        } catch (Exception ignored) {
            // Best-effort shutdown.
        }
        try {
            if (protocolClient.getClientINSConnection() != null) {
                protocolClient.getClientINSConnection().disconnect();
            }
        } catch (Exception ignored) {
            // Best-effort shutdown.
        }
    }
}