/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

package org.mozilla.javascript.tools.debugger;

import java.io.File;
import java.io.InputStream;
import java.io.PrintStream;
import java.net.URI;
import java.util.List;
import javax.swing.JFrame;
import org.mozilla.javascript.Context;
import org.mozilla.javascript.ContextFactory;
import org.mozilla.javascript.Kit;
import org.mozilla.javascript.Scriptable;
import org.mozilla.javascript.commonjs.module.ModuleScope;
import org.mozilla.javascript.tools.shell.Global;

/**
 * Rhino script debugger main class. This class links together a debugger object ({@link Dim}) and a
 * debugger GUI object ({@link SwingGui}).
 */
public class Main {

    /** The debugger. */
    private Dim dim;

    /** The debugger frame. */
    private SwingGui debugGui;

    /** Creates a new Main. */
    public Main(String title) {
        dim = new Dim();
        debugGui = new SwingGui(dim, title);
    }

    /** Returns the debugger window {@link JFrame}. */
    public JFrame getDebugFrame() {
        return debugGui;
    }

    /** Breaks execution of the script. */
    public void doBreak() {
        dim.setBreak();
    }

    /** Sets whether execution should break when a script exception is thrown. */
    public void setBreakOnExceptions(boolean value) {
        dim.setBreakOnExceptions(value);
        debugGui.getMenubar().getBreakOnExceptions().setSelected(value);
    }

    /** Sets whether execution should break when a function is entered. */
    public void setBreakOnEnter(boolean value) {
        dim.setBreakOnEnter(value);
        debugGui.getMenubar().getBreakOnEnter().setSelected(value);
    }

    /** Sets whether execution should break when a function is left. */
    public void setBreakOnReturn(boolean value) {
        dim.setBreakOnReturn(value);
        debugGui.getMenubar().getBreakOnReturn().setSelected(value);
    }

    /** Removes all breakpoints. */
    public void clearAllBreakpoints() {
        dim.clearAllBreakpoints();
    }

    /** Resumes execution of the script. */
    public void go() {
        dim.go();
    }

    /** Sets the scope to be used for script evaluation. */
    public void setScope(Scriptable scope) {
        setScopeProvider(IProxy.newScopeProvider(scope));
    }

    /** Sets the {@link ScopeProvider} that provides a scope to be used for script evaluation. */
    public void setScopeProvider(ScopeProvider p) {
        dim.setScopeProvider(p);
    }

    /**
     * Sets the {@link SourceProvider} that provides the source to be displayed for script
     * evaluation.
     */
    public void setSourceProvider(final SourceProvider sourceProvider) {
        dim.setSourceProvider(sourceProvider);
    }

    /**
     * Assign a Runnable object that will be invoked when the user selects "Exit..." or closes the
     * Debugger main window.
     */
    public void setExitAction(Runnable r) {
        debugGui.setExitAction(r);
    }

    /** Returns an {@link InputStream} for stdin from the debugger's internal Console window. */
    public InputStream getIn() {
        return debugGui.getConsole().getIn();
    }

    /** Returns a {@link PrintStream} for stdout to the debugger's internal Console window. */
    public PrintStream getOut() {
        return debugGui.getConsole().getOut();
    }

    /** Returns a {@link PrintStream} for stderr in the Debugger's internal Console window. */
    public PrintStream getErr() {
        return debugGui.getConsole().getErr();
    }

    /** Packs the debugger GUI frame. */
    public void pack() {
        debugGui.pack();
    }

    /** Sets the debugger GUI frame dimensions. */
    public void setSize(int w, int h) {
        debugGui.setSize(w, h);
    }

    /** Sets the visibility of the debugger GUI frame. */
    public void setVisible(boolean flag) {
        debugGui.setVisible(flag);
    }

    /** Returns whether the debugger GUI frame is visible. */
    public boolean isVisible() {
        return debugGui.isVisible();
    }

    /** Frees any resources held by the debugger. */
    public void dispose() {
        clearAllBreakpoints();
        dim.go();
        debugGui.dispose();
        dim = null;
    }

    /** Attaches the debugger to the given {@link ContextFactory}. */
    public void attachTo(ContextFactory factory) {
        dim.attachTo(factory);
    }

    /** Detaches from the current {@link ContextFactory}. */
    public void detach() {
        dim.detach();
    }

    /**
     * Main entry point. Creates a debugger attached to a Rhino {@link
     * org.mozilla.javascript.tools.shell.Main} shell session.
     */
    public static void main(String[] args) {
        Main main = new Main("Rhino JavaScript Debugger");
        main.doBreak();
        main.setExitAction(new IProxy(IProxy.EXIT_ACTION));

        System.setIn(main.getIn());
        System.setOut(main.getOut());
        System.setErr(main.getErr());

        main.attachTo(org.mozilla.javascript.tools.shell.Main.shellContextFactory);
        try (Context cx = Context.enter()) {
            cx.setLanguageVersion(Context.VERSION_ES6);

            Global global = org.mozilla.javascript.tools.shell.Main.getGlobal();
            global.init(cx);
            global.setIn(main.getIn());
            global.setOut(main.getOut());
            global.setErr(main.getErr());

            global.installRequire(cx, List.of(), false);

            URI uri = new File(System.getProperty("user.dir")).toURI();
            ModuleScope scope = new ModuleScope(global, uri, null);

            main.setScope(scope);

            main.pack();
            main.setSize(600, 460);
            main.setVisible(true);

            org.mozilla.javascript.tools.shell.Main.exec(args);
        }
    }

    /**
     * Entry point for embedded applications. This method attaches to the global {@link
     * ContextFactory} with a scope of a newly created {@link Global} object. No I/O redirection is
     * performed as with {@link #main(String[])}.
     */
    public static Main mainEmbedded(String title) {
        ContextFactory factory = ContextFactory.getGlobal();
        Global global = new Global();
        global.init(factory);
        return mainEmbedded(factory, global, title);
    }

    /**
     * Entry point for embedded applications. This method attaches to the given {@link
     * ContextFactory} with the given scope. No I/O redirection is performed as with {@link
     * #main(String[])}.
     */
    public static Main mainEmbedded(ContextFactory factory, Scriptable scope, String title) {
        return mainEmbeddedImpl(factory, scope, title);
    }

    /**
     * Entry point for embedded applications. This method attaches to the given {@link
     * ContextFactory} with the given scope. No I/O redirection is performed as with {@link
     * #main(String[])}.
     */
    public static Main mainEmbedded(
            ContextFactory factory, ScopeProvider scopeProvider, String title) {
        return mainEmbeddedImpl(factory, scopeProvider, title);
    }

    /** Helper method for {@link #mainEmbedded(String)}, etc. */
    private static Main mainEmbeddedImpl(
            ContextFactory factory, Object scopeProvider, String title) {
        if (title == null) {
            title = "Rhino JavaScript Debugger (embedded usage)";
        }
        Main main = new Main(title);
        main.doBreak();
        main.setExitAction(new IProxy(IProxy.EXIT_ACTION));

        main.attachTo(factory);
        if (scopeProvider instanceof ScopeProvider) {
            main.setScopeProvider((ScopeProvider) scopeProvider);
        } else {
            Scriptable scope = (Scriptable) scopeProvider;
            if (scope instanceof Global) {
                Global global = (Global) scope;
                global.setIn(main.getIn());
                global.setOut(main.getOut());
                global.setErr(main.getErr());
            }
            main.setScope(scope);
        }

        main.pack();
        main.setSize(600, 460);
        main.setVisible(true);
        return main;
    }

    // Deprecated methods

    /**
     * @deprecated Use {@link #setSize(int, int)} instead.
     */
    @Deprecated
    public void setSize(java.awt.Dimension dimension) {
        debugGui.setSize(dimension.width, dimension.height);
    }

    /**
     * @deprecated The method does nothing and is only present for compatibility.
     */
    @Deprecated
    public void setOptimizationLevel(int level) {}

    /**
     * @deprecated The method is only present for compatibility and should not be called.
     */
    @Deprecated
    public void contextEntered(Context cx) {
        throw new IllegalStateException();
    }

    /**
     * @deprecated The method is only present for compatibility and should not be called.
     */
    @Deprecated
    public void contextExited(Context cx) {
        throw new IllegalStateException();
    }

    /**
     * @deprecated The method is only present for compatibility and should not be called.
     */
    @Deprecated
    public void contextCreated(Context cx) {
        throw new IllegalStateException();
    }

    /**
     * @deprecated The method is only present for compatibility and should not be called.
     */
    @Deprecated
    public void contextReleased(Context cx) {
        throw new IllegalStateException();
    }

    /**
     * Class to consolidate all internal implementations of interfaces to avoid class generation
     * bloat.
     */
    private static class IProxy implements Runnable, ScopeProvider {

        // Constants for 'type'.
        public static final int EXIT_ACTION = 1;
        public static final int SCOPE_PROVIDER = 2;

        /** The type of interface. */
        private final int type;

        /** The scope object to expose when {@link #type} = {@link #SCOPE_PROVIDER}. */
        private Scriptable scope;

        /** Creates a new IProxy. */
        public IProxy(int type) {
            this.type = type;
        }

        /** Creates a new IProxy that acts as a {@link ScopeProvider}. */
        public static ScopeProvider newScopeProvider(Scriptable scope) {
            IProxy scopeProvider = new IProxy(SCOPE_PROVIDER);
            scopeProvider.scope = scope;
            return scopeProvider;
        }

        // ContextAction

        /** Exit action. */
        @Override
        public void run() {
            if (type != EXIT_ACTION) Kit.codeBug();
            System.exit(0);
        }

        // ScopeProvider

        /** Returns the scope for script evaluations. */
        @Override
        public Scriptable getScope() {
            if (type != SCOPE_PROVIDER) Kit.codeBug();
            if (scope == null) Kit.codeBug();
            return scope;
        }
    }
}
