/*
 * WorldEdit, a Minecraft world manipulation toolkit
 * Copyright (C) sk89q <http://www.sk89q.com>
 * Copyright (C) WorldEdit team and contributors
 *
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

package com.sk89q.worldedit.command;

import com.boydti.fawe.wrappers.LocationMaskedPlayerWrapper;
import com.sk89q.minecraft.util.commands.Command;
import com.sk89q.minecraft.util.commands.CommandContext;
import com.sk89q.minecraft.util.commands.CommandPermissions;
import com.sk89q.minecraft.util.commands.Logging;
import com.sk89q.worldedit.LocalSession;
import com.sk89q.worldedit.WorldEdit;
import com.sk89q.worldedit.WorldEditException;
import com.sk89q.worldedit.entity.Player;
import com.sk89q.worldedit.extension.platform.Actor;
import com.sk89q.worldedit.extension.platform.CommandManager;
import com.sk89q.worldedit.scripting.CraftScriptEngine;
import com.sk89q.worldedit.scripting.RhinoCraftScriptEngine;
import com.sk89q.worldedit.session.request.Request;
import org.mozilla.javascript.NativeJavaObject;

import javax.annotation.Nullable;
import javax.script.ScriptException;
import java.io.*;
import java.util.HashMap;
import java.util.Map;
import java.util.function.Function;

import static com.google.common.base.Preconditions.checkNotNull;
import static com.sk89q.minecraft.util.commands.Logging.LogMode.ALL;

/**
 * Commands related to scripting.
 */
@Command(aliases = {}, desc = "Run craftscripts: [More Info](https://goo.gl/dHDxLG)")
public class ScriptingCommands {

    private final WorldEdit worldEdit;

    /**
     * Create a new instance.
     *
     * @param worldEdit reference to WorldEdit
     */
    public ScriptingCommands(final WorldEdit worldEdit) {
        checkNotNull(worldEdit);
        this.worldEdit = worldEdit;
    }

    @Command(
            aliases = {"setupdispatcher"},
            desc = "",
            usage = "",
            min = 1,
            max = 1
    )
    public void setupdispatcher(Player player, LocalSession session, final CommandContext args) throws WorldEditException {
        CommandManager.getInstance().setupDispatcher();
    }

    public static <T> T runScript(Player player, File f, String[] args) throws WorldEditException {
        return runScript(player, f, args, null);
    }

    public static <T> T runScript(Actor actor, File f, String[] args, @Nullable Function<String, String> processor) throws WorldEditException {
        Request.reset();

        String filename = f.getPath();
        int index = filename.lastIndexOf(".");
        String ext = filename.substring(index + 1, filename.length());

        if (!ext.equalsIgnoreCase("js")) {
            actor.printError("Only .js scripts are currently supported");
            return null;
        }

        String script;

        try {
            InputStream file;

            if (!f.exists()) {
                file = WorldEdit.class.getResourceAsStream("craftscripts/" + filename);

                if (file == null) {
                    actor.printError("Script does not exist: " + filename);
                    return null;
                }
            } else {
                file = new FileInputStream(f);
            }

            DataInputStream in = new DataInputStream(file);
            byte[] data = new byte[in.available()];
            in.readFully(data);
            in.close();
            script = new String(data, 0, data.length, "utf-8");
        } catch (IOException e) {
            actor.printError("Script read error: " + e.getMessage());
            return null;
        }

        if (processor != null) {
            script = processor.apply(script);
        }

        WorldEdit worldEdit = WorldEdit.getInstance();
        LocalSession session = worldEdit.getSessionManager().get(actor);

        CraftScriptEngine engine = null;

        Object result = null;
        try {

            engine = new RhinoCraftScriptEngine();
        } catch (NoClassDefFoundError e) {
            actor.printError("Failed to find an installed script engine.");
            actor.printError("Download: https://github.com/downloads/mozilla/rhino/rhino1_7R4.zip");
            actor.printError("Extract: `js.jar` to `plugins` or `mods` directory`");
            actor.printError("More info: https://github.com/boy0001/CraftScripts/");
            return null;
        }

        engine.setTimeLimit(worldEdit.getConfiguration().scriptTimeout);

        Map<String, Object> vars = new HashMap<String, Object>();
        vars.put("argv", args);
        vars.put("actor", actor);

        try {
            result = engine.evaluate(script, filename, vars);
        } catch (ScriptException e) {
            e.printStackTrace();
            actor.printError("Failed to execute:");
            actor.printRaw(e.getMessage());
        } catch (NumberFormatException e) {
            throw e;
        } catch (WorldEditException e) {
            throw e;
        } catch (Throwable e) {
            actor.printError("Failed to execute (see console):");
            actor.printRaw(e.getClass().getCanonicalName());
        }
        if (result instanceof NativeJavaObject) {
            return (T) ((NativeJavaObject) result).unwrap();
        }
        return (T) result;
    }

    @Command(aliases = {"cs"}, usage = "<filename> [args...]", desc = "Execute a CraftScript", min = 1, max = -1)
    @CommandPermissions("worldedit.scripting.execute")
    @Logging(ALL)
    public void execute(final Player player, final LocalSession session, final CommandContext args) throws WorldEditException {
        final String[] scriptArgs = args.getSlice(1);
        final String name = args.getString(0);

        if (!player.hasPermission("worldedit.scripting.execute." + name)) {
            player.printError("You don't have permission to use that script.");
            return;
        }

        session.setLastScript(name);

        final File dir = this.worldEdit.getWorkingDirectoryFile(this.worldEdit.getConfiguration().scriptsDir);
        final File f = this.worldEdit.getSafeOpenFile(player, dir, name, "js", "js");
        try {
            new RhinoCraftScriptEngine();
        } catch (NoClassDefFoundError e) {
            player.printError("Failed to find an installed script engine.");
            player.printError("Download: https://github.com/downloads/mozilla/rhino/rhino1_7R4.zip");
            player.printError("Extract: `js.jar` to `plugins` or `mods` directory`");
            player.printError("More info: https://github.com/boy0001/CraftScripts/");
            return;
        }
        this.worldEdit.runScript(LocationMaskedPlayerWrapper.unwrap(player), f, scriptArgs);
    }

    @Command(aliases = {".s"}, usage = "[args...]", desc = "Execute last CraftScript", min = 0, max = -1)
    @CommandPermissions("worldedit.scripting.execute")
    @Logging(ALL)
    public void executeLast(final Player player, final LocalSession session, final CommandContext args) throws WorldEditException {
        final String lastScript = session.getLastScript();

        if (!player.hasPermission("worldedit.scripting.execute." + lastScript)) {
            player.printError("You don't have permission to use that script.");
            return;
        }

        if (lastScript == null) {
            player.printError("Use /cs with a script name first.");
            return;
        }

        final String[] scriptArgs = args.getSlice(0);

        final File dir = this.worldEdit.getWorkingDirectoryFile(this.worldEdit.getConfiguration().scriptsDir);
        final File f = this.worldEdit.getSafeOpenFile(player, dir, lastScript, "js", "js");

        try {
            this.worldEdit.runScript(LocationMaskedPlayerWrapper.unwrap(player), f, scriptArgs);
        } catch (final WorldEditException ex) {
            player.printError("Error while executing CraftScript.");
        }
    }


}