/*
 *
 * PlaceholderAPI
 * Copyright (C) 2019 Ryan McCarthy
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 *
 *
 */
package me.clip.placeholderapi.expansion;

import com.google.common.base.Strings;
import me.clip.placeholderapi.PlaceholderAPI;
import me.clip.placeholderapi.PlaceholderAPIPlugin;
import me.clip.placeholderapi.PlaceholderHook;
import me.clip.placeholderapi.expansion.cloud.CloudExpansion;
import me.clip.placeholderapi.util.FileUtil;
import org.bukkit.Bukkit;
import org.bukkit.configuration.file.FileConfiguration;
import org.bukkit.event.Listener;

import java.io.File;
import java.lang.reflect.Constructor;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

public final class ExpansionManager {
    private final PlaceholderAPIPlugin plugin;

    public ExpansionManager(PlaceholderAPIPlugin instance) {
        plugin = instance;

        File f = new File(plugin.getDataFolder(), "expansions");
        if (!f.exists()) f.mkdirs();
    }

    public PlaceholderExpansion getRegisteredExpansion(String name) {
        for (Entry<String, PlaceholderHook> hook : PlaceholderAPI.getPlaceholders().entrySet()) {
            if (hook.getValue().isExpansion()) {
                if (name.equalsIgnoreCase(hook.getKey())) {
                    return (PlaceholderExpansion) hook.getValue();
                }
            }
        }

        return null;
    }

    public boolean registerExpansion(PlaceholderExpansion expansion) {
        if (expansion == null || expansion.getIdentifier() == null) return false;

        if (expansion instanceof Configurable) {
            Map<String, Object> defaults = ((Configurable) expansion).getDefaults();
            String pre = expansion.getPathStarter();
            FileConfiguration cfg = plugin.getConfig();
            boolean save = false;

            if (defaults != null) {
                for (Entry<String, Object> entry : defaults.entrySet()) {
                    String key = entry.getKey();
                    if (Strings.isNullOrEmpty(key)) continue;

                    if (entry.getValue() == null) {
                        if (cfg.contains(pre + key)) {
                            save = true;
                            cfg.set(pre + key, null);
                        }
                    } else {
                        if (!cfg.contains(pre + key)) {
                            save = true;
                            cfg.set(pre + key, entry.getValue());
                        }
                    }
                }
            }

            if (save) {
                plugin.saveConfig();
                plugin.reloadConfig();
            }
        }

        if (expansion instanceof VersionSpecific) {
            VersionSpecific nms = (VersionSpecific) expansion;
            if (!nms.isCompatibleWith(PlaceholderAPIPlugin.getServerVersion())) {
                plugin.getLogger()
                        .info(
                                "Your server version is not compatible with expansion: " + expansion.getIdentifier()
                                        + " version: " + expansion.getVersion());
                return false;
            }
        }

        if (!expansion.canRegister()) return false;
        if (!expansion.register()) return false;

        if (expansion instanceof Listener) {
            Bukkit.getPluginManager().registerEvents((Listener) expansion, plugin);
        }

        plugin.getLogger().info("Successfully registered expansion: " + expansion.getIdentifier());

        if (expansion instanceof Taskable) {
            ((Taskable) expansion).start();
        }

        if (plugin.getExpansionCloud() != null) {
            CloudExpansion ce = plugin.getExpansionCloud().getCloudExpansion(expansion.getIdentifier());

            if (ce != null) {
                ce.setHasExpansion(true);
                if (!ce.getLatestVersion().equals(expansion.getVersion())) {
                    ce.setShouldUpdate(true);
                }
            }
        }

        return true;
    }


    public PlaceholderExpansion registerExpansion(String fileName) {
        List<Class<?>> subs = FileUtil.getClasses("expansions", fileName, PlaceholderExpansion.class);
        if (subs == null || subs.isEmpty()) return null;

        // Only register the first instance found as an expansion JAR should only have 1 class
        // extending PlaceholderExpansion
        PlaceholderExpansion ex = createInstance(subs.get(0));
        if (registerExpansion(ex)) return ex;
        return null;
    }

    public void registerAllExpansions() {
        List<Class<?>> subs = FileUtil.getClasses("expansions", null, PlaceholderExpansion.class);
        if (subs == null || subs.isEmpty()) return;

        for (Class<?> klass : subs) {
            PlaceholderExpansion ex = createInstance(klass);
            if (ex != null) {
                try {
                    registerExpansion(ex);
                } catch (Exception e) {
                    plugin.getLogger().info("Couldn't register " + ex.getIdentifier() + " expansion");
                    e.printStackTrace();
                }
            }
        }
    }

    private PlaceholderExpansion createInstance(Class<?> clazz) {
        if (clazz == null) return null;
        if (!PlaceholderExpansion.class.isAssignableFrom(clazz)) return null;

        PlaceholderExpansion expansion = null;
        try {
            Constructor<?>[] constructors = clazz.getConstructors();
            if (constructors.length == 0) {
                expansion = (PlaceholderExpansion) clazz.newInstance();
            } else {
                for (Constructor<?> ctor : constructors) {
                    if (ctor.getParameterTypes().length == 0) {
                        expansion = (PlaceholderExpansion) ctor.newInstance();
                        break;
                    }
                }
            }
        } catch (Throwable t) {
            plugin.getLogger()
                    .severe("Failed to init placeholder expansion from class: " + clazz.getName());
            plugin.getLogger().severe(t.getMessage());
        }

        return expansion;
    }
}