package io.gitlab.jfronny.translater.transformer;

import io.gitlab.jfronny.libjf.config.api.v2.ConfigHolder;
import io.gitlab.jfronny.translater.Cfg;
import io.gitlab.jfronny.translater.Translater;
import net.fabricmc.loader.api.FabricLoader;
import org.jetbrains.annotations.Nullable;

import java.io.*;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.Collection;
import java.util.Properties;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.stream.Stream;

public class CachingTransformer implements Transformer {
    private static final Path CACHE_FILE = FabricLoader.getInstance().getConfigDir().resolve(Translater.MOD_ID + ".cache");
    private final @Nullable Properties defaultCache;
    private final Properties cache = new Properties();
    private final Transformer transformer;

    @Override
    public String transform(String str) {
        if (str == null)
            return null;
        //Transform and cache if not present
        if (!cache.containsKey(str)) {
            if (defaultCache != null && defaultCache.containsKey(str)) return (String) defaultCache.get(str);
            String transformed = transformer.transform(str);
            if (transformed == null) {
                // The transformer failed
                return str;
            }
            cache.put(str, transformed);
            save();
        }
        //Return cached result
        return (String) cache.get(str);
    }

    @Override
    public void transformMultiple(Stream<? extends String> strings, ResultConsumer results) {
        AtomicBoolean bl = new AtomicBoolean(false);
        transformer.transformMultiple(strings.filter(s -> {
            String translation = (String) cache.get(s);
            if (translation != null) {
                results.accept(s, translation);
                return false;
            }
            if (defaultCache != null) {
                translation = (String) defaultCache.get(s);
                if (translation != null) {
                    results.accept(s, translation);
                    return false;
                }
            }
            return true;
        }), (str, translation) -> {
            cache.put(str, translation);
            bl.set(true);
        });
        if (bl.get()) save();
    }

    public CachingTransformer(Transformer baseTransformer) {
        transformer = baseTransformer;
        if (Cfg.forceRegenerate) {
            Cfg.forceRegenerate = false;
            ConfigHolder.getInstance().getRegistered().get(Translater.MOD_ID).write();
        } else {
            //Load cache
            if (Files.exists(CACHE_FILE) && Files.isRegularFile(CACHE_FILE)) {
                Translater.LOGGER.info("Loading cache");
                try (InputStream inS = Files.newInputStream(CACHE_FILE)) {
                    cache.load(inS);
                } catch (IOException e) {
                    Translater.LOGGER.error("Could not load translater cache", e);
                }
            }
        }
        //Save default cache if parameters are default
        if (!Cfg.breakFully && Cfg.rounds == 5 && "en".equals(Cfg.targetLanguage) && !Cfg.forceRegenerate) {
            Translater.LOGGER.info("Initializing default cache");
            ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
            Properties p = new Properties();
            try (InputStream inS = classLoader.getResourceAsStream("namecache.ini")) {
                if (inS == null) p = null;
                else p.load(inS);
            } catch (IOException e) {
                p = null;
                Translater.LOGGER.error("Could not initialize default translater cache", e);
            }
            defaultCache = p;
        } else defaultCache = null;
        save();
    }

    private void save() {
        if (cache.isEmpty()) return;
        try (OutputStream outS = Files.newOutputStream(CACHE_FILE)) {
            cache.store(outS, "---Lang---");
        } catch (IOException e) {
            Translater.LOGGER.error("Could not save translater cache");
        }
    }
}