package tech.techyjessy.Configuration;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileWriter;
import java.io.IOException;

import org.apache.commons.io.FileUtils;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonIOException;
import com.google.gson.JsonSyntaxException;

public class ConfigMgr {
    private static ConfigMgr static_inst;
    private File config;

    public static ConfigMgr getInstance() {
        if (static_inst == null) {
            static_inst = new ConfigMgr();
        }

        return static_inst;
    }

    public void SetConfDir(File file) {
        config = new File(file, "keeblarcraft.json");
        if (!config.exists()) {
            config.getParentFile().mkdirs();
        }
    }

    public <T> T GetJsonObjectFromFile(Class<T> classToConvertTo) {
        Gson gson = new Gson();
        String ret = "";

        // hot fix: Not sure how to return "false" for invalid conversion when I'm forced to convert or just catch... Look into a better
        // return value in the future - but for now throw JsonSyntaxException no matter what exception is caught
        try {
            ret = FileUtils.readFileToString(config, "UTF-8");
        } catch (Exception e) {
            System.out.println("Getting json object from file had errors. This is unsupported in this version of Keeblarcraft");
            e.printStackTrace();
        }

        return gson.fromJson(ret, classToConvertTo);
    }

    // WriteToJsonFile
    //
    // Will write to or append to a json file. It will search if the key exists first & update the field;
    // or add a new entry. It should be noted that json objects *can* be buried inside each other. It is
    // considered best (and only) practice to call the "GetJsonStringFromFile" function first from this
    // class and simply iterate to what you would need and then update the entire entry alongside the
    // top-level key.
    //
    // NOTE: THIS DOES NOT SAFE UPDATE THE KEY OBJECT. PRE-EXISTING DATA WILL BE DELETED FOREVER
    public void WriteToJsonFile(Object data) {
        Gson gson = new GsonBuilder().setPrettyPrinting().create();
        try {
            FileWriter writer = new FileWriter(config);
            gson.toJson(data, writer);
            writer.flush();
            writer.close();
        } catch (JsonIOException | IOException e) {
            System.out.println("Writing to json had errors. This is unhandled in this version of Keeblarcraft");
        }
    }
}