package parser;

import com.google.gson.Gson;
import com.google.gson.JsonArray;
import com.google.gson.JsonObject;

import java.io.File;
import java.io.IOException;
import java.lang.reflect.Field;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.util.Arrays;
import java.util.HashMap;

public class MapParser {

    public static final Charset ENCODING = Charset.forName("UTF-8");

    private MapParser() {}

    public static Map parse(File file) throws IOException {
        return parse(new String(Files.readAllBytes(file.toPath()), ENCODING));
    }

    public static Map parse(String json) {
        return parse(new Gson().fromJson(json, JsonObject.class));
    }

    public static Map parse(JsonObject root) {
        JsonObject jmap = root.getAsJsonObject("map");
        int w = jmap.get("width").getAsInt();
        int h = jmap.get("height").getAsInt();
        Map map = new Map(w, h);

        JsonArray jkeys = jmap.get("keys").getAsJsonArray();
        String keys[] = new String[jkeys.size()];
        for (int i = 0; i < jkeys.size(); i++)
            keys[i] = jkeys.get(i).getAsString();

        Field[] fields = new Field[keys.length];
        for (int i = 0; i < keys.length; i++)
            try {
                fields[i] = Cell.class.getDeclaredField("m" + toCamelCase(keys[i]));
                fields[i].setAccessible(true);
            } catch (NoSuchFieldException e) {
                e.printStackTrace();
            }

        JsonArray rows = jmap.getAsJsonArray("cells");
        for (int y = 0; y < h; y++) {
            JsonArray row = rows.get(y).getAsJsonArray();
            for (int x = 0; x < w; x++) {
                JsonArray jcell = row.get(x).getAsJsonObject().getAsJsonArray("values");
                Cell cell = new Cell(x, y);
                for (int i = 0; i < fields.length; i++)
                    if (fields[i] != null)
                        try {
                            fields[i].set(cell, jcell.get(i).getAsNumber());
                        } catch (IllegalAccessException e) {
                            e.printStackTrace();
                        }
                map.set(x, y, cell);
            }
        }

        JsonArray jobjs = root.getAsJsonArray("objects");
        for (int i = 0; i < jobjs.size(); i++) {
            JsonObject jobj = jobjs.get(i).getAsJsonObject();
            String name = jobj.get("name").getAsString();

            JsonArray jokeys = jobj.getAsJsonArray("keys");
            String[] okeys = new String[jokeys.size()];
            for (int j = 0; j < okeys.length; j++)
                okeys[j] = jokeys.get(j).getAsString();

            try {
                Class oc = Class.forName(toCamelCase(name));
                Field[] ofields = new Field[okeys.length];
                for (int j = 0; j < ofields.length; j++)
                    try {
                        ofields[j] = oc.getDeclaredField("m"+toCamelCase(okeys[j]));
                        ofields[j].setAccessible(true);
                    } catch (NoSuchFieldException e) {
                        e.printStackTrace();
                    }

                JsonArray objs = jobj.getAsJsonArray("instances");
                for (int j = 0; j < objs.size(); j++) {
                    JsonObject obj = objs.get(j).getAsJsonObject();
                    int x = obj.get("x").getAsInt();
                    int y = obj.get("y").getAsInt();
                    JsonArray vals = obj.getAsJsonArray("values");
                    try {
                        GameObject o = (GameObject) oc.newInstance();
                        o.setX(x);
                        o.setY(y);
                        for (int k = 0; k < ofields.length; k++)
                            if (ofields[k] != null)
                                try {
                                    ofields[k].set(o, vals.get(k).getAsNumber());
                                } catch (IllegalAccessException e) {
                                    e.printStackTrace();
                                }
                        map.at(x, y).addObject(o);
                    } catch (InstantiationException | IllegalAccessException e) {
                        e.printStackTrace();
                    }
                }
            } catch (ClassNotFoundException e) {
                e.printStackTrace();
            }
        }

        return map;
    }

    private static String toCamelCase(String str) {
        StringBuilder sb = new StringBuilder();
        String[] parts = str.replaceAll("[^ a-zA-Z0-9]", "").split("\\s+");
        for (String part : parts)
            sb.append(Character.toUpperCase(part.charAt(0))).append(part.substring(1).toLowerCase());
        return sb.toString();
    }

}