package io.gitlab.jfronny.resclone.fetchers;

import io.gitlab.jfronny.commons.HttpUtils;
import io.gitlab.jfronny.resclone.Resclone;
import io.gitlab.jfronny.resclone.data.curseforge.GetModFilesResponse;
import io.gitlab.jfronny.resclone.data.curseforge.GetModResponse;
import net.minecraft.MinecraftVersion;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.URISyntaxException;
import java.util.Date;
import java.util.Random;

public class CurseforgeFetcher extends BasePackFetcher {
    // So you found the API key.
    // Please be aware that CurseForge requires you to change this if you make any kind of derivative work
    // Creating your own API key is relatively simple, so please don't abuse this
    private static final String API_KEY = new String(unsalt(new byte[] {
            -30, 50, -60, -121, 62, -31, 35, 17, 16, -53,
            -53, -88, 21, -21, 15, -105, -115, -108, 114, -50,
            -49, -4, 56, -65, -70, 108, -65, -3, -55, -4,
            36, -86, -40, 116, 71, -5, 75, -9, -43, 4,
            91, -91, -29, 40, 66, 87, -80, -74, 71, 41,
            76, -96, 108, -61, -113, 118, 7, -39, -116, -120
    }, 1024));

    @Override
    public String getSourceTypeName() {
        return "curseforge";
    }

    @Override
    public String getDownloadUrl(String baseUrl) throws Exception {
        try {
            GetModResponse response = GET(baseUrl, GetModResponse.class);
            if (!response.data.allowModDistribution)
                throw new Exception("The author of " + baseUrl + " disabled access to this pack outside of the curseforge launcher");

            String version = MinecraftVersion.CURRENT.getName();

            GetModFilesResponse.Data latest = null;
            Date latestDate = null;
            boolean foundMatchingVersion = false;

            for (GetModFilesResponse.Data addon : GET(baseUrl + "/files", GetModFilesResponse.class).data) {
                if (foundMatchingVersion && !addon.gameVersions.contains(version)) continue;
                if (!foundMatchingVersion && addon.gameVersions.contains(version)) {
                    foundMatchingVersion = true;
                    latest = null;
                }
                if (latest == null || addon.fileDate.after(latestDate)) {
                    latest = addon;
                    latestDate = addon.fileDate;
                }
            }

            if (latest == null) throw new FileNotFoundException("Could not identify valid version");
            if (!foundMatchingVersion) Resclone.LOGGER.error("Could not find matching version of " + baseUrl + ", using latest");
            return latest.downloadUrl;
        } catch (Throwable e) {
            throw new IOException("Could not get CurseForge download for " + baseUrl, e);
        }
    }

    private static <T> T GET(String suffix, Class<T> klazz) throws URISyntaxException, IOException {
        return HttpUtils.get("https://api.curseforge.com/v1/mods/" + suffix).header("x-api-key", API_KEY).sendSerialized(klazz);
    }

    private static byte[] unsalt(byte[] data, int salt) {
        byte[] result = new byte[data.length];
        new Random(salt).nextBytes(result);
        for (int i = 0; i < data.length; i++) {
            result[i] ^= data[i];
        }
        return result;
    }
}