package io.gitlab.jfronny.resclone.fetchers;

import io.gitlab.jfronny.resclone.Resclone;
import io.gitlab.jfronny.resclone.util.Result;

import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.Path;

public abstract class PackFetcher {

    abstract public String getSourceTypeName(); // The name for users to specify in the config

    abstract String getDownloadUrl(String baseUrl) throws Exception; // Return the actual download URL for the file based on the provided string

    public Result get(String baseUrl, Path targetDir, boolean forceDownload) throws Exception {
        String url;
        try {
            url = getDownloadUrl(baseUrl);
            Resclone.urlCache.set(baseUrl, url);
        } catch (Exception e) {
            if (Resclone.urlCache.containsKey(baseUrl)) {
                e.printStackTrace();
                url = Resclone.urlCache.get(baseUrl);
            } else {
                throw e;
            }
        }
        Path p = targetDir.resolve(Integer.toHexString(url.hashCode()));
        if (!forceDownload && Files.exists(p))
            return new Result(p, false);
        Resclone.LOGGER.info("Downloading pack " + url);
        try (InputStream is = new URL(url).openStream()) {
            FileOutputStream os = new FileOutputStream(p.toFile());
            byte[] dataBuffer = new byte[1024];
            int bytesRead;
            while ((bytesRead = is.read(dataBuffer, 0, 1024)) != -1) {
                os.write(dataBuffer, 0, bytesRead);
            }
            Resclone.LOGGER.info("Completed download");
        } catch (Throwable e) {
            throw new Exception("Could not download pack", e);
        }
        return new Result(p, true);
    }

}