Inceptum/wrapper/src/main/java/io/gitlab/jfronny/inceptum/util/api/GitlabApi.java

package io.gitlab.jfronny.inceptum.util.api;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.reflect.TypeToken;
import io.gitlab.jfronny.inceptum.gson.ComparableVersionAdapter;
import io.gitlab.jfronny.inceptum.model.ComparableVersion;
import io.gitlab.jfronny.inceptum.model.gitlab.*;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.lang.reflect.Modifier;
import java.lang.reflect.Type;
import java.net.URL;
import java.util.List;
import java.util.function.Predicate;

public class GitlabApi {
    private static final Gson GSON = new GsonBuilder()
            .registerTypeAdapter(ComparableVersion.class, new ComparableVersionAdapter())
            .excludeFieldsWithModifiers(Modifier.TRANSIENT)
            .excludeFieldsWithModifiers(Modifier.PRIVATE)
            .setPrettyPrinting()
            .create();
    private static final Type packageInfoListType = new TypeToken<List<GitlabPackage>>() {}.getType();
    private static final Type jobListType = new TypeToken<List<GitlabJob>>() {}.getType();
    private static final Type packageFileInfoListType = new TypeToken<List<GitlabPackageFile>>() {}.getType();

    public static GitlabProject getProject(Long projectId) throws IOException {
        return downloadObject("projects/" + projectId, GitlabProject.class);
    }

    public static List<GitlabPackage> getPackages(GitlabProject project) throws IOException {
        List<GitlabPackage> list = downloadObject("projects/" + project.id + "/packages", packageInfoListType);
        list.sort((left, right) -> right.created_at.compareTo(left.created_at));
        return list;
    }

    public static List<GitlabJob> getJobs(GitlabProject project, Long pipelineId) throws IOException {
        return downloadObject("projects/" + project.id + "/pipelines/" + pipelineId + "/jobs", jobListType);
    }

    public static GitlabPackageFile getFile(GitlabProject project, GitlabPackage packageInfo, Predicate<GitlabPackageFile> isValid) throws IOException {
        int page = 0;
        while (true) {
            List<GitlabPackageFile> files = downloadObject("projects/" + project.id + "/packages/" + packageInfo.id + "/package_files?per_page=100&page=" + ++page, packageFileInfoListType);
            if (files.isEmpty()) return null;
            for (GitlabPackageFile file : files) {
                if (isValid.test(file))
                    return file;
            }
        }
    }

    public static <T> T downloadObject(String source, Type type) throws IOException {
        try (InputStream is = new URL("https://gitlab.com/api/v4/" + source).openStream(); InputStreamReader isr = new InputStreamReader(is)) {
            return GSON.fromJson(isr, type);
        }
    }
}