package com.nju.edu.gitlab.service.impl;

import com.nju.edu.gitlab.service.api.ProjectService;
import com.nju.edu.gitlab.util.ApplicationProperties;
import com.nju.edu.gitlab.web.dto.*;
import org.gitlab4j.api.GitLabApi;
import org.gitlab4j.api.GitLabApiException;
import org.gitlab4j.api.models.*;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import java.io.*;
import java.util.Base64;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

@Component
public class ProjectServiceImpl implements ProjectService {
    private final GitLabApi gitlabApi;

    private final String gitlabHost;
    private final String token;

    @Autowired
    public ProjectServiceImpl(ApplicationProperties properties) {
        this.gitlabHost=properties.getHost();
        this.token= properties.getToken();
        this.gitlabApi = new GitLabApi(this.gitlabHost, this.token);
    }
    @Override
    public Integer createProject(ProjectDTO projectDTO) throws GitLabApiException {
        String projectName=projectDTO.getProjectName();
        Visibility visibility=projectDTO.getVisibility();
        Project project=new Project();
        project.setName(projectName);
        project.setVisibility(visibility);
        project=gitlabApi.getProjectApi().createProject(project);
        return project.getId();
    }

    @Override
    public Integer forkProject(UserForkDTO userForkDTO) throws GitLabApiException {
        int userId=userForkDTO.getUserId();
        int projectId=userForkDTO.getProjectId();
        Integer namespaceId=fetchNameSpaceId(gitlabApi.getUserApi().getUser(userId).getUsername());
        if (namespaceId == null)
            throw new NullPointerException();
        Project project;
        try{
            gitlabApi.setSudoAsId(userId);
            project=gitlabApi.getProjectApi().forkProject(projectId,namespaceId);
            project.setVisibility(Visibility.PRIVATE);
            project=gitlabApi.getProjectApi().updateProject(project);
        }finally {
            gitlabApi.unsudo();
        }

        return project!=null?project.getId():null;
    }

    @Override
    public Integer forkGroupProject(GroupForkDTO groupForkDTO) throws GitLabApiException {
        int groupId=groupForkDTO.getGroupId();
        int projectId=groupForkDTO.getProjectId();
        Integer namespaceId=fetchGroupNameSpaceId(gitlabApi.getGroupApi().getGroup(groupId).getName());
        if (namespaceId == null)
            throw new NullPointerException();
        Project project;
        try{
            gitlabApi.sudo("root");
            project=gitlabApi.getProjectApi().forkProject(projectId,namespaceId);
            project.setVisibility(Visibility.PRIVATE);
            project=gitlabApi.getProjectApi().updateProject(project);
        }finally {
            gitlabApi.unsudo();
        }

        return project!=null?project.getId():null;
    }

    private Integer fetchGroupNameSpaceId(String name) throws GitLabApiException {
        Namespace namespace;
        namespace = gitlabApi.getNamespaceApi().findNamespaces(name)
                .stream()
                .filter(ns -> "group".equals(ns.getKind()))
                .reduce((ns1, ns2) -> ns1.getId() > ns2.getId() ? ns1 : ns2)
                .orElse(null);
        return namespace != null ? namespace.getId() : null;
    }

    @Override
    public Set<Diff> compare(int projectId, String fromBash, String toBash) throws GitLabApiException {
        CompareResults compareResults = gitlabApi.getRepositoryApi().compare(projectId, fromBash, toBash);
        return new HashSet<>(compareResults.getDiffs());
    }

    @Override
    public boolean addWebHook(WebHookDTO webHookDTO) throws GitLabApiException {
        int projectId=webHookDTO.getProjectId();
        String url= webHookDTO.getUrl();
        boolean doPushEvents=webHookDTO.isDoPushEvents();
        boolean doIssueEvents=webHookDTO.isDoIssueEvents();
        boolean doMergeRequestsEvents=webHookDTO.isDoMergeRequestsEvents();
        gitlabApi.getProjectApi().addHook(projectId, url, doPushEvents, doIssueEvents, doMergeRequestsEvents);
        return true;
    }

    @Override
    public boolean archiveProject(int projectId) throws GitLabApiException {
        gitlabApi.getProjectApi().deleteProject(projectId);
        return true;
    }

    @Override
    public String getProjectFile(int projectId,ProjectFileDTO projectFileDTO) throws UnsupportedEncodingException, GitLabApiException {
        String branch=projectFileDTO.getBranch();
        String path=projectFileDTO.getPath();
        RepositoryFile repositoryFile = gitlabApi.getRepositoryFileApi().getFile(projectId, path,branch);
        if(repositoryFile!=null){
            return new String(Base64.getDecoder().decode(repositoryFile.getContent()), "UTF-8");
        }
        return null;
    }

    @Override
    public String getProjectRawFile(int projectId, ProjectRawFileDTO projectRawFileDTO) throws GitLabApiException, IOException {
        String commitOrBranchName = projectRawFileDTO.getCommitOrBranchName();
        String path=projectRawFileDTO.getPath();
        InputStream inputStream=gitlabApi.getRepositoryFileApi().getRawFile(projectId,commitOrBranchName,path);
        if (inputStream==null){
            return null;
        }
        ByteArrayOutputStream bos=new ByteArrayOutputStream();
        byte[] buf=new byte[inputStream.available()];
        int len=-1;
        while ((len=inputStream.read(buf))!=-1){
            bos.write(buf,0,len);
        }
        String content=bos.toString();
        inputStream.close();
        bos.close();
        return content;
    }

    @Override
    public Commit createCommit(int projectId, CommitDTO commitDTO) throws GitLabApiException {
        String branch=commitDTO.getBranch();
        String commitMsg=commitDTO.getCommitMessage();
        String username=commitDTO.getUsername();
        String email=commitDTO.getEmail();
        List<CommitAction> actions=commitDTO.getActions();
        Commit commit=gitlabApi.getCommitsApi().createCommit(projectId,branch,commitMsg,null,email,username,actions);
        return commit;
    }

    @Override
    public List<Commit> getAllCommitMessage(int projectId, String commitHash) throws GitLabApiException {
        return gitlabApi.getCommitsApi().getCommits(projectId,commitHash,null,null);
    }

    @Override
    public List<Branch> getProjectBranches(int projectId) throws GitLabApiException {
        return  gitlabApi.getRepositoryApi().getBranches(projectId);
    }


    private Integer fetchNameSpaceId(String username) throws GitLabApiException {
        Namespace namespace;
        namespace = gitlabApi.getNamespaceApi().findNamespaces(username)
                .stream()
                .filter(ns -> "user".equals(ns.getKind()))
                .reduce((ns1, ns2) -> ns1.getId() > ns2.getId() ? ns1 : ns2)
                .orElse(null);
        return namespace != null ? namespace.getId() : null;
    }
}