package net.uaznia.lukanus.hudson.plugins.gitparameter;

import static java.lang.Long.parseLong;

import hudson.plugins.git.GitException;
import hudson.plugins.git.Revision;
import org.apache.commons.lang.StringUtils;
import org.eclipse.jgit.lib.ObjectId;
import org.jenkinsci.plugins.gitclient.GitClient;

import java.time.Instant;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.util.*;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class RevisionInfoFactory {

    private static final Logger LOGGER = Logger.getLogger(RevisionInfoFactory.class.getName());
    private static final Pattern AUTHOR_LINE_PATTERN = Pattern.compile("author (.* <.*@.*>) (\\d{10}) ([+-]\\d{4})");
    private static final Pattern AUTHOR_LINE_PATTERN_GENERAL_DATE = Pattern.compile("author (.* <.*@.*>) (.*)");
    private static final DateTimeFormatter DATE_FORMAT = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm");
    private static final String COMMIT_MESSAGE_PREFIX = "    ";
    private static final int MAX_COMMIT_MESSAGE_LENGTH = 150;

    private final GitClient gitClient;
    private final String branch;

    public RevisionInfoFactory(GitClient gitClient, String branch) {
        this.gitClient = gitClient;
        this.branch = branch;
    }

    public List<RevisionInfo> getRevisions() throws InterruptedException {
        List<ObjectId> objectIds;

        if (StringUtils.isEmpty(branch)) {
            objectIds = gitClient.revListAll();
        } else {
            objectIds = gitClient.revList(branch);
        }

        ArrayList<RevisionInfo> revisionInfoList = new ArrayList<>(objectIds.size());
        for (ObjectId objectId : objectIds) {
            Revision revision = new Revision(objectId);
            revisionInfoList.add(new RevisionInfo(revision.getSha1String(), prettyRevisionInfo(revision)));
        }

        return revisionInfoList;
    }

    private String prettyRevisionInfo(Revision revision) {
        String shortSha1 = revision.getSha1String().substring(0, 8);

        List<String> raw;
        try {
            raw = gitClient.showRevision(revision.getSha1());
        } catch (GitException | InterruptedException e1) {
            LOGGER.log(Level.SEVERE, Messages.GitParameterDefinition_unexpectedError(), e1);
            return shortSha1;
        }

        String commitMessage = trimMessage(getCommitMessage(raw));
        String authorLine = getAuthorLine(raw);
        Matcher matcher = AUTHOR_LINE_PATTERN.matcher(authorLine);
        if (matcher.find()) {
            String author = matcher.group(1);
            String timestamp = matcher.group(2);
            String zone = matcher.group(3);
            LocalDateTime date = LocalDateTime.ofInstant(Instant.ofEpochMilli(parseLong(timestamp) * 1000), ZoneId.of(zone));
            String stringDate = date.format(DATE_FORMAT);
            return StringUtils.join(new Object[]{shortSha1, stringDate, author, commitMessage}, " ").trim();
        }

        matcher = AUTHOR_LINE_PATTERN_GENERAL_DATE.matcher(authorLine);
        if (matcher.find()) {
            String author = matcher.group(1);
            String date = matcher.group(2);
            return StringUtils.join(new Object[]{shortSha1, date, author, commitMessage}, " ").trim();
        }

        LOGGER.log(Level.WARNING, Messages.GitParameterDefinition_notFindAuthorPattern(authorLine));
        return shortSha1;
    }

    private String getAuthorLine(List<String> rows) {
        for (String row : rows) {
            if (StringUtils.isNotEmpty(row) && row.toLowerCase().startsWith("author")) {
                return row;
            }
        }
        return "";
    }

    private String getCommitMessage(List<String> rows) {
        Set<String> commitMessages = new LinkedHashSet<>();
        for (String row : rows) {
            if (row.startsWith(COMMIT_MESSAGE_PREFIX) && row.trim().length() > 0) {
                commitMessages.add(row.trim());
            }
        }
        return StringUtils.join(commitMessages, " ");
    }

    private String trimMessage(String commitMessage) {
        if (commitMessage.length() > MAX_COMMIT_MESSAGE_LENGTH) {
            int lastSpace = commitMessage.lastIndexOf(" ", MAX_COMMIT_MESSAGE_LENGTH);
            if (lastSpace == -1) {
                lastSpace = MAX_COMMIT_MESSAGE_LENGTH;
            }
            return commitMessage.substring(0, lastSpace) + " ...";
        }
        return commitMessage;
    }
}