import { ActionConfig } from "../ActionConfig";
import { cmd } from "../CommandRunner";
import { CommitInfo } from "./CommitInfo";
import { CommitInfoSet } from "./CommitInfoSet";
import { CommitsProvider } from "./CommitsProvider";

export class DefaultCommitsProvider implements CommitsProvider {

    private changePath: string;

    constructor(config: ActionConfig) {
        this.changePath = config.changePath;
    }

    async GetCommitsAsync(startHash: string, endHash: string): Promise<CommitInfoSet> {

        const logSplitter = `@@@START_RECORD`
        const formatPlaceholders = Object.entries({
            hash: '%H',
            subject: '%s',
            body: '%b',
            author: '%an',
            authorEmail: '%ae',
            authorDate: '%aI',
            committer: '%cn',
            committerEmail: '%ce',
            committerDate: '%cI',
            tags: '%d'
        });

        const pretty = logSplitter + '%n' + formatPlaceholders
            .map(x => `@@@${x[0]}%n${x[1]}`)
            .join('%n');

        var logCommand = `git log --pretty="${pretty}" --author-date-order ${(startHash === '' ? endHash : `${startHash}..${endHash}`)}`;

        if (this.changePath !== '') {
            logCommand += ` -- ${this.changePath}`;
        }

        const log = await cmd(logCommand);

        const entries = log
            .split(logSplitter)
            .slice(1);

        const commits = entries.map(entry => {
            const fields: any = entry
                .split(`@@@`)
                .slice(1)
                .reduce((acc: any, value: string) => {
                    const firstLine = value.indexOf('\n');
                    const key = value.substring(0, firstLine);
                    acc[key] = value.substring(firstLine + 1).trim();
                    return acc;
                }, {});

            const tags = fields.tags
                .split(',')
                .map((v: string) => v.trim())
                .filter((v: string) => v.startsWith('tags: '))
                .map((v: string) => v.substring(5).trim());

            return new CommitInfo(
                fields.hash,
                fields.subject,
                fields.body,
                fields.author,
                fields.authorEmail,
                new Date(fields.authorDate),
                fields.committer,
                fields.committerEmail,
                new Date(fields.committerDate),
                tags
            );
        });

        // check for changes

        let changed = true;
        if (this.changePath !== '') {
            if (startHash === '') {
                const changedFiles = await cmd(`git log --name-only --oneline ${endHash} -- ${this.changePath}`);
                changed = changedFiles.length > 0;
            } else {
                const changedFiles = await cmd(`git diff --name-only ${startHash}..${endHash} -- ${this.changePath}`);
                changed = changedFiles.length > 0;
            }
        }

        return new CommitInfoSet(changed, commits);

    }
}