Yogu/site-manager

var Task = require('../task.js');
var ShellTask = require('../tasks/shell.js');
var Promise = require('es6-promise').Promise;
var Q = require('q');

function LoadSiteTask(site) {
    Task.call(this);
    this.site = site;
    this.name = 'Load';
}

LoadSiteTask.prototype = Object.create(Task.prototype);

LoadSiteTask.prototype.perform = function*() {
    try {
        this.cd(this.site.path);

        yield this.exec("git fetch");

        this.site.revision = (yield this.exec("git rev-parse HEAD")).stdout.trim();
        if (this.site.isMergeRequestSite) {
            // this site should be upgraded when sourceBranch changes
            this.site.branch = this.site.sourceBranch;
        } else {
            this.site.branch = (yield this.exec("git rev-parse --abbrev-ref HEAD")).stdout.trim();
        }
        if (this.site.branch == 'HEAD') {
            this.site.branch = ''; // this happens when no branch is checked out
        }
        if (this.site.isMergeRequestSite) {
            this.site.upstreamRevision = (yield this.exec("git rev-parse origin/" + this.site.sourceBranch)).stdout.trim();
            this.site.aheadBy = 0; // not really useful because we are always ahead by the merge commit
            this.site.behindBy = yield this._getCommitCountBetween('HEAD', 'origin/' + this.site.sourceBranch);
        } else  if (this.site.branch) {
            this.site.upstreamRevision = (yield this.exec("git rev-parse origin/" + this.site.branch)).stdout.trim();
            this.site.aheadBy = yield this._getCommitCountBetween('origin/' + this.site.branch, this.site.branch);
            this.site.behindBy = yield this._getCommitCountBetween(this.site.branch, 'origin/' + this.site.branch);
        } else {
            this.site.upstreamRevision = '';
            this.site.aheadBy = 0;
            this.site.behindBy = 0;
        }
        this.site.isClean = yield this._isClean();

        this.site.canUpgrade = this.site.aheadBy == 0 && this.site.isClean && this.site.behindBy > 0;
        this.site.isLoaded = true;
        this.site.emit('load');
        this.site._loadedDeferred.resolve();
    } catch (err) {
        this.site.isLoadFailed = true;
        throw err;
    }
};

LoadSiteTask.prototype._getCommitCountBetween = Q.async(function*(a, b) {
    // wc hides errors of rev-list
    var result = yield this.exec("git rev-list " + a + ".." + b);
    return result.stdout.split("\n").length - 1;
});

LoadSiteTask.prototype._isClean = Q.async(function*() {
    try {
        // discard the index
        yield this.exec("rm .git/index ; git reset && git diff-files");
        return true;
    } catch (err) {
        if (code in err && err.code === 1) {
            this.doLog('This site is dirty (hence the error)');
            return false;
        } else
            throw err;
    }
});

module.exports = LoadSiteTask;