#!/usr/bin/python
# Quick and dirty webhook to accept merge request events from gitlab and turn them into buildbot try requests
# Obsolete; see newer version https://github.com/buildbot/buildbot/pull/1820

import os
import shutil
import simplejson  # for when you want better error messages
import subprocess
import tempfile
import traceback
import sys
import urllib
from sys import version as python_version
from cgi import parse_header, parse_multipart

if python_version.startswith('3'):
    from urllib.parse import parse_qs
    from http.server import BaseHTTPRequestHandler, HTTPServer
else:
    from urlparse import parse_qs
    from BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer

def my_quote(s):
    return urllib.quote(s).replace("%20", " ")

def verbose_system(s):
    print(s)
    sys.stdout.flush()
    try:
        subprocess.check_call('( '+ s + ') > log.txt 2>&1', shell=True)
    except:
        print("Failed!  Log:")
        os.system("cat log.txt")
        raise

def do_try(project, comment, surl, sbranch, uurl, ubranch, who):
    print("project is " + project)
    print("comment is " + comment)
    secrets = simplejson.load(open(os.path.expanduser("~/gitlab-try-secrets.json")))
    try_server = secrets["try_server"]
    try_user = secrets["try_user"]
    try_pass = secrets["try_pass"]

    builders_str = subprocess.check_output("buildbot try -c pb --username=%s --passwd=%s -m %s --get-builder-names | grep -w '%s.*%s'" % (try_user, try_pass, try_server, project, ubranch), shell=True)

    print("builders_str is " + builders_str)
    opts=" ".join(["-b " + x for x in builders_str.split()])
    print("opts is " + opts)
    dirpath = tempfile.mkdtemp()
    verbose_system("git clone -b %s %s %s" % (ubranch, uurl, dirpath))
    verbose_system("cd %s && git remote add downstream %s && git fetch downstream" % (dirpath, surl))
    verbose_system("cd %s && git checkout -b branch-to-try--%s downstream/%s" % (dirpath, sbranch, sbranch))
    verbose_system("cd %s && git format-patch -M -B origin/%s --stdout > change.patch" % (dirpath, ubranch))
    verbose_system("cd %s && buildbot try -c pb --username=%s --who='%s' --passwd=%s -m %s --diff=change.patch --patchlevel 1 %s --comment '%s'" % (dirpath, try_user, my_quote(who), try_pass, try_server, opts, my_quote(comment)))
    shutil.rmtree(dirpath)

def do_merge_request(postvars):
    print("object_kind is " + postvars['object_kind'])
    print("username is " + postvars['user']['username'])
    print("name is " + postvars['user']['name'])
    o = postvars['object_attributes']
    printf("author is " + o['source']['last_commit']['author']['name'])
    printf("email is " + o['source']['last_commit']['author']['email'])
    print("title is " + o['title'])
    print("description is " + o['description'])
    print("source_branch is " + o['source_branch'])
    print("source_url is " + o['source']['ssh_url'])
    print("target_branch is " + o['target_branch'])
    print("target_url is " + o['target']['ssh_url'])
    print("target_name is " + o['target']['name'])
    print("state is " + o['state'])
    print("merge_status is " + o['merge_status'])
    if o['state'] == 'closed' or o['merge_status'] != 'unchecked':
        print("skipping to avoid multiple runs on same merge request")
        sys.stdout.flush()
        return
    sys.stdout.flush()
    do_try(project = o['target']['name'], surl = o['source']['ssh_url'], sbranch = o['source_branch'], uurl = o['target']['ssh_url'], ubranch = o['target_branch'], comment=o['title'], who=o['source']['last_commit']['author']['email'])


class RequestHandler(BaseHTTPRequestHandler):

    def reply_fail(self, val=400, reason='unknown'):
	message = 'Error: ' + reason
        self.send_response(val)
        self.send_header('Content-type', 'text')
	self.send_header("Content-length", str(len(message)))
        self.end_headers()
	self.wfile.write(message)

    def reply_ok(self):
	message = 'OK'
        self.send_response(200)
        self.send_header('Content-type', 'text')
	self.send_header("Content-length", str(len(message)))
        self.end_headers()
	self.wfile.write(message)
 
    def parse_POST(self):
        ctype, pdict = parse_header(self.headers['content-type'])
        if ctype == 'application/json':
            length = int(self.headers['content-length'])
            post = self.rfile.read(length)
            print("Got " + post)
            postvars = simplejson.loads(post)
        else:
            postvars = {}
        return postvars

    def do_POST(self):
        postvars = self.parse_POST()
        if postvars == {} or 'object_kind' not in postvars:
            self.reply_fail(400, reason='parse error')
        elif postvars['object_kind'] == "merge_request":
            try:
                # Have to reply immediately or gitlab will resend
                self.reply_ok()
                do_merge_request(postvars)
            except:
                traceback.print_exc()
        else:
            self.reply_fail(400, reason='cannot handle object_kind=%s' % postvars['object_kind'])

def run(server_class=HTTPServer, handler_class=RequestHandler, port=80):
    server_address = ('', port)
    httpd = server_class(server_address, handler_class)
    print 'Starting httpd...'
    sys.stdout.flush()
    httpd.serve_forever()
 
if __name__ == "__main__":
    from sys import argv
 
    if len(argv) == 6:
        do_try(argv[1], argv[2], argv[3], argv[4], argv[5])
    elif len(argv) == 2:
        run(port=int(argv[1]))
    else:
        run()