#!/usr/bin/env python

import sys
import urllib
import urllib2
import subprocess
import re
import json

#################################
# Begin Configuration variables #
#################################

# Url of the ttextpro.exe cgi on your web server
URL = 'http://localhost/cgi-bin/ttextpro.exe'
# Provider key from the Source Control Providers dialog
PROVIDER_KEY = '{aa858562-025a-4236-9bf2-6cf4c81e0468}:{5d723ea4-0501-4343-8ee1-60189bcf3314}'
# JSON key for the commit hash. This should match the <commitHash> name you used in the Commit URL
# and File URL fields in your Source Control Provider configuration.
COMMIT_HASH_KEY = 'commitHash'
# JSON key for the file hash. This should match the <fileHash> name you used in the File URL field
# in your Source Control Provider configuration.
FILE_HASH_KEY = 'fileHash'
# JSON key for the file parent hash. This should match the <fileParentHash> name you used in the
# File URL field in your Source Control Provider configuration.
FILE_PARENT_HASH_KEY = 'fileParentHash'
# JSON key for the commit parent hash. This should match the <commitParentHash> name you used in the
# File URL field in your Source Control Provider configuration.
COMMIT_PARENT_HASH_KEY = 'commitParentHash'
# Tags used to attach to issues, test cases, and requirements. Format is "[TAG-NUMBER]".
ISSUE_TAG = 'IS'
TEST_CASE_TAG = 'TC'
REQUIREMENT_TAG = 'RQ'

###############################
# End Configuration variables #
###############################

TAG_PATTERN = r'\[(%s|%s|%s)-(\d+)\]' % (ISSUE_TAG, TEST_CASE_TAG, REQUIREMENT_TAG)
TAG_REGEX = re.compile(TAG_PATTERN, re.IGNORECASE)
TAG_MAP = {ISSUE_TAG: 'issue',
           TEST_CASE_TAG: 'test case',
           REQUIREMENT_TAG: 'requirement'}
STATUS_MAP = {'A': 'added',
              'M': 'modified',
              'D': 'removed'}

# Run a git command.
def git(*args):
    return subprocess.Popen(('git',) + args, stdout=subprocess.PIPE).communicate()[0].strip()

# Get the full CGI URL.
def get_url():
    return URL + '?' + urllib.urlencode({ 'action': 'AddAttachment' })

# Get the branch name based on the ref name.
def get_branch_name(ref_name):
    return ref_name.replace('refs/heads/', '')

# Get the object type based on the tag.
def get_object_type(tag):
    return TAG_MAP[tag.upper()]

# Get the change type based on the file status.
def get_change_type(status):
    return STATUS_MAP[status.upper()]

# Get JSON data for a ref.
def get_data(old_value, new_value, ref_name):
    return {'providerKey': PROVIDER_KEY,
            'attachmentList': get_commits(old_value, new_value, ref_name)}

# Get JSON data for commits being pushed to a ref.
def get_commits(old_value, new_value, ref_name):
    revlist = get_revs(old_value, new_value, ref_name)
    commits = []

    for rev in revlist:
        commit_hash, commit_parent_hashes, commit_author, commit_message = rev.strip().split('\n', 3)
        commit_parent_hash = commit_parent_hashes.split(' ')[0]
        commit_message = commit_message.strip()
        to_attach = get_attachments(commit_message)

        if len(to_attach) > 0:
            files = get_files(commit_hash, commit_parent_hash)
            commits.append({COMMIT_HASH_KEY: commit_hash,
                            'attachmentAuthor': commit_author,
                            'attachmentMessage': commit_message,
                            'branchName': get_branch_name(ref_name),
                            'toAttachList': to_attach,
                            'fileList': files})

    return commits

# Get list of revisions to inspect for attachments.
def get_revs(old_value, new_value, ref_name):
    if old_value == '0000000000000000000000000000000000000000':
        revs = git('rev-parse', '--not', '--branches').split('\n')
        revs = [rev for rev in revs if rev != '^' + new_value]
        revs.append(new_value)
    else:
        revs = ['^' + old_value, new_value]

    revlist = git('rev-list', '--pretty=format:%P%n%an%n%s%n%b', '--reverse', *revs)
    revlist = revlist.split('commit ')[1:]
    return revlist

# Get JSON data for items to attach to.
def get_attachments(commit_message):
    matches = TAG_REGEX.finditer(commit_message)
    attachments = []

    for match in matches:
        attachments.append({'objectType': get_object_type(match.group(1)),
                            'number': int(match.group(2))})

    return attachments

# Get JSON data for files changed in a commit.
def get_files(commit_hash, commit_parent_hash):
    filelist = git('diff-tree', '--no-commit-id', '--root', '-r', commit_hash)
    filelist = filelist.split(':')[1:]
    files = []

    for f in filelist:
        status_line, file_name = f.strip().split('\t')
        old_mode, new_mode, old_hash, new_hash, status = status_line.split(' ')
        files.append({'changeType': get_change_type(status),
                      'fileName': file_name,
                      FILE_HASH_KEY: new_hash,
                      FILE_PARENT_HASH_KEY: old_hash,
                      COMMIT_HASH_KEY: commit_hash,
                      COMMIT_PARENT_HASH_KEY: commit_parent_hash})

    return files

# Handle attaching for a ref.
def handle_ref(old_value, new_value, ref_name):
    req = urllib2.Request(get_url(),
            json.dumps(get_data(old_value, new_value, ref_name)),
            {'Content-Type': 'application/json'})
    try:
        f = urllib2.urlopen(req)
        res = json.loads(f.read())
        f.close()

        if res['errorCode'] > 1:
            print(res['errorMessage'])
        elif res['errorCode'] == 1:
            for err in res['errorList']:
                print(err['errorMessage'])
    except urllib2.URLError as e:
        print(e)

if __name__ == '__main__':
    for line in sys.stdin:
        old_value, new_value, ref_name = line.strip().split(' ')
        if ref_name.startswith('refs/heads/'):
            handle_ref(old_value, new_value, ref_name)