"""
Exports Issues from a specified repository to a CSV file

Uses basic authentication (Github username + password) to retrieve Issues
from a repository that username has access to. Supports Github API v3.
"""
import csv
import requests


GITHUB_USER = ''
GITHUB_PASSWORD = ''
REPO = ''  # format is username/repo
ISSUES_FOR_REPO_URL = 'https://api.github.com/repos/{}/issues'.format(REPO)
AUTH = (GITHUB_USER, GITHUB_PASSWORD)

def write_issues(response):
    "output a list of issues to csv"
    if not r.status_code == 200:
        raise Exception(r.status_code)
    for issue in r.json():
        print issue
        csvout.writerow([issue['number'], issue['title'].encode('utf-8'), issue['html_url']])


r = requests.get(ISSUES_FOR_REPO_URL, auth=AUTH)
csvfile = '{}-issues.csv'.format(REPO.replace('/', '-'))
csvout = csv.writer(open(csvfile, 'wb'))
csvout.writerow(('id', 'Title', 'URL'))
write_issues(r)

#more pages? examine the 'link' header returned
if 'link' in r.headers:
    pages = dict(
        [(rel[6:-1], url[url.index('<')+1:-1]) for url, rel in
            [link.split(';') for link in
                r.headers['link'].split(',')]])
    while 'last' in pages and 'next' in pages:
        r = requests.get(pages['next'], auth=AUTH)
        write_issues(r)
        if pages['next'] == pages['last']:
            break