#!/usr/bin/env python

import os, sys, re, datetime, argparse, traceback

# boilerplate
basedir = os.path.abspath(os.path.join(os.path.dirname(__file__), "../.."))
sys.path = [ basedir ] + sys.path
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "ietf.settings")

import django.test
from django.conf import settings

# prevent memory from leaking when settings.DEBUG=True
from django.db import connection
class DontSaveQueries(object):
    def append(self, x):
        pass
connection.queries = DontSaveQueries()

MAX_URL_LENGTH = 500

# args
parser = argparse.ArgumentParser(
    description="""Perform a test crawl of the project. For each found URL, the HTTP
    response status is printed. If it's not OK/redirect, FAIL is
    printed - in case of errors, a stacktrace is also included.""")
parser.add_argument('urls', metavar='URL', nargs='*',
                    help='One or more URLs to start the crawl from')
parser.add_argument('--urls', '-u', dest='url_file',
                    help='file with URLs to start the crawl from')
parser.add_argument('--slow', dest='slow_threshold', type=float, default=1.0,
                    help='responses taking longer than this (in seconds) results in SLOW being printed')

args = parser.parse_args()

slow_threshold = args.slow_threshold

initial_urls = []
initial_urls.extend(args.urls)

if args.url_file:
    with open(args.url_file) as f:
        for line in f:
            line = line.partition("#")[0].strip()
            if line:
                initial_urls.append(line)

if not initial_urls:
    initial_urls.append("/")

visited = set()
urls = {} # url -> referrer


def strip_url(url):
    if url.startswith("http://testserver"):
        url = url[len("http://testserver"):]
    return url

def extract_html_urls(content):
    for m in re.finditer(r'(<(?:a|link) [^>]*href=[\'"]([^"]+)[\'"][^>]*>)', content):
        if re.search(r'rel=["\']?nofollow["\']', m.group(1)):
            continue

        url = strip_url(m.group(2))
        if len(url) > MAX_URL_LENGTH:
            continue # avoid infinite GET parameter appendages

        if not url.startswith("/"):
            continue

        yield url

client = django.test.Client()

for url in initial_urls:
    urls[url] = "[initial]"

errors = 0

while urls:
    url, referrer = urls.popitem()

    visited.add(url)

    try:
        timestamp = datetime.datetime.now()
        r = client.get(url)
        elapsed = datetime.datetime.now() - timestamp
    except KeyboardInterrupt:
        print "was fetching", url
        sys.exit(1)
    except:
        print 500, "%.3fs" % (datetime.datetime.now() - timestamp).total_seconds(), url, "FAIL (from %s)" % referrer
        print "============="
        print traceback.format_exc()
        print "============="
        errors += 1
    else:
        tags = []

        if r.status_code in (301, 302):
            u = strip_url(r["Location"])
            if u not in visited and u not in urls:
                urls[u] = referrer # referrer is original referrer, not redirected url

        elif r.status_code == 200:
            ctype = r["Content-Type"]
            if ";" in ctype:
                ctype = ctype[:ctype.index(";")]

            if ctype == "text/html":
                try:
                    for u in extract_html_urls(r.content):
                        if u not in visited and u not in urls:
                            urls[u] = url
                except:
                    print "error extracting HTML urls from", url
                    print "============="
                    print traceback.format_exc()
                    print "============="
        else:
            tags.append(u"FAIL (from %s)" % referrer)
            errors += 1

        if elapsed.total_seconds() > slow_threshold:
            tags.append("SLOW")

        print r.status_code, "%.3fs" % elapsed.total_seconds(), url, " ".join(tags)

if errors > 0:
    sys.stderr.write("Found %s errors, grep output for FAIL for details\n" % errors)
    sys.exit(1)