"""Crawls every internal link of a locally running Website — signed out, as a buyer, and as a seller — and reports the ones that fail.

    swift run Website &
    python3 Tests/Browser/links.py

Stdlib only. Exits non-zero when a link answers 4xx or 5xx.
"""
import html, re, sys, urllib.error, urllib.parse, urllib.request

BASE = "http://localhost:8080"

class NoRedirect(urllib.request.HTTPRedirectHandler):
    def redirect_request(self, *args, **kwargs):
        return None

opener = urllib.request.build_opener(NoRedirect)

def fetch(path, cookie=None, data=None):
    request = urllib.request.Request(BASE + path, data=data, headers={"Cookie": cookie} if cookie else {})
    try:
        response = opener.open(request)
    except urllib.error.HTTPError as error:
        response = error
    return response.status, response.headers, response.read().decode("utf-8", "replace")

def sign_in(email):
    _, headers, _ = fetch("/sign-in", data=urllib.parse.urlencode({"email": email, "return": "/"}).encode())
    return headers["Set-Cookie"].split(";")[0]

def crawl(name, cookie):
    seen, queue, broken = set(), ["/"], []
    while queue:
        path = queue.pop()
        if path in seen:
            continue
        seen.add(path)
        status, headers, body = fetch(path, cookie)
        if status >= 400:
            broken.append((status, path))
            continue
        if 300 <= status < 400:
            target = urllib.parse.urlsplit(headers["Location"])
            queue.append(target.path + ("?" + target.query if target.query else ""))
            continue
        for href in re.findall(r'href="(/[^"#]*)', body):
            href = html.unescape(href)
            # Assets are covered by the app's own tests; the crawl is for screens.
            if not re.match(r"/(css|js|font|uploads)/|/[^/]+\.(ico|svg|png|webmanifest|xml|txt)", href):
                queue.append(href)
    print(f"{name}: {len(seen)} links, {len(broken)} broken")
    for status, path in sorted(broken):
        print(f"  {status}  {path}")
    return broken

broken = crawl("signed out", None)
broken += crawl("buyer", sign_in(""))
broken += crawl("seller", sign_in("joost@kestrelrow.example"))
sys.exit(1 if broken else 0)