#!/usr/bin/env python3
"""Pinger IndexNow med de sider der er ændret i dette push. Kør efter buildet
(bruger public/sitemap-0.xml). --dry-run viser hvad der ville blive sendt."""
import json
import os
import re
import subprocess
import sys
import urllib.error
import urllib.request

HOST = "asger.weirsoe.dk"
KEY = "b68b31655cb9c1a662d53905dd0b1b06"
ORIGIN = f"https://{HOST}"


def git(*args):
    r = subprocess.run(["git", *args], capture_output=True, text=True)
    return r.stdout.strip() if r.returncode == 0 else None


def sitemap_urls():
    with open("public/sitemap-0.xml") as f:
        return set(re.findall(r"<loc>([^<]+)</loc>", f.read()))


def route_for_file(f):
    """Kanonisk form uden afsluttende skråstreg, som i sitemap'et."""
    m = re.fullmatch(r"content/(.+?)(/index|/_index|_index)?\.md", f)
    if m:
        return "/" + m[1].rstrip("/") if m[1] != "_index" else "/"
    m = re.fullmatch(r"templates/sider/(.+)\.html", f) or re.fullmatch(r"data/(.+)\.json", f)
    if m:
        name = {"forside": "", "forside-en": "en"}.get(m[1], m[1])
        return "/en/" + name[:-3] if name.endswith("-en") else "/" + name
    return None


def changed_files():
    before, sha = os.environ.get("GITHUB_EVENT_BEFORE"), os.environ.get("GITHUB_SHA")
    if before and not re.fullmatch(r"0*", before):
        d = git("diff", "--name-only", before, sha or "HEAD")
        if d is not None:
            return d.split("\n") if d else []
    d = git("diff", "--name-only", "HEAD~1", "HEAD")
    return d.split("\n") if d else None


def main():
    files = changed_files()
    if files is None:
        print("IndexNow: kan ikke bestemme hvad der ændrede sig (shallow clone?), springer over.")
        return
    valid = sitemap_urls()
    urls = sorted({ORIGIN + r for r in map(route_for_file, files) if r} & valid)
    if not urls:
        print("IndexNow: ingen sider med ændret indhold i dette push, springer over.")
        return
    print(f"IndexNow: indsender {len(urls)} URL(er):")
    for u in urls:
        print("  ", u)
    if "--dry-run" in sys.argv:
        print("IndexNow: --dry-run, sender ikke.")
        return
    body = {"host": HOST, "key": KEY, "keyLocation": f"{ORIGIN}/{KEY}.txt", "urlList": urls}
    req = urllib.request.Request("https://api.indexnow.org/indexnow", data=json.dumps(body).encode(),
                                 headers={"Content-Type": "application/json; charset=utf-8"}, method="POST")
    try:
        with urllib.request.urlopen(req, timeout=30) as r:
            print(f"IndexNow: HTTP {r.status} {r.reason}")
    except urllib.error.URLError as e:
        # Deployet er allerede ude, så vi fejler ikke buildet.
        print(f"IndexNow: afvist: {e}")


if __name__ == "__main__":
    main()