import os, time, email.utils, urllib.parse, html, re, sys, datetime

TITLE = os.environ.get("FEED_TITLE", "Cum Town Archive (local)")
DESC  = os.environ.get("FEED_DESC",  "Self-hosted archive feed served from my NAS")
BASE  = os.environ.get("BASE_URL")
LIMIT = int(os.environ.get("MAX_ITEMS","0"))           # 0 = onbeperkt
ORDER_ASC = False                                      # output-volgorde (maakt in PA meestal niet uit)
ONLY_SUBDIR = os.environ.get("ONLY_SUBDIR","").strip() # bv. '1) Cum Town Archive'
NUMBERED_PUBDATE = os.environ.get("NUMBERED_PUBDATE","0") in ("1","true","True")

if not BASE:
    raise SystemExit("BASE_URL env var ontbreekt")

AUDIO_EXTS = {".mp3",".m4a",".aac",".ogg",".opus",".flac",".wav"}

def is_audio(fn):
    return os.path.splitext(fn)[1].lower() in AUDIO_EXTS

def esc(s:str) -> str:
    return html.escape(s, quote=True)

def parse_episode_number(name: str):
    base = os.path.splitext(os.path.basename(name))[0]
    m = re.match(r'^\s*(\d+)', base)
    if m: return int(m.group(1))
    m = re.search(r'\b[Ee]p[.\s-]*(\d+)', base)
    if m: return int(m.group(1))
    m = re.search(r'\b[Bb]onus[.\s-]*(\d+)', base)
    if m: return int(m.group(1))
    return None

walk_root = "."
if ONLY_SUBDIR:
    walk_root = os.path.join(".", ONLY_SUBDIR)
    if not os.path.isdir(walk_root):
        raise SystemExit(f"ONLY_SUBDIR bestaat niet: {ONLY_SUBDIR}")

items=[]
for root,_,files in os.walk(walk_root):
    for f in files:
        if not is_audio(f):
            continue
        p=os.path.join(root,f)
        st=os.stat(p)
        rel=os.path.relpath(p,".").replace("\\","/")
        url=BASE.rstrip("/")+"/"+urllib.parse.quote(rel)
        size=str(st.st_size)
        original_title=os.path.splitext(os.path.basename(f))[0]
        epnum=parse_episode_number(f)
        items.append({
            "mtime": st.st_mtime,
            "original_title": original_title,
            "url": url,
            "size": size,
            "epnum": epnum,
            "rel": rel,
        })

# Paddingbreedte bepalen
epnums=[it["epnum"] for it in items if it["epnum"] is not None]
pad = len(str(max(epnums))) if epnums else 3

# Definitieve titels + pubDate bepalen
base_dt = datetime.datetime(2010,1,1, tzinfo=datetime.timezone.utc)  # vast begin; puur voor volgorde
for it in items:
    if it["epnum"] is not None:
        it["title"] = f"{it['epnum']:0{pad}d} — {it['original_title']}"
    else:
        it["title"] = it["original_title"]
    if NUMBERED_PUBDATE and it["epnum"] is not None:
        # volgorde volgens nummer: lagere nummers = oudere datum
        dt = base_dt + datetime.timedelta(seconds=it["epnum"])
        it["pub"] = email.utils.format_datetime(dt)
    else:
        it["pub"] = email.utils.formatdate(it["mtime"], usegmt=True)

# sorteren voor output (niet per se nodig, maar netjes)
def sort_key(it):
    # sorteer primair op epnum, secundair op mtime
    key_primary = (it["epnum"] is None, it["epnum"] if it["epnum"] is not None else it["mtime"])
    return key_primary

items.sort(key=sort_key, reverse=not ORDER_ASC)
if LIMIT>0:
    items = items[:LIMIT]

now=email.utils.formatdate(time.time(), usegmt=True)
parts=[f'''<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0" xmlns:itunes="http://www.itunes.com/dtds/podcast-1.0.dtd">
  <channel>
    <title>{esc(TITLE)}</title>
    <link>{esc(BASE)}</link>
    <description>{esc(DESC)}</description>
    <language>nl-NL</language>
    <lastBuildDate>{esc(now)}</lastBuildDate>
    <itunes:author>Self-hosted</itunes:author>
    <itunes:explicit>false</itunes:explicit>
''']

for it in items:
    ext=it["url"].split("?")[0].split(".")[-1].lower()
    mime=("audio/mpeg" if ext=="mp3" else
          "audio/mp4"  if ext in ("m4a","aac") else
          "audio/ogg"  if ext in ("ogg","opus") else
          "application/octet-stream")
    guid=urllib.parse.quote(it["url"], safe="")
    parts.append("    <item>\n")
    parts.append(f"      <title>{esc(it['title'])}</title>\n")
    if it["epnum"] is not None:
        parts.append(f"      <itunes:episode>{it['epnum']}</itunes:episode>\n")
        parts.append("      <itunes:episodeType>full</itunes:episodeType>\n")
    parts.append(f"      <pubDate>{esc(it['pub'])}</pubDate>\n")
    parts.append(f"      <guid isPermaLink=\"false\">{esc(guid)}</guid>\n")
    parts.append(f"      <enclosure url=\"{esc(it['url'])}\" length=\"{esc(it['size'])}\" type=\"{esc(mime)}\"/>\n")
    parts.append("    </item>\n")

parts.append("  </channel>\n</rss>\n")

with open("feed.xml","w",encoding="utf-8") as f:
    f.write("".join(parts))

print(f"Written feed.xml with {len(items)} items (pad width {pad}, numbered_pubdate={NUMBERED_PUBDATE})")