#!/usr/bin/env python3
"""
Patch Jellyfin home-screen section layout for every user on a given instance.

Default policy (this script):
  - Continue Watching (`resume`)          ENABLED for every user
  - Resume Audio       (`resumeaudio`)    preserved if present
  - Next Up            (`nextup`)         DISABLED (replaced with `none`)
  - Latest Media       (`latestmedia`)    preserved if present
  - If a user's layout was empty (factory default), seed slot 0 with `resume`

Idempotent. Safe to re-run.

Usage:
    JF_URL=https://arrflix.s8n.ru \
    JF_TOKEN=<admin token> \
    python3 bin/set-home-layout.py

Token retrieval (admin):
    docker cp jellyfin:/config/data/jellyfin.db /tmp/jf.db
    sqlite3 /tmp/jf.db \\
      'SELECT d.AccessToken FROM Devices d JOIN Users u ON d.UserId=u.Id
       WHERE u.Username="s8n" ORDER BY d.DateLastActivity DESC LIMIT 1'
"""
import json
import os
import sys
import urllib.request

JF_URL = os.environ.get("JF_URL")
JF_TOKEN = os.environ.get("JF_TOKEN")

if not JF_URL or not JF_TOKEN:
    sys.exit("set JF_URL and JF_TOKEN env vars")


def http(method, url, body=None):
    req = urllib.request.Request(url, method=method)
    req.add_header("X-Emby-Token", JF_TOKEN)
    data = None
    if body is not None:
        req.add_header("Content-Type", "application/json")
        data = json.dumps(body).encode()
    with urllib.request.urlopen(req, data=data) as r:
        text = r.read().decode()
        return r.status, (json.loads(text) if text else None)


def patch_user(user_id, username):
    url = f"{JF_URL}/DisplayPreferences/usersettings?userId={user_id}&client=emby"
    _, prefs = http("GET", url)
    cp = prefs.get("CustomPrefs") or {}

    sections = [cp.get(f"homesection{i}", "none") for i in range(10)]
    before = list(sections)

    sections = ["none" if s == "nextup" else s for s in sections]
    if "resume" not in sections:
        if "none" in sections:
            sections[sections.index("none")] = "resume"
        else:
            sections = ["resume"] + sections[:9]

    for i, s in enumerate(sections):
        cp[f"homesection{i}"] = s
    prefs["CustomPrefs"] = cp

    changed = before != sections
    if changed:
        http("POST", url, body=prefs)
    return changed, before, sections


def main():
    users = http("GET", f"{JF_URL}/Users")[1]
    print(f"{JF_URL} — {len(users)} users")
    for u in users:
        changed, before, after = patch_user(u["Id"], u["Name"])
        mark = "CHANGED" if changed else "  ok   "
        print(f"  [{mark}] {u['Name']:<14}  {before} -> {after}")


if __name__ == "__main__":
    main()