#!/bin/sh
# Supervise the app and keep yt-dlp fresh.
#
# yt-dlp breaks frequently against site changes, so we check PyPI once a day
# for a newer release. The app imports yt_dlp at startup, so a new version
# only takes effect on (re)start -- we therefore restart the app *only* when
# an update was actually installed. If the app exits on its own, we propagate
# its exit status so Docker's restart policy can handle it.
set -e

CHECK_INTERVAL=86400   # check for a new yt-dlp once per day
POLL=60                # how often to check on the app

# Upgrade yt-dlp only if PyPI has a newer version.
# Returns 0 if an update was installed, 1 otherwise (incl. errors / up to date).
# Versions are compared numerically: the installed version can be zero-padded
# (e.g. 2026.06.09) while PyPI reports the normalized form (e.g. 2026.6.9).
check_and_update() {
    if python3 - <<'PY'
import json, sys, urllib.request
try:
    import yt_dlp
    current = yt_dlp.version.__version__
    latest = json.load(urllib.request.urlopen(
        'https://pypi.org/pypi/yt-dlp/json', timeout=30))['info']['version']
except Exception as e:
    print(f"Could not check for yt-dlp updates ({e}); will retry.")
    sys.exit(1)

def key(v):
    try:
        return tuple(int(p) for p in v.split('.'))
    except ValueError:
        return None

ck, lk = key(current), key(latest)
newer = (lk > ck) if (ck and lk) else (current != latest)
if newer:
    print(f"New yt-dlp available: {current} -> {latest}. Updating...")
    sys.exit(0)
print(f"yt-dlp is up to date ({current}).")
sys.exit(1)
PY
    then
        pip install --upgrade --quiet --root-user-action=ignore "yt-dlp[default,curl-cffi]" \
            && return 0
        echo "yt-dlp update failed; continuing with the installed version."
    fi
    return 1
}

# Forward termination to the app so the container stops cleanly.
trap 'kill "$APP_PID" 2>/dev/null; exit 0' TERM INT

while true; do
    # Make sure we launch with the latest available yt-dlp.
    check_and_update || true

    "$@" &
    APP_PID=$!

    # Periodically check for updates; restart the app only when one is applied.
    while true; do
        waited=0
        while [ "$waited" -lt "$CHECK_INTERVAL" ] && kill -0 "$APP_PID" 2>/dev/null; do
            sleep "$POLL"
            waited=$((waited + POLL))
        done

        if ! kill -0 "$APP_PID" 2>/dev/null; then
            wait "$APP_PID"
            status=$?
            echo "App exited with status $status"
            exit "$status"
        fi

        if check_and_update; then
            echo "Restarting app to apply yt-dlp update..."
            kill "$APP_PID" 2>/dev/null || true
            wait "$APP_PID" 2>/dev/null || true
            break   # outer loop relaunches the app
        fi
    done
done