#!/bin/bash
# Retire youtube-automate and hand tube.jihakuz.xyz to ytstream.
#
#     sudo /opt/ytstream/deploy/decommission.sh
#
# This is plan.md §12 steps 4 and 5 — the two that need root. Everything it does
# is reversible: the nginx change is backed up next to the original, and the
# service is disabled rather than removed.
#
# Deliberately NOT done here, because each one destroys something:
#   * deleting /disks/Plex/YouTube (§12 step 6)
#   * removing or renaming the Jellyfin libraries (§12 step 3)
#   * removing /opt/youtube-automate, its repo, subs.db or specs.md (§12 step 7)
set -euo pipefail

CONF=/etc/nginx/sites-available/jihakuz.xyz
OLD_PORT=8085          # youtube-automate
NEW_PORT=8086          # ytstream admin
DB=/var/lib/ytstream/ytstream.db

if [[ $EUID -ne 0 ]]; then
    echo "This script needs root. Run: sudo $0" >&2
    exit 1
fi

# ---------------------------------------------------------------- preflight
# Repointing a public hostname at a service that cannot be logged into wastes an
# evening working out why. The admin UI fails closed with no password set: every
# login attempt is rejected, including your brother's.
if ! sqlite3 "$DB" \
        "SELECT 1 FROM setting WHERE key='admin_password_hash' AND value <> '';" \
        2>/dev/null | grep -q 1; then
    echo "!! No admin password is set, so nobody can log in to the UI this would" >&2
    echo "   expose. Run this first, then re-run me:" >&2
    echo "       sudo -u susan /var/lib/ytstream/venv/bin/ytstream set-password" >&2
    exit 1
fi

# And do not hand the hostname to a port nothing is listening on.
code=$(curl -s -o /dev/null -w '%{http_code}' -m 10 "http://127.0.0.1:${NEW_PORT}/" || true)
if [[ "$code" != "200" && "$code" != "303" && "$code" != "302" ]]; then
    echo "!! ytstream-admin is not answering on ${NEW_PORT} (got '${code}')." >&2
    echo "   systemctl status ytstream-admin" >&2
    exit 1
fi
echo "==> ytstream-admin answers on ${NEW_PORT} (HTTP ${code}) and has a password set"

# ------------------------------------------------------------------- nginx
if grep -q "127.0.0.1:${NEW_PORT}" "$CONF"; then
    echo "==> nginx already points tube.jihakuz.xyz at ${NEW_PORT}; skipping"
elif ! grep -q "127.0.0.1:${OLD_PORT}" "$CONF"; then
    echo "!! Found neither ${OLD_PORT} nor ${NEW_PORT} in $CONF. Not guessing." >&2
    exit 1
else
    BACKUP="${CONF}.bak-$(date +%Y%m%d%H%M%S)"
    cp -a "$CONF" "$BACKUP"
    echo "==> Backed up $CONF to $BACKUP"

    # One line. The proxy_set_header block the youtube-automate fix added is
    # already there and still correct — X-Forwarded-For in particular, because
    # the login throttle keys on it and without it one attacker locks out all.
    sed -i "s|proxy_pass http://127.0.0.1:${OLD_PORT};|proxy_pass http://127.0.0.1:${NEW_PORT};|" "$CONF"
    echo "==> Repointed tube.jihakuz.xyz at 127.0.0.1:${NEW_PORT}"

    if ! nginx -t; then
        echo "!! nginx config test failed — restoring the backup" >&2
        cp -a "$BACKUP" "$CONF"
        nginx -t
        exit 1
    fi
    systemctl reload nginx
    echo "==> nginx reloaded"
fi

# ---------------------------------------------------------------- the service
if systemctl is-enabled --quiet youtube-automate.service 2>/dev/null \
   || systemctl is-active --quiet youtube-automate.service 2>/dev/null; then
    systemctl disable --now youtube-automate.service
    echo "==> Stopped and disabled youtube-automate.service"
    echo "    Unit left in place at /etc/systemd/system/ — 'systemctl enable --now"
    echo "    youtube-automate' brings it back if this turns out to be premature."
else
    echo "==> youtube-automate.service already stopped and disabled"
fi

echo
echo "Done. tube.jihakuz.xyz now serves ytstream's admin UI."
echo "Still holding, on purpose:"
echo "  * /disks/Plex/YouTube  ($(du -sh /disks/Plex/YouTube 2>/dev/null | cut -f1)) — the old downloads"
echo "  * both Jellyfin libraries — remove/rename by hand when you are ready"
echo "  * /opt/youtube-automate, its repo, subs.db and specs.md — keep these"