#!/usr/bin/env bash
#
# One-shot deploy: systemd service + packwiz pack + player setup guides.
#
#   ./deploy.sh -n "Opengames" -a themiro -u https://games.abdelbaki.eu/mods \
#       -N 21.1.72 --accept-eula
#
# Runs, in order:
#   1. mc-service-setup.sh   (root)  — minecraft user, NeoForge, systemd units
#   2. packwiz-setup.sh      (you)   — pack, mod index from the mirror, guides
#
# Safe to re-run. Each run snapshots the dataset, stops the server if it was
# running, rebuilds config and the pack from scratch, and starts it back up.
# The world and $SHARE/mods are never touched; an existing pack is moved aside
# to <pack>.bak.<timestamp> rather than deleted.
#
#   --keep-pack     keep the existing pack instead of rebuilding it
#   --no-snapshot   skip the pre-deploy ZFS snapshot
#
# Run as your normal user; it calls sudo for the parts that need it.

set -euo pipefail

NAME=""; AUTHOR=""; BASEURL=""; NFVER="latest"; MCVER="1.21.1"
SHARE="/minecraft"; XMX="10G"; XMS="10G"; ACCEPT_EULA=""; PORT="25565"; KEEP_PACK=0; SNAPSHOT=1
HERE="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"

die()  { echo "error: $*" >&2; exit 1; }
step() { printf '\n\033[1m=== %s ===\033[0m\n\n' "$*"; }
usage() { awk 'NR>1 && /^#/ {sub(/^# ?/,""); print; next} NR>1 {exit}' "$0"; exit "${1:-0}"; }

while [ $# -gt 0 ]; do
    case "$1" in
        -n|--name)      NAME="${2:-}"; shift 2 ;;
        -a|--author)    AUTHOR="${2:-}"; shift 2 ;;
        -u|--base-url)  BASEURL="${2:-}"; shift 2 ;;
        -N|--neoforge)  NFVER="${2:-}"; shift 2 ;;
        -m|--mc)        MCVER="${2:-}"; shift 2 ;;
        -s|--share)     SHARE="${2:-}"; shift 2 ;;
        -p|--port)      PORT="${2:-}"; shift 2 ;;
        -X|--xmx)       XMX="${2:-}"; shift 2 ;;
        -x|--xms)       XMS="${2:-}"; shift 2 ;;
        --accept-eula)  ACCEPT_EULA="--accept-eula"; shift ;;
        --keep-pack)    KEEP_PACK=1; shift ;;
        --no-snapshot)  SNAPSHOT=0; shift ;;
        -h|--help)      usage 0 ;;
        *) echo "unknown option: $1" >&2; usage 1 ;;
    esac
done

[ "$(id -u)" -ne 0 ] || die "run this as your normal user, not root — it sudos where needed"
[ -n "$NAME" ]    || die "missing -n <pack name>"
[ -n "$AUTHOR" ]  || die "missing -a <author>"
[ -n "$BASEURL" ] || die "missing -u <mirror base url>, e.g. https://games.abdelbaki.eu/mods"

for s in mc-service-setup.sh packwiz-setup.sh mc-refresh-restart.sh; do
    [ -x "$HERE/$s" ] || die "missing or not executable: $HERE/$s"
done

# Fail early rather than halfway through, since step 1 makes system changes.
sudo -v || die "sudo is required"

# ------------------------------------------------------------ re-run prep ---

# Re-running is expected: a run that failed partway leaves a half-applied state,
# and later runs change settings that only take effect on a fresh start. So take
# a snapshot, stop the server, redeploy, and put it back how it was.
#
# World data and $SHARE/mods are never touched by any of this.

WAS_ACTIVE=0
if systemctl is-active --quiet minecraft.service 2>/dev/null; then
    WAS_ACTIVE=1
fi

if (( SNAPSHOT )) && mountpoint -q "$SHARE" && command -v zfs >/dev/null; then
    DATASET="$(findmnt -no SOURCE "$SHARE" 2>/dev/null || true)"
    if [ -n "$DATASET" ] && [ "$(findmnt -no FSTYPE "$SHARE")" = zfs ]; then
        SNAP="$DATASET@predeploy-$(date +%Y%m%d%H%M%S)"
        step "Snapshotting $SNAP"
        sudo zfs snapshot "$SNAP" \
            && echo "roll back with: sudo zfs rollback $SNAP" \
            || die "zfs snapshot failed — pass --no-snapshot to deploy anyway"
    fi
fi

if (( WAS_ACTIVE )); then
    step "Stopping minecraft.service for redeploy"
    sudo systemctl stop minecraft.service
fi

step "1/2  Minecraft systemd service"
sudo "$HERE/mc-service-setup.sh" \
    -s "$SHARE" -A "$USER" -X "$XMX" -x "$XMS" -m "$MCVER" -p "$PORT" \
    ${NFVER:+-N "$NFVER"} ${ACCEPT_EULA}

PACK_FORCE=""
(( KEEP_PACK )) || PACK_FORCE="--force"

step "2/2  packwiz pack and player guides"
# The admin group membership from step 1 isn't active in this shell yet, so run
# the pack setup under the new group explicitly rather than telling you to log
# out and back in.
if id -nG "$USER" | tr ' ' '\n' | grep -qx minecraft; then
    "$HERE/packwiz-setup.sh" -n "$NAME" -a "$AUTHOR" -m "$MCVER" -u "$BASEURL" -s "$SHARE" -p "$PORT" ${PACK_FORCE}
else
    sg minecraft -c "$(printf '%q ' "$HERE/packwiz-setup.sh" -n "$NAME" -a "$AUTHOR" \
        -m "$MCVER" -u "$BASEURL" -s "$SHARE" -p "$PORT" ${PACK_FORCE})"
fi

if (( WAS_ACTIVE )); then
    step "Restarting minecraft.service"
    sudo systemctl start minecraft.service
fi

step "Done"
cat <<EOF
Start the server:

  sudo systemctl start minecraft
  journalctl -u minecraft -f

Keep it in sync after adding mods to $SHARE/mods:

  $HERE/mc-refresh-restart.sh

Edit the config block at the top of mc-refresh-restart.sh first — it needs
PACK_DIR, BASE_URL and PACK_URL pointed at what this run just created.
EOF