#!/usr/bin/env bash
# spdk-ctl.sh — host-side fleet release ops for the LONG-LIVED SPDK target.
#
# Stages a release's artifacts into ./releases/<version>/ and adds/removes it on
# the running nvmf_tgt ONLINE — no container restart, no dropped connections.
# This is the operator entrypoint for rolling updates and cleanup; it wraps the
# in-container spdk-release control script (driven via `docker compose exec`).
#
#   ./spdk-ctl.sh load   <version> [oci_ref]   # stage + add live (oci_ref default: $OCI_IMAGE:<version>)
#   ./spdk-ctl.sh unload <version> [--force]    # drain-gated remove + delete staged files
#   ./spdk-ctl.sh list                          # served versions + connected hosts
#
# Typical rollout:
#   ./spdk-ctl.sh load 1.3.0            # serve the new version alongside the old
#   # ... reboot hosts onto 1.3.0 (deployment manifest digest bump) ...
#   ./spdk-ctl.sh list                  # watch 1.2.0 CONNS fall to 0
#   ./spdk-ctl.sh unload 1.2.0          # cleanup once drained (refuses if hosts remain)
set -euo pipefail

cd "$(dirname "$0")"
RELEASES_DIR="${RELEASES_DIR:-./releases}"
SVC="${NVMEOF_SVC:-nvmeof}"

# Pull OCI_IMAGE default from the stack .env if present.
if [ -f ../.env ]; then
    set -a; . ../.env; set +a
fi

# Run compose from the stack dir (one level up, where docker-compose.yml lives).
dc() { ( cd .. && docker compose "$@" ); }

usage() {
    echo "usage: $0 {load <ver> [oci_ref] | unload <ver> [--force] | list}" >&2
    exit 2
}

cmd_load() {
    local v=${1:-}; [ -n "$v" ] || usage
    local ref=${2:-}
    if [ -z "$ref" ]; then
        [ -n "${OCI_IMAGE:-}" ] || { echo "ERROR: set OCI_IMAGE in ../.env or pass an oci_ref" >&2; exit 1; }
        ref="${OCI_IMAGE}:${v}"
    fi
    local dest="$RELEASES_DIR/$v"
    if [ -s "$dest/verity.json" ]; then
        echo "==> release $v already staged in $dest (skipping extract)"
    else
        echo "==> extracting $ref -> $dest"
        mkdir -p "$dest"
        local cid
        cid=$(docker create "$ref")
        # FROM-scratch artifact image: copy the three files the target needs.
        docker cp "$cid:/artifacts/rootfs.erofs" "$dest/rootfs.erofs"
        docker cp "$cid:/artifacts/rootfs.hash"  "$dest/rootfs.hash"
        docker cp "$cid:/artifacts/verity.json"  "$dest/verity.json"
        docker rm "$cid" >/dev/null
    fi
    echo "==> adding release $v on the live target (no restart)"
    dc exec -T "$SVC" spdk-release add "$v"
    dc exec -T "$SVC" spdk-release list
}

cmd_unload() {
    local v="" force=""
    local a
    for a in "$@"; do
        case "$a" in
            --force) force="--force" ;;
            *)       v="$a" ;;
        esac
    done
    [ -n "$v" ] || usage
    echo "==> removing release $v from the live target"
    if dc exec -T "$SVC" spdk-release remove "$v" ${force:+$force}; then
        rm -rf "${RELEASES_DIR:?}/$v"
        echo "==> staged artifacts for $v deleted from $RELEASES_DIR/$v"
    else
        echo "remove refused (version still has connected hosts?) — staged files left in place." >&2
        echo "Drain those hosts first, or re-run with --force to evict them." >&2
        exit 1
    fi
}

case "${1:-}" in
    load)       shift; cmd_load "$@" ;;
    unload|rm)  shift; cmd_unload "$@" ;;
    list|ls)    dc exec -T "$SVC" spdk-release list ;;
    *)          usage ;;
esac