#!/usr/bin/env bash
# scripts/stop-services.sh — graceful stop + record the previous image SHA so
# `./scripts/deploy.sh --rollback` can find a target.

set -euo pipefail
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
. "$SCRIPT_DIR/_lib.sh"

usage() {
    cat <<'EOF'
Usage: ./scripts/stop-services.sh [--help]

Reads from the environment:
  DEPLOY_CONTAINER_NAME                          name of the container to stop
  REGISTRY_TAG (optional, for logging only)

Side-effect: writes scripts/.previous_tags.env containing PREVIOUS_SHA_TAG so
the next deploy can roll back to whatever was running just before this stop.
EOF
}

[[ "${1:-}" == "--help" || "${1:-}" == "-h" ]] && { usage; exit 0; }

require_env DEPLOY_CONTAINER_NAME
require_cmd docker

PREV_FILE="$SCRIPT_DIR/.previous_tags.env"

if container_exists "$DEPLOY_CONTAINER_NAME"; then
    REVISION="$(current_image_revision "$DEPLOY_CONTAINER_NAME")"
    if [[ -n "$REVISION" ]]; then
        SHA12="$(echo "$REVISION" | cut -c1-12)"
        SUFFIX="${REGISTRY_TAG##*-}"   # arm / amd; falls back to whatever follows the last dash
        PREV_TAG="${SHA12}-${SUFFIX:-arm}"
        printf 'PREVIOUS_SHA_TAG=%s\nPREVIOUS_REVISION=%s\nRECORDED_AT=%s\n' \
            "$PREV_TAG" "$REVISION" "$(date -u +%Y-%m-%dT%H:%M:%SZ)" > "$PREV_FILE"
        log_info "Recorded rollback target → $PREV_TAG (revision $REVISION) in $PREV_FILE"
    else
        log_warn "Could not read org.opencontainers.image.revision from $DEPLOY_CONTAINER_NAME — rollback target NOT recorded"
    fi

    if container_running "$DEPLOY_CONTAINER_NAME"; then
        # 40s matches the grace period in deployment_procedures.md §1; the app
        # itself shuts down after ShutdownTimeout=30s leaving 10s headroom.
        log_info "Stopping $DEPLOY_CONTAINER_NAME (grace 40s)"
        docker stop -t 40 "$DEPLOY_CONTAINER_NAME"
    else
        log_info "$DEPLOY_CONTAINER_NAME exists but is not running"
    fi
    log_info "Removing container $DEPLOY_CONTAINER_NAME"
    docker rm -f "$DEPLOY_CONTAINER_NAME"
else
    log_info "$DEPLOY_CONTAINER_NAME does not exist — nothing to stop"
fi