#!/bin/bash
# ==============================================================================================
# ============================= Docker Container Stop ==========================================
# ==============================================================================================
# Stops all running Docker containers one at a time, verifying each is stopped before
# moving to the next. Called by array_stop.sh as part of a planned shutdown sequence.
#
# ── STOP SEQUENCE PER CONTAINER ──────────────────────────────────────────────────────────────
#   1. docker stop -t 30 (SIGTERM + 30s grace period — docker sends SIGKILL if needed)
#   2. Verify stopped — if still running, retry up to RETRY_COUNT times
#   3. docker kill (SIGKILL) if all retries exhausted
#   4. Final verify — error if still running after force-kill
#   Never moves to the next container until the current one is confirmed stopped.
#
# ── WHY SEQUENTIAL ────────────────────────────────────────────────────────────────────────────
# Containers may have dependencies — stopping one at a time avoids abruptly severing a
# service while its dependents are still running and trying to use it.
#
# ── SAFEGUARDS ────────────────────────────────────────────────────────────────────────────────
#   Root check           — docker requires root
#   Per-container verify — confirmed stopped before proceeding to next
#   Retry loop           — RETRY_COUNT attempts before escalating to force-kill
#   SIGTERM → SIGKILL    — graceful then forced, never skips graceful
#   DOCKER_TIMEOUT       — all docker calls protected against hung daemon
#   notify on failures   — alert if any container cannot be stopped
#
# ── CONFIGURATION (master.conf) ───────────────────────────────────────────────────────────────
#   RETRY_COUNT — retry attempts before force-kill (default 3)
#   SLEEP       — seconds between retries
#
# ── USAGE ─────────────────────────────────────────────────────────────────────────────────────
#   docker_container_stop.sh              — stop all running containers
#   docker_container_stop.sh --dry-run    — show which containers would be stopped
#   docker_container_stop.sh --status     — show running containers and exit
#   docker_container_stop.sh --log        — verbose output
# ==============================================================================================

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

source "$SCRIPT_DIR/../load_config.sh"

parse_args "$@"

# ==============================================================================================
# ━━━ Setup ━━━
# ==============================================================================================
if [[ "$EUID" -ne 0 ]]; then
    error "Must be run as root"
    exit 1
fi

if ! command -v docker &>/dev/null; then
    error "Docker command not found"
    exit 1
fi

detect_hosts

[[ "$DRY_RUN" == true ]] && warn "DRY RUN — no containers will be stopped"

DOCKER_TIMEOUT=30
DOCKER_STOP_TIMEOUT=30    # grace period for SIGTERM before docker sends SIGKILL internally
_RETRY_COUNT="${RETRY_COUNT:-3}"

# ==============================================================================================
# ━━━ Status ━━━
# ==============================================================================================
if [[ "$SHOW_STATUS" == true ]]; then
    mapfile -t RUNNING < <(docker ps --format '{{.Names}}' 2>/dev/null | sort)
    echo ""
    echo "━━━━━ $ICON_SUMMARY STATUS ━━━━━"
    echo "$ICON_HOST       Identity:  $MY_ID ($LOCAL_SERVER_NAME)"
    echo "$ICON_CONTAINERS Running:   ${#RUNNING[@]} container(s)"
    echo "$ICON_RETRY      Retries:   $_RETRY_COUNT"
    for c in "${RUNNING[@]}"; do echo "  $ICON_RUNNING $c"; done
    echo "━━━━━━━━━━━━━━━━━━━━━━━"
    exit 0
fi

# ==============================================================================================
# ━━━ Stop Containers ━━━
# ==============================================================================================
mapfile -t RUNNING < <(docker ps --format '{{.Names}}' 2>/dev/null | sort)

echo ""
echo "━━━ $ICON_CONTAINERS Docker Container Stop — $(date '+%Y-%m-%d %H:%M:%S') ━━━"

if [[ ${#RUNNING[@]} -eq 0 ]]; then
    log "No running containers — nothing to do"
    exit 0
fi

echo "$ICON_CONTAINERS Containers: ${#RUNNING[@]} running"
echo ""

START=$(date +%s)
STOPPED=()
FAILED=()

for container in "${RUNNING[@]}"; do
    [[ -z "$container" ]] && continue
    echo "━━━ $ICON_CONTAINERS $container ━━━"

    if [[ "$DRY_RUN" == true ]]; then
        warn "DRY RUN — would stop $container"
        STOPPED+=("$container")
        echo ""
        continue
    fi

    attempt=1
    success=false

    while [[ "$attempt" -le "$_RETRY_COUNT" ]]; do
        log "$ICON_RETRY Attempt $attempt of $_RETRY_COUNT — stopping $container..."

        timeout "$DOCKER_TIMEOUT" docker stop -t "$DOCKER_STOP_TIMEOUT" "$container" \
            >/dev/null 2>&1

        STATE=$(timeout "$DOCKER_TIMEOUT" docker inspect \
            -f '{{.State.Running}}' "$container" 2>/dev/null || echo "unknown")

        if [[ "$STATE" != "true" ]]; then
            echo "$ICON_DONE  $container stopped ✅"
            STOPPED+=("$container")
            success=true
            break
        fi

        warn "Attempt $attempt failed — $container still running"
        (( attempt++ ))
        [[ "$attempt" -le "$_RETRY_COUNT" ]] && sleep "${SLEEP:-5}"
    done

    if [[ "$success" == false ]]; then
        warn "$container — retries exhausted, force-killing with SIGKILL..."
        timeout "$DOCKER_TIMEOUT" docker kill "$container" >/dev/null 2>&1 || true

        STATE=$(timeout "$DOCKER_TIMEOUT" docker inspect \
            -f '{{.State.Running}}' "$container" 2>/dev/null || echo "unknown")

        if [[ "$STATE" != "true" ]]; then
            warn "$container force-killed ✅"
            STOPPED+=("$container")
        else
            error "$container still running after SIGKILL — manual intervention needed"
            notify "$container could not be stopped on $(hostname) ($MY_ID)" \
                "Docker Container Stop" "warning"
            FAILED+=("$container")
        fi
    fi

    echo ""
done

END=$(date +%s)

# ==============================================================================================
# ━━━ Summary ━━━
# ==============================================================================================
echo "━━━━━ $ICON_SUMMARY DOCKER CONTAINER STOP SUMMARY ━━━━━"
echo "$ICON_HOST       Identity:  $MY_ID ($LOCAL_SERVER_NAME)"
echo "$ICON_TIME       Duration:  $(format_duration $(( END - START )))"
echo "$ICON_CONTAINERS Scope:     ${#RUNNING[@]} running → ${#STOPPED[@]} stopped"
[[ ${#STOPPED[@]} -gt 0 ]] && echo "$ICON_DONE       Stopped:   ${STOPPED[*]}"
[[ ${#FAILED[@]} -gt 0 ]]  && echo "$ICON_ERROR      Failed:    ${FAILED[*]}"

if [[ "$DRY_RUN" == true ]]; then
    warn "DRY RUN — no containers stopped"
elif [[ ${#FAILED[@]} -eq 0 ]]; then
    log "$ICON_DONE Status: done ✅ — ${#STOPPED[@]} container(s) stopped"
else
    warn "Status: ${#FAILED[@]} container(s) could not be stopped"
fi
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"

[[ ${#FAILED[@]} -gt 0 ]] && exit 1
exit 0