#!/bin/bash
# ==============================================================================================
# ================================= Docker Update ==============================================
# ==============================================================================================
# Pulls the latest image for each container in HOST*_DAILY_RESTART_CONTAINERS.
# Called by daily_sync_maintenance.sh before docker_daily_restart.sh — containers stay
# running during the pull, so there is no extra downtime.
#
# ── WHY SAME LIST AS DAILY RESTART ───────────────────────────────────────────────────────────
# Containers that restart daily (auth stack: Authelia, NPM, Mariadb, Redis, etc.) are
# exactly the containers that benefit from staying current. Reusing DAILY_RESTART_CONTAINERS
# means no second list to maintain — add/remove a container once and both update + restart
# reflect the change automatically.
#
# ── WHAT THIS DOES ────────────────────────────────────────────────────────────────────────────
#   docker pull <image>   — fetches the latest digest from the registry
#   Old vs new image ID comparison — distinguishes "updated" from "already current"
#   Containers keep running — pull does not affect the live container
#   docker_daily_restart.sh runs after — containers restart on the fresh image
#
# ── TOGGLE ────────────────────────────────────────────────────────────────────────────────────
#   DAILY_CONTAINER_UPDATES=false in master.conf — skips all pulls, exits cleanly
#   docker_daily_restart.sh still runs regardless — update and restart are independent
#
# ── CONFIGURATION ─────────────────────────────────────────────────────────────────────────────
#   master.conf:         DAILY_CONTAINER_UPDATES — enable/disable (default: true)
#   master_host*.conf:   HOST*_DAILY_RESTART_CONTAINERS — containers to update
#
# ── USAGE ─────────────────────────────────────────────────────────────────────────────────────
#   docker_update.sh              — normal run
#   docker_update.sh --dry-run    — show what would be pulled
#   docker_update.sh --log        — verbose output
#   docker_update.sh --status     — show config and exit
# ==============================================================================================

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

if [[ "${DAILY_CONTAINER_UPDATES:-true}" != "true" ]]; then
    log "DAILY_CONTAINER_UPDATES=false — skipping container updates"
    exit 0
fi

if [[ ${#DAILY_RESTART_CONTAINERS[@]} -eq 0 ]]; then
    warn "DAILY_RESTART_CONTAINERS is empty for $MY_ID — nothing to update"
    warn "Check HOST${MY_ID#HOST}_DAILY_RESTART_CONTAINERS in master_host*.conf"
    exit 0
fi

# ==============================================================================================
# ━━━ Status ━━━
# ==============================================================================================
if [[ "$SHOW_STATUS" == true ]]; then
    echo ""
    echo "━━━━━ $ICON_SUMMARY STATUS ━━━━━"
    echo "$ICON_HOST       Identity:   $MY_ID ($LOCAL_SERVER_NAME)"
    echo "$ICON_CONTAINERS Containers: ${DAILY_RESTART_CONTAINERS[*]}"
    echo "$ICON_GEAR       Enabled:    ${DAILY_CONTAINER_UPDATES:-true}"
    echo "$ICON_GEAR       Dry Run:    $DRY_RUN"
    echo "━━━━━━━━━━━━━━━━━━━━━━━"
    exit 0
fi

[[ "$DRY_RUN" == true ]] && warn "DRY RUN — no images will be pulled"

# ==============================================================================================
# ━━━ Pull Updates ━━━
# ==============================================================================================
echo ""
echo "━━━ $ICON_CONTAINERS Docker Update — $(date '+%Y-%m-%d %H:%M:%S') ━━━"
echo "$ICON_CONTAINERS Containers: ${DAILY_RESTART_CONTAINERS[*]}"
echo ""

START=$(date +%s)
UPDATED=()
UP_TO_DATE=()
FAILED=()
SKIPPED=()

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

    if ! docker inspect "$container" &>/dev/null; then
        warn "$container — not found, skipping"
        SKIPPED+=("$container")
        echo ""
        continue
    fi

    IMAGE=$(docker inspect --format='{{.Config.Image}}' "$container" 2>/dev/null)
    if [[ -z "$IMAGE" ]]; then
        warn "$container — could not determine image, skipping"
        SKIPPED+=("$container")
        echo ""
        continue
    fi

    log "$container — image: $IMAGE"

    if [[ "$DRY_RUN" == true ]]; then
        warn "DRY RUN — would pull: $IMAGE"
        UPDATED+=("$container")
        echo ""
        continue
    fi

    # Capture image ID before pull to detect whether an update landed
    OLD_ID=$(docker image inspect "$IMAGE" --format='{{.Id}}' 2>/dev/null || echo "")

    echo "$ICON_SYNC  Pulling $IMAGE..."
    if docker pull "$IMAGE" 2>&1 | grep -E "^(Status:|Digest:|Error|error)" | sed 's/^/  /'; then
        NEW_ID=$(docker image inspect "$IMAGE" --format='{{.Id}}' 2>/dev/null || echo "")

        if [[ -n "$OLD_ID" ]] && [[ "$OLD_ID" != "$NEW_ID" ]]; then
            echo "$ICON_DONE  $container — updated ✅"
            UPDATED+=("$container")
        else
            log "$container — already up to date"
            UP_TO_DATE+=("$container")
        fi
    else
        warn "$container — pull failed ($IMAGE)"
        FAILED+=("$container")
    fi

    echo ""
done

END=$(date +%s)

# ==============================================================================================
# ━━━ Summary ━━━
# ==============================================================================================
echo "━━━━━ $ICON_SUMMARY DOCKER UPDATE SUMMARY ━━━━━"
echo "$ICON_HOST       Identity:    $MY_ID ($LOCAL_SERVER_NAME)"
echo "$ICON_TIME       Duration:    $(format_duration $(( END - START )))"
[[ ${#UPDATED[@]} -gt 0 ]]    && echo "$ICON_DONE       Updated:     ${UPDATED[*]}"
[[ ${#UP_TO_DATE[@]} -gt 0 ]] && echo "$ICON_RUNNING    Up to date:  ${UP_TO_DATE[*]}"
[[ ${#SKIPPED[@]} -gt 0 ]]    && echo "$ICON_WARN       Skipped:     ${SKIPPED[*]}"
[[ ${#FAILED[@]} -gt 0 ]]     && echo "$ICON_ERROR      Failed:      ${FAILED[*]}"

if [[ "$DRY_RUN" == true ]]; then
    warn "DRY RUN — no images pulled"
elif [[ ${#FAILED[@]} -eq 0 ]]; then
    log "$ICON_DONE Status: done ✅ — ${#UPDATED[@]} updated, ${#UP_TO_DATE[@]} current"
else
    warn "Status: ${#FAILED[@]} pull(s) failed — restart will proceed with existing images"
fi
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"

# Pull failures are non-fatal — restart proceeds regardless
exit 0