#!/usr/bin/env bash
set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
# shellcheck source=darktable_common.sh
source "$SCRIPT_DIR/darktable_common.sh"

log_step "Darktable Sync gestartet (PID $$, Argumente: ${*:-keine})"

check_dependency rsync
check_dependency ssh openssh-client
check_dependency notify-send libnotify-bin
check_dependency darktable
log "Alle Abhängigkeiten vorhanden."

load_config
validate_config
log "Konfiguration geladen: Server=$SERVER_USER@$SERVER_IP:$SERVER_SSH_PORT"
log "  DB lokal:    $LOCAL_DARKTABLE_DB_DIR"
log "  DB Server:   $SERVER_DB_DIR"
log "  Fotos lokal: $LOCAL_PHOTO_DIR"
log "  Fotos Server:$SERVER_PHOTO_DIR"

export DISPLAY="${DISPLAY:-:0}"

DRY_RUN=true
SHOW_NOTIFY_START_STOP=false
for arg in "$@"; do
    case "$arg" in
        --execute|-e)             DRY_RUN=false ;;
        --with-notify-start-stop) SHOW_NOTIFY_START_STOP=true ;;
    esac
done

count_synced_files() {
    local log_file="$1" direction="$2" count=0
    case "$direction" in
        up)   count=$(grep -cE '^>f|^cd' "$log_file" 2>/dev/null) || count=0 ;;
        down) count=$(grep -cE '^<f|^cd' "$log_file" 2>/dev/null) || count=0 ;;
    esac
    echo "$count"
}

LOCKDIR="$CONFIG_DIR/sync.lock"
LOCKPID="$LOCKDIR/pid"
TMPFILES=()

log "Lock anfordern: $LOCKDIR"
if ! mkdir "$LOCKDIR" 2>/dev/null; then
    EXISTING_PID=$(cat "$LOCKPID" 2>/dev/null || true)
    if [ -n "$EXISTING_PID" ] && ! kill -0 "$EXISTING_PID" 2>/dev/null; then
        log "Verwaisten Lock gefunden (PID $EXISTING_PID läuft nicht mehr) – wird entfernt."
        rm -f "$LOCKPID"
        rmdir "$LOCKDIR" 2>/dev/null || true
        mkdir "$LOCKDIR"
    else
        log_error "Sync läuft bereits (PID ${EXISTING_PID:-unbekannt}). Lock: $LOCKDIR"
        echo "  rmdir $LOCKDIR" >&2
        exit 1
    fi
fi
echo "$$" > "$LOCKPID"
log "Lock erworben (PID $$)."
trap 'rm -f "${TMPFILES[@]}" "$LOCKPID"; rmdir "$LOCKDIR" 2>/dev/null || true; log "Lock freigegeben."' EXIT

if [ "$DRY_RUN" = true ]; then
    log_step "TROCKENLAUF – keine Änderungen werden vorgenommen"
    log "Dieser Aufruf zeigt nur, was synchronisiert werden würde."
    log "Für echten Sync: $(basename "$0") --execute  oder  -e"
    log ""
    if ! confirm_dry_run; then
        log "Trockenlauf abgebrochen."
        exit 0
    fi
fi

log "Prüfen ob Darktable läuft..."
if pgrep -x darktable > /dev/null 2>&1; then
    log "Darktable läuft (PID: $(pgrep -x darktable | tr '\n' ' ')) – Sync übersprungen."
    notify-send "Darktable Sync – Abbruch" \
        "Darktable ist gerade geöffnet. Sync erst nach dem Beenden möglich." \
        -u normal -t 8000
    exit 0
fi
log "Darktable läuft nicht – Sync kann fortfahren."

if [ -f "$CONFIG_DIR/sync_pending" ]; then
    log "Ausstehender Sync aus vorherigem Lauf wird jetzt nachgeholt."
    notify-send "Darktable Sync" "Ausstehender Sync wird jetzt ausgeführt..." -t 3000
fi

log "Serververbindung prüfen ($SERVER_USER@$SERVER_IP Port $SERVER_SSH_PORT)..."
if ! server_reachable; then
    log "Server nicht erreichbar – Sync übersprungen, sync_pending gesetzt."
    touch "$CONFIG_DIR/sync_pending"
    exit 0
fi
log "Server erreichbar."

if [ "$SHOW_NOTIFY_START_STOP" = true ]; then
    notify-send "Darktable Sync" "Sync gestartet..." -t 3000
fi

log "Active-Marker auf Server prüfen..."
ACTIVE=$(ssh_server "cat '$SERVER_DB_DIR/darktable.active' 2>/dev/null || true")
if [ -n "$ACTIVE" ]; then
    log "WARNUNG: Active-Marker vorhanden: $ACTIVE"
    notify-send "Darktable Sync – Warnung" \
        "Darktable läuft möglicherweise auf: $ACTIVE" -u normal -t 10000
else
    log "Kein Active-Marker – kein anderer Client aktiv."
fi

log "Darktable-Versionen prüfen..."
SERVER_VERSION=$(ssh_server "cat '$SERVER_DB_DIR/darktable_version' 2>/dev/null || true")
LOCAL_VERSION=$(darktable --version 2>&1 | head -1 || true)
log "  Lokal:  ${LOCAL_VERSION:-unbekannt}"
log "  Server: ${SERVER_VERSION:-noch nicht gespeichert}"

if [ -n "$SERVER_VERSION" ]; then
    LOCAL_MM=$(echo "$LOCAL_VERSION" | grep -oP '\d+\.\d+' | head -1 || true)
    SERVER_MM=$(echo "$SERVER_VERSION" | grep -oP '\d+\.\d+' | head -1 || true)
    if [ -n "$SERVER_MM" ] && [ "$LOCAL_MM" != "$SERVER_MM" ]; then
        log_error "Versionskonflikt: lokal=$LOCAL_MM, server=$SERVER_MM"
        log_error "Bitte beide Rechner auf gleichen Stand bringen."
        notify-send "Darktable Sync – Versionskonflikt" \
            "Lokal: $LOCAL_MM  Server: $SERVER_MM\nBitte angleichen!" \
            -u critical
        touch "$CONFIG_DIR/sync_pending"
        exit 1
    fi
    log "Versionen übereinstimmend ($LOCAL_MM)."
fi

log "Sync-Token prüfen..."
SAVED_TOKEN=$(read_sync_token)
SERVER_TOKEN=$(server_db_mtime)
log "  Gespeicherter Token: ${SAVED_TOKEN:-keiner (erster Sync)}"
log "  Aktueller Server-Token: $SERVER_TOKEN"

UPLOAD_ALLOWED=true
if [ -n "$SAVED_TOKEN" ] && [ "$SAVED_TOKEN" != "$SERVER_TOKEN" ]; then
    log "WARNUNG: Token-Konflikt (gespeichert=$SAVED_TOKEN, server=$SERVER_TOKEN) – Benutzer wird gefragt."
    RESOLUTION=$(ask_conflict_resolution)
    log "Benutzerentscheidung: $RESOLUTION"
    case "$RESOLUTION" in
        upload)
            log "Upload erzwungen – lokale Version überschreibt Server."
            ;;
        abort)
            log "Sync abgebrochen durch Benutzer."
            exit 0
            ;;
        *)
            log "Nur Download – Server-Stand wird übernommen."
            UPLOAD_ALLOWED=false
            ;;
    esac
else
    log "Token stimmt überein – Upload erlaubt."
fi

if [ "$DRY_RUN" = false ]; then
    log_step "Datenbank-Backup"
    log "  $LOCAL_DARKTABLE_DB_DIR/library.db → library.db.bak"
    cp "$LOCAL_DARKTABLE_DB_DIR/library.db" "$LOCAL_DARKTABLE_DB_DIR/library.db.bak"
    log "  $LOCAL_DARKTABLE_DB_DIR/data.db    → data.db.bak"
    cp "$LOCAL_DARKTABLE_DB_DIR/data.db"    "$LOCAL_DARKTABLE_DB_DIR/data.db.bak"
    log "Backup abgeschlossen."
fi

SYNC_LOG=$(mktemp)
TMPFILES+=("$SYNC_LOG")
UPLOAD_LOG_DB=$(mktemp)
TMPFILES+=("$UPLOAD_LOG_DB")
UPLOAD_LOG_PHOTOS=$(mktemp)
TMPFILES+=("$UPLOAD_LOG_PHOTOS")
DOWNLOAD_LOG_DB=$(mktemp)
TMPFILES+=("$DOWNLOAD_LOG_DB")
DOWNLOAD_LOG_PHOTOS=$(mktemp)
TMPFILES+=("$DOWNLOAD_LOG_PHOTOS")

RSYNC_DRY_FLAG=()
[ "$DRY_RUN" = true ] && RSYNC_DRY_FLAG=(--dry-run)
[ "$DRY_RUN" = true ] && DRY_SUFFIX=" (Trockenlauf)" || DRY_SUFFIX=""

SENT_DB=0
SENT_PHOTOS=0

if [ "$UPLOAD_ALLOWED" = true ]; then
    log_step "Upload: Datenbank${DRY_SUFFIX}"
    log "  Quelle: $LOCAL_DARKTABLE_DB_DIR/"
    log "  Ziel:   $SERVER_USER@$SERVER_IP:$SERVER_DB_DIR/"
    if ! rsync -uavh --itemize-changes \
        "${RSYNC_DRY_FLAG[@]}" \
        --exclude '*.lock' \
        --exclude 'darktable_version' \
        -e "ssh -p $SERVER_SSH_PORT" \
        "$LOCAL_DARKTABLE_DB_DIR/" "$SERVER_USER@$SERVER_IP:$SERVER_DB_DIR/" \
        2>&1 | tee -a "$SYNC_LOG" "$UPLOAD_LOG_DB"; then
        log_error "Upload Datenbank fehlgeschlagen (Quelle: $LOCAL_DARKTABLE_DB_DIR)"
        touch "$CONFIG_DIR/sync_pending"
        exit 1
    fi
    SENT_DB=$(count_synced_files "$UPLOAD_LOG_DB" "up")
    log "Datenbank-Upload abgeschlossen: $SENT_DB Datei(en) übertragen."

    log_step "Upload: Fotos${DRY_SUFFIX}"
    log "  Quelle: $LOCAL_PHOTO_DIR/"
    log "  Ziel:   $SERVER_USER@$SERVER_IP:$SERVER_PHOTO_DIR/"
    if ! rsync -uavh --itemize-changes \
        "${RSYNC_DRY_FLAG[@]}" \
        --exclude '*.lock' \
        -e "ssh -p $SERVER_SSH_PORT" \
        "$LOCAL_PHOTO_DIR/" "$SERVER_USER@$SERVER_IP:$SERVER_PHOTO_DIR/" \
        2>&1 | tee -a "$SYNC_LOG" "$UPLOAD_LOG_PHOTOS"; then
        log_error "Upload Fotos fehlgeschlagen (Quelle: $LOCAL_PHOTO_DIR)"
        touch "$CONFIG_DIR/sync_pending"
        exit 1
    fi
    SENT_PHOTOS=$(count_synced_files "$UPLOAD_LOG_PHOTOS" "up")
    log "Foto-Upload abgeschlossen: $SENT_PHOTOS Datei(en) übertragen."
else
    log "Upload übersprungen (Token-Konflikt)."
fi

log_step "Download: Datenbank${DRY_SUFFIX}"
log "  Quelle: $SERVER_USER@$SERVER_IP:$SERVER_DB_DIR/"
log "  Ziel:   $LOCAL_DARKTABLE_DB_DIR/"
if ! rsync -uavh --itemize-changes \
    "${RSYNC_DRY_FLAG[@]}" \
    --exclude '*.lock' \
    -e "ssh -p $SERVER_SSH_PORT" \
    "$SERVER_USER@$SERVER_IP:$SERVER_DB_DIR/" "$LOCAL_DARKTABLE_DB_DIR/" \
    2>&1 | tee -a "$SYNC_LOG" "$DOWNLOAD_LOG_DB"; then
    log_error "Download Datenbank fehlgeschlagen (Ziel: $LOCAL_DARKTABLE_DB_DIR)"
    touch "$CONFIG_DIR/sync_pending"
    exit 1
fi
RECEIVED_DB=$(count_synced_files "$DOWNLOAD_LOG_DB" "down")
log "Datenbank-Download abgeschlossen: $RECEIVED_DB Datei(en) empfangen."

log_step "Download: Fotos${DRY_SUFFIX}"
log "  Quelle: $SERVER_USER@$SERVER_IP:$SERVER_PHOTO_DIR/"
log "  Ziel:   $LOCAL_PHOTO_DIR/"
if ! rsync -uavh --itemize-changes \
    "${RSYNC_DRY_FLAG[@]}" \
    --exclude '*.lock' \
    -e "ssh -p $SERVER_SSH_PORT" \
    "$SERVER_USER@$SERVER_IP:$SERVER_PHOTO_DIR/" "$LOCAL_PHOTO_DIR/" \
    2>&1 | tee -a "$SYNC_LOG" "$DOWNLOAD_LOG_PHOTOS"; then
    log_error "Download Fotos fehlgeschlagen (Ziel: $LOCAL_PHOTO_DIR)"
    touch "$CONFIG_DIR/sync_pending"
    exit 1
fi
RECEIVED_PHOTOS=$(count_synced_files "$DOWNLOAD_LOG_PHOTOS" "down")
log "Foto-Download abgeschlossen: $RECEIVED_PHOTOS Datei(en) empfangen."

if [ "$DRY_RUN" = false ]; then
    NEW_TOKEN=$(server_db_mtime)
    save_sync_token "$NEW_TOKEN"
    log "Sync-Token gespeichert: $NEW_TOKEN"

    log "Versionsdatei aktualisieren: $LOCAL_DARKTABLE_DB_DIR/darktable_version"
    echo "$LOCAL_VERSION" > "$LOCAL_DARKTABLE_DB_DIR/darktable_version"

    rm -f "$CONFIG_DIR/sync_pending"
    log "sync_pending entfernt."
fi

TOTAL_SENT=$((SENT_DB + SENT_PHOTOS))
TOTAL_RECEIVED=$((RECEIVED_DB + RECEIVED_PHOTOS))

if [ "$DRY_RUN" = true ]; then
    upload_log=$(cat "$UPLOAD_LOG_DB" "$UPLOAD_LOG_PHOTOS" 2>/dev/null || true)
    download_log=$(cat "$DOWNLOAD_LOG_DB" "$DOWNLOAD_LOG_PHOTOS" 2>/dev/null || true)

    UP_NEW=$(  echo "$upload_log" | grep -cE '^>f[+]{9}' || echo 0)
    UP_UPD=$(  echo "$upload_log" | grep -E  '^>f'       | grep -cvE '^>f[+]{9}' || echo 0)
    UP_DEL=$(  echo "$upload_log" | grep -cE '^\*deleting' || echo 0)
    DN_NEW=$(  echo "$download_log" | grep -cE '^<f[+]{9}' || echo 0)
    DN_UPD=$(  echo "$download_log" | grep -E  '^<f'       | grep -cvE '^<f[+]{9}' || echo 0)
    DN_DEL=$(  echo "$download_log" | grep -cE '^\*deleting' || echo 0)

    log_step "Trockenlauf-Ergebnis"
    log "  Upload:   $UP_NEW neu | $UP_UPD aktualisiert | $UP_DEL gelöscht"
    log "  Download: $DN_NEW neu | $DN_UPD aktualisiert | $DN_DEL gelöscht"

    if [ "$((TOTAL_SENT + TOTAL_RECEIVED))" -gt 0 ]; then
        if ask_user "Details" "Details der zu übertragenden Dateien anzeigen?"; then
            format_rsync_details "$UPLOAD_LOG_DB"       "Upload"   "up"
            format_rsync_details "$UPLOAD_LOG_PHOTOS"   "Upload"   "up"
            format_rsync_details "$DOWNLOAD_LOG_DB"     "Download" "down"
            format_rsync_details "$DOWNLOAD_LOG_PHOTOS" "Download" "down"
        fi
    else
        log "Keine Änderungen – alles aktuell."
    fi
else
    log_step "Sync abgeschlossen"
    log "  Hochgeladen:     $TOTAL_SENT ($SENT_DB DB + $SENT_PHOTOS Fotos)"
    log "  Heruntergeladen: $TOTAL_RECEIVED ($RECEIVED_DB DB + $RECEIVED_PHOTOS Fotos)"

    if [ "$TOTAL_SENT" -gt 0 ] || [ "$TOTAL_RECEIVED" -gt 0 ]; then
        notify-send "Darktable Sync" \
            "↑ $TOTAL_SENT hochgeladen | ↓ $TOTAL_RECEIVED heruntergeladen" -t 10000
    else
        log "Keine Änderungen – alles aktuell."
    fi

    if [ "$SHOW_NOTIFY_START_STOP" = true ]; then
        notify-send "Darktable Sync" "Sync abgeschlossen." -t 3000
    fi
fi