#!/usr/bin/env bash
#
# PDF OCR Hotfolder — Update-Script
#
# Aktualisiert Code und venv unter /opt/pdf-ocr-hotfolder/ sowie die
# systemd Template-Unit. Danach werden alle laufenden Instanzen neu gestartet.
# Config-Dateien unter /etc/pdf-ocr-hotfolder/ bleiben unverändert.
#
set -euo pipefail

RED='\033[0;31m'; GREEN='\033[0;32m'; YELLOW='\033[1;33m'; NC='\033[0m'
log_info()  { echo -e "${GREEN}[INFO]${NC} $*"; }
log_warn()  { echo -e "${YELLOW}[WARN]${NC} $*"; }
log_error() { echo -e "${RED}[ERROR]${NC} $*"; }

if [ "${EUID}" -ne 0 ]; then
    log_error "Bitte als root ausführen: sudo ./update.sh"
    exit 1
fi

INSTALL_DIR="/opt/pdf-ocr-hotfolder"
CONFIG_DIR="/etc/pdf-ocr-hotfolder"
SERVICE_TEMPLATE="pdf-ocr-hotfolder@.service"

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
if [ -f "$SCRIPT_DIR/pdf_ocr_hotfolder/__init__.py" ]; then
    REPO_DIR="$SCRIPT_DIR"
elif [ -f "$INSTALL_DIR/.repo_path" ]; then
    REPO_DIR="$(cat "$INSTALL_DIR/.repo_path")"
    [ -d "$REPO_DIR" ] || { log_error "Gespeicherter Repo-Pfad existiert nicht: $REPO_DIR"; exit 1; }
else
    log_error "Repo nicht gefunden. update.sh aus dem Repo ausführen."
    exit 1
fi

[ -d "$INSTALL_DIR" ] || { log_error "Installation nicht gefunden. Erst install.sh ausführen."; exit 1; }

OLD_VERSION="$(cat "$INSTALL_DIR/VERSION" 2>/dev/null || echo unknown)"
NEW_VERSION="$(cat "$REPO_DIR/VERSION" 2>/dev/null || echo unknown)"

echo
echo "=========================================="
echo "  PDF OCR Hotfolder — Update"
echo "=========================================="
log_info "Repo:    $REPO_DIR"
log_info "Install: $INSTALL_DIR"
log_info "Version: $OLD_VERSION → $NEW_VERSION"
echo

# Laufende Instanzen ermitteln
mapfile -t RUNNING < <(systemctl list-units --no-legend --state=active 'pdf-ocr-hotfolder@*.service' 2>/dev/null | awk '{print $1}')
if [ "${#RUNNING[@]}" -gt 0 ]; then
    log_info "Laufende Instanzen: ${RUNNING[*]}"
else
    log_info "Keine laufenden Instanzen."
fi

log_info "Stoppe laufende Instanzen..."
for unit in "${RUNNING[@]}"; do
    systemctl stop "$unit" || true
done

log_info "Backup erstellen..."
BACKUP_DIR="/var/backups/pdf-ocr-hotfolder"
mkdir -p "$BACKUP_DIR"
tar -czf "$BACKUP_DIR/backup-$(date +%Y%m%d-%H%M%S).tar.gz" \
    -C "$INSTALL_DIR" --exclude=venv --exclude=__pycache__ . 2>/dev/null || true

log_info "Code aktualisieren..."
rm -rf "$INSTALL_DIR/pdf_ocr_hotfolder"
cp -r "$REPO_DIR/pdf_ocr_hotfolder" "$INSTALL_DIR/"
cp "$REPO_DIR/requirements.txt" "$INSTALL_DIR/"
cp "$REPO_DIR/VERSION" "$INSTALL_DIR/"
cp "$REPO_DIR/config.example.toml" "$INSTALL_DIR/"
echo "$REPO_DIR" > "$INSTALL_DIR/.repo_path"

log_info "Dependencies aktualisieren..."
"$INSTALL_DIR/venv/bin/pip" install --upgrade pip -q
"$INSTALL_DIR/venv/bin/pip" install --upgrade -r "$INSTALL_DIR/requirements.txt" -q

log_info "systemd Template-Unit aktualisieren..."
cp "$REPO_DIR/systemd/$SERVICE_TEMPLATE" "/etc/systemd/system/$SERVICE_TEMPLATE"
systemctl daemon-reload

log_info "Berechtigungen setzen..."
# Eigentümer des Codes bleibt der primäre User (pdfocr); Instanzen laufen
# ggf. als anderer User, lesen aber nur den Code.
PRIMARY_USER="$(stat -c '%U' "$INSTALL_DIR/venv" 2>/dev/null || echo pdfocr)"
chown -R "$PRIMARY_USER":"$PRIMARY_USER" "$INSTALL_DIR"

log_info "Starte Instanzen wieder..."
FAIL=0
for unit in "${RUNNING[@]}"; do
    systemctl start "$unit" || true
    sleep 1
    if systemctl is-active --quiet "$unit"; then
        log_info "  ✅ $unit"
    else
        log_error "  ❌ $unit — journalctl -u $unit -n 30"
        FAIL=1
    fi
done

echo
if [ "$FAIL" -eq 0 ]; then
    log_info "Update auf $NEW_VERSION abgeschlossen ✓"
else
    log_warn "Update abgeschlossen, aber mindestens eine Instanz läuft nicht."
    exit 1
fi