#!/bin/bash
#
# Payload CMS - PostgreSQL Restore-Skript
# Stellt die Datenbank aus einem Backup wieder her.
#
# Verwendung:
#   ./restore-db.sh                           # Interaktiv (zeigt verfügbare Backups)
#   ./restore-db.sh <backup-datei>            # Direktes Restore
#   ./restore-db.sh --from-s3                 # Restore aus S3 (interaktiv)
#   ./restore-db.sh --from-s3 <backup-name>   # Restore aus S3 (direkt)
#   ./restore-db.sh --list                    # Backups auflisten
#   ./restore-db.sh --list-s3                 # S3-Backups auflisten
#
# Voraussetzungen:
#   - ~/.pgpass mit korrekten Berechtigungen (chmod 600)
#   - ~/.s3cfg für S3-Restore (chmod 600)
#

set -euo pipefail

# ============================================================================
# Konfiguration
# ============================================================================

# Datenbank-Verbindung (Passwort via ~/.pgpass)
DB_HOST="${PGHOST:-10.10.181.101}"
DB_PORT="${PGPORT:-5432}"
DB_NAME="${PGDATABASE:-payload_db}"
DB_USER="${PGUSER:-payload}"

# Backup-Verzeichnis
BACKUP_DIR="/home/payload/backups/postgres"

# S3-Konfiguration
S3_BUCKET="${S3_BUCKET:-c2s}"
S3_PATH="${S3_PATH:-backups/postgres}"

# Temporäres Verzeichnis für S3-Downloads
TEMP_DIR="/tmp/payload-restore"

# ============================================================================
# Farben und Formatierung
# ============================================================================

RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

# ============================================================================
# Funktionen
# ============================================================================

print_header() {
    echo ""
    echo -e "${BLUE}==============================================${NC}"
    echo -e "${BLUE}  Payload CMS - Datenbank Restore${NC}"
    echo -e "${BLUE}==============================================${NC}"
    echo ""
}

print_step() {
    echo -e "${BLUE}[$(date '+%H:%M:%S')]${NC} $1"
}

print_success() {
    echo -e "${GREEN}[✓]${NC} $1"
}

print_warning() {
    echo -e "${YELLOW}[!]${NC} $1"
}

print_error() {
    echo -e "${RED}[✗]${NC} ERROR: $1" >&2
}

check_pgpass() {
    local pgpass_file="$HOME/.pgpass"

    if [[ ! -f "$pgpass_file" ]]; then
        print_error ".pgpass nicht gefunden: $pgpass_file"
        exit 1
    fi

    local perms
    perms=$(stat -c%a "$pgpass_file" 2>/dev/null || echo "000")

    if [[ "$perms" != "600" ]]; then
        print_error ".pgpass hat unsichere Berechtigungen: $perms (erwartet: 600)"
        exit 1
    fi
}

check_s3cfg() {
    local s3cfg_file="$HOME/.s3cfg"

    if [[ ! -f "$s3cfg_file" ]]; then
        print_error ".s3cfg nicht gefunden - S3-Restore nicht möglich"
        return 1
    fi

    if ! command -v s3cmd &> /dev/null; then
        print_error "s3cmd nicht installiert"
        return 1
    fi

    return 0
}

test_db_connection() {
    print_step "Teste Datenbankverbindung..."

    if ! psql -h "$DB_HOST" -p "$DB_PORT" -U "$DB_USER" -d "$DB_NAME" -c "SELECT 1" > /dev/null 2>&1; then
        print_error "Datenbankverbindung fehlgeschlagen!"
        print_error "Prüfe ~/.pgpass und Netzwerkverbindung zu $DB_HOST:$DB_PORT"
        exit 1
    fi

    print_success "Datenbankverbindung OK"
}

list_local_backups() {
    echo ""
    echo -e "${BLUE}Lokale Backups in ${BACKUP_DIR}:${NC}"
    echo ""

    if [[ ! -d "$BACKUP_DIR" ]]; then
        print_warning "Backup-Verzeichnis existiert nicht"
        return 1
    fi

    local count=0
    while IFS= read -r file; do
        if [[ -n "$file" ]]; then
            local size
            size=$(du -h "$file" | cut -f1)
            local date
            date=$(stat -c%y "$file" | cut -d'.' -f1)
            local basename
            basename=$(basename "$file")

            count=$((count + 1))
            printf "  %2d) %-45s %6s  %s\n" "$count" "$basename" "$size" "$date"
        fi
    done < <(find "$BACKUP_DIR" -name "payload_db_*.sql.gz" -type f | sort -r)

    if [[ $count -eq 0 ]]; then
        print_warning "Keine Backups gefunden"
        return 1
    fi

    echo ""
    return 0
}

list_s3_backups() {
    echo ""
    echo -e "${BLUE}S3-Backups in s3://${S3_BUCKET}/${S3_PATH}/:${NC}"
    echo ""

    if ! check_s3cfg; then
        return 1
    fi

    local count=0
    while IFS= read -r line; do
        if [[ -n "$line" ]]; then
            local date size path
            date=$(echo "$line" | awk '{print $1, $2}')
            size=$(echo "$line" | awk '{print $3}')
            path=$(echo "$line" | awk '{print $4}')
            local basename
            basename=$(basename "$path")

            # Größe formatieren
            if [[ $size -gt 1048576 ]]; then
                size="$((size / 1048576))M"
            elif [[ $size -gt 1024 ]]; then
                size="$((size / 1024))K"
            else
                size="${size}B"
            fi

            count=$((count + 1))
            printf "  %2d) %-45s %6s  %s\n" "$count" "$basename" "$size" "$date"
        fi
    done < <(s3cmd ls "s3://${S3_BUCKET}/${S3_PATH}/" 2>/dev/null | grep "payload_db_.*\.sql\.gz" | sort -r)

    if [[ $count -eq 0 ]]; then
        print_warning "Keine S3-Backups gefunden"
        return 1
    fi

    echo ""
    return 0
}

select_local_backup() {
    local backups=()

    while IFS= read -r file; do
        if [[ -n "$file" ]]; then
            backups+=("$file")
        fi
    done < <(find "$BACKUP_DIR" -name "payload_db_*.sql.gz" -type f | sort -r)

    if [[ ${#backups[@]} -eq 0 ]]; then
        print_error "Keine lokalen Backups gefunden"
        exit 1
    fi

    list_local_backups

    read -p "Backup-Nummer auswählen (1-${#backups[@]}): " selection

    if ! [[ "$selection" =~ ^[0-9]+$ ]] || [[ $selection -lt 1 ]] || [[ $selection -gt ${#backups[@]} ]]; then
        print_error "Ungültige Auswahl"
        exit 1
    fi

    echo "${backups[$((selection-1))]}"
}

select_s3_backup() {
    local backups=()

    while IFS= read -r line; do
        if [[ -n "$line" ]]; then
            local path
            path=$(echo "$line" | awk '{print $4}')
            backups+=("$path")
        fi
    done < <(s3cmd ls "s3://${S3_BUCKET}/${S3_PATH}/" 2>/dev/null | grep "payload_db_.*\.sql\.gz" | sort -r)

    if [[ ${#backups[@]} -eq 0 ]]; then
        print_error "Keine S3-Backups gefunden"
        exit 1
    fi

    list_s3_backups

    read -p "Backup-Nummer auswählen (1-${#backups[@]}): " selection

    if ! [[ "$selection" =~ ^[0-9]+$ ]] || [[ $selection -lt 1 ]] || [[ $selection -gt ${#backups[@]} ]]; then
        print_error "Ungültige Auswahl"
        exit 1
    fi

    echo "${backups[$((selection-1))]}"
}

download_from_s3() {
    local s3_path="$1"
    local filename
    filename=$(basename "$s3_path")
    local local_path="${TEMP_DIR}/${filename}"

    mkdir -p "$TEMP_DIR"

    print_step "Lade Backup von S3 herunter: $filename"

    if s3cmd get "$s3_path" "$local_path" 2>/dev/null; then
        print_success "Download abgeschlossen"
        echo "$local_path"
    else
        print_error "Download fehlgeschlagen"
        exit 1
    fi
}

verify_backup() {
    local backup_file="$1"

    print_step "Verifiziere Backup-Integrität..."

    if ! gzip -t "$backup_file" 2>/dev/null; then
        print_error "Backup-Datei ist beschädigt (gzip-Test fehlgeschlagen)"
        exit 1
    fi

    print_success "Backup-Integrität OK"
}

get_db_stats() {
    local table_count row_count

    table_count=$(psql -h "$DB_HOST" -p "$DB_PORT" -U "$DB_USER" -d "$DB_NAME" -t -c \
        "SELECT COUNT(*) FROM information_schema.tables WHERE table_schema = 'public';" 2>/dev/null | tr -d ' ')

    row_count=$(psql -h "$DB_HOST" -p "$DB_PORT" -U "$DB_USER" -d "$DB_NAME" -t -c \
        "SELECT SUM(n_live_tup) FROM pg_stat_user_tables;" 2>/dev/null | tr -d ' ')

    echo "Tabellen: ${table_count:-0}, Zeilen: ${row_count:-0}"
}

stop_application() {
    print_step "Stoppe Payload CMS..."

    if command -v pm2 &> /dev/null; then
        if pm2 list 2>/dev/null | grep -q "payload"; then
            pm2 stop payload 2>/dev/null || true
            print_success "Payload gestoppt"
        else
            print_warning "Payload läuft nicht unter PM2"
        fi

        if pm2 list 2>/dev/null | grep -q "queue-worker"; then
            pm2 stop queue-worker 2>/dev/null || true
            print_success "Queue-Worker gestoppt"
        fi
    else
        print_warning "PM2 nicht verfügbar - bitte Anwendung manuell stoppen!"
        read -p "Weiter wenn Anwendung gestoppt? [Enter] " -r
    fi
}

start_application() {
    print_step "Starte Payload CMS..."

    if command -v pm2 &> /dev/null; then
        pm2 start payload 2>/dev/null || true
        pm2 start queue-worker 2>/dev/null || true
        print_success "Anwendung gestartet"
    else
        print_warning "PM2 nicht verfügbar - bitte Anwendung manuell starten!"
    fi
}

perform_restore() {
    local backup_file="$1"
    local filename
    filename=$(basename "$backup_file")

    echo ""
    echo -e "${YELLOW}╔════════════════════════════════════════════════════════════╗${NC}"
    echo -e "${YELLOW}║  WARNUNG: Datenbank-Restore überschreibt alle Daten!       ║${NC}"
    echo -e "${YELLOW}╚════════════════════════════════════════════════════════════╝${NC}"
    echo ""
    echo "  Backup:     $filename"
    echo "  Ziel:       $DB_NAME @ $DB_HOST:$DB_PORT"
    echo "  Aktuell:    $(get_db_stats)"
    echo ""

    read -p "Restore durchführen? Tippe 'RESTORE' zur Bestätigung: " confirmation

    if [[ "$confirmation" != "RESTORE" ]]; then
        print_warning "Restore abgebrochen"
        exit 0
    fi

    echo ""

    # Anwendung stoppen
    stop_application

    # Restore durchführen
    print_step "Führe Restore durch..."

    local start_time
    start_time=$(date +%s)

    if gunzip -c "$backup_file" | psql -h "$DB_HOST" -p "$DB_PORT" -U "$DB_USER" -d "$DB_NAME" -q 2>/dev/null; then
        local end_time
        end_time=$(date +%s)
        local duration=$((end_time - start_time))

        print_success "Restore abgeschlossen (${duration}s)"
    else
        print_error "Restore fehlgeschlagen!"
        start_application
        exit 1
    fi

    # Statistik nach Restore
    print_step "Verifiziere Restore..."
    echo "  Neue Statistik: $(get_db_stats)"

    # Anwendung starten
    start_application

    echo ""
    echo -e "${GREEN}╔════════════════════════════════════════════════════════════╗${NC}"
    echo -e "${GREEN}║  Restore erfolgreich abgeschlossen!                        ║${NC}"
    echo -e "${GREEN}╚════════════════════════════════════════════════════════════╝${NC}"
    echo ""
}

cleanup_temp() {
    if [[ -d "$TEMP_DIR" ]]; then
        rm -rf "$TEMP_DIR"
    fi
}

show_usage() {
    echo "Verwendung: $0 [OPTION] [BACKUP-DATEI]"
    echo ""
    echo "Optionen:"
    echo "  (keine)              Interaktive Auswahl aus lokalen Backups"
    echo "  <backup-datei>       Direktes Restore aus lokaler Datei"
    echo "  --from-s3            Interaktive Auswahl aus S3-Backups"
    echo "  --from-s3 <name>     Direktes Restore aus S3 (Dateiname)"
    echo "  --list               Lokale Backups auflisten"
    echo "  --list-s3            S3-Backups auflisten"
    echo "  --help               Diese Hilfe anzeigen"
    echo ""
    echo "Beispiele:"
    echo "  $0                                    # Interaktiv"
    echo "  $0 /path/to/backup.sql.gz            # Direkt lokal"
    echo "  $0 --from-s3                         # Interaktiv von S3"
    echo "  $0 --from-s3 payload_db_2025-12-11_03-00-00.sql.gz"
    echo ""
}

# ============================================================================
# Hauptprogramm
# ============================================================================

main() {
    trap cleanup_temp EXIT

    # Hilfe anzeigen
    if [[ "${1:-}" == "--help" || "${1:-}" == "-h" ]]; then
        show_usage
        exit 0
    fi

    # Backups auflisten
    if [[ "${1:-}" == "--list" ]]; then
        list_local_backups
        exit 0
    fi

    if [[ "${1:-}" == "--list-s3" ]]; then
        list_s3_backups
        exit 0
    fi

    print_header

    # Voraussetzungen prüfen
    check_pgpass
    test_db_connection

    local backup_file=""

    # S3-Restore
    if [[ "${1:-}" == "--from-s3" ]]; then
        if ! check_s3cfg; then
            exit 1
        fi

        local s3_path

        if [[ -n "${2:-}" ]]; then
            # Direkter S3-Pfad
            s3_path="s3://${S3_BUCKET}/${S3_PATH}/${2}"
        else
            # Interaktive Auswahl
            s3_path=$(select_s3_backup)
        fi

        backup_file=$(download_from_s3 "$s3_path")

    # Lokales Restore mit Dateiangabe
    elif [[ -n "${1:-}" ]]; then
        backup_file="$1"

        if [[ ! -f "$backup_file" ]]; then
            print_error "Backup-Datei nicht gefunden: $backup_file"
            exit 1
        fi

    # Interaktive lokale Auswahl
    else
        backup_file=$(select_local_backup)
    fi

    # Backup verifizieren
    verify_backup "$backup_file"

    # Restore durchführen
    perform_restore "$backup_file"
}

main "$@"