// tenantbackup-cli ist der Aufrufpunkt fuer BAK-04: Sicherung/
// Wiederherstellung EINES einzelnen Mandanten (Datenbank UND
// Objekt-Storage-Root), unabhaengig vom Gesamt-Backup (BAK-01/BAK-02)
// planbar - eigener systemd-Timer, eigenes Log.
package main

import (
	"context"
	"flag"
	"fmt"
	"log"
	"os"
	"time"

	"gitea.perlbach24.de/scripte/nexarch/archive/internal/objectbackup"
	"gitea.perlbach24.de/scripte/nexarch/archive/internal/tenantbackup"
)

func main() {
	if len(os.Args) < 2 {
		usage()
		os.Exit(2)
	}
	logPath := os.Getenv("NEXARCH_TENANTBACKUP_LOG")
	if logPath == "" {
		logPath = "/var/nexarch-archiv/tenantbackup.log"
	}

	switch os.Args[1] {
	case "backup":
		runBackup(logPath, os.Args[2:])
	case "restore":
		runRestore(logPath, os.Args[2:])
	default:
		usage()
		os.Exit(2)
	}
}

func usage() {
	fmt.Fprintln(os.Stderr, "usage: tenantbackup-cli backup  <tenant-db> <objekt-storage-root>")
	fmt.Fprintln(os.Stderr, "       tenantbackup-cli restore <tenant-db> <ziel-db> <dump-datei> [<snapshot-id> <objekt-ziel-verzeichnis>]")
}

func dbConfig() tenantbackup.Config {
	return tenantbackup.Config{
		Host:      os.Getenv("NEXARCH_BACKUP_PG_HOST"),
		Port:      os.Getenv("NEXARCH_BACKUP_PG_PORT"),
		User:      os.Getenv("NEXARCH_BACKUP_PG_USER"),
		Password:  os.Getenv("NEXARCH_BACKUP_PG_PASSWORD"),
		BackupDir: os.Getenv("NEXARCH_TENANTBACKUP_DIR"),
	}
}

func objConfig(tenantDB string) objectbackup.Config {
	return objectbackup.Config{
		RepoDir:  os.Getenv("NEXARCH_TENANTBACKUP_OBJECT_REPO_ROOT") + "/" + tenantDB,
		Password: os.Getenv("NEXARCH_OBJECTBACKUP_PASSWORD"),
	}
}

func runBackup(logPath string, args []string) {
	fs := flag.NewFlagSet("backup", flag.ExitOnError)
	if err := fs.Parse(args); err != nil {
		os.Exit(2)
	}
	if fs.NArg() != 2 {
		usage()
		os.Exit(2)
	}
	tenantDB, storageRoot := fs.Arg(0), fs.Arg(1)
	ctx := context.Background()
	genID := time.Now().UTC().Format("20060102T150405Z")

	dbCfg := dbConfig()
	dumpPath, err := tenantbackup.Backup(ctx, dbCfg, tenantDB, genID)
	logEntry(logPath, tenantbackup.OpBackupDB, tenantDB, "", dumpPath, err)
	if err != nil {
		log.Fatalf("datenbank-sicherung: %v", err)
	}
	if err := tenantbackup.Verify(ctx, dbCfg, dumpPath); err != nil {
		log.Fatalf("datenbank-sicherung verifizieren: %v", err)
	}

	objCfg := objConfig(tenantDB)
	if err := objectbackup.InitRepo(ctx, objCfg); err != nil {
		log.Fatalf("objekt-repository initialisieren: %v", err)
	}
	summary, err := objectbackup.Backup(ctx, objCfg, storageRoot)
	logEntry(logPath, tenantbackup.OpBackupObj, tenantDB, storageRoot, summary.SnapshotID, err)
	if err != nil {
		log.Fatalf("objekt-storage-sicherung: %v", err)
	}

	fmt.Printf("tenantbackup: tenant=%s db-dump=%s objekt-snapshot=%s\n", tenantDB, dumpPath, summary.SnapshotID)
}

func runRestore(logPath string, args []string) {
	fs := flag.NewFlagSet("restore", flag.ExitOnError)
	if err := fs.Parse(args); err != nil {
		os.Exit(2)
	}
	if fs.NArg() < 3 {
		usage()
		os.Exit(2)
	}
	tenantDB, targetDB, dumpPath := fs.Arg(0), fs.Arg(1), fs.Arg(2)
	ctx := context.Background()

	dbCfg := dbConfig()
	err := tenantbackup.CreateEmptyDatabase(ctx, dbCfg, targetDB)
	if err == nil {
		err = tenantbackup.Restore(ctx, dbCfg, dumpPath, targetDB)
	}
	logEntry(logPath, tenantbackup.OpRestoreDB, tenantDB, dumpPath, targetDB, err)
	if err != nil {
		log.Fatalf("datenbank-restore: %v", err)
	}
	fmt.Printf("tenantbackup restore: tenant=%s ziel-db=%s ergebnis=ok\n", tenantDB, targetDB)

	if fs.NArg() < 5 {
		return
	}
	snapshotID, objTarget := fs.Arg(3), fs.Arg(4)
	objCfg := objConfig(tenantDB)
	err = objectbackup.Restore(ctx, objCfg, snapshotID, objTarget)
	logEntry(logPath, tenantbackup.OpRestoreObj, tenantDB, snapshotID, objTarget, err)
	if err != nil {
		log.Fatalf("objekt-storage-restore: %v", err)
	}
	fmt.Printf("tenantbackup restore: tenant=%s objekt-ziel=%s ergebnis=ok\n", tenantDB, objTarget)
}

func logEntry(logPath string, op tenantbackup.Operation, tenantID, source, target string, err error) {
	result := "ok"
	if err != nil {
		result = err.Error()
	}
	entry := tenantbackup.LogEntry{
		Timestamp: time.Now().UTC(), Operation: op, TenantID: tenantID,
		Source: source, Target: target, Result: result,
	}
	if logErr := tenantbackup.AppendLog(logPath, entry); logErr != nil {
		log.Fatalf("protokoll schreiben: %v", logErr)
	}
}