// Command zfs-restore is a CLI tool for restoring ZFS snapshots from a backup server.
// It provides commands for listing, restoring, and mounting snapshots.
package main

import (
	"fmt"
	"os"
	"sort"

	"git.ma-al.com/goc_marek/zfs/internal/restore"
)

func main() {
	if len(os.Args) < 2 {
		printUsage()
		os.Exit(1)
	}

	// Load configuration from environment and .env file
	cfg := restore.LoadConfig()
	client := restore.New(cfg.ClientID, cfg.APIKey, cfg.ServerURL)

	command := os.Args[1]

	switch command {
	case "list":
		snapshots, err := client.ListSnapshots()
		if err != nil {
			fmt.Printf("Error: %v\n", err)
			os.Exit(1)
		}
		client.DisplaySnapshots(snapshots)

	case "restore":
		if len(os.Args) < 4 {
			fmt.Println("Usage: zfs-restore restore <snapshot-number> <target-dataset> [--force]")
			os.Exit(1)
		}

		snapshots, err := client.ListSnapshots()
		if err != nil {
			fmt.Printf("Error: %v\n", err)
			os.Exit(1)
		}

		// Sort by timestamp (newest first)
		sort.Slice(snapshots, func(i, j int) bool {
			return snapshots[i].Timestamp.After(snapshots[j].Timestamp)
		})

		// Parse snapshot number
		var snapNum int
		fmt.Sscanf(os.Args[2], "%d", &snapNum)

		if snapNum < 1 || snapNum > len(snapshots) {
			fmt.Printf("Invalid snapshot number. Use 'list' to see available snapshots.\n")
			os.Exit(1)
		}

		snapshot := snapshots[snapNum-1]
		targetDataset := os.Args[3]
		force := len(os.Args) > 4 && os.Args[4] == "--force"

		if err := client.RestoreSnapshot(snapshot, targetDataset, force); err != nil {
			fmt.Printf("Error: %v\n", err)
			os.Exit(1)
		}

	case "save":
		if len(os.Args) < 4 {
			fmt.Println("Usage: zfs-restore save <snapshot-number> <output-file>")
			os.Exit(1)
		}

		snapshots, err := client.ListSnapshots()
		if err != nil {
			fmt.Printf("Error: %v\n", err)
			os.Exit(1)
		}

		sort.Slice(snapshots, func(i, j int) bool {
			return snapshots[i].Timestamp.After(snapshots[j].Timestamp)
		})

		var snapNum int
		fmt.Sscanf(os.Args[2], "%d", &snapNum)

		if snapNum < 1 || snapNum > len(snapshots) {
			fmt.Printf("Invalid snapshot number.\n")
			os.Exit(1)
		}

		snapshot := snapshots[snapNum-1]
		outputFile := os.Args[3]

		if err := client.RestoreToFile(snapshot, outputFile); err != nil {
			fmt.Printf("Error: %v\n", err)
			os.Exit(1)
		}

	case "mount":
		if len(os.Args) < 4 {
			fmt.Println("Usage: zfs-restore mount <dataset> <mountpoint>")
			os.Exit(1)
		}

		dataset := os.Args[2]
		mountpoint := os.Args[3]

		if err := client.MountSnapshot(dataset, mountpoint); err != nil {
			fmt.Printf("Error: %v\n", err)
			os.Exit(1)
		}

	case "latest":
		if len(os.Args) < 3 {
			fmt.Println("Usage: zfs-restore latest <target-dataset> [--force]")
			os.Exit(1)
		}

		snapshots, err := client.ListSnapshots()
		if err != nil {
			fmt.Printf("Error: %v\n", err)
			os.Exit(1)
		}

		if len(snapshots) == 0 {
			fmt.Println("No snapshots available")
			os.Exit(1)
		}

		// Sort and get latest
		sort.Slice(snapshots, func(i, j int) bool {
			return snapshots[i].Timestamp.After(snapshots[j].Timestamp)
		})

		latest := snapshots[0]
		targetDataset := os.Args[2]
		force := len(os.Args) > 3 && os.Args[3] == "--force"

		fmt.Printf("Restoring latest snapshot from %s\n", latest.Timestamp.Format("2006-01-02 15:04:05"))

		if err := client.RestoreSnapshot(latest, targetDataset, force); err != nil {
			fmt.Printf("Error: %v\n", err)
			os.Exit(1)
		}

	case "help", "-h", "--help":
		printUsage()

	default:
		fmt.Printf("Unknown command: %s\n", command)
		printUsage()
		os.Exit(1)
	}
}

func printUsage() {
	fmt.Println("ZFS Snapshot Restore Tool")
	fmt.Println("\nUsage: zfs-restore [command] [options]")
	fmt.Println("\nCommands:")
	fmt.Println("  list                              - List available snapshots")
	fmt.Println("  restore <#> <dataset> [--force]   - Restore snapshot to ZFS dataset")
	fmt.Println("  latest <dataset> [--force]        - Restore most recent snapshot")
	fmt.Println("  save <#> <file>                   - Save snapshot to file")
	fmt.Println("  mount <dataset> <mountpoint>      - Mount restored dataset")
	fmt.Println("  help                              - Show this help message")
	fmt.Println("\nExamples:")
	fmt.Println("  zfs-restore list")
	fmt.Println("  zfs-restore restore 1 tank/restored")
	fmt.Println("  zfs-restore latest tank/restored --force")
	fmt.Println("  zfs-restore save 2 backup.zfs.lz4")
	fmt.Println("  zfs-restore mount tank/restored /mnt/restore")
	fmt.Println("\nEnvironment Variables (can be set in .env file):")
	fmt.Println("  CLIENT_ID    - Client identifier (default: client1)")
	fmt.Println("  API_KEY      - API key for authentication (default: secret123)")
	fmt.Println("  SERVER_URL   - Backup server URL (default: http://localhost:8080)")
}