// Package client provides ZFS snapshot backup client functionality.
// This file contains snapshot management functions for creating and sending snapshots.
package client

import (
	"fmt"
	"os/exec"
	"strings"

	"github.com/mistifyio/go-zfs"
)

// CreateBookmark creates a ZFS bookmark from a snapshot.
// Bookmarks allow incremental sends even after the source snapshot is deleted.
func (c *Client) CreateBookmark(snapshot *zfs.Dataset) error {
	// Extract snapshot name from full path (dataset@snapshot -> snapshot)
	parts := strings.Split(snapshot.Name, "@")
	if len(parts) != 2 {
		return fmt.Errorf("invalid snapshot name format: %s", snapshot.Name)
	}
	snapshotName := parts[1]
	bookmarkName := fmt.Sprintf("%s#%s", c.config.LocalDataset, snapshotName)

	// Create bookmark using zfs command
	cmd := exec.Command("zfs", "bookmark", snapshot.Name, bookmarkName)
	output, err := cmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("failed to create bookmark: %v: %s", err, string(output))
	}

	fmt.Printf("✓ Created bookmark: %s\n", bookmarkName)
	return nil
}

// GetLastBookmark returns the most recent bookmark for the dataset.
// Bookmarks are used as the base for incremental sends.
func (c *Client) GetLastBookmark() (string, error) {
	// List all bookmarks for the dataset
	cmd := exec.Command("zfs", "list", "-t", "bookmark", "-o", "name", "-H", "-r", c.config.LocalDataset)
	output, err := cmd.Output()
	if err != nil {
		return "", nil // No bookmarks yet
	}

	bookmarks := strings.Split(strings.TrimSpace(string(output)), "\n")
	if len(bookmarks) == 0 || bookmarks[0] == "" {
		return "", nil
	}

	// Return the last bookmark (most recent)
	return bookmarks[len(bookmarks)-1], nil
}

// GetLastSnapshot returns the most recent snapshot for the dataset.
func (c *Client) GetLastSnapshot() (*zfs.Dataset, error) {
	ds, err := zfs.GetDataset(c.config.LocalDataset)
	if err != nil {
		return nil, fmt.Errorf("failed to get dataset: %v", err)
	}

	snapshots, err := ds.Snapshots()
	if err != nil {
		return nil, fmt.Errorf("failed to list snapshots: %v", err)
	}

	if len(snapshots) == 0 {
		return nil, nil
	}

	// Return the last snapshot (most recent)
	return snapshots[len(snapshots)-1], nil
}

// SendIncremental is kept for API compatibility - now just calls HTTP version
func (c *Client) SendIncremental(snapshot *zfs.Dataset, base string) error {
	return c.SendIncrementalHTTP(snapshot, base)
}