package plan

import (
	"fmt"
	"os/exec"
	"path/filepath"

	"metis/pkg/image"
	"metis/pkg/inventory"
)

// Execute performs a burn if confirm is true. With confirm=false, it only downloads/verifies and returns the plan.
func Execute(inv *inventory.Inventory, nodeName, device, cacheDir string, confirm bool) (*Plan, error) {
	p, err := Build(inv, nodeName, device, cacheDir)
	if err != nil {
		return nil, err
	}
	cacheImage := filepath.Join(cacheDir, filepath.Base(p.Image))
	if err := image.Download(p.Image, cacheImage); err != nil {
		return p, fmt.Errorf("download image: %w", err)
	}
	if err := image.VerifyChecksum(cacheImage, checksumFromInventory(inv, nodeName)); err != nil {
		return p, err
	}
	if !confirm {
		return p, nil
	}
	if device == "" || device == "/dev/sdX" {
		return p, fmt.Errorf("refusing to write to placeholder device")
	}
	ddCmd := []string{"dd", fmt.Sprintf("if=%s", cacheImage), fmt.Sprintf("of=%s", device), "bs=4M", "status=progress", "conv=fsync"}
	cmd := exec.Command(ddCmd[0], ddCmd[1:]...)
	cmd.Stdout = nil
	cmd.Stderr = nil
	if err := cmd.Run(); err != nil {
		return p, fmt.Errorf("dd failed: %w", err)
	}
	return p, nil
}

func checksumFromInventory(inv *inventory.Inventory, node string) string {
	_, cls, err := inv.FindNode(node)
	if err != nil || cls == nil {
		return ""
	}
	return cls.Checksum
}