package qcow2

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

	"github.com/bazelbuild/rules_go/go/runfiles"
)

var (
	// These are filled by bazel at linking time with the canonical path of
	// their corresponding file. Inside the init function we resolve it
	// with the rules_go runfiles package to the real path.
	xQemuImgPath string
)

func init() {
	var err error
	for _, path := range []*string{
		&xQemuImgPath,
	} {
		*path, err = runfiles.Rlocation(*path)
		if err != nil {
			panic(err)
		}
	}
}

// TestGenerate exercises the Generate function for a variety of image sizes.
func TestGenerate(t *testing.T) {
	// Test all orders of magnitude from 1KiB to 1PiB.
	for i := 20; i < 50; i++ {
		t.Run(fmt.Sprintf("%d", 1<<i), func(t *testing.T) {
			path := filepath.Join(t.TempDir(), "test.qcow2")

			f, err := os.Create(path)
			if err != nil {
				t.Fatalf("Could not create test image file: %v", err)
			}
			if err := Generate(f, GenerateWithFileSize(1<<i)); err != nil {
				t.Fatalf("Generate(%d bytes): %v", 1<<i, err)
			}
			if err := f.Close(); err != nil {
				t.Fatalf("Close: %v", err)
			}

			cmd := exec.Command(xQemuImgPath, "check", path)
			if err := cmd.Run(); err != nil {
				t.Fatalf("qemu-img check failed: %v", err)
			}
		})
	}
}