package partition

import (
	"os"
	"path/filepath"
	"testing"
)

func TestReadVersion(t *testing.T) {
	dir := t.TempDir()
	versionFile := filepath.Join(dir, "version")
	if err := os.WriteFile(versionFile, []byte("1.2.3\n"), 0o644); err != nil {
		t.Fatal(err)
	}

	version, err := ReadVersion(dir)
	if err != nil {
		t.Fatal(err)
	}
	if version != "1.2.3" {
		t.Errorf("expected 1.2.3, got %s", version)
	}
}

func TestReadVersionMissing(t *testing.T) {
	dir := t.TempDir()
	_, err := ReadVersion(dir)
	if err == nil {
		t.Fatal("expected error for missing version file")
	}
}

func TestWriteSystemImage(t *testing.T) {
	mountPoint := t.TempDir()
	srcDir := t.TempDir()

	// Create source files
	vmlinuzPath := filepath.Join(srcDir, "vmlinuz")
	initramfsPath := filepath.Join(srcDir, "kubesolo-os.gz")

	if err := os.WriteFile(vmlinuzPath, []byte("kernel data"), 0o644); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(initramfsPath, []byte("initramfs data"), 0o644); err != nil {
		t.Fatal(err)
	}

	if err := WriteSystemImage(mountPoint, vmlinuzPath, initramfsPath, "2.0.0"); err != nil {
		t.Fatal(err)
	}

	// Verify files were copied
	data, err := os.ReadFile(filepath.Join(mountPoint, "vmlinuz"))
	if err != nil {
		t.Fatal(err)
	}
	if string(data) != "kernel data" {
		t.Errorf("vmlinuz content mismatch")
	}

	data, err = os.ReadFile(filepath.Join(mountPoint, "kubesolo-os.gz"))
	if err != nil {
		t.Fatal(err)
	}
	if string(data) != "initramfs data" {
		t.Errorf("initramfs content mismatch")
	}

	// Verify version file
	version, err := ReadVersion(mountPoint)
	if err != nil {
		t.Fatal(err)
	}
	if version != "2.0.0" {
		t.Errorf("expected version 2.0.0, got %s", version)
	}
}

func TestCopyFile(t *testing.T) {
	dir := t.TempDir()
	src := filepath.Join(dir, "src")
	dst := filepath.Join(dir, "dst")

	if err := os.WriteFile(src, []byte("test content"), 0o644); err != nil {
		t.Fatal(err)
	}

	if err := copyFile(src, dst); err != nil {
		t.Fatal(err)
	}

	data, err := os.ReadFile(dst)
	if err != nil {
		t.Fatal(err)
	}
	if string(data) != "test content" {
		t.Errorf("copy content mismatch")
	}
}

func TestCopyFileNotFound(t *testing.T) {
	dir := t.TempDir()
	err := copyFile("/nonexistent", filepath.Join(dir, "dst"))
	if err == nil {
		t.Fatal("expected error for nonexistent source")
	}
}

func TestGetSlotPartitionInvalid(t *testing.T) {
	_, err := GetSlotPartition("C")
	if err == nil {
		t.Fatal("expected error for invalid slot")
	}
}

func TestConstants(t *testing.T) {
	if LabelSystemA != "KSOLOA" {
		t.Errorf("unexpected LabelSystemA: %s", LabelSystemA)
	}
	if LabelSystemB != "KSOLOB" {
		t.Errorf("unexpected LabelSystemB: %s", LabelSystemB)
	}
	if LabelData != "KSOLODATA" {
		t.Errorf("unexpected LabelData: %s", LabelData)
	}
	if LabelEFI != "KSOLOEFI" {
		t.Errorf("unexpected LabelEFI: %s", LabelEFI)
	}
}