/*
   Copyright The containerd Authors.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/

package main

import (
	"os"
	"os/exec"
	"testing"

	"github.com/containerd/go-dmverity/pkg/utils"
)

func TestVerify(t *testing.T) {
	utils.RequireTool(t, "veritysetup")

	data, hash, rootHex := utils.CreateFormattedFiles(t)

	params := utils.DefaultVerityTestParams()
	args := params.BuildVerifyArgs(data, hash, rootHex)
	_, _ = utils.RunGoCLI(t, args...)

	cArgs := params.BuildCVeritysetupVerifyArgs(data, hash, rootHex)
	out, err := exec.Command("veritysetup", cArgs...).CombinedOutput()
	if err != nil {
		t.Fatalf("veritysetup verify failed: %v\n%s", err, string(out))
	}
}

func TestVerify_CrossImplementation(t *testing.T) {
	utils.RequireTool(t, "veritysetup")

	data, hash := utils.MakeTempFile(t, 4096*16), utils.MakeTempFile(t, 0)
	params := utils.DefaultVerityTestParams()

	formatArgs := []string{"format"}
	if params.Hash != "" {
		formatArgs = append(formatArgs, "--hash", params.Hash)
	}
	if params.DataBlockSize != "" {
		formatArgs = append(formatArgs, "--data-block-size", params.DataBlockSize)
	}
	if params.HashBlockSize != "" {
		formatArgs = append(formatArgs, "--hash-block-size", params.HashBlockSize)
	}
	if params.Salt != "" {
		formatArgs = append(formatArgs, "--salt", params.Salt)
	}
	if params.NoSuperblock {
		formatArgs = append(formatArgs, "--no-superblock")
		if params.HashOffset != "" {
			formatArgs = append(formatArgs, "--hash-offset", params.HashOffset)
		}
	}
	formatArgs = append(formatArgs, data, hash)

	outC, err := exec.Command("veritysetup", formatArgs...).CombinedOutput()
	if err != nil {
		t.Fatalf("veritysetup format failed: %v\n%s", err, string(outC))
	}
	rootHex := utils.ExtractRootHex(t, string(outC))

	verifyArgs := params.BuildVerifyArgs(data, hash, rootHex)
	_, _ = utils.RunGoCLI(t, verifyArgs...)
}

func TestVerify_WithSuperblock(t *testing.T) {
	data := utils.MakeTempFile(t, 4096*16)
	hash := utils.MakeTempFile(t, 0)

	outGo, _ := utils.RunGoCLI(t, "format", "--hash", "sha256", "--data-block-size", "4096", "--hash-block-size", "4096", "--salt", "-", data, hash)
	rootHex := utils.ExtractRootHex(t, outGo)

	_, _ = utils.RunGoCLI(t, "verify", data, hash, rootHex)
}

func TestVerify_NoSuperblock(t *testing.T) {
	data := utils.MakeTempFile(t, 4096*16)
	hash := utils.MakeTempFile(t, 0)

	outGo, _ := utils.RunGoCLI(t, "format", "--hash", "sha256", "--data-block-size", "4096", "--hash-block-size", "4096", "--salt", "-", "--no-superblock", "--hash-offset", "0", data, hash)
	rootHex := utils.ExtractRootHex(t, outGo)

	params := utils.DefaultVerityTestParams()
	args := params.BuildVerifyArgs(data, hash, rootHex)
	_, _ = utils.RunGoCLI(t, args...)
}

func TestVerify_CorruptedData(t *testing.T) {
	data := utils.MakeTempFile(t, 4096*16)
	hash := utils.MakeTempFile(t, 0)

	outGo, _ := utils.RunGoCLI(t, "format", "--hash", "sha256", "--data-block-size", "4096", "--hash-block-size", "4096", "--salt", "-", data, hash)
	rootHex := utils.ExtractRootHex(t, outGo)

	f, err := os.OpenFile(data, os.O_WRONLY, 0)
	if err != nil {
		t.Fatalf("failed to open data file: %v", err)
	}
	if _, err := f.WriteAt([]byte("corrupted"), 0); err != nil {
		t.Fatalf("failed to corrupt data: %v", err)
	}
	f.Close()

	cmd := exec.Command("go-dmverity", "verify", data, hash, rootHex)
	out, err := cmd.CombinedOutput()
	if err == nil {
		t.Errorf("expected verification to fail for corrupted data, got output: %s", string(out))
	}
}

func TestVerify_WrongRootHash(t *testing.T) {
	data, hash, _ := utils.CreateFormattedFiles(t)

	wrongRoot := "0000000000000000000000000000000000000000000000000000000000000000"
	cmd := exec.Command("go-dmverity", "verify", "--hash", "sha256", "--data-block-size", "4096", "--hash-block-size", "4096", "--salt", "-", data, hash, wrongRoot)
	out, err := cmd.CombinedOutput()
	if err == nil {
		t.Errorf("expected verification to fail with wrong root hash, got output: %s", string(out))
	}
}

func TestParseVerifyArgs_InvalidArgs(t *testing.T) {
	tests := []struct {
		name string
		args []string
	}{
		{
			name: "missing arguments",
			args: []string{"data", "hash"},
		},
		{
			name: "invalid data block size",
			args: []string{"--data-block-size", "1000", "data", "hash", "root"},
		},
		{
			name: "invalid hash block size",
			args: []string{"--hash-block-size", "1000", "data", "hash", "root"},
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			_, _, _, _, err := parseVerifyArgs(tt.args)
			if err == nil {
				t.Error("expected error, got nil")
			}
		})
	}
}