//
// Copyright 2021 The Sigstore 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 importkeypair

import (
	"context"
	"crypto/rand"
	"crypto/rsa"
	"crypto/x509"
	"encoding/pem"
	"os"
	"testing"

	"github.com/google/go-cmp/cmp"
	"github.com/sigstore/cosign/v3/cmd/cosign/cli/options"
	icos "github.com/sigstore/cosign/v3/internal/pkg/cosign"
)

func TestReadPasswordFn_env(t *testing.T) {
	t.Setenv("COSIGN_PASSWORD", "foo")
	b, err := readPasswordFn(true)()
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if diff := cmp.Diff("foo", string(b)); diff != "" {
		t.Fatal(diff)
	}
}

func TestReadPasswordFn_envEmptyVal(t *testing.T) {
	t.Setenv("COSIGN_PASSWORD", "")
	b, err := readPasswordFn(true)()
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if len(b) > 0 {
		t.Fatalf("expected empty string; got %q", string(b))
	}
}

func TestImportOfKeys(t *testing.T) {
	t.Setenv("COSIGN_PASSWORD", "test")

	privateKeyFileName := "my-private-key.pem"
	createTemporaryPrivateKeyForImporting(privateKeyFileName)

	// we pass in a custom outVal `my-test` because the ImportKeyPairCmd
	// doesn't care where the value comes from, only that it has a value.
	// be default it's set to `import-cosign`, but this is done by the CLI flag
	// framework if there is no value set by the user when running the
	// command.
	outputtedKeyPairFileName := "my-test"
	ImportKeyPairCmd(context.Background(), options.ImportKeyPairOptions{
		Key:              privateKeyFileName,
		OutputKeyPrefix:  outputtedKeyPairFileName,
		SkipConfirmation: false,
	}, nil)

	// removes temporary RSA private key used for test
	checkIfFileExistsThenDelete(privateKeyFileName, t)

	// checks if the outputted key pairs have been created based on
	// the imported RSA private key, and then deletes them as per test
	// cleanup
	checkIfFileExistsThenDelete(outputtedKeyPairFileName+".key", t)
	checkIfFileExistsThenDelete(outputtedKeyPairFileName+".pub", t)
}

func createTemporaryPrivateKeyForImporting(privateKeyName string) {
	bitSize := 4096

	// Generate RSA key.
	key, err := rsa.GenerateKey(rand.Reader, bitSize)
	if err != nil {
		panic(err)
	}

	// Encode private key to PKCS#1 ASN.1 PEM.
	keyPEM := pem.EncodeToMemory(
		&pem.Block{
			Type:  "RSA PRIVATE KEY",
			Bytes: x509.MarshalPKCS1PrivateKey(key),
		},
	)

	// Write private key to file.
	if err := os.WriteFile(privateKeyName, keyPEM, 0700); err != nil {
		panic(err)
	}
}

func checkIfFileExistsThenDelete(fileName string, t *testing.T) {
	fileExists, err := icos.FileExists(fileName)
	if err != nil {
		t.Fatalf("failed checking if %s exists: %v", fileName, err)
	}

	if !fileExists {
		t.Fatalf("key generation for key %s failed", fileName)
	}

	t.Logf("key generation for key %s succeeded", fileName)

	deleteKeyFile(fileName, t)
}

func deleteKeyFile(fileName string, t *testing.T) {
	t.Cleanup(func() {
		t.Logf("Removing keyfile %s...", fileName)
		os.Remove(fileName)
		t.Logf("Removed keyfile %s", fileName)
	})
}