package cmd

import (
	"fmt"
	piperhttp "github.com/SAP/jenkins-library/pkg/http"
	"github.com/stretchr/testify/assert"
	"io"
	"io/ioutil"
	"net/http"
	"strings"
	"testing"
)

var malwareScanConfig = malwareExecuteScanOptions{
	Host:     "https://example.org/malwarescanner",
	Username: "me",
	Password: "********",
	File:     "target/myFile",
	Timeout:  "60",
}

func TestMalwareScanTests(t *testing.T) {

	open = openFileMock()

	getSHA256 = func(path string) (string, error) {
		return "96ca802fbd54d31903f1115a1d95590c685160637d9262bd340ab30d0f817e85", nil
	}
	defer func() {
		open = _open
		getSHA256 = _getSHA256
	}()

	t.Run("No malware, no encrypted content", func(t *testing.T) {
		httpClient := httpMock{StatusCode: 200, ResponseBody: "{\"malwareDetected\":false,\"encryptedContentDetected\":false,\"scanSize\":298782,\"mimeType\":\"application/octet-stream\",\"SHA256\":\"96ca802fbd54d31903f1115a1d95590c685160637d9262bd340ab30d0f817e85\"}"}

		error := runMalwareScan(&malwareScanConfig, nil, nil, &httpClient)

		if assert.NoError(t, error) {

			t.Run("check url", func(t *testing.T) {
				assert.Equal(t, "https://example.org/malwarescanner/scan", httpClient.URL)
			})

			t.Run("check method", func(t *testing.T) {
				assert.Equal(t, "POST", httpClient.Method)
			})

			t.Run("check user", func(t *testing.T) {
				assert.Equal(t, "me", httpClient.Options.Username)
			})

			t.Run("check password", func(t *testing.T) {
				assert.Equal(t, "********", httpClient.Options.Password)
			})
		}
	})

	t.Run("Malware detected", func(t *testing.T) {

		httpClient := httpMock{StatusCode: 200, ResponseBody: "{\"malwareDetected\":true,\"encryptedContentDetected\":false,\"scanSize\":298782,\"mimeType\":\"application/octet-stream\",\"SHA256\":\"96ca802fbd54d31903f1115a1d95590c685160637d9262bd340ab30d0f817e85\"}"}
		error := runMalwareScan(&malwareScanConfig, nil, nil, &httpClient)
		assert.EqualError(t, error, "Malware scan failed for file 'target/myFile'. Malware detected: true, encrypted content detected: false")
	})

	t.Run("Encrypted content detected", func(t *testing.T) {

		httpClient := httpMock{StatusCode: 200, ResponseBody: "{\"malwareDetected\": false, \"encryptedContentDetected\": true, \"scanSize\":298782,\"mimeType\":\"application/octet-stream\",\"SHA256\":\"96ca802fbd54d31903f1115a1d95590c685160637d9262bd340ab30d0f817e85\"}"}
		error := runMalwareScan(&malwareScanConfig, nil, nil, &httpClient)
		assert.EqualError(t, error, "Malware scan failed for file 'target/myFile'. Malware detected: false, encrypted content detected: true")
	})

	t.Run("Malware and encrypted content detected", func(t *testing.T) {

		httpClient := httpMock{StatusCode: 200, ResponseBody: "{\"malwareDetected\": true, \"encryptedContentDetected\": true, \"scanSize\":298782,\"mimeType\":\"application/octet-stream\",\"SHA256\":\"96ca802fbd54d31903f1115a1d95590c685160637d9262bd340ab30d0f817e85\"}"}
		error := runMalwareScan(&malwareScanConfig, nil, nil, &httpClient)
		assert.EqualError(t, error, "Malware scan failed for file 'target/myFile'. Malware detected: true, encrypted content detected: true")
	})
}

func TestMalwareScanRequest(t *testing.T) {

	httpClient := httpMock{StatusCode: 200, ResponseBody: "{\"malwareDetected\":false,\"encryptedContentDetected\":false,\"scanSize\":298782,\"mimeType\":\"application/octet-stream\",\"SHA256\":\"96ca802fbd54d31903f1115a1d95590c685160637d9262bd340ab30d0f817e85\"}"}
	candidate := readCloserMock{Content: "HELLO"}

	malWareScanResponse, err := sendMalwareScanRequest(&httpClient, "POST", "https://example.org/malwarescanner", candidate)

	t.Run("Malware - scanRequest - check response body closed", func(t *testing.T) {
		if assert.NoError(t, err) {
			assert.True(t, httpClient.Body.Closed)
		}
	})

	t.Run("Malware - scanRequest - check scan response", func(t *testing.T) {

		if assert.NoError(t, err) {
			assert.False(t, malWareScanResponse.MalwareDetected)
			assert.False(t, malWareScanResponse.EncryptedContentDetected)
			assert.Equal(t, 298782, malWareScanResponse.ScanSize)
			assert.Equal(t, "96ca802fbd54d31903f1115a1d95590c685160637d9262bd340ab30d0f817e85", malWareScanResponse.SHA256)
		}
	})
}

func TestMalwareMarshalBody(t *testing.T) {

	t.Run("Malware - marshalResponse - body uninitialized", func(t *testing.T) {
		var body []byte
		r, error := marshalResponse(body)
		assert.Nil(t, r)
		assert.EqualError(t, error, "Unmarshalling of response body failed. Body: '': unexpected end of JSON input")
	})
}

func TestMalwareValidateResponse(t *testing.T) {

	t.Run("Malware - validateResponse - HTTP error", func(t *testing.T) {
		r, e := validateResponse(nil, fmt.Errorf("request error"))
		assert.Nil(t, r)
		assert.EqualError(t, e, "HTTP request failed with error: request error. Details: \"\"")
	})
	t.Run("Malware - validateResponse - empty response", func(t *testing.T) {
		r, e := validateResponse(&http.Response{}, fmt.Errorf("request error"))
		assert.Nil(t, r)
		assert.EqualError(t, e, "HTTP request failed with error: request error. Details: \"\"")
	})

	t.Run("Malware - validateResponse - status code 500", func(t *testing.T) {
		mock := responseMock(500, true)
		r, e := validateResponse(mock, nil)
		assert.Nil(t, r)
		assert.True(t, strings.HasPrefix(e.Error(), "Unexpected response code (500)"))
	})

	t.Run("Malware - validateResponse - malwareDetected", func(t *testing.T) {
		mock := responseMock(200, true)
		r, e := validateResponse(mock, nil)
		assert.NotNil(t, r)
		assert.Nil(t, e)
	})

}

func responseMock(code int, malwareDetected bool) *http.Response {
	if malwareDetected {
		return &http.Response{StatusCode: code, Body: &readCloserMock{Content: "{\"malwareDetected\":true,\"encryptedContentDetected\":false,\"scanSize\":298782,\"mimeType\":\"application/octet-stream\",\"SHA256\":\"96ca802fbd54d31903f1115a1d95590c685160637d9262bd340ab30d0f817e85\"}"}}
	}
	return &http.Response{StatusCode: code, Body: &readCloserMock{Content: "{\"malwareDetected\":false,\"encryptedContentDetected\":false,\"scanSize\":298782,\"mimeType\":\"application/octet-stream\",\"SHA256\":\"96ca802fbd54d31903f1115a1d95590c685160637d9262bd340ab30d0f817e85\"}"}}
}

func TestMalwareFileNotFound(t *testing.T) {

	httpClient := httpMock{StatusCode: 200}

	open = func(path string) (io.ReadCloser, error) {
		return nil, fmt.Errorf("open %s: no such file or directory", path)
	}
	defer func() { open = _open }()
	error := runMalwareScan(&malwareScanConfig, nil, nil, &httpClient)

	assert.Error(t, error, "open target/myFile: no such file or directory")
}

func TestMalwareInternalServerError(t *testing.T) {

	httpClient := httpMock{StatusCode: 500, ResponseBody: "internal server error"}

	open = openFileMock()

	defer func() { open = _open }()

	err := runMalwareScan(&malwareScanConfig, nil, nil, &httpClient)

	assert.Error(t, err, "Unexpected response code (500). 200 expected. Details: \"internal server error\"")
}

func TestMalwareRetrieveHash(t *testing.T) {

	open = openFileMock()

	defer func() {
		open = _open
	}()
	hash, err := _getSHA256("target/myFile")

	if assert.NoError(t, err) {
		assert.Equal(t, "3733cd977ff8eb18b987357e22ced99f46097f31ecb239e878ae63760e83e4d5", hash)
	}
}

func openFileMock() func(path string) (io.ReadCloser, error) {
	return func(path string) (io.ReadCloser, error) {
		if path == "target/myFile" {
			return &readCloserMock{Content: "HELLO"}, nil // the content does not matter
		}
		return nil, fmt.Errorf("open %s: no such file or directory", path)
	}
}

type httpMock struct {
	Method       string                  // is set during test execution
	URL          string                  // is set before test execution
	ResponseBody string                  // is set before test execution
	Options      piperhttp.ClientOptions // is set during test
	StatusCode   int                     // is set during test
	Body         readCloserMock          // is set during test
}

func (c *httpMock) SetOptions(options piperhttp.ClientOptions) {
	c.Options = options
}

func (c *httpMock) SendRequest(method string, url string, r io.Reader, header http.Header, cookies []*http.Cookie) (*http.Response, error) {

	c.Method = method
	c.URL = url

	_, err := ioutil.ReadAll(r)

	if err != nil {
		return nil, err
	}

	c.Body = readCloserMock{Content: c.ResponseBody}
	res := http.Response{StatusCode: c.StatusCode, Body: &c.Body}

	return &res, nil
}

type readCloserMock struct {
	Content string
	Closed  bool
}

func (rc readCloserMock) Read(b []byte) (n int, err error) {

	if len(b) < len(rc.Content) {
		// in real life we would fill the buffer according to buffer size ...
		return 0, fmt.Errorf("Buffer size (%d) not sufficient, need: %d", len(b), len(rc.Content))
	}
	copy(b, rc.Content)
	return len(rc.Content), io.EOF
}

func (rc *readCloserMock) Close() error {
	rc.Closed = true
	return nil
}