package filestore_test

import (
	"context"
	"errors"
	"io"
	"io/ioutil"
	"strings"
	"testing"
	"time"

	"git.netflux.io/rob/clipper/filestore"
	"git.netflux.io/rob/clipper/generated/mocks"
	signerv4 "github.com/aws/aws-sdk-go-v2/aws/signer/v4"
	"github.com/aws/aws-sdk-go-v2/service/s3"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/mock"
	"github.com/stretchr/testify/require"
	"go.uber.org/zap"
)

func TestS3GetObject(t *testing.T) {
	const (
		bucket  = "some-bucket"
		key     = "foo/bar"
		content = "hello world"
	)
	body := io.NopCloser(strings.NewReader(content))

	var s3Client mocks.S3Client
	s3Client.On("GetObject", mock.Anything, mock.MatchedBy(func(input *s3.GetObjectInput) bool {
		return *input.Bucket == bucket && *input.Key == key
	})).Return(&s3.GetObjectOutput{Body: body}, nil)
	defer s3Client.AssertExpectations(t)

	store := filestore.NewS3FileStore(filestore.S3API{S3Client: &s3Client}, bucket, time.Minute, zap.NewNop().Sugar())
	output, err := store.GetObject(context.Background(), key)
	require.NoError(t, err)
	defer output.Close()

	actual, err := ioutil.ReadAll(output)
	require.NoError(t, err)
	assert.Equal(t, content, string(actual))
}

func TestS3GetObjectWithRange(t *testing.T) {
	const (
		bucket  = "some-bucket"
		key     = "foo/bar"
		content = "hello world"
		start   = 256
		end     = 32_768
	)
	body := io.NopCloser(strings.NewReader(content))

	var s3Client mocks.S3Client
	s3Client.On("GetObject", mock.Anything, mock.MatchedBy(func(input *s3.GetObjectInput) bool {
		return *input.Bucket == bucket && *input.Key == key && *input.Range == "bytes=256-32768"
	})).Return(&s3.GetObjectOutput{Body: body}, nil)
	defer s3Client.AssertExpectations(t)

	store := filestore.NewS3FileStore(filestore.S3API{S3Client: &s3Client}, bucket, time.Minute, zap.NewNop().Sugar())
	output, err := store.GetObjectWithRange(context.Background(), key, start, end)
	require.NoError(t, err)
	defer output.Close()

	actual, err := ioutil.ReadAll(output)
	require.NoError(t, err)
	assert.Equal(t, content, string(actual))
}

func TestS3GetURL(t *testing.T) {
	const (
		bucket    = "some-bucket"
		key       = "foo/bar"
		urlExpiry = time.Minute * 10
		wantURL   = "https://foo.s3.example.com/foo/bar"
	)
	var presignClient mocks.S3PresignClient
	presignClient.On("PresignGetObject", mock.Anything, mock.MatchedBy(func(input *s3.GetObjectInput) bool {
		return *input.Bucket == bucket && *input.Key == key
	}), mock.Anything).Return(&signerv4.PresignedHTTPRequest{URL: wantURL}, nil)
	defer presignClient.AssertExpectations(t)

	store := filestore.NewS3FileStore(filestore.S3API{S3PresignClient: &presignClient}, bucket, urlExpiry, zap.NewNop().Sugar())
	url, err := store.GetURL(context.Background(), key)
	require.NoError(t, err)
	assert.Equal(t, wantURL, url)
}

type testReader struct {
	count, exp int
}

func (r *testReader) Read(p []byte) (int, error) {
	max := r.exp - r.count
	if max <= len(p) {
		r.count += max
		return max, io.EOF
	}
	r.count += len(p)
	return len(p), nil
}

func TestS3PutObject(t *testing.T) {
	const (
		bucket        = "some-bucket"
		key           = "foo/bar"
		contentType   = "audio/mp3"
		contentLength = 20_000_000
	)

	uploadID := "abc123"

	mockS3Client := func() *mocks.S3Client {
		var s3Client mocks.S3Client
		s3Client.On("CreateMultipartUpload", mock.Anything, mock.MatchedBy(func(input *s3.CreateMultipartUploadInput) bool {
			return *input.Bucket == bucket && *input.Key == key && *input.ContentType == contentType
		})).Return(&s3.CreateMultipartUploadOutput{UploadId: &uploadID}, nil)
		return &s3Client
	}

	t.Run("OK", func(t *testing.T) {
		s3Client := mockS3Client()
		eTag := `"foo"`
		var partLengths []int64
		s3Client.On("UploadPart", mock.Anything, mock.MatchedBy(func(input *s3.UploadPartInput) bool {
			partLengths = append(partLengths, input.ContentLength)
			return *input.Bucket == bucket && *input.Key == key && *input.UploadId == uploadID
		})).Return(&s3.UploadPartOutput{ETag: &eTag}, nil)
		s3Client.On("CompleteMultipartUpload", mock.Anything, mock.MatchedBy(func(input *s3.CompleteMultipartUploadInput) bool {
			return *input.Bucket == bucket && *input.Key == key && *input.UploadId == uploadID
		})).Return(nil, nil)
		defer s3Client.AssertExpectations(t)

		store := filestore.NewS3FileStore(filestore.S3API{S3Client: s3Client}, bucket, time.Hour, zap.NewNop().Sugar())

		n, err := store.PutObject(context.Background(), key, &testReader{exp: contentLength}, contentType)
		require.NoError(t, err)
		assert.Equal(t, int64(contentLength), n)
		assert.ElementsMatch(t, []int64{5_242_880, 5_242_880, 5_242_880, 4_271_360}, partLengths)
	})

	t.Run("NOK,UploadPartFailure", func(t *testing.T) {
		s3Client := mockS3Client()
		s3Client.On("UploadPart", mock.Anything, mock.Anything).Return(nil, errors.New("boom"))
		s3Client.On("AbortMultipartUpload", mock.Anything, mock.MatchedBy(func(input *s3.AbortMultipartUploadInput) bool {
			return *input.Bucket == bucket && *input.Key == key && *input.UploadId == uploadID
		})).Return(nil, nil)
		defer s3Client.AssertExpectations(t)

		store := filestore.NewS3FileStore(filestore.S3API{S3Client: s3Client}, bucket, time.Hour, zap.NewNop().Sugar())
		_, err := store.PutObject(context.Background(), key, &testReader{exp: contentLength}, contentType)
		assert.EqualError(t, err, "error while uploading part: boom")
	})
}