// Copyright (C) 2018 Storj Labs, Inc.
// See LICENSE for copying information

package sync2_test

import (
	"errors"
	"io"
	"io/ioutil"
	"testing"

	"github.com/stretchr/testify/assert"
	"golang.org/x/sync/errgroup"

	"storj.io/storj/internal/sync2"
)

func TestPipe_Basic(t *testing.T) {
	testPipes(t, func(t *testing.T, reader sync2.PipeReader, writer sync2.PipeWriter) {
		var group errgroup.Group
		group.Go(func() error {
			n, err := writer.Write([]byte{1, 2, 3})
			assert.Equal(t, n, 3)
			assert.NoError(t, err)

			n, err = writer.Write([]byte{1, 2, 3})
			assert.Equal(t, n, 3)
			assert.NoError(t, err)

			assert.NoError(t, writer.Close())
			return nil
		})

		group.Go(func() error {
			data, err := ioutil.ReadAll(reader)
			assert.Equal(t, []byte{1, 2, 3, 1, 2, 3}, data)
			if err != nil {
				assert.Equal(t, io.EOF, err)
			}
			assert.NoError(t, reader.Close())
			return nil
		})

		assert.NoError(t, group.Wait())
	})
}

func TestPipe_CloseWithError(t *testing.T) {
	testPipes(t, func(t *testing.T, reader sync2.PipeReader, writer sync2.PipeWriter) {
		var failure = errors.New("write failure")

		var group errgroup.Group
		group.Go(func() error {
			n, err := writer.Write([]byte{1, 2, 3})
			assert.Equal(t, n, 3)
			assert.NoError(t, err)

			err = writer.CloseWithError(failure)
			assert.NoError(t, err)

			return nil
		})

		group.Go(func() error {
			data, err := ioutil.ReadAll(reader)
			assert.Equal(t, []byte{1, 2, 3}, data)
			if err != nil {
				assert.Equal(t, failure, err)
			}
			assert.NoError(t, reader.Close())
			return nil
		})

		assert.NoError(t, group.Wait())
	})
}

func testPipes(t *testing.T, test func(t *testing.T, reader sync2.PipeReader, writer sync2.PipeWriter)) {
	t.Run("Memory", func(t *testing.T) {
		reader, writer, err := sync2.NewPipeFile("")
		if err != nil {
			t.Fatal(err)
		}
		test(t, reader, writer)
	})
	t.Run("File", func(t *testing.T) {
		reader, writer, err := sync2.NewPipeMemory(1024)
		if err != nil {
			t.Fatal(err)
		}
		test(t, reader, writer)
	})
}