package test

import (
	imageDomain "RenewCMS/internal/domain/image"
	"RenewCMS/internal/infrastructure/useCases"
	"bytes"
	"errors"
	"testing"
)

func validBytesFor(t *testing.T, contentType string) []byte {
	t.Helper()
	switch contentType {
	case "image/png":
		return pngBytes(t, 3, 2)
	case "image/jpeg":
		return jpegBytes(t, 3, 2)
	case "image/webp":
		return webpBytes(t)
	default:
		return []byte(svgFixture)
	}
}

func paddedTo(data []byte, size int) []byte {
	padding := byte(0)
	if bytes.HasPrefix(data, []byte("<svg")) {
		padding = ' '
	}
	return append(append([]byte{}, data...), bytes.Repeat([]byte{padding}, size-len(data))...)
}

func inputOf(content []byte, contentType string) imageDomain.ImageInput {
	return imageDomain.ImageInput{Content: bytes.NewReader(content), Filename: "upload", ContentType: contentType}
}

func TestImageUploadRules(t *testing.T) {
	t.Run("CreateImage accepts every allowed content type within the size limit", func(t *testing.T) {
		for _, contentType := range []string{"image/png", "image/jpeg", "image/webp", "image/svg+xml"} {
			t.Run(contentType, func(t *testing.T) {
				repo := newMockImageRepo()
				createUc := useCases.NewCreateImageUseCase(repo, newMockImageStorage(), discardRecorder)

				result, err := createUc.CreateImage(testCtx, inputOf(paddedTo(validBytesFor(t, contentType), int(imageDomain.MaxImageSize)), contentType))

				if err != nil {
					t.Fatalf("expected no error, got %v", err)
				}
				if result.ID == 0 {
					t.Errorf("expected the created image, got zero value")
				}
				if len(repo.images) != 1 {
					t.Errorf("expected Create to be called once, got %d calls", len(repo.images))
				}
			})
		}
	})

	t.Run("CreateImage rejects a disallowed content type before reaching the repository", func(t *testing.T) {
		repo := newMockImageRepo()
		createUc := useCases.NewCreateImageUseCase(repo, newMockImageStorage(), discardRecorder)

		_, err := createUc.CreateImage(testCtx, inputOf([]byte("%PDF"), "application/pdf"))

		if !errors.Is(err, imageDomain.ErrImageTypeNotAllowed) {
			t.Fatalf("expected ErrImageTypeNotAllowed, got %v", err)
		}
		if len(repo.images) != 0 {
			t.Errorf("expected Create to never be called, got %d calls", len(repo.images))
		}
	})

	t.Run("CreateImage rejects a file that exceeds the size limit", func(t *testing.T) {
		repo := newMockImageRepo()
		createUc := useCases.NewCreateImageUseCase(repo, newMockImageStorage(), discardRecorder)

		_, err := createUc.CreateImage(testCtx, inputOf(paddedTo(pngBytes(t, 3, 2), int(imageDomain.MaxImageSize)+1), "image/png"))

		if !errors.Is(err, imageDomain.ErrImageTooLarge) {
			t.Fatalf("expected ErrImageTooLarge, got %v", err)
		}
		if len(repo.images) != 0 {
			t.Errorf("expected Create to never be called, got %d calls", len(repo.images))
		}
	})

	t.Run("A file exactly at the size limit is accepted, one byte over is not", func(t *testing.T) {
		repo := newMockImageRepo()
		createUc := useCases.NewCreateImageUseCase(repo, newMockImageStorage(), discardRecorder)

		_, err := createUc.CreateImage(testCtx, inputOf(paddedTo(pngBytes(t, 3, 2), int(imageDomain.MaxImageSize)), "image/png"))
		if err != nil {
			t.Fatalf("expected no error at the exact limit, got %v", err)
		}
		if len(repo.images) != 1 {
			t.Fatalf("expected Create to be called once, got %d calls", len(repo.images))
		}

		_, err = createUc.CreateImage(testCtx, inputOf(paddedTo(pngBytes(t, 3, 2), int(imageDomain.MaxImageSize)+1), "image/png"))
		if !errors.Is(err, imageDomain.ErrImageTooLarge) {
			t.Fatalf("expected ErrImageTooLarge, got %v", err)
		}
		if len(repo.images) != 1 {
			t.Errorf("expected Create to still be called exactly once in total, got %d calls", len(repo.images))
		}
	})

	t.Run("A repository failure unrelated to type or size still propagates unchanged", func(t *testing.T) {
		repo := newMockImageRepo()
		repo.fail.failNextWith("Create", errRepositoryFailure)
		createUc := useCases.NewCreateImageUseCase(repo, newMockImageStorage(), discardRecorder)

		_, err := createUc.CreateImage(testCtx, inputOf(pngBytes(t, 3, 2), "image/png"))

		if !errors.Is(err, errRepositoryFailure) {
			t.Fatalf("expected the generic repository error, got %v", err)
		}
	})
}