package collage

import (
	"embed"
	"fmt"
	"image"
	"image/jpeg"
	"io"
	"io/fs"
	"log"
	"os"
	"testing"
)

//go:embed test_data/*
var testData embed.FS

var testDataFS fs.FS

func init() {
	var err error
	testDataFS, err = fs.Sub(testData, "test_data")
	if err != nil {
		log.Panicf("getting test_data subdir failed %v", err)
	}
}

func TestMake(t *testing.T) {
	req := Request{
		BackgroundImage: "",
		Aspect: Dimension{
			Width:  816 * 4,
			Height: 528 * 4 * 2,
		},
		Dimension: Dimension{
			Width:  816,
			Height: 528 * 2,
		},
		Photos: []Photo{
			{
				ImageName: "img1.jpg",
				Crop: Rectangle{
					Start: Point{
						X: 431,
						Y: 697,
					},
					End: Point{
						X: 2514,
						Y: 2047,
					},
				},
				Frame: Rectangle{
					Start: Point{
						X: 0,
						Y: 0,
					},
					End: Point{
						X: 816,
						Y: 528,
					},
				},
			},
		},
	}
	out, err := os.Create("./test_op.jpg")
	if err != nil {
		t.Fatalf("failed to create ouput image file %v", err)
	}

	err = Make(&req, testDataFS, out)
	if err != nil {
		t.Fatalf("failed to make collage %v", err)
	}

}

func TestCrop(t *testing.T) {
	img, err := GetImage(testDataFS, "img1.jpg")
	if err != nil {
		t.Fatalf("failed to get image %v", err)
	}
	r := Rectangle{
		Start: Point{X: 431, Y: 697},
		End:   Point{X: 2514, Y: 2047},
	}
	cropped, err := Crop(img, r)
	if err != nil {
		t.Fatalf("failed to crop image %v", err)
	}

	croppedImgPrefix := fmt.Sprint(cropped)[:1000]

	refPrefixf, err := testDataFS.Open("cropped_image_prefix.txt")
	if err != nil {
		t.Fatalf("failed to open ref prefix %v", err)
	}

	refImgPrefix, err := io.ReadAll(refPrefixf)

	if err != nil {
		t.Fatalf("failed to read ref prefix %v", err)
	}

	if string(refImgPrefix) != croppedImgPrefix {
		t.Fatalf("Cropped image is not the same as reference image")
	}
}

// Save first 1000 bytes of string representation to compare against reference
func SavePrefix(img image.Image) error {
	imgStr := fmt.Sprint(img)
	prefix := imgStr[:1000]
	return os.WriteFile("./test_data_prefix.txt", []byte(prefix), 0644)
}

func SaveImage(img image.Image) {
	out, err := os.Create("./test_output.jpg")
	if err != nil {
		fmt.Println(err)
	}

	var opt jpeg.Options
	opt.Quality = 100

	jpeg.Encode(out, img, &opt)
}