// Copyright 2017 The goimagehash Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package goimagehash

import (
	"image"
	"image/jpeg"
	"os"
	"testing"
)

func TestHashCompute(t *testing.T) {
	for _, tt := range []struct {
		img1     string
		img2     string
		method   func(img image.Image) (*ImageHash, error)
		name     string
		distance int
	}{
		{"_examples/sample1.jpg", "_examples/sample1.jpg", AverageHash, "AverageHash", 0},
		{"_examples/sample2.jpg", "_examples/sample2.jpg", AverageHash, "AverageHash", 0},
		{"_examples/sample3.jpg", "_examples/sample3.jpg", AverageHash, "AverageHash", 0},
		{"_examples/sample4.jpg", "_examples/sample4.jpg", AverageHash, "AverageHash", 0},
		{"_examples/sample1.jpg", "_examples/sample2.jpg", AverageHash, "AverageHash", 40},
		{"_examples/sample1.jpg", "_examples/sample3.jpg", AverageHash, "AverageHash", 0},
		{"_examples/sample1.jpg", "_examples/sample4.jpg", AverageHash, "AverageHash", 34},
		{"_examples/sample2.jpg", "_examples/sample3.jpg", AverageHash, "AverageHash", 40},
		{"_examples/sample2.jpg", "_examples/sample4.jpg", AverageHash, "AverageHash", 6},
		{"_examples/sample1.jpg", "_examples/sample1.jpg", DifferenceHash, "DifferenceHash", 0},
		{"_examples/sample2.jpg", "_examples/sample2.jpg", DifferenceHash, "DifferenceHash", 0},
		{"_examples/sample3.jpg", "_examples/sample3.jpg", DifferenceHash, "DifferenceHash", 0},
		{"_examples/sample4.jpg", "_examples/sample4.jpg", DifferenceHash, "DifferenceHash", 0},
		{"_examples/sample1.jpg", "_examples/sample2.jpg", DifferenceHash, "DifferenceHash", 40},
		{"_examples/sample1.jpg", "_examples/sample3.jpg", DifferenceHash, "DifferenceHash", 2},
		{"_examples/sample1.jpg", "_examples/sample4.jpg", DifferenceHash, "DifferenceHash", 38},
		{"_examples/sample2.jpg", "_examples/sample3.jpg", DifferenceHash, "DifferenceHash", 42},
		{"_examples/sample2.jpg", "_examples/sample4.jpg", DifferenceHash, "DifferenceHash", 20},
		{"_examples/sample1.jpg", "_examples/sample1.jpg", PerceptionHash, "PerceptionHash", 0},
		{"_examples/sample2.jpg", "_examples/sample2.jpg", PerceptionHash, "PerceptionHash", 0},
		{"_examples/sample3.jpg", "_examples/sample3.jpg", PerceptionHash, "PerceptionHash", 0},
		{"_examples/sample4.jpg", "_examples/sample4.jpg", PerceptionHash, "PerceptionHash", 0},
		{"_examples/sample1.jpg", "_examples/sample2.jpg", PerceptionHash, "PerceptionHash", 34},
		{"_examples/sample1.jpg", "_examples/sample3.jpg", PerceptionHash, "PerceptionHash", 0},
		{"_examples/sample1.jpg", "_examples/sample4.jpg", PerceptionHash, "PerceptionHash", 30},
		{"_examples/sample2.jpg", "_examples/sample3.jpg", PerceptionHash, "PerceptionHash", 34},
		{"_examples/sample2.jpg", "_examples/sample4.jpg", PerceptionHash, "PerceptionHash", 20},
	} {
		file1, err := os.Open(tt.img1)
		if err != nil {
		}
		defer file1.Close()

		file2, err := os.Open(tt.img2)
		if err != nil {
			t.Errorf("%s", err)
		}
		defer file2.Close()

		img1, err := jpeg.Decode(file1)
		if err != nil {
			t.Errorf("%s", err)
		}

		img2, err := jpeg.Decode(file2)
		if err != nil {
			t.Errorf("%s", err)
		}

		hash1, err := tt.method(img1)
		if err != nil {
			t.Errorf("%s", err)
		}
		hash2, err := tt.method(img2)
		if err != nil {
			t.Errorf("%s", err)
		}

		dis1, err := hash1.Distance(hash2)
		if err != nil {
			t.Errorf("%s", err)
		}

		dis2, err := hash2.Distance(hash1)
		if err != nil {
			t.Errorf("%s", err)
		}

		if dis1 != dis2 {
			t.Errorf("Distance should be identical %v vs %v", dis1, dis2)
		}

		if dis1 != tt.distance {
			t.Errorf("%s: Distance between %v and %v is expected %v but got %v", tt.name, tt.img1, tt.img2, tt.distance, dis1)
		}
	}
}

func TestNilHashCompute(t *testing.T) {
	hash, err := AverageHash(nil)
	if err == nil {
		t.Errorf("Error should be got.")
	}
	if hash != nil {
		t.Errorf("Nil hash should be got. but got %v", hash)
	}

	hash, err = DifferenceHash(nil)
	if err == nil {
		t.Errorf("Error should be got.")
	}
	if hash != nil {
		t.Errorf("Nil hash should be got. but got %v", hash)
	}

	hash, err = PerceptionHash(nil)
	if err == nil {
		t.Errorf("Error should be got.")
	}
	if hash != nil {
		t.Errorf("Nil hash should be got. but got %v", hash)
	}
}

func TestExtendHashCompute(t *testing.T) {
	file, err := os.Open("_examples/sample1.jpg")
	if err != nil {
		t.Errorf("%s", err)
	}
	defer file.Close()
	img, err := jpeg.Decode(file)
	if err != nil {
		t.Errorf("%s", err)
	}

	hash, err := ExtPerceptionHash(img, 0, 8)
	if err == nil {
		t.Errorf("Error should be got.")
	}
	if hash != nil {
		t.Errorf("Nil hash should be got. but got %v", hash)
	}

	hash, err = ExtPerceptionHash(img, 16, 2)
	if err != nil {
		t.Errorf("%s", err)
	}
	if hash == nil {
		t.Errorf("Hash should be got.")
	}
}

// func TestNilExtendHashCompute(t *testing.T) {
// 	hash, err := ExtAverageHash(nil, 8, 8)
// 	if err == nil {
// 		t.Errorf("Error should be got.")
// 	}
// 	if hash != nil {
// 		t.Errorf("Nil hash should be got. but got %v", hash)
// 	}

// 	hash, err = ExtDifferenceHash(nil, 8, 8)
// 	if err == nil {
// 		t.Errorf("Error should be got.")
// 	}
// 	if hash != nil {
// 		t.Errorf("Nil hash should be got. but got %v", hash)
// 	}

// 	hash, err = ExtPerceptionHash(nil, 8, 8)
// 	if err == nil {
// 		t.Errorf("Error should be got.")
// 	}
// 	if hash != nil {
// 		t.Errorf("Nil hash should be got. but got %v", hash)
// 	}

// 	hash, err = ExtPerceptionHash(nil, 8, 9)
// 	if err == nil {
// 		t.Errorf("Error should be got.")
// 	}
// 	if hash != nil {
// 		t.Errorf("Nil hash should be got. but got %v", hash)
// 	}
// }

func BenchmarkDistanceIdentical(b *testing.B) {
	h1 := &ImageHash{hash: 0xe48ae53c05e502f7}
	h2 := &ImageHash{hash: 0xe48ae53c05e502f7}

	for i := 0; i < b.N; i++ {
		h1.Distance(h2)
	}
}

func BenchmarkDistanceDifferent(b *testing.B) {
	h1 := &ImageHash{hash: 0xe48ae53c05e502f7}
	h2 := &ImageHash{hash: 0x678be53815e510f7} // 8 bits flipped

	for i := 0; i < b.N; i++ {
		h1.Distance(h2)
	}
}

// func TestExtImageHashCompute(t *testing.T) {
// 	for _, tt := range []struct {
// 		img1     string
// 		img2     string
// 		width    int
// 		height   int
// 		method   func(img image.Image, width, height int) (*ExtImageHash, error)
// 		name     string
// 		distance int
// 	}{
// 		{"_examples/sample1.jpg", "_examples/sample1.jpg", 8, 8, ExtAverageHash, "ExtAverageHash", 0},
// 		{"_examples/sample2.jpg", "_examples/sample2.jpg", 8, 8, ExtAverageHash, "ExtAverageHash", 0},
// 		{"_examples/sample3.jpg", "_examples/sample3.jpg", 8, 8, ExtAverageHash, "ExtAverageHash", 0},
// 		{"_examples/sample4.jpg", "_examples/sample4.jpg", 8, 8, ExtAverageHash, "ExtAverageHash", 0},
// 		{"_examples/sample1.jpg", "_examples/sample2.jpg", 8, 8, ExtAverageHash, "ExtAverageHash", 40},
// 		{"_examples/sample1.jpg", "_examples/sample3.jpg", 8, 8, ExtAverageHash, "ExtAverageHash", 0},
// 		{"_examples/sample1.jpg", "_examples/sample4.jpg", 8, 8, ExtAverageHash, "ExtAverageHash", 34},
// 		{"_examples/sample2.jpg", "_examples/sample3.jpg", 8, 8, ExtAverageHash, "ExtAverageHash", 40},
// 		{"_examples/sample2.jpg", "_examples/sample4.jpg", 8, 8, ExtAverageHash, "ExtAverageHash", 6},
// 		{"_examples/sample1.jpg", "_examples/sample1.jpg", 16, 16, ExtAverageHash, "ExtAverageHash", 0},
// 		{"_examples/sample2.jpg", "_examples/sample2.jpg", 16, 16, ExtAverageHash, "ExtAverageHash", 0},
// 		{"_examples/sample3.jpg", "_examples/sample3.jpg", 16, 16, ExtAverageHash, "ExtAverageHash", 0},
// 		{"_examples/sample4.jpg", "_examples/sample4.jpg", 16, 16, ExtAverageHash, "ExtAverageHash", 0},
// 		{"_examples/sample1.jpg", "_examples/sample2.jpg", 16, 16, ExtAverageHash, "ExtAverageHash", 143},
// 		{"_examples/sample1.jpg", "_examples/sample3.jpg", 16, 16, ExtAverageHash, "ExtAverageHash", 3},
// 		{"_examples/sample1.jpg", "_examples/sample4.jpg", 16, 16, ExtAverageHash, "ExtAverageHash", 148},
// 		{"_examples/sample2.jpg", "_examples/sample3.jpg", 16, 16, ExtAverageHash, "ExtAverageHash", 146},
// 		{"_examples/sample2.jpg", "_examples/sample4.jpg", 16, 16, ExtAverageHash, "ExtAverageHash", 31},
// 		{"_examples/sample1.jpg", "_examples/sample1.jpg", 17, 17, ExtAverageHash, "ExtAverageHash", 0},
// 		{"_examples/sample2.jpg", "_examples/sample2.jpg", 17, 17, ExtAverageHash, "ExtAverageHash", 0},
// 		{"_examples/sample3.jpg", "_examples/sample3.jpg", 17, 17, ExtAverageHash, "ExtAverageHash", 0},
// 		{"_examples/sample4.jpg", "_examples/sample4.jpg", 17, 17, ExtAverageHash, "ExtAverageHash", 0},
// 		{"_examples/sample1.jpg", "_examples/sample1.jpg", 8, 4, ExtPerceptionHash, "ExtPerceptionHash", 0},
// 		{"_examples/sample2.jpg", "_examples/sample2.jpg", 8, 4, ExtPerceptionHash, "ExtPerceptionHash", 0},
// 		{"_examples/sample3.jpg", "_examples/sample3.jpg", 8, 4, ExtPerceptionHash, "ExtPerceptionHash", 0},
// 		{"_examples/sample4.jpg", "_examples/sample4.jpg", 8, 4, ExtPerceptionHash, "ExtPerceptionHash", 0},
// 		{"_examples/sample1.jpg", "_examples/sample2.jpg", 8, 4, ExtPerceptionHash, "ExtPerceptionHash", 32},
// 		{"_examples/sample1.jpg", "_examples/sample3.jpg", 8, 4, ExtPerceptionHash, "ExtPerceptionHash", 2},
// 		{"_examples/sample1.jpg", "_examples/sample4.jpg", 8, 4, ExtPerceptionHash, "ExtPerceptionHash", 30},
// 		{"_examples/sample2.jpg", "_examples/sample3.jpg", 8, 4, ExtPerceptionHash, "ExtPerceptionHash", 34},
// 		{"_examples/sample2.jpg", "_examples/sample4.jpg", 8, 4, ExtPerceptionHash, "ExtPerceptionHash", 20},
// 		{"_examples/sample1.jpg", "_examples/sample1.jpg", 16, 4, ExtPerceptionHash, "ExtPerceptionHash", 0},
// 		{"_examples/sample2.jpg", "_examples/sample2.jpg", 16, 4, ExtPerceptionHash, "ExtPerceptionHash", 0},
// 		{"_examples/sample3.jpg", "_examples/sample3.jpg", 16, 4, ExtPerceptionHash, "ExtPerceptionHash", 0},
// 		{"_examples/sample4.jpg", "_examples/sample4.jpg", 16, 4, ExtPerceptionHash, "ExtPerceptionHash", 0},
// 		{"_examples/sample1.jpg", "_examples/sample2.jpg", 16, 4, ExtPerceptionHash, "ExtPerceptionHash", 124},
// 		{"_examples/sample1.jpg", "_examples/sample3.jpg", 16, 4, ExtPerceptionHash, "ExtPerceptionHash", 14},
// 		{"_examples/sample1.jpg", "_examples/sample4.jpg", 16, 4, ExtPerceptionHash, "ExtPerceptionHash", 122},
// 		{"_examples/sample2.jpg", "_examples/sample3.jpg", 16, 4, ExtPerceptionHash, "ExtPerceptionHash", 120},
// 		{"_examples/sample2.jpg", "_examples/sample4.jpg", 16, 4, ExtPerceptionHash, "ExtPerceptionHash", 102},
// 		{"_examples/sample1.jpg", "_examples/sample1.jpg", 8, 8, ExtDifferenceHash, "ExtDifferenceHash", 0},
// 		{"_examples/sample2.jpg", "_examples/sample2.jpg", 8, 8, ExtDifferenceHash, "ExtDifferenceHash", 0},
// 		{"_examples/sample3.jpg", "_examples/sample3.jpg", 8, 8, ExtDifferenceHash, "ExtDifferenceHash", 0},
// 		{"_examples/sample4.jpg", "_examples/sample4.jpg", 8, 8, ExtDifferenceHash, "ExtDifferenceHash", 0},
// 		{"_examples/sample1.jpg", "_examples/sample2.jpg", 8, 8, ExtDifferenceHash, "ExtDifferenceHash", 40},
// 		{"_examples/sample1.jpg", "_examples/sample3.jpg", 8, 8, ExtDifferenceHash, "ExtDifferenceHash", 2},
// 		{"_examples/sample1.jpg", "_examples/sample4.jpg", 8, 8, ExtDifferenceHash, "ExtDifferenceHash", 38},
// 		{"_examples/sample2.jpg", "_examples/sample3.jpg", 8, 8, ExtDifferenceHash, "ExtDifferenceHash", 42},
// 		{"_examples/sample2.jpg", "_examples/sample4.jpg", 8, 8, ExtDifferenceHash, "ExtDifferenceHash", 20},
// 		{"_examples/sample1.jpg", "_examples/sample1.jpg", 16, 16, ExtDifferenceHash, "ExtDifferenceHash", 0},
// 		{"_examples/sample2.jpg", "_examples/sample2.jpg", 16, 16, ExtDifferenceHash, "ExtDifferenceHash", 0},
// 		{"_examples/sample3.jpg", "_examples/sample3.jpg", 16, 16, ExtDifferenceHash, "ExtDifferenceHash", 0},
// 		{"_examples/sample4.jpg", "_examples/sample4.jpg", 16, 16, ExtDifferenceHash, "ExtDifferenceHash", 0},
// 		{"_examples/sample1.jpg", "_examples/sample2.jpg", 16, 16, ExtDifferenceHash, "ExtDifferenceHash", 137},
// 		{"_examples/sample1.jpg", "_examples/sample3.jpg", 16, 16, ExtDifferenceHash, "ExtDifferenceHash", 13},
// 		{"_examples/sample1.jpg", "_examples/sample4.jpg", 16, 16, ExtDifferenceHash, "ExtDifferenceHash", 124},
// 		{"_examples/sample2.jpg", "_examples/sample3.jpg", 16, 16, ExtDifferenceHash, "ExtDifferenceHash", 140},
// 		{"_examples/sample2.jpg", "_examples/sample4.jpg", 16, 16, ExtDifferenceHash, "ExtDifferenceHash", 109},
// 		{"_examples/sample1.jpg", "_examples/sample1.jpg", 17, 17, ExtDifferenceHash, "ExtDifferenceHash", 0},
// 		{"_examples/sample2.jpg", "_examples/sample2.jpg", 17, 17, ExtDifferenceHash, "ExtDifferenceHash", 0},
// 		{"_examples/sample3.jpg", "_examples/sample3.jpg", 17, 17, ExtDifferenceHash, "ExtDifferenceHash", 0},
// 		{"_examples/sample4.jpg", "_examples/sample4.jpg", 17, 17, ExtDifferenceHash, "ExtDifferenceHash", 0},
// 	} {
// 		file1, err := os.Open(tt.img1)
// 		if err != nil {
// 			t.Errorf("%s", err)
// 		}
// 		defer file1.Close()

// 		file2, err := os.Open(tt.img2)
// 		if err != nil {
// 			t.Errorf("%s", err)
// 		}
// 		defer file2.Close()

// 		img1, err := jpeg.Decode(file1)
// 		if err != nil {
// 			t.Errorf("%s", err)
// 		}

// 		img2, err := jpeg.Decode(file2)
// 		if err != nil {
// 			t.Errorf("%s", err)
// 		}

// 		hash1, err := tt.method(img1, tt.width, tt.height)
// 		if err != nil {
// 			t.Errorf("%s", err)
// 		}
// 		hash2, err := tt.method(img2, tt.width, tt.height)
// 		if err != nil {
// 			t.Errorf("%s", err)
// 		}

// 		dis1, err := hash1.Distance(hash2)
// 		if err != nil {
// 			t.Errorf("%s", err)
// 		}

// 		dis2, err := hash2.Distance(hash1)
// 		if err != nil {
// 			t.Errorf("%s", err)
// 		}

// 		if dis1 != dis2 {
// 			t.Errorf("Distance should be identical %v vs %v", dis1, dis2)
// 		}

// 		if dis1 != tt.distance {
// 			t.Errorf("%s: Distance between %v and %v is expected %v but got %v: %v %v", tt.name, tt.img1, tt.img2, tt.distance, dis1, hash1, hash2)
// 		}
// 	}
// }

func BenchmarkExtImageHashDistanceDifferent(b *testing.B) {
	h1 := &ExtImageHash{hash: []uint64{0xe48ae53c05e502f7}}
	h2 := &ExtImageHash{hash: []uint64{0x678be53815e510f7}} // 8 bits flipped

	for i := 0; i < b.N; i++ {
		_, err := h1.Distance(h2)
		if err != nil {
			b.Errorf("%s", err)
		}
	}
}

func BenchmarkPerceptionHash(b *testing.B) {
	file1, err := os.Open("_examples/sample3.jpg")
	if err != nil {
		b.Errorf("%s", err)
	}
	defer file1.Close()
	img1, err := jpeg.Decode(file1)
	if err != nil {
		b.Errorf("%s", err)
	}
	for i := 0; i < b.N; i++ {
		_, err := ExtPerceptionHash(img1, 8, 8)
		if err != nil {
			b.Errorf("%s", err)
		}
	}
}

// func BenchmarkAverageHash(b *testing.B) {
// 	file1, err := os.Open("_examples/sample3.jpg")
// 	if err != nil {
// 		b.Errorf("%s", err)
// 	}
// 	defer file1.Close()
// 	img1, err := jpeg.Decode(file1)
// 	if err != nil {
// 		b.Errorf("%s", err)
// 	}
// 	for i := 0; i < b.N; i++ {
// 		_, err := ExtAverageHash(img1, 8, 8)
// 		if err != nil {
// 			b.Errorf("%s", err)
// 		}
// 	}
// }

// func BenchmarkDifferenceHash(b *testing.B) {
// 	file1, err := os.Open("_examples/sample3.jpg")
// 	if err != nil {
// 		b.Errorf("%s", err)
// 	}
// 	defer file1.Close()
// 	img1, err := jpeg.Decode(file1)
// 	if err != nil {
// 		b.Errorf("%s", err)
// 	}
// 	for i := 0; i < b.N; i++ {
// 		_, err := ExtDifferenceHash(img1, 8, 8)
// 		if err != nil {
// 			b.Errorf("%s", err)
// 		}
// 	}
// }