package avatar

import (
	"bytes"
	"encoding/hex"
	"image"
	"image/color"
	"image/jpeg"
	"os"
	"path/filepath"
	"testing"
)

// Reference values from the previous implementation. They pin the identicon
// algorithm, so existing users keep the same picture.
func TestIdenticonMatchesReference(t *testing.T) {
	tests := []struct {
		name  string
		bytes string
		rgb   [3]uint8
	}{
		{"alice", "a554a5a173394418a17c66ae57445638", [3]uint8{156, 178, 31}},
		{"admin", "7c212d2be8af0b70a0dd6542c4f55b32", [3]uint8{166, 33, 186}},
		{"bob-42", "07c21f2cb96afe78a3f481297d2f9406", [3]uint8{197, 27, 53}},
		{"ünïcode", "6f73f4fe71b1d1c57b611ae2556e8766", [3]uint8{219, 140, 57}},
	}
	for _, tt := range tests {
		b := hashBytes(tt.name, 16)
		if got := hex.EncodeToString(b); got != tt.bytes {
			t.Errorf("hashBytes(%q) = %s, want %s", tt.name, got, tt.bytes)
		}
		r, g, bl := hslToRGB(float64((int(b[0])|int(b[1])<<8)%360), float64(int(b[2])%20+65), float64(int(b[3])%20+40))
		if [3]uint8{r, g, bl} != tt.rgb {
			t.Errorf("color(%q) = %v, want %v", tt.name, [3]uint8{r, g, bl}, tt.rgb)
		}
	}
}

func TestIdenticonPixels(t *testing.T) {
	img := Identicon("alice")
	if img.Bounds() != image.Rect(0, 0, 128, 128) {
		t.Fatalf("bounds = %v", img.Bounds())
	}
	// The padding area is always background.
	if got := img.NRGBAAt(0, 0); got != (color.NRGBA{240, 240, 240, 255}) {
		t.Errorf("corner = %v", got)
	}
	// Column 0 and column 4 mirror each other.
	for y := 24; y < 104; y++ {
		if img.NRGBAAt(24, y) != img.NRGBAAt(127-24, y) {
			t.Fatalf("identicon not symmetric at y=%d", y)
		}
	}
}

func TestSaveResizesAndRejectsNonImages(t *testing.T) {
	dir := t.TempDir()

	src := image.NewRGBA(image.Rect(0, 0, 400, 200))
	var buf bytes.Buffer
	if err := jpeg.Encode(&buf, src, nil); err != nil {
		t.Fatal(err)
	}
	if err := Save(dir, 7, buf.Bytes()); err != nil {
		t.Fatal(err)
	}
	f, err := os.Open(filepath.Join(dir, "7.png"))
	if err != nil {
		t.Fatal(err)
	}
	defer f.Close()
	cfg, format, err := image.DecodeConfig(f)
	if err != nil {
		t.Fatal(err)
	}
	if format != "png" || cfg.Width != 128 || cfg.Height != 128 {
		t.Errorf("stored %s %dx%d", format, cfg.Width, cfg.Height)
	}

	if err := Save(dir, 8, []byte("not an image at all")); err == nil {
		t.Error("expected an error for a non-image upload")
	}
}

func TestPath(t *testing.T) {
	if got := Path("/data/avatars", 42); got != "/data/avatars/42.png" {
		t.Errorf("Path = %q", got)
	}
}