package classes_test

import (
	"bytes"
	"encoding/hex"
	"image"
	"image/color"
	"image/gif"
	"image/jpeg"
	"image/png"
	"testing"

	"git.golem15.com/golem15/sm-feedback-plugin/classes"
	"git.golem15.com/golem15/summercms/modules/lagoon/attach"
)

func mustHex(t *testing.T, s string) []byte {
	t.Helper()
	b, err := hex.DecodeString(s)
	if err != nil {
		t.Fatal(err)
	}
	return b
}

func encoded(t *testing.T, enc func(*bytes.Buffer, image.Image) error) []byte {
	t.Helper()
	img := image.NewRGBA(image.Rect(0, 0, 3, 2))
	img.Set(1, 1, color.RGBA{R: 200, A: 255})
	var buf bytes.Buffer
	if err := enc(&buf, img); err != nil {
		t.Fatal(err)
	}
	return buf.Bytes()
}

// TestImageGuardCopy pins the feedback copy of ImageContentGuard: the
// shared vectors (the PHP-recorded screenshot fixtures among them) get the
// verdicts PHP gave and the framework's own guard (attach.IsAllowedImage)
// gives, and the sniffed type of each accepted image is one of the four.
func TestImageGuardCopy(t *testing.T) {
	cases := []struct {
		name string
		data []byte
		want bool
	}{
		{"png", encoded(t, func(b *bytes.Buffer, i image.Image) error { return png.Encode(b, i) }), true},
		{"jpeg", encoded(t, func(b *bytes.Buffer, i image.Image) error { return jpeg.Encode(b, i, nil) }), true},
		{"gif", encoded(t, func(b *bytes.Buffer, i image.Image) error { return gif.Encode(b, i, nil) }), true},
		// The parity fixtures: a PNG and a WebP PHP accepted, and a JPEG
		// header without an image PHP refused ("The file is not a valid
		// image.").
		{"fixture-png", mustHex(t, "89504e470d0a1a0a0000000d49484452000000080000000808020000004b6d29dc0000001949444154789c626160a8906360c0442c20021b189c128001005509023d9970f43c0000000049454e44ae426082"), true},
		{"fixture-webp", mustHex(t, "524946464800000057454250565038203c0000005003009d012a180010003e6d2c9245a422a19804004006c4a009d3284600fc000108a000feec35853fff497f283d1d7ff3f3396879687ee0b7790000"), true},
		{"fixture-spoofed-jpeg", mustHex(t, "ffd8ffe000104a46494600010100000100010000706f6c79676c6f743a2061204a5045472068656164657220776974686f757420616e7920696d616765ffd9"), false},
		{"text", []byte("plain text, not a picture"), false},
		{"empty", nil, false},
		{"svg", []byte(`<svg xmlns="http://www.w3.org/2000/svg" width="1" height="1"></svg>`), false},
		{"bmp", append([]byte("BM"), make([]byte, 60)...), false},
		{"png-header-only", mustHex(t, "89504e470d0a1a0a"), false},
	}
	for _, c := range cases {
		got := classes.IsAllowedImage(c.data)
		if got != c.want {
			t.Errorf("%s: IsAllowedImage = %v, want %v", c.name, got, c.want)
		}
		if fw := attach.IsAllowedImage(c.data); fw != got {
			t.Errorf("%s: the framework guard says %v, the copy %v", c.name, fw, got)
		}
		if got {
			switch classes.SniffImageMIME(c.data) {
			case "image/png", "image/jpeg", "image/gif", "image/webp":
			default:
				t.Errorf("%s: sniffed %q", c.name, classes.SniffImageMIME(c.data))
			}
		}
	}
}