package windsurf

import (
	"bytes"
	"encoding/hex"
	"testing"
)

// 对比官方规划里给出的 known-good hex vector：
// base64Data="QQ==", mimeType="image/png", caption="a"
// 内部 body: 0a 04 51 51 3d 3d  12 09 69 6d 61 67 65 2f 70 6e 67  1a 01 61
func TestEncodeCodeiumImage_KnownVector(t *testing.T) {
	img := CascadeImage{
		Base64Data: "QQ==",
		MimeType:   "image/png",
		Caption:    "a",
	}
	got := encodeCodeiumImage(img)
	want, _ := hex.DecodeString("0a045151" + "3d3d" + "120969" + "6d6167652f706e67" + "1a0161")
	if !bytes.Equal(got, want) {
		t.Errorf("encoded mismatch:\n got=%x\nwant=%x", got, want)
	}
}

func TestEncodeCodeiumImage_OmitsCaptionWhenEmpty(t *testing.T) {
	img := CascadeImage{
		Base64Data: "QQ==",
		MimeType:   "image/png",
	}
	got := encodeCodeiumImage(img)
	// 不含 field 3 tag (0x1a)
	if bytes.Contains(got, []byte{0x1a}) {
		t.Errorf("should not contain field 3 tag when caption empty: %x", got)
	}
}

func TestAppendSendUserCascadeImages_WrapsField6(t *testing.T) {
	imgs := []CascadeImage{
		{Base64Data: "QQ==", MimeType: "image/png", Caption: "a"},
	}
	body := appendSendUserCascadeImages(nil, imgs)
	// 外层：field 6 tag (0x32) + varint 长度 + 内层 body
	// 内层 body 长度 = 6 + 11 + 3 = 20 (0x14)
	want, _ := hex.DecodeString("3214" + "0a045151" + "3d3d" + "120969" + "6d6167652f706e67" + "1a0161")
	if !bytes.Equal(body, want) {
		t.Errorf("wrapped field 6 segment mismatch:\n got=%x\nwant=%x", body, want)
	}
}

func TestAppendSendUserCascadeImages_MultipleImagesIndependentSegments(t *testing.T) {
	imgs := []CascadeImage{
		{Base64Data: "QQ==", MimeType: "image/png"},
		{Base64Data: "Qg==", MimeType: "image/jpeg"},
	}
	body := appendSendUserCascadeImages(nil, imgs)
	// 应该有两次 field 6 tag (0x32)
	count := bytes.Count(body, []byte{0x32})
	if count != 2 {
		t.Errorf("expected 2 field-6 segments, got %d in %x", count, body)
	}
}

func TestAppendSendUserCascadeImages_NilInput(t *testing.T) {
	body := appendSendUserCascadeImages(nil, nil)
	if len(body) != 0 {
		t.Errorf("nil input should produce empty bytes, got %x", body)
	}
}