package avatar

import (
	"strings"
	"testing"
)

func TestGetInitials(t *testing.T) {
	tests := []struct {
		name     string
		username string
		want     string
	}{
		{"中文用户名", "张三", "张"},
		{"英文用户名", "John", "J"},
		{"英文全名", "John Doe", "JD"},
		{"带下划线", "john_doe", "JD"},
		{"带连字符", "john-doe", "JD"},
		{"空字符串", "", "?"},
		{"小写英文", "alice", "A"},
		{"中文复合", "李小龙", "李"},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := getInitials(tt.username)
			if got != tt.want {
				t.Errorf("getInitials(%q) = %q, want %q", tt.username, got, tt.want)
			}
		})
	}
}

func TestStringToColor(t *testing.T) {
	// 测试同一用户名生成的颜色一致
	color1 := stringToColor("张三")
	color2 := stringToColor("张三")
	if color1 != color2 {
		t.Errorf("stringToColor should return consistent colors for the same input")
	}

	// 测试不同用户名生成不同颜色（大概率）
	color3 := stringToColor("李四")
	if color1 == color3 {
		t.Logf("Warning: different usernames generated the same color (possible but unlikely)")
	}

	// 测试空字符串
	color4 := stringToColor("")
	if color4 == "" {
		t.Errorf("stringToColor should return a color for empty string")
	}

	// 验证颜色格式
	if !strings.HasPrefix(color4, "#") {
		t.Errorf("stringToColor should return hex color format starting with #")
	}
}

func TestGenerateSVGAvatar(t *testing.T) {
	svg := GenerateSVGAvatar("张三", 100)

	// 验证SVG结构
	if !strings.Contains(svg, "<svg") {
		t.Errorf("SVG should contain <svg tag")
	}
	if !strings.Contains(svg, "</svg>") {
		t.Errorf("SVG should contain </svg> tag")
	}
	if !strings.Contains(svg, "width=\"100\"") {
		t.Errorf("SVG should have width=100")
	}
	if !strings.Contains(svg, "height=\"100\"") {
		t.Errorf("SVG should have height=100")
	}
	if !strings.Contains(svg, "张") {
		t.Errorf("SVG should contain the initial character")
	}
}

func TestGenerateAvatarDataURI(t *testing.T) {
	dataURI := GenerateAvatarDataURI("张三", 100)

	// 验证Data URI格式
	if !strings.HasPrefix(dataURI, "data:image/svg+xml;base64,") {
		t.Errorf("Data URI should start with data:image/svg+xml;base64,")
	}

	// 验证base64部分不为空
	parts := strings.Split(dataURI, ",")
	if len(parts) != 2 {
		t.Errorf("Data URI should have two parts separated by comma")
	}
	if parts[1] == "" {
		t.Errorf("Base64 part should not be empty")
	}
}

func TestIsChinese(t *testing.T) {
	tests := []struct {
		r    rune
		want bool
	}{
		{'中', true},
		{'文', true},
		{'a', false},
		{'Z', false},
		{'0', false},
		{'_', false},
	}

	for _, tt := range tests {
		got := isChinese(tt.r)
		if got != tt.want {
			t.Errorf("isChinese(%q) = %v, want %v", tt.r, got, tt.want)
		}
	}
}