package imglib

import (
	"os"
	"testing"

	"github.com/fogleman/gg"
)

// TestAddChineseWatermark 给桌面 kbk.png 添加豆包AI风格斜纹平铺水印
func TestAddChineseWatermark(t *testing.T) {
	srcPath := `C:\Users\Administrator\Desktop\kbk.png`

	srcImg, _, err := NewImageInputFromFile(srcPath).Load()
	if err != nil {
		t.Fatalf("加载源图片失败: %v", err)
	}

	bounds := srcImg.Bounds()
	dc := gg.NewContext(bounds.Dx(), bounds.Dy())
	dc.DrawImage(srcImg, 0, 0)

	fontPath := getDefaultFontPath()
	if fontPath == "" {
		t.Skip("未找到中文字体")
	}

	if err := dc.LoadFontFace(fontPath, 48); err != nil {
		t.Fatalf("加载字体失败: %v", err)
	}

	// 斜纹平铺水印
	tileW, tileH := 500, 400
	for y := -tileH; y < bounds.Dy()+tileH; y += tileH {
		for x := -tileW; x < bounds.Dx()+tileW; x += tileW {
			cx := float64(x) + 250
			cy := float64(y) + 200
			dc.Push()
			dc.RotateAbout(-0.35, cx, cy)
			dc.SetRGB(1, 1, 1)
			dc.SetAlpha(0.25)
			dc.DrawStringAnchored("这是一个水印", cx, cy, 0.5, 0.5)
			dc.SetRGBA(1, 1, 1, 0.15)
			dc.DrawStringAnchored("这是一个水印", float64(x)+250, float64(y)+200, 0.5, 0.5)
			dc.Pop()
		}
	}

	outPath := "d:\\source\\daShangDao_utils\\kbk_watermarked.png"
	f, err := os.Create(outPath)
	if err != nil {
		t.Fatalf("创建文件失败: %v", err)
	}
	defer f.Close()
	err = SavePNG(dc.Image(), outPath)
	if err != nil {
		t.Fatalf("保存图片失败: %v", err)
	}
	t.Logf("水印图片已保存到: %s", outPath)
}