Merge pull request #21 from ctwj/feat_seo

Feat seo

handlers/og_image.go

@@ -0,0 +1,243 @@
+package handlers
+
+import (
+	"bytes"
+	"net/http"
+	"strconv"
+	"strings"
+
+	"github.com/ctwj/urldb/utils"
+	"github.com/gin-gonic/gin"
+	"github.com/fogleman/gg"
+	"image/color"
+)
+
+// OGImageHandler 处理OG图片生成请求
+type OGImageHandler struct{}
+
+// NewOGImageHandler 创建新的OG图片处理器
+func NewOGImageHandler() *OGImageHandler {
+	return &OGImageHandler{}
+}
+
+// GenerateOGImage 生成OG图片
+func (h *OGImageHandler) GenerateOGImage(c *gin.Context) {
+	// 获取请求参数
+	title := strings.TrimSpace(c.Query("title"))
+	description := strings.TrimSpace(c.Query("description"))
+	siteName := strings.TrimSpace(c.Query("site_name"))
+	theme := strings.TrimSpace(c.Query("theme"))
+
+	width, _ := strconv.Atoi(c.Query("width"))
+	height, _ := strconv.Atoi(c.Query("height"))
+
+	// 设置默认值
+	if title == "" {
+		title = "老九网盘资源数据库"
+	}
+	if siteName == "" {
+		siteName = "老九网盘"
+	}
+	if width <= 0 || width > 2000 {
+		width = 1200
+	}
+	if height <= 0 || height > 2000 {
+		height = 630
+	}
+
+	// 生成图片
+	imageBuffer, err := createOGImage(title, description, siteName, theme, width, height)
+	if err != nil {
+		utils.Error("生成OG图片失败: %v", err)
+		c.JSON(http.StatusInternalServerError, gin.H{
+			"error": "Failed to generate image: " + err.Error(),
+		})
+		return
+	}
+
+	// 返回图片
+	c.Data(http.StatusOK, "image/png", imageBuffer.Bytes())
+	c.Header("Content-Type", "image/png")
+	c.Header("Cache-Control", "public, max-age=3600")
+}
+
+// createOGImage 创建OG图片
+func createOGImage(title, description, siteName, theme string, width, height int) (*bytes.Buffer, error) {
+	dc := gg.NewContext(width, height)
+
+	// 设置背景色
+	bgColor := getBackgroundColor(theme)
+	dc.SetColor(bgColor)
+	dc.DrawRectangle(0, 0, float64(width), float64(height))
+	dc.Fill()
+
+	// 绘制渐变效果
+	gradient := gg.NewLinearGradient(0, 0, float64(width), float64(height))
+	gradient.AddColorStop(0, getGradientStartColor(theme))
+	gradient.AddColorStop(1, getGradientEndColor(theme))
+	dc.SetFillStyle(gradient)
+	dc.DrawRectangle(0, 0, float64(width), float64(height))
+	dc.Fill()
+
+	// 设置站点标识
+	dc.SetHexColor("#ffffff")
+	// 尝试加载字体，如果失败则使用默认字体
+	if err := dc.LoadFontFace("assets/fonts/SourceHanSansCN-Regular.ttc", 24); err != nil {
+		// 使用默认字体设置
+	}
+
+	dc.DrawStringAnchored(siteName, 60, 50, 0, 0.5)
+
+	// 绘制标题
+	dc.SetHexColor("#ffffff")
+	if err := dc.LoadFontFace("assets/fonts/SourceHanSansCN-Bold.ttc", 48); err != nil {
+		// 使用默认字体设置
+	}
+
+	// 文字居中处理
+	titleWidth, _ := dc.MeasureString(title)
+	if titleWidth > float64(width-120) {
+		// 如果标题过长，尝试加载较小字体
+		if err := dc.LoadFontFace("assets/fonts/SourceHanSansCN-Bold.ttc", 42); err != nil {
+			// 使用默认字体设置
+		}
+		titleWidth, _ = dc.MeasureString(title)
+		if titleWidth > float64(width-120) {
+			if err := dc.LoadFontFace("assets/fonts/SourceHanSansCN-Bold.ttc", 36); err != nil {
+				// 使用默认字体设置
+			}
+		}
+	}
+
+	dc.DrawStringAnchored(title, float64(width)/2, float64(height)/2-30, 0.5, 0.5)
+
+	// 绘制描述
+	if description != "" {
+		dc.SetHexColor("#e5e7eb")
+		// 尝试加载较小字体
+		if err := dc.LoadFontFace("assets/fonts/SourceHanSansCN-Regular.ttc", 28); err != nil {
+			// 使用默认字体设置
+		}
+
+		// 自动换行处理
+		wrappedDesc := wrapText(dc, description, float64(width-120))
+		startY := float64(height)/2 + 40
+
+		for i, line := range wrappedDesc {
+			y := startY + float64(i)*35
+			dc.DrawStringAnchored(line, float64(width)/2, y, 0.5, 0.5)
+		}
+	}
+
+	// 添加装饰性元素
+	drawDecorativeElements(dc, width, height, theme)
+
+	// 生成图片
+	buf := &bytes.Buffer{}
+	err := dc.EncodePNG(buf)
+	if err != nil {
+		return nil, err
+	}
+
+	return buf, nil
+}
+
+// getBackgroundColor 获取背景色
+func getBackgroundColor(theme string) color.RGBA {
+	switch theme {
+	case "dark":
+		return color.RGBA{31, 41, 55, 255} // slate-800
+	case "blue":
+		return color.RGBA{29, 78, 216, 255} // blue-700
+	case "green":
+		return color.RGBA{6, 95, 70, 255} // emerald-800
+	case "purple":
+		return color.RGBA{109, 40, 217, 255} // violet-700
+	default:
+		return color.RGBA{55, 65, 81, 255} // gray-800
+	}
+}
+
+// getGradientStartColor 获取渐变起始色
+func getGradientStartColor(theme string) color.Color {
+	switch theme {
+	case "dark":
+		return color.RGBA{15, 23, 42, 255} // slate-900
+	case "blue":
+		return color.RGBA{30, 58, 138, 255} // blue-900
+	case "green":
+		return color.RGBA{6, 78, 59, 255} // emerald-900
+	case "purple":
+		return color.RGBA{91, 33, 182, 255} // violet-800
+	default:
+		return color.RGBA{31, 41, 55, 255} // gray-800
+	}
+}
+
+// getGradientEndColor 获取渐变结束色
+func getGradientEndColor(theme string) color.Color {
+	switch theme {
+	case "dark":
+		return color.RGBA{55, 65, 81, 255} // slate-700
+	case "blue":
+		return color.RGBA{59, 130, 246, 255} // blue-500
+	case "green":
+		return color.RGBA{16, 185, 129, 255} // emerald-500
+	case "purple":
+		return color.RGBA{139, 92, 246, 255} // violet-500
+	default:
+		return color.RGBA{75, 85, 99, 255} // gray-600
+	}
+}
+
+// wrapText 文本自动换行处理
+func wrapText(dc *gg.Context, text string, maxWidth float64) []string {
+	var lines []string
+	words := []rune(text)
+
+	currentLine := ""
+	for _, word := range words {
+		testLine := currentLine + string(word)
+		width, _ := dc.MeasureString(testLine)
+
+		if width > maxWidth && len(currentLine) > 0 {
+			lines = append(lines, currentLine)
+			currentLine = string(word)
+		} else {
+			currentLine = testLine
+		}
+	}
+
+	if currentLine != "" {
+		lines = append(lines, currentLine)
+	}
+
+	// 最多显示3行
+	if len(lines) > 3 {
+		lines = lines[:3]
+		// 在最后一行添加省略号
+		if len(lines[2]) > 3 {
+			lines[2] = lines[2][:len(lines[2])-3] + "..."
+		}
+	}
+
+	return lines
+}
+
+// drawDecorativeElements 绘制装饰性元素
+func drawDecorativeElements(dc *gg.Context, width, height int, theme string) {
+	// 绘制装饰性圆点
+	dc.SetHexColor("#ffffff")
+	dc.SetLineWidth(2)
+
+	for i := 0; i < 5; i++ {
+		x := float64(100 + i*150)
+		y := float64(100 + (i%2)*200)
+		dc.DrawCircle(x, y, 8)
+		dc.Stroke()
+	}
+
+	// 绘制底部装饰线
+	dc.DrawLine(60, float64(height-80), float64(width-60), float64(height-80))
+	dc.Stroke()
+}