serve frontend

server/middleware/frontend_middleware.go

@@ -0,0 +1,106 @@
+package middleware
+
+import (
+	"fmt"
+	"nysoure/server/config"
+	"nysoure/server/service"
+	"os"
+	"strconv"
+	"strings"
+
+	"github.com/gofiber/fiber/v3"
+	"github.com/gomarkdown/markdown"
+	"github.com/gomarkdown/markdown/html"
+	"github.com/gomarkdown/markdown/parser"
+	"github.com/k3a/html2text"
+)
+
+func FrontendMiddleware(c fiber.Ctx) error {
+	if strings.HasPrefix(c.Path(), "/api") {
+		return c.Next()
+	}
+
+	path := c.Path()
+	file := "static" + path
+
+	if _, err := os.Stat(file); path == "/" || os.IsNotExist(err) {
+		return serveIndexHtml(c)
+	} else {
+		return c.SendFile(file)
+	}
+}
+
+func serveIndexHtml(c fiber.Ctx) error {
+	data, err := os.ReadFile("static/index.html")
+	if err != nil {
+		return c.Status(fiber.StatusInternalServerError).SendString("Internal Server Error")
+	}
+	content := string(data)
+
+	siteName := config.ServerName()
+	description := config.ServerDescription()
+	preview := "/icon-192.png"
+	title := siteName
+	url := c.OriginalURL()
+	cfTurnstileSiteKey := config.CloudflareTurnstileSiteKey()
+
+	if strings.HasPrefix(url, "/resources/") {
+		idStr := strings.TrimPrefix(url, "/resources/")
+		id, err := strconv.Atoi(idStr)
+		if err == nil {
+			r, err := service.GetResource(uint(id))
+			if err == nil {
+				if len(r.Images) > 0 {
+					preview = fmt.Sprintf("/images/%d", r.Images[0].ID)
+				}
+				title = r.Title
+				description = getResourceDescription(r.Article)
+			}
+		}
+	} else if strings.HasPrefix(url, "/user/") {
+		username := strings.TrimPrefix(url, "/user/")
+		u, err := service.GetUserByUsername(username)
+		if err == nil {
+			preview = fmt.Sprintf("/avatar/%d", u.ID)
+			title = u.Username
+			description = "User " + u.Username + "'s profile"
+		}
+	}
+
+	content = strings.ReplaceAll(content, "{{SiteName}}", siteName)
+	content = strings.ReplaceAll(content, "{{Description}}", description)
+	content = strings.ReplaceAll(content, "{{Preview}}", preview)
+	content = strings.ReplaceAll(content, "{{Title}}", title)
+	content = strings.ReplaceAll(content, "{{Url}}", url)
+	content = strings.ReplaceAll(content, "{{CFTurnstileSiteKey}}", cfTurnstileSiteKey)
+
+	c.Set("Content-Type", "text/html; charset=utf-8")
+	return c.SendString(content)
+}
+
+func getResourceDescription(article string) string {
+	htmlContent := mdToHTML([]byte(article))
+	plain := html2text.HTML2Text(string(htmlContent))
+	if len([]rune(plain)) > 100 {
+		plain = string([]rune(plain)[:100])
+	}
+	plain = strings.ReplaceAll(plain, "\n", " ")
+	plain = strings.ReplaceAll(plain, "\r", "")
+	plain = strings.ReplaceAll(plain, "\t", "")
+	plain = strings.TrimSpace(plain)
+	return plain
+}
+
+func mdToHTML(md []byte) []byte {
+	// create Markdown parser with extensions
+	extensions := parser.CommonExtensions | parser.NoEmptyLineBeforeBlock | parser.MathJax
+	p := parser.NewWithExtensions(extensions)
+	doc := p.Parse(md)
+
+	// create HTML renderer with extensions
+	htmlFlags := html.CommonFlags | html.HrefTargetBlank
+	opts := html.RendererOptions{Flags: htmlFlags}
+	renderer := html.NewRenderer(opts)
+
+	return markdown.Render(doc, renderer)
+}