server/qa/static.go

package main

import (
	"bytes"
	"embed"
	"io/ioutil"
	"log"
	"net/http"
	"os"
	"path"
	"strings"

	"github.com/gin-gonic/gin"
)

//go:embed static
var assets embed.FS

var BaseURL = "/"

var indexTmpl []byte

func getIndexHtml(c *gin.Context) {
	if len(indexTmpl) == 0 {
		if file, err := os.Open(path.Join(StaticDir, "index.html")); err != nil {
			log.Println("Unable to open index.html: ", err)
		} else {
			defer file.Close()

			if indexTmpl, err = ioutil.ReadAll(file); err != nil {
				log.Println("Cannot read whole index.html: ", err)
			} else {
				indexTmpl = bytes.Replace(indexTmpl, []byte("{{.urlbase}}"), []byte(path.Clean(path.Join(BaseURL+"/", "nuke"))[:len(path.Clean(path.Join(BaseURL+"/", "nuke")))-4]), -1)
			}
		}
	}

	c.Writer.Write(indexTmpl)
}

var staticFS http.FileSystem

func serveFile(c *gin.Context, url string) {
	c.Request.URL.Path = url
	http.FileServer(staticFS).ServeHTTP(c.Writer, c.Request)
}

func declareStaticRoutes(router *gin.RouterGroup, baseURL string) {
	router.GET("/", func(c *gin.Context) {
		getIndexHtml(c)
	})

	router.GET("/exercices/*_", func(c *gin.Context) {
		getIndexHtml(c)
	})
	router.GET("/themes/*_", func(c *gin.Context) {
		getIndexHtml(c)
	})

	router.GET("/css/*_", func(c *gin.Context) {
		serveFile(c, strings.TrimPrefix(c.Request.URL.Path, baseURL))
	})
	router.GET("/fonts/*_", func(c *gin.Context) {
		serveFile(c, strings.TrimPrefix(c.Request.URL.Path, baseURL))
	})
	router.GET("/img/*_", func(c *gin.Context) {
		serveFile(c, strings.TrimPrefix(c.Request.URL.Path, baseURL))
	})
	router.GET("/js/*_", func(c *gin.Context) {
		serveFile(c, strings.TrimPrefix(c.Request.URL.Path, baseURL))
	})
	router.GET("/views/*_", func(c *gin.Context) {
		serveFile(c, strings.TrimPrefix(c.Request.URL.Path, baseURL))
	})
}