gitea-pages/main.go

package main

import (
	"embed"
	"encoding/json"
	"fmt"
	"html/template"
	"io"
	"mime"
	"net/http"
	"os"
	"path/filepath"
	"strings"

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

//go:embed pages
var embeddedFiles embed.FS

type transport struct {
	apiKey              string
	underlyingTransport http.RoundTripper
}

func (t *transport) RoundTrip(req *http.Request) (*http.Response, error) {
	if t.apiKey != "" {
		req.Header.Add("Authorization", "token "+t.apiKey)
	}
	return t.underlyingTransport.RoundTrip(req)
}

func main() {
	godotenv.Load()
	// if os.Args[len(os.Args)-1] == "gencrt" {
	// 	GenCerts()
	// 	os.Exit(0)
	// }
	// if _, err := os.Stat("./certs/cert.crt"); err != nil {
	// 	fmt.Println("Not found cert file")
	// 	GenCerts()
	// }
	// if _, err := os.Stat("./certs/priv.key"); err != nil {
	// 	fmt.Println("Not fount cert key file")
	// 	GenCerts()
	// }
	//certFile, _ := os.ReadFile("./certs/cert.crt")
	//block, _ := pem.Decode(certFile)
	//if block == nil {
	// 	fmt.Println("invalid certificate")
	// 	GenCerts()
	// }
	// cert, _ := x509.ParseCertificate(block.Bytes)
	// certExpired := time.Now().After(cert.NotAfter)
	// if certExpired {
	// 	GenCerts()
	// }
	rootDomain, exists := os.LookupEnv("ROOT_DOMAIN")
	if !exists {
		rootDomain = "localhost"
	}
	giteaUrl, exists := os.LookupEnv("GITEA_URL")
	if !exists {
		giteaUrl = "https://codeberg.org"
	}
	defaultRef, exists := os.LookupEnv("DEFAULT_REF")
	if !exists {
		defaultRef = "pages"
	}
	indexFile, exists := os.LookupEnv("INDEX_FILE")
	if !exists {
		indexFile = "index.html"
	}
	directoryIndexStr := os.Getenv("DIRECTORY_INDEX")
	fmt.Println(rootDomain, giteaUrl)
	directoryIndex := false
	if directoryIndexStr == "true" {
		directoryIndex = true
	}
	defaultUser := os.Getenv("DEFAULT_USER")
	servePort, exists := os.LookupEnv("SERVE_PORT")
	if !exists {
		servePort = "8080"
	}
	giteaToken := os.Getenv("GITEA_TOKEN")

	gitea := http.Client{Transport: &transport{underlyingTransport: http.DefaultTransport, apiKey: giteaToken}}

	r := gin.Default()

	templ := template.Must(template.New("").ParseFS(embeddedFiles, "pages/*"))
	r.SetHTMLTemplate(templ)

	r.GET("/*path", func(ctx *gin.Context) {
		path := ctx.Params.ByName("path")

		rawHost := ctx.Request.Host
		if !strings.HasSuffix(rawHost, rootDomain) {
			ctx.HTML(404, "error.html", gin.H{
				"error_code":    "400",
				"error_message": "invalid root domain",
			})
			return
		}
		hostPrefix := strings.TrimSuffix(rawHost, rootDomain)
		host := strings.Split(hostPrefix, ".")

		var owner string
		switch len(host) - 1 {
		case 0:
			ctx.HTML(200, "index.html", gin.H{
				"root_domain": rootDomain,
			})
			return
		case 2:
			owner = host[1]
		case 1:
			if defaultUser == "" {
				goto godefault
			}
			owner = defaultUser
			break
		godefault:
			fallthrough
		default:
			ctx.HTML(400, "index.html", gin.H{
				"root_domain": rootDomain,
			})
			return
		}

		repo := host[0]

		contentPath := giteaUrl + "/api/v1/repos/" + owner + "/" + repo + "/contents/" + path + "?ref=" + defaultRef
		apiPath := giteaUrl + "/api/v1/repos/" + owner + "/" + repo + "/raw" + path
		resp, err := gitea.Get(apiPath + "?ref=" + defaultRef)
		if err != nil {
			ctx.AbortWithError(500, err)
		}
		body, _ := io.ReadAll(resp.Body)
		var message struct {
			Message string
		}
		if resp.StatusCode == 200 {
			// if file found
			ct := mime.TypeByExtension(filepath.Ext(path))
			ctx.Data(200, ct, body)
		} else {
			// if file not found, and get err message
			json.Unmarshal(body, &message)

			if message.Message != "getBlobForEntry" && path != "/" {
				ctx.HTML(404, "error.html", gin.H{
					"error_code":    "404",
					"error_message": "file not found",
				})
				return
			}
			// check is index file (from env) exists
			indexPath := apiPath + "/" + indexFile + "?ref=" + defaultRef
			resp, _ := gitea.Get(indexPath)
			if resp.StatusCode == 200 {
				// index file exist
				body, _ := io.ReadAll(resp.Body)
				ctx.Data(200, "text/html", body)
				return
			} else {
				// else this is directory
				resp, _ := gitea.Get(contentPath)
				body, _ := io.ReadAll(resp.Body)
				var dir []struct {
					Name string
					Path string
				}
				json.Unmarshal(body, &dir)
				if len(dir) == 0 {
					// zero files, empty or non-existent repo
					ctx.HTML(404, "error.html", gin.H{
						"error_code":    "404",
						"error_message": "pages for repository not found",
					})
					return
				}
				if !directoryIndex {
					// if directory index disabled
					ctx.HTML(401, "error.html", gin.H{
						"error_code":    "401",
						"error_message": "directory index disabled",
					})
					return
				}
				var html string
				html += "<h1>Index of " + path + "</h1>"
				html += "<a href=\"" + filepath.Dir(path) + "\">Parrent directory</a><br/>"
				for _, file := range dir {
					html += "<a href=\"/" + file.Path + "\">" + file.Name + "</a><br/>"
				}
				ctx.Data(200, "text/html", []byte(html))
				return
			}
		}

		//ctx.JSON(200, gin.H{"host": host, "path": path})
	})
	r.Run(":" + servePort)
}