From 830f43f467ad4f9dc0aef9335bb2756e57dfed4c Mon Sep 17 00:00:00 2001
From: Mitchell Riedstra <mitch@riedstra.dev>
Date: Tue, 27 Jul 2021 00:16:31 -0400
Subject: Initial

---
 main.go | 235 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 235 insertions(+)
 create mode 100644 main.go

(limited to 'main.go')

diff --git a/main.go b/main.go
new file mode 100644
index 0000000..ee53f7e
--- /dev/null
+++ b/main.go
@@ -0,0 +1,235 @@
+package main
+
+import (
+	"compress/gzip"
+	"crypto/rand"
+	_ "embed"
+	"encoding/base64"
+	"encoding/gob"
+	"errors"
+	"flag"
+	"html/template"
+	"log"
+	"net/http"
+	"os"
+	"time"
+
+	"github.com/gorilla/mux"
+)
+
+var logger = log.New(os.Stderr, "", 0)
+
+// const ID_BYTES = 5
+const ID_BYTES = 16
+
+//go:embed index.tpl
+var indexTemplateContent string
+var indexTemplate = template.Must(template.New("index").Parse(indexTemplateContent))
+
+//go:embed view.tpl
+var viewTemplateContent string
+var viewTemplate = template.Must(template.New("view").Parse(viewTemplateContent))
+
+//go:embed error.tpl
+var errorTemplateContent string
+var errorTemplate = template.Must(template.New("error").Parse(errorTemplateContent))
+
+//go:embed style.css
+var stylesheetContent []byte
+
+type Paste struct {
+	Id      string
+	Title   string
+	Content []byte
+}
+
+func (p Paste) GetContent() string {
+	return string(p.Content)
+}
+
+func (p *Paste) Load() error {
+	fh, err := os.Open(p.Id)
+	if err != nil {
+		return err
+	}
+
+	zrdr, err := gzip.NewReader(fh)
+	if err != nil {
+		return err
+	}
+
+	dec := gob.NewDecoder(zrdr)
+	err = dec.Decode(&p)
+	if err != nil {
+		return err
+	}
+
+	zrdr.Close()
+
+	return fh.Close()
+}
+
+func (p Paste) Save() error {
+	fh, err := os.OpenFile(p.Id, os.O_CREATE|os.O_RDWR, 0666)
+	if err != nil {
+		return err
+	}
+
+	zwr := gzip.NewWriter(fh)
+
+	enc := gob.NewEncoder(zwr)
+	err = enc.Encode(&p)
+	if err != nil {
+		return err
+	}
+
+	zwr.Close()
+
+	return fh.Close()
+}
+
+func GenId() string {
+	r := make([]byte, ID_BYTES)
+	_, err := rand.Read(r)
+	if err != nil {
+		logger.Fatal(err)
+	}
+
+	return base64.RawURLEncoding.EncodeToString(r)
+}
+
+func main() {
+	fl := flag.NewFlagSet("Brutally simple pastebin", flag.ExitOnError)
+	listen := fl.String("listen", ":6130", "Address to bind to, LISTEN_ADDR environment variable overrides")
+	debug := fl.Bool("d", false, "debugging add information to the logging output DEBUG=true|false controls this as well")
+	storage := fl.String("s", "", "Directory to serve, must be supplied via flag or STORAGE_DIR environment variable")
+	_ = fl.Parse(os.Args[1:])
+
+	if addr := os.Getenv("LISTEN_ADDR"); addr != "" {
+		*listen = addr
+	}
+	if d := os.Getenv("DEBUG"); d == "true" || *debug {
+		logger.SetFlags(log.LstdFlags | log.Llongfile)
+	}
+	if d := os.Getenv("STORAGE_DIR"); d != "" {
+		*storage = d
+	}
+
+	if *storage == "" {
+		logger.Fatal("Cannot continue without storage directory, set `-s` flag or STORAGE_DIR environment variable")
+	}
+
+	err := os.Chdir(*storage)
+	if err != nil {
+		logger.Fatal(err)
+	}
+
+	mux := mux.NewRouter()
+
+	mux.HandleFunc("/new", newPaste)
+	mux.HandleFunc("/view/{id}", loadPaste)
+	mux.HandleFunc("/style.css", stylesheet)
+	mux.HandleFunc("/", index)
+
+	logger.Println("listening on: ", *listen)
+
+	srv := &http.Server{
+		Handler:      mux,
+		Addr:         *listen,
+		WriteTimeout: 15 * time.Second,
+		ReadTimeout:  15 * time.Second,
+	}
+	logger.Fatal(srv.ListenAndServe())
+}
+
+func newPaste(w http.ResponseWriter, r *http.Request) {
+	err := r.ParseForm()
+	if err != nil {
+		logger.Println(err)
+		http.Error(w, "Internal server error", http.StatusInternalServerError)
+		return
+	}
+
+	title := r.FormValue("title")
+	content := r.FormValue("content")
+
+	if title == "" || content == "" {
+		logger.Println("Empty title or content")
+		http.Error(w, "Internal server error", http.StatusInternalServerError)
+		return
+	}
+
+	p := &Paste{
+		Id:      GenId(),
+		Title:   title,
+		Content: []byte(content),
+	}
+
+	err = p.Save()
+	if err != nil {
+		logger.Println(err)
+		http.Error(w, "Internal server error", http.StatusInternalServerError)
+		return
+	}
+
+	http.Redirect(w, r, "/view/"+p.Id, http.StatusFound)
+}
+
+func loadPaste(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+
+	id, ok := vars["id"]
+	if !ok {
+		w.WriteHeader(http.StatusBadRequest)
+		err := errorTemplate.Execute(w, map[string]string{
+			"Short": "ID Not found",
+			"Long":  "There was no ID supplied",
+		})
+		if err != nil {
+			logger.Println(err)
+		}
+		return
+	}
+
+	p := &Paste{Id: id}
+
+	err := p.Load()
+	if err != nil {
+		logger.Println(err)
+		if errors.Is(err, os.ErrNotExist) {
+			w.WriteHeader(http.StatusNotFound)
+			err = errorTemplate.Execute(w, map[string]string{
+				"Short": "ID Not found",
+				"Long":  "ID: " + p.Id + "Was not found",
+			})
+		} else {
+			w.WriteHeader(http.StatusInternalServerError)
+			err = errorTemplate.Execute(w, map[string]string{
+				"Short": "ID Not found",
+				"Long":  "There was an issue reading ID: " + p.Id,
+			})
+		}
+		if err != nil {
+			logger.Println(err)
+		}
+		return
+	}
+
+	err = viewTemplate.Execute(w, p)
+	if err != nil {
+		logger.Println(err)
+	}
+}
+
+func stylesheet(w http.ResponseWriter, r *http.Request) {
+	w.Header().Add("Content-type", "text/css")
+	_, _ = w.Write(stylesheetContent)
+}
+
+func index(w http.ResponseWriter, r *http.Request) {
+	err := indexTemplate.Execute(w, nil)
+	if err != nil {
+		logger.Println(err)
+		http.Error(w, "Internal server error", http.StatusInternalServerError)
+	}
+}
-- 
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