From 59aeab60c18c531be4b59e0e66fddbbe7c93ca58 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20M=C3=BCller?= <no@way.click>
Date: Mon, 18 Sep 2017 22:12:09 +0200
Subject: [PATCH] note editing implemented

---
 .../{public/new.html => templates/form.html}  | 13 ++--
 assets/templates/stats.html                   |  4 +-
 server.go                                     | 29 +++++++--
 storage.go                                    | 60 +++++++++++++++----
 4 files changed, 82 insertions(+), 24 deletions(-)
 rename assets/{public/new.html => templates/form.html} (75%)
diff --git a/assets/public/new.html b/assets/templates/form.html
similarity index 75%
rename from assets/public/new.html
rename to assets/templates/form.html
index 76ff8e2..9a2e314 100644
--- a/assets/public/new.html
+++ b/assets/templates/form.html
@@ -1,7 +1,8 @@
+{{define "Form"}}
 <!DOCTYPE html>
 <html>
     <head>
-        <title>NoteHub &mdash; Add note</title>
+        <title>NoteHub &mdash; {{if .ID}}Edit{{else}}Add{{end}} note</title>
         <meta charset="UTF-8">
         <meta content="width=device-width, initial-scale=1.0" name="viewport">
         <link href="/style.css" rel="stylesheet" type="text/css" />
@@ -9,13 +10,10 @@
     </head>
     <body>
         <form action="/note" autocomplete="off" method="POST" target="_self">
-            <textarea autofocus name="text"></textarea>
+            <textarea autofocus name="text">{{.Text}}</textarea>
             <fieldset>
-                <input class="ui-elem" 
-                       name="plain-password" 
-                       placeholder="Password for editing" 
-                       type="text" 
-                       autocomplete="off">
+                <input id="id" name="id" value="{{.ID}}" type="hidden" />
+                <input class="ui-elem" id="password" name="password" placeholder="Password for editing" type="text" autocomplete="off">
                 <label style="margin-right: 1em">
                     <input id="tos" name="tos" type="checkbox" onClick="toggleButton()">
                     Accept <a href="/TOS.md">Terms of Service</a>
@@ -33,3 +31,4 @@
         </script>
     </body>
 </html>
+{{end}}
diff --git a/assets/templates/stats.html b/assets/templates/stats.html
index 159ced2..1192ac1 100644
--- a/assets/templates/stats.html
+++ b/assets/templates/stats.html
@@ -1,8 +1,8 @@
 {{define "Stats"}}
 <h2>Statistics</h2>
 <table>
-    <tr><td>Published</td><td>{{.Published}}</td></tr>
-    <tr><td>Edited</td><td>{{.Edited}}</td></tr>
+    <tr><td>Published</td><td>{{.Published.Format "Jan 02, 2006 15:04:05 UTC"}}</td></tr>
+    <tr><td>Edited</td><td>{{.Edited.Format "Jan 02, 2006 15:04:05 UTC"}}</td></tr>
     <tr><td>Views</td><td>{{.Views}}</td></tr>
 </table>
 {{end}}
diff --git a/server.go b/server.go
index 7a16f2f..1cd5243 100644
--- a/server.go
+++ b/server.go
@@ -35,21 +35,24 @@ func main() {
 	e.File("/robots.txt", "assets/public/robots.txt")
 	e.File("/style.css", "assets/public/style.css")
 	e.File("/index.html", "assets/public/index.html")
-	e.File("/new", "assets/public/new.html")
 	e.File("/", "assets/public/index.html")
 
 	e.GET("/TOS.md", func(c echo.Context) error {
 		n, code := md2html(c, "TOS")
 		return c.Render(code, "Page", n)
 	})
+
 	e.GET("/:id", func(c echo.Context) error {
 		n, code := load(c, db)
+		n.prepare()
 		return c.Render(code, "Note", n)
 	})
+
 	e.GET("/:id/export", func(c echo.Context) error {
 		n, code := load(c, db)
 		return c.String(code, n.Text)
 	})
+
 	e.GET("/:id/stats", func(c echo.Context) error {
 		n, code := load(c, db)
 		buf := bytes.NewBuffer([]byte{})
@@ -58,6 +61,15 @@ func main() {
 		return c.Render(code, "Note", n)
 	})
 
+	e.GET("/:id/edit", func(c echo.Context) error {
+		n, code := load(c, db)
+		return c.Render(code, "Form", n)
+	})
+
+	e.GET("/new", func(c echo.Context) error {
+		return c.Render(http.StatusOK, "Form", nil)
+	})
+
 	e.POST("/note", func(c echo.Context) error {
 		vals, err := c.FormParams()
 		if err != nil {
@@ -73,18 +85,25 @@ func main() {
 			return c.Render(code, "Note",
 				errPage(code, "note length not accepted"))
 		}
-		n := Note{
+		id := get(vals, "id")
+		n := &Note{
+			ID:       id,
 			Text:     text,
 			Password: get(vals, "password"),
 		}
-		id, err := save(c, db, &n)
+		n, err = save(c, db, n)
 		if err != nil {
 			c.Logger().Error(err)
 			code := http.StatusServiceUnavailable
+			if err == errorUnathorised {
+				code = http.StatusUnauthorized
+			} else if err == errorBadRequest {
+				code = http.StatusBadRequest
+			}
 			return c.Render(code, "Note", errPage(code))
 		}
-		c.Logger().Infof("new note %q created", n.ID)
-		return c.Redirect(http.StatusMovedPermanently, "/"+id)
+		c.Logger().Infof("note %q saved", n.ID)
+		return c.Redirect(http.StatusMovedPermanently, "/"+n.ID)
 	})
 
 	e.Logger.Fatal(e.Start(":3000"))
diff --git a/storage.go b/storage.go
index 58628a9..d9fc57a 100644
--- a/storage.go
+++ b/storage.go
@@ -2,7 +2,9 @@ package main
 
 import (
 	"bytes"
+	"crypto/sha256"
 	"database/sql"
+	"errors"
 	"fmt"
 	"html/template"
 	"math/rand"
@@ -24,12 +26,17 @@ const idLength = 5
 var (
 	errorCodes = map[int]string{
 		400: "Bad request",
+		401: "Unauthorized",
 		404: "Not found",
 		412: "Precondition failed",
 		503: "Service unavailable",
 	}
-	rexpNewLine     = regexp.MustCompile("[\n\r]")
-	rexpNonAlphaNum = regexp.MustCompile("[`~!@#$%^&*_|+=?;:'\",.<>{}\\/]")
+	rexpNewLine        = regexp.MustCompile("[\n\r]")
+	rexpNonAlphaNum    = regexp.MustCompile("[`~!@#$%^&*_|+=?;:'\",.<>{}\\/]")
+	rexpNoScriptIframe = regexp.MustCompile("<.*?(iframe|script).*?>")
+
+	errorUnathorised = errors.New("id or password is wrong")
+	errorBadRequest  = errors.New("password is empty")
 )
 
 type Note struct {
@@ -50,35 +57,69 @@ func errPage(code int, details ...string) Note {
 	}
 }
 
-func (n *Note) render() {
+func (n *Note) prepare() {
 	fstLine := rexpNewLine.Split(n.Text, -1)[0]
 	maxLength := 25
 	if len(fstLine) < 25 {
 		maxLength = len(fstLine)
 	}
+	n.Text = rexpNoScriptIframe.ReplaceAllString(n.Text, "")
 	n.Title = strings.TrimSpace(rexpNonAlphaNum.ReplaceAllString(fstLine[:maxLength], ""))
-	n.Password = ""
 	n.Content = mdTmplHTML([]byte(n.Text))
 }
 
-func save(c echo.Context, db *sql.DB, n *Note) (string, error) {
+func save(c echo.Context, db *sql.DB, n *Note) (*Note, error) {
+	if n.Password != "" {
+		n.Password = fmt.Sprintf("%x", sha256.Sum256([]byte(n.Password)))
+	}
+	if n.ID == "" {
+		return insert(c, db, n)
+	}
+	return update(c, db, n)
+}
+
+func update(c echo.Context, db *sql.DB, n *Note) (*Note, error) {
+	if n.Password == "" {
+		return nil, errorBadRequest
+	}
+	tx, err := db.Begin()
+	if err != nil {
+		return nil, err
+	}
+	stmt, _ := tx.Prepare("update notes set (text, edited) = (?, ?) where id = ? and password = ?")
+	defer stmt.Close()
+	res, err := stmt.Exec(n.Text, time.Now(), n.ID, n.Password)
+	if err != nil {
+		tx.Rollback()
+		return nil, err
+	}
+	rows, err := res.RowsAffected()
+	if rows != 1 {
+		tx.Rollback()
+		return nil, errorUnathorised
+	}
+	return n, tx.Commit()
+}
+
+func insert(c echo.Context, db *sql.DB, n *Note) (*Note, error) {
 	tx, err := db.Begin()
 	if err != nil {
-		return "", err
+		return nil, err
 	}
 	stmt, _ := tx.Prepare("insert into notes(id, text, password) values(?, ?, ?)")
 	defer stmt.Close()
 	id := randId()
 	_, err = stmt.Exec(id, n.Text, n.Password)
 	if err != nil {
+		tx.Rollback()
 		if strings.HasPrefix(err.Error(), "UNIQUE constraint failed") {
-			tx.Rollback()
 			c.Logger().Infof("collision on id %q", id)
 			return save(c, db, n)
 		}
-		return "", err
+		return nil, err
 	}
-	return id, tx.Commit()
+	n.ID = id
+	return n, tx.Commit()
 }
 
 func randId() string {
@@ -119,7 +160,6 @@ func load(c echo.Context, db *sql.DB) (Note, int) {
 		Published: published,
 		Edited:    edited,
 	}
-	n.render()
 	return *n, http.StatusOK
 }
 

Published	{{.Published}}
Edited	{{.Edited}}
Published	{{.Published.Format "Jan 02, 2006 15:04:05 UTC"}}
Edited	{{.Edited.Format "Jan 02, 2006 15:04:05 UTC"}}
Views	{{.Views}}