136 lines
3.3 KiB
Go
136 lines
3.3 KiB
Go
package models
|
|
|
|
import (
|
|
"bytes"
|
|
"strings"
|
|
"time"
|
|
|
|
"github.com/microcosm-cc/bluemonday"
|
|
"github.com/teris-io/shortid"
|
|
"github.com/yuin/goldmark"
|
|
"github.com/yuin/goldmark/extension"
|
|
"github.com/yuin/goldmark/renderer/html"
|
|
"mvdan.cc/xurls"
|
|
)
|
|
|
|
// ChatEvent represents a single chat message.
|
|
type ChatEvent struct {
|
|
ClientID string `json:"-"`
|
|
|
|
Author string `json:"author,omitempty"`
|
|
Body string `json:"body,omitempty"`
|
|
RawBody string `json:"-"`
|
|
ID string `json:"id"`
|
|
MessageType EventType `json:"type"`
|
|
Visible bool `json:"visible"`
|
|
Timestamp time.Time `json:"timestamp,omitempty"`
|
|
Ephemeral bool `json:"ephemeral,omitempty"`
|
|
}
|
|
|
|
// Valid checks to ensure the message is valid.
|
|
func (m ChatEvent) Valid() bool {
|
|
return m.Author != "" && m.Body != "" && m.ID != ""
|
|
}
|
|
|
|
// SetDefaults will set default values on a chat event object.
|
|
func (m *ChatEvent) SetDefaults() {
|
|
id, _ := shortid.Generate()
|
|
m.ID = id
|
|
m.Timestamp = time.Now()
|
|
m.Visible = true
|
|
}
|
|
|
|
// RenderAndSanitizeMessageBody will turn markdown into HTML, sanitize raw user-supplied HTML and standardize
|
|
// the message into something safe and renderable for clients.
|
|
func (m *ChatEvent) RenderAndSanitizeMessageBody() {
|
|
m.RawBody = m.Body
|
|
|
|
// Set the new, sanitized and rendered message body
|
|
m.Body = RenderAndSanitize(m.RawBody)
|
|
}
|
|
|
|
// Empty will return if this message's contents is empty.
|
|
func (m *ChatEvent) Empty() bool {
|
|
return m.Body == ""
|
|
}
|
|
|
|
// RenderAndSanitize will turn markdown into HTML, sanitize raw user-supplied HTML and standardize
|
|
// the message into something safe and renderable for clients.
|
|
func RenderAndSanitize(raw string) string {
|
|
rendered := renderMarkdown(raw)
|
|
safe := sanitize(rendered)
|
|
|
|
// Set the new, sanitized and rendered message body
|
|
return strings.TrimSpace(safe)
|
|
}
|
|
|
|
func renderMarkdown(raw string) string {
|
|
markdown := goldmark.New(
|
|
goldmark.WithRendererOptions(
|
|
html.WithUnsafe(),
|
|
),
|
|
goldmark.WithExtensions(
|
|
extension.NewLinkify(
|
|
extension.WithLinkifyAllowedProtocols([][]byte{
|
|
[]byte("http:"),
|
|
[]byte("https:"),
|
|
}),
|
|
extension.WithLinkifyURLRegexp(
|
|
xurls.Strict,
|
|
),
|
|
),
|
|
),
|
|
)
|
|
|
|
trimmed := strings.TrimSpace(raw)
|
|
var buf bytes.Buffer
|
|
if err := markdown.Convert([]byte(trimmed), &buf); err != nil {
|
|
panic(err)
|
|
}
|
|
|
|
return buf.String()
|
|
}
|
|
|
|
func sanitize(raw string) string {
|
|
p := bluemonday.StrictPolicy()
|
|
|
|
// Require URLs to be parseable by net/url.Parse
|
|
p.AllowStandardURLs()
|
|
|
|
// Allow links
|
|
p.AllowAttrs("href").OnElements("a")
|
|
|
|
// Force all URLs to have "noreferrer" in their rel attribute.
|
|
p.RequireNoReferrerOnLinks(true)
|
|
|
|
// Links will get target="_blank" added to them.
|
|
p.AddTargetBlankToFullyQualifiedLinks(true)
|
|
|
|
// Allow paragraphs
|
|
p.AllowElements("br")
|
|
p.AllowElements("p")
|
|
|
|
// Allow img tags
|
|
p.AllowElements("img")
|
|
p.AllowAttrs("src").OnElements("img")
|
|
p.AllowAttrs("alt").OnElements("img")
|
|
p.AllowAttrs("title").OnElements("img")
|
|
|
|
// Custom emoji have a class already specified.
|
|
// We should only allow classes on emoji, not *all* imgs.
|
|
// But TODO.
|
|
p.AllowAttrs("class").OnElements("img")
|
|
|
|
// Allow bold
|
|
p.AllowElements("strong")
|
|
|
|
// Allow emphasis
|
|
p.AllowElements("em")
|
|
|
|
// Allow code blocks
|
|
p.AllowElements("code")
|
|
p.AllowElements("pre")
|
|
|
|
return p.Sanitize(raw)
|
|
}
|