Refactoring: rename modules -> pkg

Reasons to change:

1. Shorter than 'modules'
2. More generally used by other Go projects
3. Corresponds to the naming of '$GOPATH/pkg' directory

6 files changed, 986 insertions, 0 deletions

diff --git a/pkg/markup/markdown.go b/pkg/markup/markdown.go
new file mode 100644
index 00000000..3414a58c
--- /dev/null
+++ b/pkg/markup/markdown.go
@@ -0,0 +1,167 @@
+// Copyright 2014 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package markup
+
+import (
+	"bytes"
+	"fmt"
+	"path"
+	"path/filepath"
+	"regexp"
+	"strings"
+
+	"github.com/russross/blackfriday"
+
+	"github.com/gogits/gogs/pkg/base"
+	"github.com/gogits/gogs/pkg/setting"
+)
+
+// IsMarkdownFile reports whether name looks like a Markdown file based on its extension.
+func IsMarkdownFile(name string) bool {
+	extension := strings.ToLower(filepath.Ext(name))
+	for _, ext := range setting.Markdown.FileExtensions {
+		if strings.ToLower(ext) == extension {
+			return true
+		}
+	}
+	return false
+}
+
+// MarkdownRenderer is a extended version of underlying Markdown render object.
+type MarkdownRenderer struct {
+	blackfriday.Renderer
+	urlPrefix string
+}
+
+var validLinksPattern = regexp.MustCompile(`^[a-z][\w-]+://|^mailto:`)
+
+// isLink reports whether link fits valid format.
+func isLink(link []byte) bool {
+	return validLinksPattern.Match(link)
+}
+
+// Link defines how formal links should be processed to produce corresponding HTML elements.
+func (r *MarkdownRenderer) Link(out *bytes.Buffer, link []byte, title []byte, content []byte) {
+	if len(link) > 0 && !isLink(link) {
+		if link[0] != '#' {
+			link = []byte(path.Join(r.urlPrefix, string(link)))
+		}
+	}
+
+	r.Renderer.Link(out, link, title, content)
+}
+
+// AutoLink defines how auto-detected links should be processed to produce corresponding HTML elements.
+// Reference for kind: https://github.com/russross/blackfriday/blob/master/markdown.go#L69-L76
+func (r *MarkdownRenderer) AutoLink(out *bytes.Buffer, link []byte, kind int) {
+	if kind != blackfriday.LINK_TYPE_NORMAL {
+		r.Renderer.AutoLink(out, link, kind)
+		return
+	}
+
+	// Since this method could only possibly serve one link at a time,
+	// we do not need to find all.
+	if bytes.HasPrefix(link, []byte(setting.AppUrl)) {
+		m := CommitPattern.Find(link)
+		if m != nil {
+			m = bytes.TrimSpace(m)
+			i := strings.Index(string(m), "commit/")
+			j := strings.Index(string(m), "#")
+			if j == -1 {
+				j = len(m)
+			}
+			out.WriteString(fmt.Sprintf(` <code><a href="%s">%s</a></code>`, m, base.ShortSha(string(m[i+7:j]))))
+			return
+		}
+
+		m = IssueFullPattern.Find(link)
+		if m != nil {
+			m = bytes.TrimSpace(m)
+			i := strings.Index(string(m), "issues/")
+			j := strings.Index(string(m), "#")
+			if j == -1 {
+				j = len(m)
+			}
+
+			index := string(m[i+7 : j])
+			fullRepoURL := setting.AppUrl + strings.TrimPrefix(r.urlPrefix, "/")
+			var link string
+			if strings.HasPrefix(string(m), fullRepoURL) {
+				// Use a short issue reference if the URL refers to this repository
+				link = fmt.Sprintf(`<a href="%s">#%s</a>`, m, index)
+			} else {
+				// Use a cross-repository issue reference if the URL refers to a different repository
+				repo := string(m[len(setting.AppUrl) : i-1])
+				link = fmt.Sprintf(`<a href="%s">%s#%s</a>`, m, repo, index)
+			}
+			out.WriteString(link)
+			return
+		}
+	}
+
+	r.Renderer.AutoLink(out, link, kind)
+}
+
+// ListItem defines how list items should be processed to produce corresponding HTML elements.
+func (options *MarkdownRenderer) ListItem(out *bytes.Buffer, text []byte, flags int) {
+	// Detect procedures to draw checkboxes.
+	switch {
+	case bytes.HasPrefix(text, []byte("[ ] ")):
+		text = append([]byte(`<input type="checkbox" disabled="" />`), text[3:]...)
+	case bytes.HasPrefix(text, []byte("[x] ")):
+		text = append([]byte(`<input type="checkbox" disabled="" checked="" />`), text[3:]...)
+	}
+	options.Renderer.ListItem(out, text, flags)
+}
+
+// RawMarkdown renders Markdown to HTML without handling special links.
+func RawMarkdown(body []byte, urlPrefix string) []byte {
+	htmlFlags := 0
+	htmlFlags |= blackfriday.HTML_SKIP_STYLE
+	htmlFlags |= blackfriday.HTML_OMIT_CONTENTS
+
+	if setting.Smartypants.Enabled {
+		htmlFlags |= blackfriday.HTML_USE_SMARTYPANTS
+		if setting.Smartypants.Fractions {
+			htmlFlags |= blackfriday.HTML_SMARTYPANTS_FRACTIONS
+		}
+		if setting.Smartypants.Dashes {
+			htmlFlags |= blackfriday.HTML_SMARTYPANTS_DASHES
+		}
+		if setting.Smartypants.LatexDashes {
+			htmlFlags |= blackfriday.HTML_SMARTYPANTS_LATEX_DASHES
+		}
+		if setting.Smartypants.AngledQuotes {
+			htmlFlags |= blackfriday.HTML_SMARTYPANTS_ANGLED_QUOTES
+		}
+	}
+
+	renderer := &MarkdownRenderer{
+		Renderer:  blackfriday.HtmlRenderer(htmlFlags, "", ""),
+		urlPrefix: urlPrefix,
+	}
+
+	// set up the parser
+	extensions := 0
+	extensions |= blackfriday.EXTENSION_NO_INTRA_EMPHASIS
+	extensions |= blackfriday.EXTENSION_TABLES
+	extensions |= blackfriday.EXTENSION_FENCED_CODE
+	extensions |= blackfriday.EXTENSION_AUTOLINK
+	extensions |= blackfriday.EXTENSION_STRIKETHROUGH
+	extensions |= blackfriday.EXTENSION_SPACE_HEADERS
+	extensions |= blackfriday.EXTENSION_NO_EMPTY_LINE_BEFORE_BLOCK
+
+	if setting.Markdown.EnableHardLineBreak {
+		extensions |= blackfriday.EXTENSION_HARD_LINE_BREAK
+	}
+
+	body = blackfriday.Markdown(body, renderer, extensions)
+	return body
+}
+
+// Markdown takes a string or []byte and renders to HTML in Markdown syntax with special links.
+func Markdown(input interface{}, urlPrefix string, metas map[string]string) []byte {
+	return Render(MARKDOWN, input, urlPrefix, metas)
+}
diff --git a/pkg/markup/markdown_test.go b/pkg/markup/markdown_test.go
new file mode 100644
index 00000000..a4bf074f
--- /dev/null
+++ b/pkg/markup/markdown_test.go
@@ -0,0 +1,111 @@
+// Copyright 2016 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package markup_test
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+
+	"github.com/russross/blackfriday"
+	. "github.com/smartystreets/goconvey/convey"
+
+	. "github.com/gogits/gogs/pkg/markup"
+	"github.com/gogits/gogs/pkg/setting"
+)
+
+func Test_IsMarkdownFile(t *testing.T) {
+	setting.Markdown.FileExtensions = strings.Split(".md,.markdown,.mdown,.mkd", ",")
+	Convey("Detect Markdown file extension", t, func() {
+		testCases := []struct {
+			ext   string
+			match bool
+		}{
+			{".md", true},
+			{".markdown", true},
+			{".mdown", true},
+			{".mkd", true},
+			{".org", false},
+			{".rst", false},
+			{".asciidoc", false},
+		}
+
+		for _, tc := range testCases {
+			So(IsMarkdownFile(tc.ext), ShouldEqual, tc.match)
+		}
+	})
+}
+
+func Test_Markdown(t *testing.T) {
+	Convey("Rendering an issue URL", t, func() {
+		setting.AppUrl = "http://localhost:3000/"
+		htmlFlags := 0
+		htmlFlags |= blackfriday.HTML_SKIP_STYLE
+		htmlFlags |= blackfriday.HTML_OMIT_CONTENTS
+		renderer := &MarkdownRenderer{
+			Renderer: blackfriday.HtmlRenderer(htmlFlags, "", ""),
+		}
+		buffer := new(bytes.Buffer)
+		Convey("To the internal issue tracker", func() {
+			Convey("It should render valid issue URLs", func() {
+				testCases := []string{
+					"http://localhost:3000/user/repo/issues/3333", "<a href=\"http://localhost:3000/user/repo/issues/3333\">#3333</a>",
+				}
+
+				for i := 0; i < len(testCases); i += 2 {
+					renderer.AutoLink(buffer, []byte(testCases[i]), blackfriday.LINK_TYPE_NORMAL)
+
+					line, _ := buffer.ReadString(0)
+					So(line, ShouldEqual, testCases[i+1])
+				}
+			})
+			Convey("It should render but not change non-issue URLs", func() {
+				testCases := []string{
+					"http://1111/2222/ssss-issues/3333?param=blah&blahh=333", "<a href=\"http://1111/2222/ssss-issues/3333?param=blah&amp;blahh=333\">http://1111/2222/ssss-issues/3333?param=blah&amp;blahh=333</a>",
+					"http://test.com/issues/33333", "<a href=\"http://test.com/issues/33333\">http://test.com/issues/33333</a>",
+					"http://test.com/issues/3", "<a href=\"http://test.com/issues/3\">http://test.com/issues/3</a>",
+					"http://issues/333", "<a href=\"http://issues/333\">http://issues/333</a>",
+					"https://issues/333", "<a href=\"https://issues/333\">https://issues/333</a>",
+					"http://tissues/0", "<a href=\"http://tissues/0\">http://tissues/0</a>",
+				}
+
+				for i := 0; i < len(testCases); i += 2 {
+					renderer.AutoLink(buffer, []byte(testCases[i]), blackfriday.LINK_TYPE_NORMAL)
+
+					line, _ := buffer.ReadString(0)
+					So(line, ShouldEqual, testCases[i+1])
+				}
+			})
+		})
+	})
+
+	Convey("Rendering a commit URL", t, func() {
+		setting.AppUrl = "http://localhost:3000/"
+		htmlFlags := 0
+		htmlFlags |= blackfriday.HTML_SKIP_STYLE
+		htmlFlags |= blackfriday.HTML_OMIT_CONTENTS
+		renderer := &MarkdownRenderer{
+			Renderer: blackfriday.HtmlRenderer(htmlFlags, "", ""),
+		}
+		buffer := new(bytes.Buffer)
+		Convey("To the internal issue tracker", func() {
+			Convey("It should correctly convert URLs", func() {
+				testCases := []string{
+					"http://localhost:3000/user/project/commit/d8a994ef243349f321568f9e36d5c3f444b99cae", " <code><a href=\"http://localhost:3000/user/project/commit/d8a994ef243349f321568f9e36d5c3f444b99cae\">d8a994ef24</a></code>",
+					"http://localhost:3000/user/project/commit/d8a994ef243349f321568f9e36d5c3f444b99cae#diff-2", " <code><a href=\"http://localhost:3000/user/project/commit/d8a994ef243349f321568f9e36d5c3f444b99cae#diff-2\">d8a994ef24</a></code>",
+					"https://external-link.gogs.io/gogs/gogs/commit/d8a994ef243349f321568f9e36d5c3f444b99cae#diff-2", "<a href=\"https://external-link.gogs.io/gogs/gogs/commit/d8a994ef243349f321568f9e36d5c3f444b99cae#diff-2\">https://external-link.gogs.io/gogs/gogs/commit/d8a994ef243349f321568f9e36d5c3f444b99cae#diff-2</a>",
+					"https://commit/d8a994ef243349f321568f9e36d5c3f444b99cae", "<a href=\"https://commit/d8a994ef243349f321568f9e36d5c3f444b99cae\">https://commit/d8a994ef243349f321568f9e36d5c3f444b99cae</a>",
+				}
+
+				for i := 0; i < len(testCases); i += 2 {
+					renderer.AutoLink(buffer, []byte(testCases[i]), blackfriday.LINK_TYPE_NORMAL)
+
+					line, _ := buffer.ReadString(0)
+					So(line, ShouldEqual, testCases[i+1])
+				}
+			})
+		})
+	})
+}
diff --git a/pkg/markup/markup.go b/pkg/markup/markup.go
new file mode 100644
index 00000000..5c92b74a
--- /dev/null
+++ b/pkg/markup/markup.go
@@ -0,0 +1,335 @@
+// Copyright 2017 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package markup
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"regexp"
+	"strings"
+
+	"github.com/Unknwon/com"
+	"golang.org/x/net/html"
+
+	"github.com/gogits/gogs/pkg/base"
+	"github.com/gogits/gogs/pkg/setting"
+)
+
+// IsReadmeFile reports whether name looks like a README file based on its extension.
+func IsReadmeFile(name string) bool {
+	return strings.HasPrefix(strings.ToLower(name), "readme")
+}
+
+const (
+	ISSUE_NAME_STYLE_NUMERIC      = "numeric"
+	ISSUE_NAME_STYLE_ALPHANUMERIC = "alphanumeric"
+)
+
+var (
+	// MentionPattern matches string that mentions someone, e.g. @Unknwon
+	MentionPattern = regexp.MustCompile(`(\s|^|\W)@[0-9a-zA-Z-_\.]+`)
+
+	// CommitPattern matches link to certain commit with or without trailing hash,
+	// e.g. https://try.gogs.io/gogs/gogs/commit/d8a994ef243349f321568f9e36d5c3f444b99cae#diff-2
+	CommitPattern = regexp.MustCompile(`(\s|^)https?.*commit/[0-9a-zA-Z]+(#+[0-9a-zA-Z-]*)?`)
+
+	// IssueFullPattern matches link to an issue with or without trailing hash,
+	// e.g. https://try.gogs.io/gogs/gogs/issues/4#issue-685
+	IssueFullPattern = regexp.MustCompile(`(\s|^)https?.*issues/[0-9]+(#+[0-9a-zA-Z-]*)?`)
+	// IssueNumericPattern matches string that references to a numeric issue, e.g. #1287
+	IssueNumericPattern = regexp.MustCompile(`( |^|\()#[0-9]+\b`)
+	// IssueAlphanumericPattern matches string that references to an alphanumeric issue, e.g. ABC-1234
+	IssueAlphanumericPattern = regexp.MustCompile(`( |^|\()[A-Z]{1,10}-[1-9][0-9]*\b`)
+	// CrossReferenceIssueNumericPattern matches string that references a numeric issue in a difference repository
+	// e.g. gogits/gogs#12345
+	CrossReferenceIssueNumericPattern = regexp.MustCompile(`( |^)[0-9a-zA-Z-_\.]+/[0-9a-zA-Z-_\.]+#[0-9]+\b`)
+
+	// Sha1CurrentPattern matches string that represents a commit SHA, e.g. d8a994ef243349f321568f9e36d5c3f444b99cae
+	// FIXME: this pattern matches pure numbers as well, right now we do a hack to check in RenderSha1CurrentPattern
+	// by converting string to a number.
+	Sha1CurrentPattern = regexp.MustCompile(`\b[0-9a-f]{40}\b`)
+)
+
+// FindAllMentions matches mention patterns in given content
+// and returns a list of found user names without @ prefix.
+func FindAllMentions(content string) []string {
+	mentions := MentionPattern.FindAllString(content, -1)
+	for i := range mentions {
+		mentions[i] = mentions[i][strings.Index(mentions[i], "@")+1:] // Strip @ character
+	}
+	return mentions
+}
+
+// cutoutVerbosePrefix cutouts URL prefix including sub-path to
+// return a clean unified string of request URL path.
+func cutoutVerbosePrefix(prefix string) string {
+	if len(prefix) == 0 || prefix[0] != '/' {
+		return prefix
+	}
+	count := 0
+	for i := 0; i < len(prefix); i++ {
+		if prefix[i] == '/' {
+			count++
+		}
+		if count >= 3+setting.AppSubUrlDepth {
+			return prefix[:i]
+		}
+	}
+	return prefix
+}
+
+// RenderIssueIndexPattern renders issue indexes to corresponding links.
+func RenderIssueIndexPattern(rawBytes []byte, urlPrefix string, metas map[string]string) []byte {
+	urlPrefix = cutoutVerbosePrefix(urlPrefix)
+
+	pattern := IssueNumericPattern
+	if metas["style"] == ISSUE_NAME_STYLE_ALPHANUMERIC {
+		pattern = IssueAlphanumericPattern
+	}
+
+	ms := pattern.FindAll(rawBytes, -1)
+	for _, m := range ms {
+		if m[0] == ' ' || m[0] == '(' {
+			m = m[1:] // ignore leading space or opening parentheses
+		}
+		var link string
+		if metas == nil {
+			link = fmt.Sprintf(`<a href="%s/issues/%s">%s</a>`, urlPrefix, m[1:], m)
+		} else {
+			// Support for external issue tracker
+			if metas["style"] == ISSUE_NAME_STYLE_ALPHANUMERIC {
+				metas["index"] = string(m)
+			} else {
+				metas["index"] = string(m[1:])
+			}
+			link = fmt.Sprintf(`<a href="%s">%s</a>`, com.Expand(metas["format"], metas), m)
+		}
+		rawBytes = bytes.Replace(rawBytes, m, []byte(link), 1)
+	}
+	return rawBytes
+}
+
+// Note: this section is for purpose of increase performance and
+// reduce memory allocation at runtime since they are constant literals.
+var pound = []byte("#")
+
+// RenderCrossReferenceIssueIndexPattern renders issue indexes from other repositories to corresponding links.
+func RenderCrossReferenceIssueIndexPattern(rawBytes []byte, urlPrefix string, metas map[string]string) []byte {
+	ms := CrossReferenceIssueNumericPattern.FindAll(rawBytes, -1)
+	for _, m := range ms {
+		if m[0] == ' ' || m[0] == '(' {
+			m = m[1:] // ignore leading space or opening parentheses
+		}
+
+		delimIdx := bytes.Index(m, pound)
+		repo := string(m[:delimIdx])
+		index := string(m[delimIdx+1:])
+
+		link := fmt.Sprintf(`<a href="%s%s/issues/%s">%s</a>`, setting.AppUrl, repo, index, m)
+		rawBytes = bytes.Replace(rawBytes, m, []byte(link), 1)
+	}
+	return rawBytes
+}
+
+// RenderSha1CurrentPattern renders SHA1 strings to corresponding links that assumes in the same repository.
+func RenderSha1CurrentPattern(rawBytes []byte, urlPrefix string) []byte {
+	return []byte(Sha1CurrentPattern.ReplaceAllStringFunc(string(rawBytes[:]), func(m string) string {
+		if com.StrTo(m).MustInt() > 0 {
+			return m
+		}
+		return fmt.Sprintf(`<a href="%s/commit/%s"><code>%s</code></a>`, urlPrefix, m, base.ShortSha(string(m)))
+	}))
+}
+
+// RenderSpecialLink renders mentions, indexes and SHA1 strings to corresponding links.
+func RenderSpecialLink(rawBytes []byte, urlPrefix string, metas map[string]string) []byte {
+	ms := MentionPattern.FindAll(rawBytes, -1)
+	for _, m := range ms {
+		m = m[bytes.Index(m, []byte("@")):]
+		rawBytes = bytes.Replace(rawBytes, m,
+			[]byte(fmt.Sprintf(`<a href="%s/%s">%s</a>`, setting.AppSubUrl, m[1:], m)), -1)
+	}
+
+	rawBytes = RenderIssueIndexPattern(rawBytes, urlPrefix, metas)
+	rawBytes = RenderCrossReferenceIssueIndexPattern(rawBytes, urlPrefix, metas)
+	rawBytes = RenderSha1CurrentPattern(rawBytes, urlPrefix)
+	return rawBytes
+}
+
+var (
+	leftAngleBracket  = []byte("</")
+	rightAngleBracket = []byte(">")
+)
+
+var noEndTags = []string{"input", "br", "hr", "img"}
+
+// wrapImgWithLink warps link to standalone <img> tags.
+func wrapImgWithLink(urlPrefix string, buf *bytes.Buffer, token html.Token) {
+	// Extract "src" and "alt" attributes
+	var src, alt string
+	for i := range token.Attr {
+		switch token.Attr[i].Key {
+		case "src":
+			src = token.Attr[i].Val
+		case "alt":
+			alt = token.Attr[i].Val
+		}
+	}
+
+	// Skip in case the "src" is empty
+	if len(src) == 0 {
+		buf.WriteString(token.String())
+		return
+	}
+
+	// Prepend repository base URL for internal links
+	needPrepend := !isLink([]byte(src))
+	if needPrepend {
+		urlPrefix = strings.Replace(urlPrefix, "/src/", "/raw/", 1)
+		if src[0] != '/' {
+			urlPrefix += "/"
+		}
+	}
+
+	buf.WriteString(`<a href="`)
+	if needPrepend {
+		buf.WriteString(urlPrefix)
+		buf.WriteString(src)
+	} else {
+		buf.WriteString(src)
+	}
+	buf.WriteString(`">`)
+
+	if needPrepend {
+		src = strings.Replace(urlPrefix+string(src), " ", "%20", -1)
+		buf.WriteString(`<img src="`)
+		buf.WriteString(src)
+		buf.WriteString(`"`)
+
+		if len(alt) > 0 {
+			buf.WriteString(` alt="`)
+			buf.WriteString(alt)
+			buf.WriteString(`"`)
+		}
+
+		buf.WriteString(`>`)
+
+	} else {
+		buf.WriteString(token.String())
+	}
+
+	buf.WriteString(`</a>`)
+}
+
+// postProcessHTML treats different types of HTML differently,
+// and only renders special links for plain text blocks.
+func postProcessHTML(rawHTML []byte, urlPrefix string, metas map[string]string) []byte {
+	startTags := make([]string, 0, 5)
+	buf := bytes.NewBuffer(nil)
+	tokenizer := html.NewTokenizer(bytes.NewReader(rawHTML))
+
+OUTER_LOOP:
+	for html.ErrorToken != tokenizer.Next() {
+		token := tokenizer.Token()
+		switch token.Type {
+		case html.TextToken:
+			buf.Write(RenderSpecialLink([]byte(token.String()), urlPrefix, metas))
+
+		case html.StartTagToken:
+			tagName := token.Data
+
+			if tagName == "img" {
+				wrapImgWithLink(urlPrefix, buf, token)
+				continue OUTER_LOOP
+			}
+
+			buf.WriteString(token.String())
+			// If this is an excluded tag, we skip processing all output until a close tag is encountered.
+			if strings.EqualFold("a", tagName) || strings.EqualFold("code", tagName) || strings.EqualFold("pre", tagName) {
+				stackNum := 1
+				for html.ErrorToken != tokenizer.Next() {
+					token = tokenizer.Token()
+
+					// Copy the token to the output verbatim
+					buf.WriteString(token.String())
+
+					// Stack number doesn't increate for tags without end tags.
+					if token.Type == html.StartTagToken && !com.IsSliceContainsStr(noEndTags, token.Data) {
+						stackNum++
+					}
+
+					// If this is the close tag to the outer-most, we are done
+					if token.Type == html.EndTagToken {
+						stackNum--
+						if stackNum <= 0 && strings.EqualFold(tagName, token.Data) {
+							break
+						}
+					}
+				}
+				continue OUTER_LOOP
+			}
+
+			if !com.IsSliceContainsStr(noEndTags, tagName) {
+				startTags = append(startTags, tagName)
+			}
+
+		case html.EndTagToken:
+			if len(startTags) == 0 {
+				buf.WriteString(token.String())
+				break
+			}
+
+			buf.Write(leftAngleBracket)
+			buf.WriteString(startTags[len(startTags)-1])
+			buf.Write(rightAngleBracket)
+			startTags = startTags[:len(startTags)-1]
+		default:
+			buf.WriteString(token.String())
+		}
+	}
+
+	if io.EOF == tokenizer.Err() {
+		return buf.Bytes()
+	}
+
+	// If we are not at the end of the input, then some other parsing error has occurred,
+	// so return the input verbatim.
+	return rawHTML
+}
+
+type Type string
+
+const (
+	UNRECOGNIZED Type = "unrecognized"
+	MARKDOWN     Type = "markdown"
+	ORG_MODE     Type = "orgmode"
+)
+
+// Render takes a string or []byte and renders to HTML in given type of syntax with special links.
+func Render(typ Type, input interface{}, urlPrefix string, metas map[string]string) []byte {
+	var rawBytes []byte
+	switch v := input.(type) {
+	case []byte:
+		rawBytes = v
+	case string:
+		rawBytes = []byte(v)
+	default:
+		panic(fmt.Sprintf("unrecognized input content type: %T", input))
+	}
+
+	urlPrefix = strings.Replace(urlPrefix, " ", "%20", -1)
+	var rawHTML []byte
+	switch typ {
+	case MARKDOWN:
+		rawHTML = RawMarkdown(rawBytes, urlPrefix)
+	case ORG_MODE:
+	default:
+		return rawBytes // Do nothing if syntax type is not recognized
+	}
+
+	rawHTML = postProcessHTML(rawHTML, urlPrefix, metas)
+	return SanitizeBytes(rawHTML)
+}
diff --git a/pkg/markup/markup_test.go b/pkg/markup/markup_test.go
new file mode 100644
index 00000000..d3d72091
--- /dev/null
+++ b/pkg/markup/markup_test.go
@@ -0,0 +1,284 @@
+// Copyright 2017 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package markup_test
+
+import (
+	"strings"
+	"testing"
+
+	. "github.com/smartystreets/goconvey/convey"
+
+	. "github.com/gogits/gogs/pkg/markup"
+	"github.com/gogits/gogs/pkg/setting"
+)
+
+func Test_IsReadmeFile(t *testing.T) {
+	Convey("Detect README file extension", t, func() {
+		testCases := []struct {
+			ext   string
+			match bool
+		}{
+			{"readme", true},
+			{"README", true},
+			{"readme.md", true},
+			{"readme.markdown", true},
+			{"readme.mdown", true},
+			{"readme.mkd", true},
+			{"readme.org", true},
+			{"readme.rst", true},
+			{"readme.asciidoc", true},
+			{"readme_ZH", true},
+		}
+
+		for _, tc := range testCases {
+			So(IsReadmeFile(tc.ext), ShouldEqual, tc.match)
+		}
+	})
+}
+
+func Test_FindAllMentions(t *testing.T) {
+	Convey("Find all mention patterns", t, func() {
+		testCases := []struct {
+			content string
+			matches string
+		}{
+			{"@Unknwon, what do you think?", "Unknwon"},
+			{"@Unknwon what do you think?", "Unknwon"},
+			{"Hi @Unknwon, sounds good to me", "Unknwon"},
+			{"cc/ @Unknwon @User", "Unknwon,User"},
+		}
+
+		for _, tc := range testCases {
+			So(strings.Join(FindAllMentions(tc.content), ","), ShouldEqual, tc.matches)
+		}
+	})
+}
+
+func Test_RenderIssueIndexPattern(t *testing.T) {
+	Convey("Rendering an issue reference", t, func() {
+		var (
+			urlPrefix                   = "/prefix"
+			metas     map[string]string = nil
+		)
+		setting.AppSubUrlDepth = 0
+
+		Convey("To the internal issue tracker", func() {
+			Convey("It should not render anything when there are no mentions", func() {
+				testCases := []string{
+					"",
+					"this is a test",
+					"test 123 123 1234",
+					"#",
+					"# # #",
+					"# 123",
+					"#abcd",
+					"##1234",
+					"test#1234",
+					"#1234test",
+					" test #1234test",
+				}
+
+				for i := 0; i < len(testCases); i++ {
+					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i])
+				}
+			})
+			Convey("It should render freestanding mentions", func() {
+				testCases := []string{
+					"#1234 test", "<a href=\"/prefix/issues/1234\">#1234</a> test",
+					"test #1234 issue", "test <a href=\"/prefix/issues/1234\">#1234</a> issue",
+					"test issue #1234", "test issue <a href=\"/prefix/issues/1234\">#1234</a>",
+					"#5 test", "<a href=\"/prefix/issues/5\">#5</a> test",
+					"test #5 issue", "test <a href=\"/prefix/issues/5\">#5</a> issue",
+					"test issue #5", "test issue <a href=\"/prefix/issues/5\">#5</a>",
+				}
+
+				for i := 0; i < len(testCases); i += 2 {
+					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
+				}
+			})
+			Convey("It should not render issue mention without leading space", func() {
+				input := []byte("test#54321 issue")
+				expected := "test#54321 issue"
+				So(string(RenderIssueIndexPattern(input, urlPrefix, metas)), ShouldEqual, expected)
+			})
+			Convey("It should not render issue mention without trailing space", func() {
+				input := []byte("test #54321issue")
+				expected := "test #54321issue"
+				So(string(RenderIssueIndexPattern(input, urlPrefix, metas)), ShouldEqual, expected)
+			})
+			Convey("It should render issue mention in parentheses", func() {
+				testCases := []string{
+					"(#54321 issue)", "(<a href=\"/prefix/issues/54321\">#54321</a> issue)",
+					"test (#54321) issue", "test (<a href=\"/prefix/issues/54321\">#54321</a>) issue",
+					"test (#54321 extra) issue", "test (<a href=\"/prefix/issues/54321\">#54321</a> extra) issue",
+					"test (#54321 issue)", "test (<a href=\"/prefix/issues/54321\">#54321</a> issue)",
+					"test (#54321)", "test (<a href=\"/prefix/issues/54321\">#54321</a>)",
+				}
+
+				for i := 0; i < len(testCases); i += 2 {
+					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
+				}
+			})
+			Convey("It should render multiple issue mentions in the same line", func() {
+				testCases := []string{
+					"#54321 #1243", "<a href=\"/prefix/issues/54321\">#54321</a> <a href=\"/prefix/issues/1243\">#1243</a>",
+					"test #54321 #1243", "test <a href=\"/prefix/issues/54321\">#54321</a> <a href=\"/prefix/issues/1243\">#1243</a>",
+					"(#54321 #1243)", "(<a href=\"/prefix/issues/54321\">#54321</a> <a href=\"/prefix/issues/1243\">#1243</a>)",
+					"(#54321)(#1243)", "(<a href=\"/prefix/issues/54321\">#54321</a>)(<a href=\"/prefix/issues/1243\">#1243</a>)",
+					"text #54321 test #1243 issue", "text <a href=\"/prefix/issues/54321\">#54321</a> test <a href=\"/prefix/issues/1243\">#1243</a> issue",
+					"#1 (#4321) test", "<a href=\"/prefix/issues/1\">#1</a> (<a href=\"/prefix/issues/4321\">#4321</a>) test",
+				}
+
+				for i := 0; i < len(testCases); i += 2 {
+					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
+				}
+			})
+		})
+		Convey("To an external issue tracker with numeric style", func() {
+			metas = make(map[string]string)
+			metas["format"] = "https://someurl.com/{user}/{repo}/{index}"
+			metas["user"] = "someuser"
+			metas["repo"] = "somerepo"
+			metas["style"] = ISSUE_NAME_STYLE_NUMERIC
+
+			Convey("should not render anything when there are no mentions", func() {
+				testCases := []string{
+					"this is a test",
+					"test 123 123 1234",
+					"#",
+					"# # #",
+					"# 123",
+					"#abcd",
+				}
+
+				for i := 0; i < len(testCases); i++ {
+					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i])
+				}
+			})
+			Convey("It should render freestanding issue mentions", func() {
+				testCases := []string{
+					"#1234 test", "<a href=\"https://someurl.com/someuser/somerepo/1234\">#1234</a> test",
+					"test #1234 issue", "test <a href=\"https://someurl.com/someuser/somerepo/1234\">#1234</a> issue",
+					"test issue #1234", "test issue <a href=\"https://someurl.com/someuser/somerepo/1234\">#1234</a>",
+					"#5 test", "<a href=\"https://someurl.com/someuser/somerepo/5\">#5</a> test",
+					"test #5 issue", "test <a href=\"https://someurl.com/someuser/somerepo/5\">#5</a> issue",
+					"test issue #5", "test issue <a href=\"https://someurl.com/someuser/somerepo/5\">#5</a>",
+				}
+				for i := 0; i < len(testCases); i += 2 {
+					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
+				}
+			})
+			Convey("It should not render issue mention without leading space", func() {
+				input := []byte("test#54321 issue")
+				expected := "test#54321 issue"
+				So(string(RenderIssueIndexPattern(input, urlPrefix, metas)), ShouldEqual, expected)
+			})
+			Convey("It should not render issue mention without trailing space", func() {
+				input := []byte("test #54321issue")
+				expected := "test #54321issue"
+				So(string(RenderIssueIndexPattern(input, urlPrefix, metas)), ShouldEqual, expected)
+			})
+			Convey("It should render issue mention in parentheses", func() {
+				testCases := []string{
+					"(#54321 issue)", "(<a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a> issue)",
+					"test (#54321) issue", "test (<a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a>) issue",
+					"test (#54321 extra) issue", "test (<a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a> extra) issue",
+					"test (#54321 issue)", "test (<a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a> issue)",
+					"test (#54321)", "test (<a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a>)",
+				}
+
+				for i := 0; i < len(testCases); i += 2 {
+					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
+				}
+			})
+			Convey("It should render multiple issue mentions in the same line", func() {
+				testCases := []string{
+					"#54321 #1243", "<a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a> <a href=\"https://someurl.com/someuser/somerepo/1243\">#1243</a>",
+					"test #54321 #1243", "test <a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a> <a href=\"https://someurl.com/someuser/somerepo/1243\">#1243</a>",
+					"(#54321 #1243)", "(<a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a> <a href=\"https://someurl.com/someuser/somerepo/1243\">#1243</a>)",
+					"(#54321)(#1243)", "(<a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a>)(<a href=\"https://someurl.com/someuser/somerepo/1243\">#1243</a>)",
+					"text #54321 test #1243 issue", "text <a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a> test <a href=\"https://someurl.com/someuser/somerepo/1243\">#1243</a> issue",
+					"#1 (#4321) test", "<a href=\"https://someurl.com/someuser/somerepo/1\">#1</a> (<a href=\"https://someurl.com/someuser/somerepo/4321\">#4321</a>) test",
+				}
+
+				for i := 0; i < len(testCases); i += 2 {
+					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
+				}
+			})
+		})
+		Convey("To an external issue tracker with alphanumeric style", func() {
+			metas = make(map[string]string)
+			metas["format"] = "https://someurl.com/{user}/{repo}/?b={index}"
+			metas["user"] = "someuser"
+			metas["repo"] = "somerepo"
+			metas["style"] = ISSUE_NAME_STYLE_ALPHANUMERIC
+			Convey("It should not render anything when there are no mentions", func() {
+				testCases := []string{
+					"",
+					"this is a test",
+					"test 123 123 1234",
+					"#",
+					"##1234",
+					"# 123",
+					"#abcd",
+					"test #123",
+					"abc-1234",         // issue prefix must be capital
+					"ABc-1234",         // issue prefix must be _all_ capital
+					"ABCDEFGHIJK-1234", // the limit is 10 characters in the prefix
+					"ABC1234",          // dash is required
+					"test ABC- test",   // number is required
+					"test -1234 test",  // prefix is required
+					"testABC-123 test", // leading space is required
+					"test ABC-123test", // trailing space is required
+					"ABC-0123",         // no leading zero
+				}
+
+				for i := 0; i < len(testCases); i += 2 {
+					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i])
+				}
+			})
+			Convey("It should render freestanding issue mention", func() {
+				testCases := []string{
+					"OTT-1234 test", "<a href=\"https://someurl.com/someuser/somerepo/?b=OTT-1234\">OTT-1234</a> test",
+					"test T-12 issue", "test <a href=\"https://someurl.com/someuser/somerepo/?b=T-12\">T-12</a> issue",
+					"test issue ABCDEFGHIJ-1234567890", "test issue <a href=\"https://someurl.com/someuser/somerepo/?b=ABCDEFGHIJ-1234567890\">ABCDEFGHIJ-1234567890</a>",
+					"A-1 test", "<a href=\"https://someurl.com/someuser/somerepo/?b=A-1\">A-1</a> test",
+					"test ZED-1 issue", "test <a href=\"https://someurl.com/someuser/somerepo/?b=ZED-1\">ZED-1</a> issue",
+					"test issue DEED-7154", "test issue <a href=\"https://someurl.com/someuser/somerepo/?b=DEED-7154\">DEED-7154</a>",
+				}
+				for i := 0; i < len(testCases); i += 2 {
+					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
+				}
+			})
+			Convey("It should render issue mention in parentheses", func() {
+				testCases := []string{
+					"(ABG-124 issue)", "(<a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a> issue)",
+					"test (ABG-124) issue", "test (<a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a>) issue",
+					"test (ABG-124 extra) issue", "test (<a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a> extra) issue",
+					"test (ABG-124 issue)", "test (<a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a> issue)",
+					"test (ABG-124)", "test (<a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a>)",
+				}
+
+				for i := 0; i < len(testCases); i += 2 {
+					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
+				}
+			})
+			Convey("It should render multiple issue mentions in the same line", func() {
+				testCases := []string{
+					"ABG-124 OTT-4321", "<a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a> <a href=\"https://someurl.com/someuser/somerepo/?b=OTT-4321\">OTT-4321</a>",
+					"test ABG-124 OTT-4321", "test <a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a> <a href=\"https://someurl.com/someuser/somerepo/?b=OTT-4321\">OTT-4321</a>",
+					"(ABG-124 OTT-4321)", "(<a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a> <a href=\"https://someurl.com/someuser/somerepo/?b=OTT-4321\">OTT-4321</a>)",
+					"(ABG-124)(OTT-4321)", "(<a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a>)(<a href=\"https://someurl.com/someuser/somerepo/?b=OTT-4321\">OTT-4321</a>)",
+					"text ABG-124 test OTT-4321 issue", "text <a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a> test <a href=\"https://someurl.com/someuser/somerepo/?b=OTT-4321\">OTT-4321</a> issue",
+					"A-1 (RRE-345) test", "<a href=\"https://someurl.com/someuser/somerepo/?b=A-1\">A-1</a> (<a href=\"https://someurl.com/someuser/somerepo/?b=RRE-345\">RRE-345</a>) test",
+				}
+
+				for i := 0; i < len(testCases); i += 2 {
+					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
+				}
+			})
+		})
+	})
+}
diff --git a/pkg/markup/sanitizer.go b/pkg/markup/sanitizer.go
new file mode 100644
index 00000000..63ead6df
--- /dev/null
+++ b/pkg/markup/sanitizer.go
@@ -0,0 +1,51 @@
+// Copyright 2017 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package markup
+
+import (
+	"regexp"
+	"sync"
+
+	"github.com/microcosm-cc/bluemonday"
+
+	"github.com/gogits/gogs/pkg/setting"
+)
+
+// Sanitizer is a protection wrapper of *bluemonday.Policy which does not allow
+// any modification to the underlying policies once it's been created.
+type Sanitizer struct {
+	policy *bluemonday.Policy
+	init   sync.Once
+}
+
+var sanitizer = &Sanitizer{}
+
+// NewSanitizer initializes sanitizer with allowed attributes based on settings.
+// Multiple calls to this function will only create one instance of Sanitizer during
+// entire application lifecycle.
+func NewSanitizer() {
+	sanitizer.init.Do(func() {
+		sanitizer.policy = bluemonday.UGCPolicy()
+		// We only want to allow HighlightJS specific classes for code blocks
+		sanitizer.policy.AllowAttrs("class").Matching(regexp.MustCompile(`^language-\w+$`)).OnElements("code")
+
+		// Checkboxes
+		sanitizer.policy.AllowAttrs("type").Matching(regexp.MustCompile(`^checkbox$`)).OnElements("input")
+		sanitizer.policy.AllowAttrs("checked", "disabled").OnElements("input")
+
+		// Custom URL-Schemes
+		sanitizer.policy.AllowURLSchemes(setting.Markdown.CustomURLSchemes...)
+	})
+}
+
+// Sanitize takes a string that contains a HTML fragment or document and applies policy whitelist.
+func Sanitize(s string) string {
+	return sanitizer.policy.Sanitize(s)
+}
+
+// SanitizeBytes takes a []byte slice that contains a HTML fragment or document and applies policy whitelist.
+func SanitizeBytes(b []byte) []byte {
+	return sanitizer.policy.SanitizeBytes(b)
+}
diff --git a/pkg/markup/sanitizer_test.go b/pkg/markup/sanitizer_test.go
new file mode 100644
index 00000000..ae341acc
--- /dev/null
+++ b/pkg/markup/sanitizer_test.go
@@ -0,0 +1,38 @@
+// Copyright 2017 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package markup_test
+
+import (
+	"testing"
+
+	. "github.com/smartystreets/goconvey/convey"
+
+	. "github.com/gogits/gogs/pkg/markup"
+)
+
+func Test_Sanitizer(t *testing.T) {
+	NewSanitizer()
+	Convey("Sanitize HTML string and bytes", t, func() {
+		testCases := []string{
+			// Regular
+			`<a onblur="alert(secret)" href="http://www.google.com">Google</a>`, `<a href="http://www.google.com" rel="nofollow">Google</a>`,
+
+			// Code highlighting class
+			`<code class="random string"></code>`, `<code></code>`,
+			`<code class="language-random ui tab active menu attached animating sidebar following bar center"></code>`, `<code></code>`,
+			`<code class="language-go"></code>`, `<code class="language-go"></code>`,
+
+			// Input checkbox
+			`<input type="hidden">`, ``,
+			`<input type="checkbox">`, `<input type="checkbox">`,
+			`<input checked disabled autofocus>`, `<input checked="" disabled="">`,
+		}
+
+		for i := 0; i < len(testCases); i += 2 {
+			So(Sanitize(testCases[i]), ShouldEqual, testCases[i+1])
+			So(string(SanitizeBytes([]byte(testCases[i]))), ShouldEqual, testCases[i+1])
+		}
+	})
+}