gosora/plugin_markdown.go

376 lines
10 KiB
Go

package main
//import "fmt"
import (
"log"
"strings"
)
var markdownMaxDepth = 25 // How deep the parser will go when parsing Markdown strings
var markdownUnclosedElement []byte
var markdownBoldTagOpen []byte
var markdownBoldTagClose []byte
var markdownItalicTagOpen []byte
var markdownItalicTagClose []byte
var markdownUnderlineTagOpen []byte
var markdownUnderlineTagClose []byte
var markdownStrikeTagOpen []byte
var markdownStrikeTagClose []byte
func init() {
plugins["markdown"] = NewPlugin("markdown", "Markdown", "Azareal", "http://github.com/Azareal", "", "", "", initMarkdown, nil, deactivateMarkdown, nil, nil)
}
func initMarkdown() error {
plugins["markdown"].AddHook("parse_assign", markdownParse)
markdownUnclosedElement = []byte("<span style='color: red;'>[Unclosed Element]</span>")
markdownBoldTagOpen = []byte("<b>")
markdownBoldTagClose = []byte("</b>")
markdownItalicTagOpen = []byte("<i>")
markdownItalicTagClose = []byte("</i>")
markdownUnderlineTagOpen = []byte("<u>")
markdownUnderlineTagClose = []byte("</u>")
markdownStrikeTagOpen = []byte("<s>")
markdownStrikeTagClose = []byte("</s>")
return nil
}
func deactivateMarkdown() {
plugins["markdown"].RemoveHook("parse_assign", markdownParse)
}
// An adapter for the parser, so that the parser can call itself recursively.
// This is less for the simple Markdown elements like bold and italics and more for the really complicated ones I plan on adding at some point.
func markdownParse(msg string) string {
msg = _markdownParse(msg+" ", 0)
if msg[len(msg)-1] == ' ' {
msg = msg[:len(msg)-1]
}
log.Print("final msg: ", msg)
return msg
}
// Under Construction!
func _markdownParse(msg string, n int) string {
if n > markdownMaxDepth {
return "<span style='color: red;'>[Markdown Error: Overflowed the max depth of 20]</span>"
}
var outbytes []byte
var lastElement int
log.Printf("Initial Message: %+v\n", strings.Replace(msg, "\r", "\\r", -1))
for index := 0; index < len(msg); index++ {
//log.Print("--OUTER MARKDOWN LOOP START--")
//log.Print("index: ", index)
//log.Print("msg[index]: ", msg[index])
//log.Print("string(msg[index]): ", string(msg[index]))
//log.Printf("--OUTER MARKDOWN LOOP END--\n\n")
switch msg[index] {
// TODO: Do something slightly less hacky for skipping URLs
case '/':
if len(msg) > (index+2) && msg[index+1] == '/' {
for ; index < len(msg) && msg[index] != ' '; index++ {
}
index--
continue
}
case '_':
var startIndex = index
if (index + 1) >= len(msg) {
break
}
index++
index = markdownSkipUntilChar(msg, index, '_')
if (index-(startIndex+1)) < 1 || index >= len(msg) {
break
}
sIndex := startIndex + 1
lIndex := index
index++
outbytes = append(outbytes, msg[lastElement:startIndex]...)
outbytes = append(outbytes, markdownUnderlineTagOpen...)
// TODO: Implement this without as many type conversions
outbytes = append(outbytes, []byte(_markdownParse(msg[sIndex:lIndex], n+1))...)
outbytes = append(outbytes, markdownUnderlineTagClose...)
lastElement = index
index--
case '~':
var startIndex = index
if (index + 1) >= len(msg) {
break
}
index++
index = markdownSkipUntilChar(msg, index, '~')
if (index-(startIndex+1)) < 1 || index >= len(msg) {
break
}
sIndex := startIndex + 1
lIndex := index
index++
outbytes = append(outbytes, msg[lastElement:startIndex]...)
outbytes = append(outbytes, markdownStrikeTagOpen...)
// TODO: Implement this without as many type conversions
outbytes = append(outbytes, []byte(_markdownParse(msg[sIndex:lIndex], n+1))...)
outbytes = append(outbytes, markdownStrikeTagClose...)
lastElement = index
index--
case '*':
//log.Print("------")
//log.Print("[]byte(msg): ", []byte(msg))
//log.Print("len(msg): ", len(msg))
//log.Print("start index: ", index)
//log.Print("start msg[index]: ", msg[index])
//log.Print("start string(msg[index]): ", string(msg[index]))
//log.Print("start []byte(msg[:index]): ", []byte(msg[:index]))
var startIndex = index
var italic = true
var bold = false
if (index + 2) < len(msg) {
//log.Print("start index + 1: ", index + 1)
//log.Print("start msg[index]: ", msg[index + 1])
//log.Print("start string(msg[index]): ", string(msg[index + 1]))
if msg[index+1] == '*' {
//log.Print("two asterisks")
bold = true
index++
if msg[index+1] != '*' {
italic = false
} else {
//log.Print("three asterisks")
index++
}
}
}
//log.Print("lastElement: ", lastElement)
//log.Print("startIndex: ", startIndex)
//log.Print("msg[startIndex]: ", msg[startIndex])
//log.Print("string(msg[startIndex]): ", string(msg[startIndex]))
//log.Print("preabrupt index: ", index)
//log.Print("preabrupt msg[index]: ", msg[index])
//log.Print("preabrupt string(msg[index]): ", string(msg[index]))
//log.Print("preabrupt []byte(msg[:index]): ", []byte(msg[:index]))
//log.Print("preabrupt msg[:index]: ", msg[:index])
// Does the string terminate abruptly?
if (index + 1) >= len(msg) {
break
}
index++
//log.Print("preskip index: ", index)
//log.Print("preskip msg[index]: ", msg[index])
//log.Print("preskip string(msg[index]): ", string(msg[index]))
index = markdownSkipUntilAsterisk(msg, index)
if index >= len(msg) {
break
}
//log.Print("index: ", index)
//log.Print("[]byte(msg[:index]): ", []byte(msg[:index]))
//log.Print("msg[index]: ", msg[index])
sIndex := startIndex
lIndex := index
if bold && italic {
//log.Print("bold & italic final code")
if (index + 3) >= len(msg) {
//log.Print("unclosed markdown element @ exit element")
outbytes = append(outbytes, msg[lastElement:startIndex]...)
//outbytes = append(outbytes, markdownUnclosedElement...)
lastElement = startIndex
break
}
index += 3
sIndex += 3
} else if bold {
//log.Print("bold final code")
if (index + 2) >= len(msg) {
//log.Print("true unclosed markdown element @ exit element")
outbytes = append(outbytes, msg[lastElement:startIndex]...)
//outbytes = append(outbytes, markdownUnclosedElement...)
lastElement = startIndex
break
}
index += 2
sIndex += 2
} else {
//log.Print("italic final code")
if (index + 1) >= len(msg) {
//log.Print("true unclosed markdown element @ exit element")
outbytes = append(outbytes, msg[lastElement:startIndex]...)
//outbytes = append(outbytes, markdownUnclosedElement...)
lastElement = startIndex
break
}
index++
sIndex++
}
//log.Print("sIndex: ", sIndex)
//log.Print("lIndex: ", lIndex)
if lIndex <= sIndex {
//log.Print("unclosed markdown element @ lIndex <= sIndex")
outbytes = append(outbytes, msg[lastElement:startIndex]...)
//outbytes = append(outbytes, markdownUnclosedElement...)
lastElement = startIndex
break
}
if sIndex < 0 || lIndex < 0 {
//log.Print("unclosed markdown element @ sIndex < 0 || lIndex < 0")
outbytes = append(outbytes, msg[lastElement:startIndex]...)
//outbytes = append(outbytes, markdownUnclosedElement...)
lastElement = startIndex
break
}
//log.Print("final sIndex: ", sIndex)
//log.Print("final lIndex: ",lIndex)
//log.Print("final index: ", index)
//log.Print("final msg[index]: ", msg[index])
//log.Print("final string(msg[index]): ", string(msg[index]))
//log.Print("final msg[sIndex]: ", msg[sIndex])
//log.Print("final string(msg[sIndex]): ", string(msg[sIndex]))
//log.Print("final msg[lIndex]: ", msg[lIndex])
//log.Print("final string(msg[lIndex]): ", string(msg[lIndex]))
//log.Print("[]byte(msg[:sIndex]): ", []byte(msg[:sIndex]))
//log.Print("[]byte(msg[:lIndex]): ", []byte(msg[:lIndex]))
outbytes = append(outbytes, msg[lastElement:startIndex]...)
if bold {
outbytes = append(outbytes, markdownBoldTagOpen...)
}
if italic {
outbytes = append(outbytes, markdownItalicTagOpen...)
}
// TODO: Implement this without as many type conversions
outbytes = append(outbytes, []byte(_markdownParse(msg[sIndex:lIndex], n+1))...)
if italic {
outbytes = append(outbytes, markdownItalicTagClose...)
}
if bold {
outbytes = append(outbytes, markdownBoldTagClose...)
}
lastElement = index
index--
case '\\':
if (index + 1) < len(msg) {
if isMarkdownStartChar(msg[index+1]) && msg[index+1] != '\\' {
outbytes = append(outbytes, msg[lastElement:index]...)
index++
lastElement = index
}
}
//case '`':
//case 10: // newline
}
}
//log.Print("exit message loop")
if len(outbytes) == 0 {
return msg
//return msg[:len(msg)-1]
} else if lastElement < (len(msg) - 1) {
msg = string(outbytes) + msg[lastElement:]
return msg
//return msg[:len(msg)-1]
}
//return string(outbytes[:len(outbytes)-1])
return string(outbytes)
}
func isMarkdownStartChar(char byte) bool {
return char == '\\' || char == '~' || char == '_' || char == 10 || char == '`' || char == '*'
}
func markdownFindChar(data string, index int, char byte) bool {
for ; index < len(data); index++ {
item := data[index]
if item > 32 {
return (item == char)
}
}
return false
}
func markdownSkipUntilChar(data string, index int, char byte) int {
for ; index < len(data); index++ {
if data[index] == char {
break
}
}
return index
}
func markdownSkipUntilAsterisk(data string, index int) int {
SwitchLoop:
for ; index < len(data); index++ {
switch data[index] {
case 10:
if ((index + 1) < len(data)) && markdownFindChar(data, index, '*') {
index = markdownSkipList(data, index)
}
case '*':
break SwitchLoop
}
}
return index
}
// plugin_markdown doesn't support lists yet, but I want it to be easy to have nested lists when we do have them
func markdownSkipList(data string, index int) int {
var lastNewline int
var datalen = len(data)
for ; index < datalen; index++ {
SkipListInnerLoop:
if data[index] == 10 {
lastNewline = index
for ; index < datalen; index++ {
if data[index] > 32 {
break
} else if data[index] == 10 {
goto SkipListInnerLoop
}
}
if index >= datalen {
if data[index] != '*' && data[index] != '-' {
if (lastNewline + 1) < datalen {
return lastNewline + 1
}
return lastNewline
}
}
}
}
return index
}