gosora/common/parser.go

package common

import (
	"bytes"
	"html"
	"net/url"
	"regexp"
	"strconv"
	"strings"
)

var SpaceGap = []byte("          ")
var httpProtBytes = []byte("http://")
var InvalidURL = []byte("<span style='color: red;'>[Invalid URL]</span>")
var InvalidTopic = []byte("<span style='color: red;'>[Invalid Topic]</span>")
var InvalidProfile = []byte("<span style='color: red;'>[Invalid Profile]</span>")
var InvalidForum = []byte("<span style='color: red;'>[Invalid Forum]</span>")
var unknownMedia = []byte("<span style='color: red;'>[Unknown Media]</span>")
var UrlOpen = []byte("<a href='")
var UrlOpen2 = []byte("'>")
var bytesSinglequote = []byte("'")
var bytesGreaterthan = []byte(">")
var urlMention = []byte(" class='mention'")
var UrlClose = []byte("</a>")
var imageOpen = []byte("<a href=\"")
var imageOpen2 = []byte("\"><img src='")
var imageClose = []byte("' class='postImage' /></a>")
var urlPattern = `(?s)([ {1}])((http|https|ftp|mailto)*)(:{??)\/\/([\.a-zA-Z\/]+)([ {1}])`
var urlReg *regexp.Regexp

func init() {
	urlReg = regexp.MustCompile(urlPattern)
}

// TODO: Write a test for this
func shortcodeToUnicode(msg string) string {
	//re := regexp.MustCompile(":(.):")
	msg = strings.Replace(msg, ":grinning:", "😀", -1)
	msg = strings.Replace(msg, ":grin:", "😁", -1)
	msg = strings.Replace(msg, ":joy:", "😂", -1)
	msg = strings.Replace(msg, ":rofl:", "🤣", -1)
	msg = strings.Replace(msg, ":smiley:", "😃", -1)
	msg = strings.Replace(msg, ":smile:", "😄", -1)
	msg = strings.Replace(msg, ":sweat_smile:", "😅", -1)
	msg = strings.Replace(msg, ":laughing:", "😆", -1)
	msg = strings.Replace(msg, ":satisfied:", "😆", -1)
	msg = strings.Replace(msg, ":wink:", "😉", -1)
	msg = strings.Replace(msg, ":blush:", "😊", -1)
	msg = strings.Replace(msg, ":yum:", "😋", -1)
	msg = strings.Replace(msg, ":sunglasses:", "😎", -1)
	msg = strings.Replace(msg, ":heart_eyes:", "😍", -1)
	msg = strings.Replace(msg, ":kissing_heart:", "😘", -1)
	msg = strings.Replace(msg, ":kissing:", "😗", -1)
	msg = strings.Replace(msg, ":kissing_smiling_eyes:", "😙", -1)
	msg = strings.Replace(msg, ":kissing_closed_eyes:", "😚", -1)
	msg = strings.Replace(msg, ":relaxed:", "☺️", -1)
	msg = strings.Replace(msg, ":slight_smile:", "🙂", -1)
	msg = strings.Replace(msg, ":hugging:", "🤗", -1)
	msg = strings.Replace(msg, ":thinking:", "🤔", -1)
	msg = strings.Replace(msg, ":neutral_face:", "😐", -1)
	msg = strings.Replace(msg, ":expressionless:", "😑", -1)
	msg = strings.Replace(msg, ":no_mouth:", "😶", -1)
	msg = strings.Replace(msg, ":rolling_eyes:", "🙄", -1)
	msg = strings.Replace(msg, ":smirk:", "😏", -1)
	msg = strings.Replace(msg, ":persevere:", "😣", -1)
	msg = strings.Replace(msg, ":disappointed_relieved:", "😥", -1)
	msg = strings.Replace(msg, ":open_mouth:", "😮", -1)
	msg = strings.Replace(msg, ":zipper_mouth:", "🤐", -1)
	msg = strings.Replace(msg, ":hushed:", "😯", -1)
	msg = strings.Replace(msg, ":sleepy:", "😪", -1)
	msg = strings.Replace(msg, ":tired_face:", "😫", -1)
	msg = strings.Replace(msg, ":sleeping:", "😴", -1)
	msg = strings.Replace(msg, ":relieved:", "😌", -1)
	msg = strings.Replace(msg, ":nerd:", "🤓", -1)
	msg = strings.Replace(msg, ":stuck_out_tongue:", "😛", -1)
	msg = strings.Replace(msg, ":worried:", "😟", -1)
	msg = strings.Replace(msg, ":drooling_face:", "🤤", -1)
	msg = strings.Replace(msg, ":disappointed:", "😞", -1)
	msg = strings.Replace(msg, ":astonished:", "😲", -1)
	msg = strings.Replace(msg, ":slight_frown:", "🙁", -1)
	msg = strings.Replace(msg, ":skull_crossbones:", "☠️", -1)
	msg = strings.Replace(msg, ":skull:", "💀", -1)
	msg = strings.Replace(msg, ":point_up:", "☝️", -1)
	msg = strings.Replace(msg, ":v:", "✌️️", -1)
	msg = strings.Replace(msg, ":writing_hand:", "✍️", -1)
	msg = strings.Replace(msg, ":heart:", "❤️️", -1)
	msg = strings.Replace(msg, ":heart_exclamation:", "❣️", -1)
	msg = strings.Replace(msg, ":hotsprings:", "♨️", -1)
	msg = strings.Replace(msg, ":airplane:", "✈️️", -1)
	msg = strings.Replace(msg, ":hourglass:", "⌛", -1)
	msg = strings.Replace(msg, ":watch:", "⌚", -1)
	msg = strings.Replace(msg, ":comet:", "☄️", -1)
	msg = strings.Replace(msg, ":snowflake:", "❄️", -1)
	msg = strings.Replace(msg, ":cloud:", "☁️", -1)
	msg = strings.Replace(msg, ":sunny:", "☀️", -1)
	msg = strings.Replace(msg, ":spades:", "♠️", -1)
	msg = strings.Replace(msg, ":hearts:", "♥️️", -1)
	msg = strings.Replace(msg, ":diamonds:", "♦️", -1)
	msg = strings.Replace(msg, ":clubs:", "♣️", -1)
	msg = strings.Replace(msg, ":phone:", "☎️", -1)
	msg = strings.Replace(msg, ":telephone:", "☎️", -1)
	msg = strings.Replace(msg, ":biohazard:", "☣️", -1)
	msg = strings.Replace(msg, ":radioactive:", "☢️", -1)
	msg = strings.Replace(msg, ":scissors:", "✂️", -1)
	msg = strings.Replace(msg, ":arrow_upper_right:", "↗️", -1)
	msg = strings.Replace(msg, ":arrow_right:", "➡️", -1)
	msg = strings.Replace(msg, ":arrow_lower_right:", "↘️", -1)
	msg = strings.Replace(msg, ":arrow_lower_left:", "↙️", -1)
	msg = strings.Replace(msg, ":arrow_upper_left:", "↖️", -1)
	msg = strings.Replace(msg, ":arrow_up_down:", "↕️", -1)
	msg = strings.Replace(msg, ":left_right_arrow:", "↔️", -1)
	msg = strings.Replace(msg, ":leftwards_arrow_with_hook:", "↩️", -1)
	msg = strings.Replace(msg, ":arrow_right_hook:", "↪️", -1)
	msg = strings.Replace(msg, ":arrow_forward:", "▶️", -1)
	msg = strings.Replace(msg, ":arrow_backward:", "◀️", -1)
	msg = strings.Replace(msg, ":female:", "♀️", -1)
	msg = strings.Replace(msg, ":male:", "♂️", -1)
	msg = strings.Replace(msg, ":ballot_box_with_check:", "☑️", -1)
	msg = strings.Replace(msg, ":heavy_check_mark:", "✔️️", -1)
	msg = strings.Replace(msg, ":heavy_multiplication_x:", "✖️", -1)
	msg = strings.Replace(msg, ":pisces:", "♓", -1)
	msg = strings.Replace(msg, ":aquarius:", "♒", -1)
	msg = strings.Replace(msg, ":capricorn:", "♑", -1)
	msg = strings.Replace(msg, ":sagittarius:", "♐", -1)
	msg = strings.Replace(msg, ":scorpius:", "♏", -1)
	msg = strings.Replace(msg, ":libra:", "♎", -1)
	msg = strings.Replace(msg, ":virgo:", "♍", -1)
	msg = strings.Replace(msg, ":leo:", "♌", -1)
	msg = strings.Replace(msg, ":cancer:", "♋", -1)
	msg = strings.Replace(msg, ":gemini:", "♊", -1)
	msg = strings.Replace(msg, ":taurus:", "♉", -1)
	msg = strings.Replace(msg, ":aries:", "♈", -1)
	msg = strings.Replace(msg, ":peace:", "☮️", -1)
	msg = strings.Replace(msg, ":eight_spoked_asterisk:", "✳️", -1)
	msg = strings.Replace(msg, ":eight_pointed_black_star:", "✴️", -1)
	msg = strings.Replace(msg, ":snowman2:", "☃️", -1)
	msg = strings.Replace(msg, ":umbrella2:", "☂️", -1)
	msg = strings.Replace(msg, ":pencil2:", "✏️", -1)
	msg = strings.Replace(msg, ":black_nib:", "✒️", -1)
	msg = strings.Replace(msg, ":email:", "✉️", -1)
	msg = strings.Replace(msg, ":envelope:", "✉️", -1)
	msg = strings.Replace(msg, ":keyboard:", "⌨️", -1)
	msg = strings.Replace(msg, ":white_small_square:", "▫️", -1)
	msg = strings.Replace(msg, ":black_small_square:", "▪️", -1)
	msg = strings.Replace(msg, ":secret:", "㊙️", -1)
	msg = strings.Replace(msg, ":congratulations:", "㊗️", -1)
	msg = strings.Replace(msg, ":m:", "Ⓜ️", -1)
	msg = strings.Replace(msg, ":tm:", "™️️", -1)
	msg = strings.Replace(msg, ":registered:", "®️", -1)
	msg = strings.Replace(msg, ":copyright:", "©️", -1)
	msg = strings.Replace(msg, ":wavy_dash:", "〰️", -1)
	msg = strings.Replace(msg, ":bangbang:", "‼️", -1)
	msg = strings.Replace(msg, ":sparkle:", "❇️", -1)
	msg = strings.Replace(msg, ":star_of_david:", "✡️", -1)
	msg = strings.Replace(msg, ":wheel_of_dharma:", "☸️", -1)
	msg = strings.Replace(msg, ":yin_yang:", "☯️", -1)
	msg = strings.Replace(msg, ":cross:", "✝️", -1)
	msg = strings.Replace(msg, ":orthodox_cross:", "☦️", -1)
	msg = strings.Replace(msg, ":star_and_crescent:", "☪️", -1)
	msg = strings.Replace(msg, ":frowning2:", "☹️", -1)
	msg = strings.Replace(msg, ":information_source:", "ℹ️", -1)
	msg = strings.Replace(msg, ":interrobang:", "⁉️", -1)

	return msg
}

// TODO: Write tests for this
// TODO: Preparse Markdown and normalize it into HTML?
func PreparseMessage(msg string) string {
	msg = strings.Replace(msg, "<p><br>", "\n\n", -1)
	msg = strings.Replace(msg, "<p>", "\n\n", -1)
	msg = strings.Replace(msg, "</p>", "", -1)
	msg = strings.Replace(msg, "<br>", "\n\n", -1)
	msg = strings.TrimSpace(msg) // There are a few useful cases for having spaces, but I'd like to stop the WYSIWYG from inserting random lines here and there
	msg = RunSshook("preparse_preassign", msg)
	msg = html.EscapeString(msg)
	msg = strings.Replace(msg, "&nbsp;", "", -1)

	var runes = []rune(msg)
	msg = ""
	var inBold = false
	var inItalic = false
	var inStrike = false
	var inUnderline = false
	var stepForward = func(i int, step int, runes []rune) int {
		i += step
		if i < len(runes) {
			return i
		}
		return i - step
	}
	for i := 0; i < len(runes); i++ {
		char := runes[i]
		if char == '&' && peek(i, 1, runes) == 'l' && peek(i, 2, runes) == 't' && peek(i, 3, runes) == ';' {
			i = stepForward(i, 4, runes)
			char := runes[i]
			if char == '/' {
				i = stepForward(i, 1, runes)
				char := runes[i]
				if inItalic && char == 'e' && peekMatch(i, "m&gt;", runes) {
					i += 5
					inItalic = false
					msg += "</em>"
				} else if inBold && char == 's' && peekMatch(i, "trong&gt;", runes) {
					i += 9
					inBold = false
					msg += "</strong>"
				} else if inStrike && char == 'd' && peekMatch(i, "el&gt;", runes) {
					i += 6
					inStrike = false
					msg += "</del>"
				} else if inUnderline && char == 'u' && peekMatch(i, "&gt;", runes) {
					i += 4
					inUnderline = false
					msg += "</u>"
				}
			} else if !inItalic && char == 'e' && peekMatch(i, "m&gt;", runes) {
				i += 5
				inItalic = true
				msg += "<em>"
			} else if !inBold && char == 's' && peekMatch(i, "trong&gt;", runes) {
				i += 9
				inBold = true
				msg += "<strong>"
			} else if !inStrike && char == 'd' && peekMatch(i, "el&gt;", runes) {
				i += 6
				inStrike = true
				msg += "<del>"
			} else if !inUnderline && char == 'u' && peekMatch(i, "&gt;", runes) {
				i += 4
				inUnderline = true
				msg += "<u>"
			}
		} else {
			msg += string(char)
		}
	}

	if inItalic {
		msg += "</em>"
	}
	if inBold {
		msg += "</strong>"
	}
	if inStrike {
		msg += "</del>"
	}
	if inUnderline {
		msg += "</u>"
	}

	return shortcodeToUnicode(msg)
}

// TODO: Test this
// TODO: Use this elsewhere in the parser?
func peek(cur int, skip int, runes []rune) rune {
	if (cur + skip) < len(runes) {
		return runes[cur+skip]
	}
	return 0 // null byte
}

// TODO: Test this
func peekMatch(cur int, phrase string, runes []rune) bool {
	if cur+len(phrase) > len(runes) {
		return false
	}
	for i, char := range phrase {
		if runes[cur+i+1] != char {
			return false
		}
	}
	return true
}

// TODO: Write a test for this
// TODO: We need a lot more hooks here. E.g. To add custom media types and handlers.
func ParseMessage(msg string, sectionID int, sectionType string /*, user User*/) string {
	msg = strings.Replace(msg, ":)", "😀", -1)
	msg = strings.Replace(msg, ":(", "😞", -1)
	msg = strings.Replace(msg, ":D", "😃", -1)
	msg = strings.Replace(msg, ":P", "😛", -1)
	msg = strings.Replace(msg, ":O", "😲", -1)
	msg = strings.Replace(msg, ":p", "😛", -1)
	msg = strings.Replace(msg, ":o", "😲", -1)
	msg = strings.Replace(msg, ";)", "😉", -1)
	//msg = url_reg.ReplaceAllString(msg,"<a href=\"$2$3//$4\" rel=\"nofollow\">$2$3//$4</a>")

	// Word filter list. E.g. Swear words and other things the admins don't like
	wordFilters := WordFilterBox.Load().(WordFilterMap)
	for _, filter := range wordFilters {
		msg = strings.Replace(msg, filter.Find, filter.Replacement, -1)
	}

	// Search for URLs, mentions and hashlinks in the messages...
	var msgbytes = []byte(msg)
	var outbytes []byte
	msgbytes = append(msgbytes, SpaceGap...)
	var lastItem = 0
	var i = 0
	for ; len(msgbytes) > (i + 1); i++ {
		if (i == 0 && (msgbytes[0] > 32)) || ((msgbytes[i] < 33) && (msgbytes[i+1] > 32)) {
			if (i != 0) || msgbytes[i] < 33 {
				i++
			}

			if msgbytes[i] == '#' {
				if bytes.Equal(msgbytes[i+1:i+5], []byte("tid-")) {
					outbytes = append(outbytes, msgbytes[lastItem:i]...)
					i += 5
					start := i
					tid, intLen := CoerceIntBytes(msgbytes[start:])
					i += intLen

					topic, err := Topics.Get(tid)
					if err != nil || !Forums.Exists(topic.ParentID) {
						outbytes = append(outbytes, InvalidTopic...)
						lastItem = i
						continue
					}

					outbytes = append(outbytes, UrlOpen...)
					var urlBit = []byte(BuildTopicURL("", tid))
					outbytes = append(outbytes, urlBit...)
					outbytes = append(outbytes, UrlOpen2...)
					var tidBit = []byte("#tid-" + strconv.Itoa(tid))
					outbytes = append(outbytes, tidBit...)
					outbytes = append(outbytes, UrlClose...)
					lastItem = i
				} else if bytes.Equal(msgbytes[i+1:i+5], []byte("rid-")) {
					outbytes = append(outbytes, msgbytes[lastItem:i]...)
					i += 5
					start := i
					rid, intLen := CoerceIntBytes(msgbytes[start:])
					i += intLen

					topic, err := TopicByReplyID(rid)
					if err != nil || !Forums.Exists(topic.ParentID) {
						outbytes = append(outbytes, InvalidTopic...)
						lastItem = i
						continue
					}

					outbytes = append(outbytes, UrlOpen...)
					var urlBit = []byte(BuildTopicURL("", topic.ID))
					outbytes = append(outbytes, urlBit...)
					outbytes = append(outbytes, UrlOpen2...)
					var ridBit = []byte("#rid-" + strconv.Itoa(rid))
					outbytes = append(outbytes, ridBit...)
					outbytes = append(outbytes, UrlClose...)
					lastItem = i
				} else if bytes.Equal(msgbytes[i+1:i+5], []byte("fid-")) {
					outbytes = append(outbytes, msgbytes[lastItem:i]...)
					i += 5
					start := i
					fid, intLen := CoerceIntBytes(msgbytes[start:])
					i += intLen

					if !Forums.Exists(fid) {
						outbytes = append(outbytes, InvalidForum...)
						lastItem = i
						continue
					}

					outbytes = append(outbytes, UrlOpen...)
					var urlBit = []byte(BuildForumURL("", fid))
					outbytes = append(outbytes, urlBit...)
					outbytes = append(outbytes, UrlOpen2...)
					var fidBit = []byte("#fid-" + strconv.Itoa(fid))
					outbytes = append(outbytes, fidBit...)
					outbytes = append(outbytes, UrlClose...)
					lastItem = i
				} else {
					// TODO: Forum Shortcode Link
				}
			} else if msgbytes[i] == '@' {
				outbytes = append(outbytes, msgbytes[lastItem:i]...)
				i++
				start := i
				uid, intLen := CoerceIntBytes(msgbytes[start:])
				i += intLen

				menUser, err := Users.Get(uid)
				if err != nil {
					outbytes = append(outbytes, InvalidProfile...)
					lastItem = i
					continue
				}

				outbytes = append(outbytes, UrlOpen...)
				var urlBit = []byte(menUser.Link)
				outbytes = append(outbytes, urlBit...)
				outbytes = append(outbytes, bytesSinglequote...)
				outbytes = append(outbytes, urlMention...)
				outbytes = append(outbytes, bytesGreaterthan...)
				var uidBit = []byte("@" + menUser.Name)
				outbytes = append(outbytes, uidBit...)
				outbytes = append(outbytes, UrlClose...)
				lastItem = i
			} else if msgbytes[i] == 'h' || msgbytes[i] == 'f' || msgbytes[i] == 'g' || msgbytes[i] == '/' {
				if msgbytes[i+1] == 't' && msgbytes[i+2] == 't' && msgbytes[i+3] == 'p' {
					if msgbytes[i+4] == 's' && msgbytes[i+5] == ':' && msgbytes[i+6] == '/' {
						// Do nothing
					} else if msgbytes[i+4] == ':' && msgbytes[i+5] == '/' {
						// Do nothing
					} else {
						continue
					}
				} else if msgbytes[i+1] == 't' && msgbytes[i+2] == 'p' && msgbytes[i+3] == ':' && msgbytes[i+4] == '/' {
					// Do nothing
				} else if msgbytes[i+1] == 'i' && msgbytes[i+2] == 't' && msgbytes[i+3] == ':' && msgbytes[i+4] == '/' {
					// Do nothing
				} else if msgbytes[i+1] == '/' {
					// Do nothing
				} else {
					continue
				}

				//log.Print("Normal URL")
				outbytes = append(outbytes, msgbytes[lastItem:i]...)
				urlLen := PartialURLBytesLen(msgbytes[i:])
				if msgbytes[i+urlLen] > 32 { // space and invisibles
					//log.Print("INVALID URL")
					outbytes = append(outbytes, InvalidURL...)
					i += urlLen
					continue
				}

				media, ok := parseMediaBytes(msgbytes[i : i+urlLen])
				if !ok {
					outbytes = append(outbytes, InvalidURL...)
					i += urlLen
					continue
				}

				// TODO: Reduce the amount of code duplication
				if media.Type == "attach" {
					outbytes = append(outbytes, imageOpen...)
					outbytes = append(outbytes, []byte(media.URL+"?sectionID="+strconv.Itoa(sectionID)+"&sectionType="+sectionType)...)
					outbytes = append(outbytes, imageOpen2...)
					outbytes = append(outbytes, []byte(media.URL+"?sectionID="+strconv.Itoa(sectionID)+"&sectionType="+sectionType)...)
					outbytes = append(outbytes, imageClose...)
					i += urlLen
					lastItem = i
					continue
				} else if media.Type == "image" {
					outbytes = append(outbytes, imageOpen...)
					outbytes = append(outbytes, []byte(media.URL)...)
					outbytes = append(outbytes, imageOpen2...)
					outbytes = append(outbytes, []byte(media.URL)...)
					outbytes = append(outbytes, imageClose...)
					i += urlLen
					lastItem = i
					continue
				} else if media.Type == "raw" {
					outbytes = append(outbytes, []byte(media.Body)...)
					i += urlLen
					lastItem = i
					continue
				} else if media.Type != "" {
					outbytes = append(outbytes, unknownMedia...)
					i += urlLen
					continue
				}

				outbytes = append(outbytes, UrlOpen...)
				outbytes = append(outbytes, msgbytes[i:i+urlLen]...)
				outbytes = append(outbytes, UrlOpen2...)
				outbytes = append(outbytes, msgbytes[i:i+urlLen]...)
				outbytes = append(outbytes, UrlClose...)
				i += urlLen
				lastItem = i
			}
		}
	}

	if lastItem != i && len(outbytes) != 0 {
		calclen := len(msgbytes) - 10
		if calclen <= lastItem {
			calclen = lastItem
		}
		outbytes = append(outbytes, msgbytes[lastItem:calclen]...)
		msg = string(outbytes)
	}

	msg = strings.Replace(msg, "\n", "<br>", -1)
	msg = RunSshook("parse_assign", msg)
	return msg
}

// 6, 7, 8, 6, 2, 7
// ftp://, http://, https:// git://, //, mailto: (not a URL, just here for length comparison purposes)
// TODO: Write a test for this
func validateURLBytes(data []byte) bool {
	datalen := len(data)
	i := 0

	if datalen >= 6 {
		if bytes.Equal(data[0:6], []byte("ftp://")) || bytes.Equal(data[0:6], []byte("git://")) {
			i = 6
		} else if datalen >= 7 && bytes.Equal(data[0:7], httpProtBytes) {
			i = 7
		} else if datalen >= 8 && bytes.Equal(data[0:8], []byte("https://")) {
			i = 8
		}
	} else if datalen >= 2 && data[0] == '/' && data[1] == '/' {
		i = 2
	}

	// ? - There should only be one : and that's only if the URL is on a non-standard port. Same for ?s.
	for ; datalen > i; i++ {
		if data[i] != '\\' && data[i] != '_' && data[i] != ':' && data[i] != '?' && data[i] != '&' && data[i] != '=' && data[i] != ';' && data[i] != '@' && !(data[i] > 44 && data[i] < 58) && !(data[i] > 64 && data[i] < 91) && !(data[i] > 96 && data[i] < 123) {
			return false
		}
	}
	return true
}

// TODO: Write a test for this
func validatedURLBytes(data []byte) (url []byte) {
	datalen := len(data)
	i := 0

	if datalen >= 6 {
		if bytes.Equal(data[0:6], []byte("ftp://")) || bytes.Equal(data[0:6], []byte("git://")) {
			i = 6
		} else if datalen >= 7 && bytes.Equal(data[0:7], httpProtBytes) {
			i = 7
		} else if datalen >= 8 && bytes.Equal(data[0:8], []byte("https://")) {
			i = 8
		}
	} else if datalen >= 2 && data[0] == '/' && data[1] == '/' {
		i = 2
	}

	// ? - There should only be one : and that's only if the URL is on a non-standard port. Same for ?s.
	for ; datalen > i; i++ {
		if data[i] != '\\' && data[i] != '_' && data[i] != ':' && data[i] != '?' && data[i] != '&' && data[i] != '=' && data[i] != ';' && data[i] != '@' && !(data[i] > 44 && data[i] < 58) && !(data[i] > 64 && data[i] < 91) && !(data[i] > 96 && data[i] < 123) {
			return InvalidURL
		}
	}

	url = append(url, data...)
	return url
}

// TODO: Write a test for this
func PartialURLBytes(data []byte) (url []byte) {
	datalen := len(data)
	i := 0
	end := datalen - 1

	if datalen >= 6 {
		if bytes.Equal(data[0:6], []byte("ftp://")) || bytes.Equal(data[0:6], []byte("git://")) {
			i = 6
		} else if datalen >= 7 && bytes.Equal(data[0:7], httpProtBytes) {
			i = 7
		} else if datalen >= 8 && bytes.Equal(data[0:8], []byte("https://")) {
			i = 8
		}
	} else if datalen >= 2 && data[0] == '/' && data[1] == '/' {
		i = 2
	}

	// ? - There should only be one : and that's only if the URL is on a non-standard port. Same for ?s.
	for ; end >= i; i++ {
		if data[i] != '\\' && data[i] != '_' && data[i] != ':' && data[i] != '?' && data[i] != '&' && data[i] != '=' && data[i] != ';' && data[i] != '@' && !(data[i] > 44 && data[i] < 58) && !(data[i] > 64 && data[i] < 91) && !(data[i] > 96 && data[i] < 123) {
			end = i
		}
	}

	url = append(url, data[0:end]...)
	return url
}

// TODO: Write a test for this
func PartialURLBytesLen(data []byte) int {
	datalen := len(data)
	i := 0

	if datalen >= 6 {
		//log.Print(string(data[0:5]))
		if bytes.Equal(data[0:6], []byte("ftp://")) || bytes.Equal(data[0:6], []byte("git://")) {
			i = 6
		} else if datalen >= 7 && bytes.Equal(data[0:7], httpProtBytes) {
			i = 7
		} else if datalen >= 8 && bytes.Equal(data[0:8], []byte("https://")) {
			i = 8
		}
	} else if datalen >= 2 && data[0] == '/' && data[1] == '/' {
		i = 2
	}

	// ? - There should only be one : and that's only if the URL is on a non-standard port. Same for ?s.
	for ; datalen > i; i++ {
		if data[i] != '\\' && data[i] != '_' && data[i] != ':' && data[i] != '?' && data[i] != '&' && data[i] != '=' && data[i] != ';' && data[i] != '@' && !(data[i] > 44 && data[i] < 58) && !(data[i] > 64 && data[i] < 91) && !(data[i] > 96 && data[i] < 123) {
			//log.Print("Bad Character: ", data[i])
			return i
		}
	}
	//log.Print("Data Length: ",datalen)
	return datalen
}

type MediaEmbed struct {
	Type string //image
	URL  string
	Body string
}

// TODO: Write a test for this
func parseMediaBytes(data []byte) (media MediaEmbed, ok bool) {
	if !validateURLBytes(data) {
		return media, false
	}
	url, err := parseURL(data)
	if err != nil {
		return media, false
	}

	hostname := url.Hostname()
	scheme := url.Scheme
	port := url.Port()
	query := url.Query()

	var samesite = hostname == "localhost" || hostname == Site.URL
	if samesite {
		hostname = strings.Split(Site.URL, ":")[0]
		// ?- Test this as I'm not sure it'll do what it should. If someone's running SSL on port 80 or non-SSL on port 443 then... Well... They're in far worse trouble than this...
		port = Site.Port
		if scheme == "" && Site.EnableSsl {
			scheme = "https"
		}
	}
	if scheme == "" {
		scheme = "http"
	}

	path := url.EscapedPath()
	pathFrags := strings.Split(path, "/")
	if len(pathFrags) >= 2 {
		if samesite && pathFrags[1] == "attachs" && (scheme == "http" || scheme == "https") {
			media.Type = "attach"
			var sport string
			// ? - Assumes the sysadmin hasn't mixed up the two standard ports
			if port != "443" && port != "80" {
				sport = ":" + port
			}
			media.URL = scheme + "://" + hostname + sport + path
			return media, true
		}
	}

	// ? - I don't think this hostname will hit every YT domain
	// TODO: Make this a more customisable handler rather than hard-coding it in here
	if hostname == "www.youtube.com" && path == "/watch" {
		video, ok := query["v"]
		if ok && len(video) >= 1 && video[0] != "" {
			media.Type = "raw"
			// TODO: Filter the URL to make sure no nasties end up in there
			media.Body = "<iframe class='postIframe' src='https://www.youtube-nocookie.com/embed/" + video[0] + "' frameborder='0' allowfullscreen></iframe>"
			return media, true
		}
	}

	lastFrag := pathFrags[len(pathFrags)-1]
	if lastFrag != "" {
		// TODO: Write a function for getting the file extension of a string
		extarr := strings.Split(lastFrag, ".")
		if len(extarr) >= 2 {
			ext := extarr[len(extarr)-1]
			if ImageFileExts.Contains(ext) {
				media.Type = "image"
				var sport string
				if port != "443" && port != "80" {
					sport = ":" + port
				}
				media.URL = scheme + "://" + hostname + sport + path
				return media, true
			}
		}
	}

	return media, true
}

func parseURL(data []byte) (*url.URL, error) {
	return url.Parse(string(data))
}

// TODO: Write a test for this
func CoerceIntBytes(data []byte) (res int, length int) {
	if !(data[0] > 47 && data[0] < 58) {
		return 0, 1
	}

	i := 0
	for ; len(data) > i; i++ {
		if !(data[i] > 47 && data[i] < 58) {
			conv, err := strconv.Atoi(string(data[0:i]))
			if err != nil {
				return 0, i
			}
			return conv, i
		}
	}

	conv, err := strconv.Atoi(string(data))
	if err != nil {
		return 0, i
	}
	return conv, i
}

// TODO: Write tests for this
func Paginate(count int, perPage int, maxPages int) []int {
	if count < perPage {
		return []int{1}
	}
	var page int
	var out []int
	for current := 0; current < count; current += perPage {
		page++
		out = append(out, page)
		if len(out) >= maxPages {
			break
		}
	}
	return out
}

// TODO: Write tests for this
func PageOffset(count int, page int, perPage int) (int, int, int) {
	var offset int
	lastPage := (count / perPage) + 1
	if page > 1 {
		offset = (perPage * page) - perPage
	} else if page == -1 {
		page = lastPage
		offset = (perPage * page) - perPage
	} else {
		page = 1
	}

	// We don't want the offset to overflow the slices, if everything's in memory
	if offset >= (count - 1) {
		offset = 0
	}
	return offset, page, lastPage
}