epicyon/content.py

__filename__ = "content.py"
__author__ = "Bob Mottram"
__license__ = "AGPL3+"
__version__ = "0.0.1"
__maintainer__ = "Bob Mottram"
__email__ = "bob@freedombone.net"
__status__ = "Production"

import os
import commentjson

def validHashTag(hashtag: str) -> bool:
    """Returns true if the give hashtag contains valid characters
    """
    validChars = set('0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ')
    if set(hashtag).issubset(validChars):
        return True
    return False

def addHashTags(wordStr: str,httpPrefix: str,domain: str,replaceHashTags: {},postHashtags: {}) -> bool:
    """Detects hashtags and adds them to the replacements dict
    Also updates the hashtags list to be added to the post
    """
    if not wordStr.startswith('#'):
        return False
    if len(wordStr)<2:
        return False
    if replaceHashTags.get(wordStr):
       return True
    hashtag=wordStr[1:]
    if not validHashTag(hashtag):
        return False
    hashtagUrl=httpPrefix+"://"+domain+"/tags/"+hashtag
    postHashtags[hashtag]= {
        'href': hashtagUrl,
        'name': '#'+hashtag,
        'type': 'Hashtag'
    }
    replaceHashTags[wordStr]= \
        "<a href=\""+hashtagUrl+"\" class=\"mention hashtag\" rel=\"tag\">#<span>"+hashtag+"</span></a>"
    return True

def addMention(wordStr: str,httpPrefix: str,following: str,replaceMentions: {},recipients: []) -> bool:
    """Detects mentions and adds them to the replacements dict and recipients list
    """
    if not wordStr.startswith('@'):
        return False
    if len(wordStr)<2:
        return False
    possibleHandle=wordStr[1:]
    if '@' not in possibleHandle:
        # fall back to a best effort match against the following list
        # if no domain was specified. eg. @nick
        possibleNickname=possibleHandle
        for follow in following:
            if follow.startswith(possibleNickname+'@'):
                replaceDomain=follow.replace('\n','').split('@')[1]
                recipientActor=httpPrefix+"://"+replaceDomain+"/users/"+possibleNickname
                if recipientActor not in recipients:
                    recipients.append(recipientActor)
                replaceMentions[wordStr]="<span class=\"h-card\"><a href=\""+httpPrefix+"://"+replaceDomain+"/@"+possibleNickname+"\" class=\"u-url mention\">@<span>"+possibleNickname+"</span></a></span>"
                replaceFound=True
                return True
        return False
    possibleNickname=possibleHandle.split('@')[0]
    possibleDomain=possibleHandle.split('@')[1]
    for follow in following:
        if follow.replace('\n','')==possibleHandle:
            recipientActor=httpPrefix+"://"+possibleDomain+"/users/"+possibleNickname
            if recipientActor not in recipients:
                recipients.append(recipientActor)
            replaceMentions[wordStr]="<span class=\"h-card\"><a href=\""+httpPrefix+"://"+possibleDomain+"/@"+possibleNickname+"\" class=\"u-url mention\">@<span>"+possibleNickname+"</span></a></span>"
            return True
    return False

def addHtmlTags(baseDir: str,httpPrefix: str, \
                nickname: str,domain: str,content: str, \
                recipients: [],hashtags: {}) -> str:
    """ Replaces plaintext mentions such as @nick@domain into html
    by matching against known following accounts
    """
    if content.startswith('<p>'):
        return content
    wordsOnly=content.replace(',',' ').replace(';',' ').replace('.',' ').replace(':',' ')
    words=wordsOnly.split(' ')
    replaceMentions={}
    replaceHashTags={}
    if ':' in domain:
        domain=domain.split(':')[0]
    followingFilename=baseDir+'/accounts/'+nickname+'@'+domain+'/following.txt'
    if not os.path.isfile(followingFilename):
        content=content.replace('\n','</p><p>')
        content='<p>'+content+'</p>'
        return content.replace('<p></p>','')

    # read the following list so that we can detect just @nick
    # in addition to @nick@domain
    with open(followingFilename, "r") as f:
        following = f.readlines()

    # extract mentions and tags from words
    for wordStr in words:
        if addMention(wordStr,httpPrefix,following,replaceMentions,recipients):
            continue
        addHashTags(wordStr,httpPrefix,domain,replaceHashTags,hashtags)

    # replace words with their html versions
    for wordStr,replaceStr in replaceMentions.items():
        content=content.replace(wordStr,replaceStr)
    for wordStr,replaceStr in replaceHashTags.items():
        content=content.replace(wordStr,replaceStr)
        
    content=content.replace('\n','</p><p>')
    return '<p>'+content+'</p>'
                
def getMentionsFromHtml(htmlText: str,matchStr="<span class=\"h-card\"><a href=\"") -> []:
    """Extracts mentioned actors from the given html content string
    """
    mentions=[]
    if matchStr not in htmlText:
        return mentions
    mentionsList=htmlText.split(matchStr)
    for mentionStr in mentionsList:
        if '"' not in mentionStr:
            continue
        actorStr=mentionStr.split('"')[0]
        if actorStr.startswith('http') or \
           actorStr.startswith('dat:'):
            mentions.append(actorStr)
    return mentions