__filename__ = "webapp_search.py"
__author__ = "Bob Mottram"
__license__ = "AGPL3+"
__version__ = "1.1.0"
__maintainer__ = "Bob Mottram"
__email__ = "bob@freedombone.net"
__status__ = "Production"

import os
from shutil import copyfile
import urllib.parse
from datetime import datetime
from utils import isEditor
from utils import loadJson
from utils import getDomainFromActor
from utils import getNicknameFromActor
from utils import getConfigParam
from utils import locatePost
from utils import isPublicPost
from utils import firstParagraphFromString
from utils import searchBoxPosts
from utils import getHashtagCategory
from feeds import rss2TagHeader
from feeds import rss2TagFooter
from webapp_utils import getAltPath
from webapp_utils import getImageFile
from webapp_utils import htmlHeaderWithExternalStyle
from webapp_utils import htmlFooter
from webapp_utils import getSearchBannerFile
from webapp_utils import htmlPostSeparator
from webapp_post import individualPostAsHtml
from webapp_hashtagswarm import htmlHashTagSwarm


def htmlSearchEmoji(cssCache: {}, translate: {},
                    baseDir: str, httpPrefix: str,
                    searchStr: str) -> str:
    """Search results for emoji
    """
    # emoji.json is generated so that it can be customized and the changes
    # will be retained even if default_emoji.json is subsequently updated
    if not os.path.isfile(baseDir + '/emoji/emoji.json'):
        copyfile(baseDir + '/emoji/default_emoji.json',
                 baseDir + '/emoji/emoji.json')

    searchStr = searchStr.lower().replace(':', '').strip('\n').strip('\r')
    cssFilename = baseDir + '/epicyon-profile.css'
    if os.path.isfile(baseDir + '/epicyon.css'):
        cssFilename = baseDir + '/epicyon.css'

    emojiLookupFilename = baseDir + '/emoji/emoji.json'

    # create header
    emojiForm = htmlHeaderWithExternalStyle(cssFilename)
    emojiForm += '<center><h1>' + \
        translate['Emoji Search'] + \
        '</h1></center>'

    # does the lookup file exist?
    if not os.path.isfile(emojiLookupFilename):
        emojiForm += '<center><h5>' + \
            translate['No results'] + '</h5></center>'
        emojiForm += htmlFooter()
        return emojiForm

    emojiJson = loadJson(emojiLookupFilename)
    if emojiJson:
        results = {}
        for emojiName, filename in emojiJson.items():
            if searchStr in emojiName:
                results[emojiName] = filename + '.png'
        for emojiName, filename in emojiJson.items():
            if emojiName in searchStr:
                results[emojiName] = filename + '.png'
        headingShown = False
        emojiForm += '<center>'
        msgStr1 = translate['Copy the text then paste it into your post']
        msgStr2 = ':<img loading="lazy" class="searchEmoji" src="/emoji/'
        for emojiName, filename in results.items():
            if os.path.isfile(baseDir + '/emoji/' + filename):
                if not headingShown:
                    emojiForm += \
                        '<center><h5>' + msgStr1 + \
                        '</h5></center>'
                    headingShown = True
                emojiForm += \
                    '<h3>:' + emojiName + msgStr2 + \
                    filename + '"/></h3>'
        emojiForm += '</center>'

    emojiForm += htmlFooter()
    return emojiForm


def htmlSearchSharedItems(cssCache: {}, translate: {},
                          baseDir: str, searchStr: str,
                          pageNumber: int,
                          resultsPerPage: int,
                          httpPrefix: str,
                          domainFull: str, actor: str,
                          callingDomain: str) -> str:
    """Search results for shared items
    """
    currPage = 1
    ctr = 0
    sharedItemsForm = ''
    searchStrLower = urllib.parse.unquote(searchStr)
    searchStrLower = searchStrLower.lower().strip('\n').strip('\r')
    searchStrLowerList = searchStrLower.split('+')
    cssFilename = baseDir + '/epicyon-profile.css'
    if os.path.isfile(baseDir + '/epicyon.css'):
        cssFilename = baseDir + '/epicyon.css'

    sharedItemsForm = \
        htmlHeaderWithExternalStyle(cssFilename)
    sharedItemsForm += \
        '<center><h1>' + \
        '<a href="' + actor + '/search">' + \
        translate['Shared Items Search'] + \
        '</a></h1></center>'
    resultsExist = False
    for subdir, dirs, files in os.walk(baseDir + '/accounts'):
        for handle in dirs:
            if '@' not in handle:
                continue
            contactNickname = handle.split('@')[0]
            sharesFilename = baseDir + '/accounts/' + handle + \
                '/shares.json'
            if not os.path.isfile(sharesFilename):
                continue

            sharesJson = loadJson(sharesFilename)
            if not sharesJson:
                continue

            for name, sharedItem in sharesJson.items():
                matched = True
                for searchSubstr in searchStrLowerList:
                    subStrMatched = False
                    searchSubstr = searchSubstr.strip()
                    if searchSubstr in sharedItem['location'].lower():
                        subStrMatched = True
                    elif searchSubstr in sharedItem['summary'].lower():
                        subStrMatched = True
                    elif searchSubstr in sharedItem['displayName'].lower():
                        subStrMatched = True
                    elif searchSubstr in sharedItem['category'].lower():
                        subStrMatched = True
                    if not subStrMatched:
                        matched = False
                        break
                if matched:
                    if currPage == pageNumber:
                        sharedItemsForm += '<div class="container">\n'
                        sharedItemsForm += \
                            '<p class="share-title">' + \
                            sharedItem['displayName'] + '</p>\n'
                        if sharedItem.get('imageUrl'):
                            sharedItemsForm += \
                                '<a href="' + \
                                sharedItem['imageUrl'] + '">\n'
                            sharedItemsForm += \
                                '<img loading="lazy" src="' + \
                                sharedItem['imageUrl'] + \
                                '" alt="Item image"></a>\n'
                        sharedItemsForm += \
                            '<p>' + sharedItem['summary'] + '</p>\n'
                        sharedItemsForm += \
                            '<p><b>' + translate['Type'] + \
                            ':</b> ' + sharedItem['itemType'] + ' '
                        sharedItemsForm += \
                            '<b>' + translate['Category'] + \
                            ':</b> ' + sharedItem['category'] + ' '
                        sharedItemsForm += \
                            '<b>' + translate['Location'] + \
                            ':</b> ' + sharedItem['location'] + '</p>\n'
                        contactActor = \
                            httpPrefix + '://' + domainFull + \
                            '/users/' + contactNickname
                        sharedItemsForm += \
                            '<p><a href="' + actor + \
                            '?replydm=sharedesc:' + \
                            sharedItem['displayName'] + \
                            '?mention=' + contactActor + \
                            '"><button class="button">' + \
                            translate['Contact'] + '</button></a>\n'
                        if actor.endswith('/users/' + contactNickname):
                            sharedItemsForm += \
                                ' <a href="' + actor + '?rmshare=' + \
                                name + '"><button class="button">' + \
                                translate['Remove'] + '</button></a>\n'
                        sharedItemsForm += '</p></div>\n'
                        if not resultsExist and currPage > 1:
                            postActor = \
                                getAltPath(actor, domainFull,
                                           callingDomain)
                            # previous page link, needs to be a POST
                            sharedItemsForm += \
                                '<form method="POST" action="' + \
                                postActor + \
                                '/searchhandle?page=' + \
                                str(pageNumber - 1) + '">\n'
                            sharedItemsForm += \
                                '  <input type="hidden" ' + \
                                'name="actor" value="' + actor + '">\n'
                            sharedItemsForm += \
                                '  <input type="hidden" ' + \
                                'name="searchtext" value="' + \
                                searchStrLower + '"><br>\n'
                            sharedItemsForm += \
                                '  <center>\n' + \
                                '    <a href="' + actor + \
                                '" type="submit" name="submitSearch">\n'
                            sharedItemsForm += \
                                '    <img loading="lazy" ' + \
                                'class="pageicon" src="/icons' + \
                                '/pageup.png" title="' + \
                                translate['Page up'] + \
                                '" alt="' + translate['Page up'] + \
                                '"/></a>\n'
                            sharedItemsForm += '  </center>\n'
                            sharedItemsForm += '</form>\n'
                        resultsExist = True
                    ctr += 1
                    if ctr >= resultsPerPage:
                        currPage += 1
                        if currPage > pageNumber:
                            postActor = \
                                getAltPath(actor, domainFull,
                                           callingDomain)
                            # next page link, needs to be a POST
                            sharedItemsForm += \
                                '<form method="POST" action="' + \
                                postActor + \
                                '/searchhandle?page=' + \
                                str(pageNumber + 1) + '">\n'
                            sharedItemsForm += \
                                '  <input type="hidden" ' + \
                                'name="actor" value="' + actor + '">\n'
                            sharedItemsForm += \
                                '  <input type="hidden" ' + \
                                'name="searchtext" value="' + \
                                searchStrLower + '"><br>\n'
                            sharedItemsForm += \
                                '  <center>\n' + \
                                '    <a href="' + actor + \
                                '" type="submit" name="submitSearch">\n'
                            sharedItemsForm += \
                                '    <img loading="lazy" ' + \
                                'class="pageicon" src="/icons' + \
                                '/pagedown.png" title="' + \
                                translate['Page down'] + \
                                '" alt="' + translate['Page down'] + \
                                '"/></a>\n'
                            sharedItemsForm += '  </center>\n'
                            sharedItemsForm += '</form>\n'
                            break
                        ctr = 0
        break
    if not resultsExist:
        sharedItemsForm += \
            '<center><h5>' + translate['No results'] + '</h5></center>\n'
    sharedItemsForm += htmlFooter()
    return sharedItemsForm


def htmlSearchEmojiTextEntry(cssCache: {}, translate: {},
                             baseDir: str, path: str) -> str:
    """Search for an emoji by name
    """
    # emoji.json is generated so that it can be customized and the changes
    # will be retained even if default_emoji.json is subsequently updated
    if not os.path.isfile(baseDir + '/emoji/emoji.json'):
        copyfile(baseDir + '/emoji/default_emoji.json',
                 baseDir + '/emoji/emoji.json')

    actor = path.replace('/search', '')
    domain, port = getDomainFromActor(actor)

    if os.path.isfile(baseDir + '/img/search-background.png'):
        if not os.path.isfile(baseDir + '/accounts/search-background.png'):
            copyfile(baseDir + '/img/search-background.png',
                     baseDir + '/accounts/search-background.png')

    cssFilename = baseDir + '/epicyon-follow.css'
    if os.path.isfile(baseDir + '/follow.css'):
        cssFilename = baseDir + '/follow.css'

    emojiStr = htmlHeaderWithExternalStyle(cssFilename)
    emojiStr += '<div class="follow">\n'
    emojiStr += '  <div class="followAvatar">\n'
    emojiStr += '  <center>\n'
    emojiStr += \
        '  <p class="followText">' + \
        translate['Enter an emoji name to search for'] + '</p>\n'
    emojiStr += '  <form method="POST" action="' + \
        actor + '/searchhandleemoji">\n'
    emojiStr += '    <input type="hidden" name="actor" value="' + \
        actor + '">\n'
    emojiStr += '    <input type="text" name="searchtext" autofocus><br>\n'
    emojiStr += \
        '    <button type="submit" class="button" name="submitSearch">' + \
        translate['Submit'] + '</button>\n'
    emojiStr += '  </form>\n'
    emojiStr += '  </center>\n'
    emojiStr += '  </div>\n'
    emojiStr += '</div>\n'
    emojiStr += htmlFooter()
    return emojiStr


def htmlSearch(cssCache: {}, translate: {},
               baseDir: str, path: str, domain: str,
               defaultTimeline: str) -> str:
    """Search called from the timeline icon
    """
    actor = path.replace('/search', '')
    searchNickname = getNicknameFromActor(actor)

    if os.path.isfile(baseDir + '/img/search-background.png'):
        if not os.path.isfile(baseDir + '/accounts/search-background.png'):
            copyfile(baseDir + '/img/search-background.png',
                     baseDir + '/accounts/search-background.png')

    cssFilename = baseDir + '/epicyon-search.css'
    if os.path.isfile(baseDir + '/search.css'):
        cssFilename = baseDir + '/search.css'

    followStr = htmlHeaderWithExternalStyle(cssFilename)

    # show a banner above the search box
    searchBannerFile, searchBannerFilename = \
        getSearchBannerFile(baseDir, searchNickname, domain)
    if not os.path.isfile(searchBannerFilename):
        # get the default search banner for the theme
        theme = getConfigParam(baseDir, 'theme').lower()
        if theme == 'default':
            theme = ''
        else:
            theme = '_' + theme
        themeSearchImageFile, themeSearchBannerFilename = \
            getImageFile(baseDir, 'search_banner', baseDir + '/img',
                         searchNickname, domain)
        if os.path.isfile(themeSearchBannerFilename):
            searchBannerFilename = \
                baseDir + '/accounts/' + \
                searchNickname + '@' + domain + '/' + themeSearchImageFile
            copyfile(themeSearchBannerFilename,
                     searchBannerFilename)
            searchBannerFile = themeSearchImageFile

    if os.path.isfile(searchBannerFilename):
        usersPath = '/users/' + searchNickname
        followStr += \
            '<a href="' + usersPath + '/' + defaultTimeline + '" title="' + \
            translate['Switch to timeline view'] + '" alt="' + \
            translate['Switch to timeline view'] + '">\n'
        followStr += '<img loading="lazy" class="timeline-banner" src="' + \
            usersPath + '/' + searchBannerFile + '" /></a>\n'

    # show the search box
    followStr += '<div class="follow">\n'
    followStr += '  <div class="followAvatar">\n'
    followStr += '  <center>\n'
    idx = 'Enter an address, shared item, !history, #hashtag, ' + \
        '*skill or :emoji: to search for'
    followStr += \
        '  <p class="followText">' + translate[idx] + '</p>\n'
    followStr += '  <form method="POST" ' + \
        'accept-charset="UTF-8" action="' + actor + '/searchhandle">\n'
    followStr += \
        '    <input type="hidden" name="actor" value="' + actor + '">\n'
    followStr += '    <input type="text" name="searchtext" autofocus><br>\n'
    followStr += '    <button type="submit" class="button" ' + \
        'name="submitSearch">' + translate['Submit'] + '</button>\n'
    followStr += '  </form>\n'
    followStr += '  <p class="hashtagswarm">' + \
        htmlHashTagSwarm(baseDir, actor, translate) + '</p>\n'
    followStr += '  </center>\n'
    followStr += '  </div>\n'
    followStr += '</div>\n'
    followStr += htmlFooter()
    return followStr


def htmlSkillsSearch(actor: str,
                     cssCache: {}, translate: {}, baseDir: str,
                     httpPrefix: str,
                     skillsearch: str, instanceOnly: bool,
                     postsPerPage: int) -> str:
    """Show a page containing search results for a skill
    """
    if skillsearch.startswith('*'):
        skillsearch = skillsearch[1:].strip()

    skillsearch = skillsearch.lower().strip('\n').strip('\r')

    results = []
    # search instance accounts
    for subdir, dirs, files in os.walk(baseDir + '/accounts/'):
        for f in files:
            if not f.endswith('.json'):
                continue
            if '@' not in f:
                continue
            if f.startswith('inbox@'):
                continue
            actorFilename = os.path.join(subdir, f)
            actorJson = loadJson(actorFilename)
            if actorJson:
                if actorJson.get('id') and \
                   actorJson.get('skills') and \
                   actorJson.get('name') and \
                   actorJson.get('icon'):
                    actor = actorJson['id']
                    for skillName, skillLevel in actorJson['skills'].items():
                        skillName = skillName.lower()
                        if not (skillName in skillsearch or
                                skillsearch in skillName):
                            continue
                        skillLevelStr = str(skillLevel)
                        if skillLevel < 100:
                            skillLevelStr = '0' + skillLevelStr
                        if skillLevel < 10:
                            skillLevelStr = '0' + skillLevelStr
                        indexStr = \
                            skillLevelStr + ';' + actor + ';' + \
                            actorJson['name'] + \
                            ';' + actorJson['icon']['url']
                        if indexStr not in results:
                            results.append(indexStr)
        break
    if not instanceOnly:
        # search actor cache
        for subdir, dirs, files in os.walk(baseDir + '/cache/actors/'):
            for f in files:
                if not f.endswith('.json'):
                    continue
                if '@' not in f:
                    continue
                if f.startswith('inbox@'):
                    continue
                actorFilename = os.path.join(subdir, f)
                cachedActorJson = loadJson(actorFilename)
                if cachedActorJson:
                    if cachedActorJson.get('actor'):
                        actorJson = cachedActorJson['actor']
                        if actorJson.get('id') and \
                           actorJson.get('skills') and \
                           actorJson.get('name') and \
                           actorJson.get('icon'):
                            actor = actorJson['id']
                            for skillName, skillLevel in \
                                    actorJson['skills'].items():
                                skillName = skillName.lower()
                                if not (skillName in skillsearch or
                                        skillsearch in skillName):
                                    continue
                                skillLevelStr = str(skillLevel)
                                if skillLevel < 100:
                                    skillLevelStr = '0' + skillLevelStr
                                if skillLevel < 10:
                                    skillLevelStr = '0' + skillLevelStr
                                indexStr = \
                                    skillLevelStr + ';' + actor + ';' + \
                                    actorJson['name'] + \
                                    ';' + actorJson['icon']['url']
                                if indexStr not in results:
                                    results.append(indexStr)
            break

    results.sort(reverse=True)

    cssFilename = baseDir + '/epicyon-profile.css'
    if os.path.isfile(baseDir + '/epicyon.css'):
        cssFilename = baseDir + '/epicyon.css'

    skillSearchForm = htmlHeaderWithExternalStyle(cssFilename)
    skillSearchForm += \
        '<center><h1><a href = "' + actor + '/search">' + \
        translate['Skills search'] + ': ' + \
        skillsearch + \
        '</a></h1></center>'

    if len(results) == 0:
        skillSearchForm += \
            '<center><h5>' + translate['No results'] + \
            '</h5></center>'
    else:
        skillSearchForm += '<center>'
        ctr = 0
        for skillMatch in results:
            skillMatchFields = skillMatch.split(';')
            if len(skillMatchFields) != 4:
                continue
            actor = skillMatchFields[1]
            actorName = skillMatchFields[2]
            avatarUrl = skillMatchFields[3]
            skillSearchForm += \
                '<div class="search-result""><a href="' + \
                actor + '/skills">'
            skillSearchForm += \
                '<img loading="lazy" src="' + avatarUrl + \
                '"/><span class="search-result-text">' + actorName + \
                '</span></a></div>'
            ctr += 1
            if ctr >= postsPerPage:
                break
        skillSearchForm += '</center>'
    skillSearchForm += htmlFooter()
    return skillSearchForm


def htmlHistorySearch(cssCache: {}, translate: {}, baseDir: str,
                      httpPrefix: str,
                      nickname: str, domain: str,
                      historysearch: str,
                      postsPerPage: int, pageNumber: int,
                      projectVersion: str,
                      recentPostsCache: {},
                      maxRecentPosts: int,
                      session,
                      wfRequest,
                      personCache: {},
                      port: int,
                      YTReplacementDomain: str,
                      showPublishedDateOnly: bool) -> str:
    """Show a page containing search results for your post history
    """
    if historysearch.startswith('!'):
        historysearch = historysearch[1:].strip()

    historysearch = historysearch.lower().strip('\n').strip('\r')

    boxFilenames = \
        searchBoxPosts(baseDir, nickname, domain,
                       historysearch, postsPerPage)

    cssFilename = baseDir + '/epicyon-profile.css'
    if os.path.isfile(baseDir + '/epicyon.css'):
        cssFilename = baseDir + '/epicyon.css'

    historySearchForm = \
        htmlHeaderWithExternalStyle(cssFilename)

    # add the page title
    domainFull = domain
    if port:
        if port != 80 and port != 443:
            domainFull = domain + ':' + str(port)
    actor = httpPrefix + '://' + domainFull + '/users/' + nickname
    historySearchForm += \
        '<center><h1><a href="' + actor + '/search">' + \
        translate['Your Posts'] + \
        '</a></h1></center>'

    if len(boxFilenames) == 0:
        historySearchForm += \
            '<center><h5>' + translate['No results'] + \
            '</h5></center>'
        return historySearchForm

    separatorStr = htmlPostSeparator(baseDir, None)

    # ensure that the page number is in bounds
    if not pageNumber:
        pageNumber = 1
    elif pageNumber < 1:
        pageNumber = 1

    # get the start end end within the index file
    startIndex = int((pageNumber - 1) * postsPerPage)
    endIndex = startIndex + postsPerPage
    noOfBoxFilenames = len(boxFilenames)
    if endIndex >= noOfBoxFilenames and noOfBoxFilenames > 0:
        endIndex = noOfBoxFilenames - 1

    index = startIndex
    while index <= endIndex:
        postFilename = boxFilenames[index]
        if not postFilename:
            index += 1
            continue
        postJsonObject = loadJson(postFilename)
        if not postJsonObject:
            index += 1
            continue
        showIndividualPostIcons = True
        allowDeletion = False
        postStr = \
            individualPostAsHtml(True, recentPostsCache,
                                 maxRecentPosts,
                                 translate, None,
                                 baseDir, session, wfRequest,
                                 personCache,
                                 nickname, domain, port,
                                 postJsonObject,
                                 None, True, allowDeletion,
                                 httpPrefix, projectVersion,
                                 'search',
                                 YTReplacementDomain,
                                 showPublishedDateOnly,
                                 showIndividualPostIcons,
                                 showIndividualPostIcons,
                                 False, False, False)
        if postStr:
            historySearchForm += separatorStr + postStr
        index += 1

    historySearchForm += htmlFooter()
    return historySearchForm


def htmlHashtagSearch(cssCache: {},
                      nickname: str, domain: str, port: int,
                      recentPostsCache: {}, maxRecentPosts: int,
                      translate: {},
                      baseDir: str, hashtag: str, pageNumber: int,
                      postsPerPage: int,
                      session, wfRequest: {}, personCache: {},
                      httpPrefix: str, projectVersion: str,
                      YTReplacementDomain: str,
                      showPublishedDateOnly: bool) -> str:
    """Show a page containing search results for a hashtag
    """
    if hashtag.startswith('#'):
        hashtag = hashtag[1:]
    hashtag = urllib.parse.unquote(hashtag)
    hashtagIndexFile = baseDir + '/tags/' + hashtag + '.txt'
    if not os.path.isfile(hashtagIndexFile):
        if hashtag != hashtag.lower():
            hashtag = hashtag.lower()
            hashtagIndexFile = baseDir + '/tags/' + hashtag + '.txt'
    if not os.path.isfile(hashtagIndexFile):
        print('WARN: hashtag file not found ' + hashtagIndexFile)
        return None

    separatorStr = htmlPostSeparator(baseDir, None)

    # check that the directory for the nickname exists
    if nickname:
        if not os.path.isdir(baseDir + '/accounts/' +
                             nickname + '@' + domain):
            nickname = None

    # read the index
    with open(hashtagIndexFile, "r") as f:
        lines = f.readlines()

    # read the css
    cssFilename = baseDir + '/epicyon-profile.css'
    if os.path.isfile(baseDir + '/epicyon.css'):
        cssFilename = baseDir + '/epicyon.css'

    # ensure that the page number is in bounds
    if not pageNumber:
        pageNumber = 1
    elif pageNumber < 1:
        pageNumber = 1

    # get the start end end within the index file
    startIndex = int((pageNumber - 1) * postsPerPage)
    endIndex = startIndex + postsPerPage
    noOfLines = len(lines)
    if endIndex >= noOfLines and noOfLines > 0:
        endIndex = noOfLines - 1

    # add the page title
    hashtagSearchForm = \
        htmlHeaderWithExternalStyle(cssFilename)
    if nickname:
        hashtagSearchForm += '<center>\n' + \
            '<h1><a href="/users/' + nickname + '/search">#' + \
            hashtag + '</a></h1>\n'
    else:
        hashtagSearchForm += '<center>\n' + \
            '<h1>#' + hashtag + '</h1>\n'

    # RSS link for hashtag feed
    hashtagSearchForm += '<a href="/tags/rss2/' + hashtag + '">'
    hashtagSearchForm += \
        '<img style="width:3%;min-width:50px" ' + \
        'loading="lazy" alt="RSS 2.0" title="RSS 2.0" src="/' + \
        'icons/logorss.png" /></a></center>\n'

    # edit the category for this hashtag
    if isEditor(baseDir, nickname):
        category = getHashtagCategory(baseDir, hashtag)
        hashtagSearchForm += '<div class="hashtagCategoryContainer">\n'
        hashtagSearchForm += '  <form enctype="multipart/form-data" ' + \
            'method="POST" accept-charset="UTF-8" action="' + \
            '/users/' + nickname + '/tags/' + hashtag + \
            '/sethashtagcategory">\n'
        hashtagSearchForm += '    <center>\n'
        hashtagSearchForm += translate['Category']
        hashtagSearchForm += \
            '      <input type="text" style="width: 20ch" ' + \
            'name="hashtagCategory" value="' + category + '">\n'
        hashtagSearchForm += \
            '      <button type="submit" class="button" name="submitYes">' + \
            translate['Submit'] + '</button>\n'
        hashtagSearchForm += '    </center>\n'
        hashtagSearchForm += '  </form>\n'
        hashtagSearchForm += '</div>\n'

    if startIndex > 0:
        # previous page link
        hashtagSearchForm += \
            '  <center>\n' + \
            '    <a href="/tags/' + hashtag + '?page=' + \
            str(pageNumber - 1) + \
            '"><img loading="lazy" class="pageicon" src="/' + \
            'icons/pageup.png" title="' + \
            translate['Page up'] + \
            '" alt="' + translate['Page up'] + \
            '"></a>\n  </center>\n'
    index = startIndex
    while index <= endIndex:
        postId = lines[index].strip('\n').strip('\r')
        if '  ' not in postId:
            nickname = getNicknameFromActor(postId)
            if not nickname:
                index += 1
                continue
        else:
            postFields = postId.split('  ')
            if len(postFields) != 3:
                index += 1
                continue
            nickname = postFields[1]
            postId = postFields[2]
        postFilename = locatePost(baseDir, nickname, domain, postId)
        if not postFilename:
            index += 1
            continue
        postJsonObject = loadJson(postFilename)
        if not postJsonObject:
            index += 1
            continue
        if not isPublicPost(postJsonObject):
            index += 1
            continue
        showIndividualPostIcons = False
        if nickname:
            showIndividualPostIcons = True
        allowDeletion = False
        showRepeats = showIndividualPostIcons
        showIcons = showIndividualPostIcons
        manuallyApprovesFollowers = False
        showPublicOnly = False
        storeToCache = False
        allowDownloads = True
        avatarUrl = None
        showAvatarOptions = True
        postStr = \
            individualPostAsHtml(allowDownloads, recentPostsCache,
                                 maxRecentPosts,
                                 translate, None,
                                 baseDir, session, wfRequest,
                                 personCache,
                                 nickname, domain, port,
                                 postJsonObject,
                                 avatarUrl, showAvatarOptions,
                                 allowDeletion,
                                 httpPrefix, projectVersion,
                                 'search',
                                 YTReplacementDomain,
                                 showPublishedDateOnly,
                                 showRepeats, showIcons,
                                 manuallyApprovesFollowers,
                                 showPublicOnly,
                                 storeToCache)
        if postStr:
            hashtagSearchForm += separatorStr + postStr
        index += 1

    if endIndex < noOfLines - 1:
        # next page link
        hashtagSearchForm += \
            '  <center>\n' + \
            '    <a href="/tags/' + hashtag + \
            '?page=' + str(pageNumber + 1) + \
            '"><img loading="lazy" class="pageicon" src="/icons' + \
            '/pagedown.png" title="' + translate['Page down'] + \
            '" alt="' + translate['Page down'] + '"></a>' + \
            '  </center>'
    hashtagSearchForm += htmlFooter()
    return hashtagSearchForm


def rssHashtagSearch(nickname: str, domain: str, port: int,
                     recentPostsCache: {}, maxRecentPosts: int,
                     translate: {},
                     baseDir: str, hashtag: str,
                     postsPerPage: int,
                     session, wfRequest: {}, personCache: {},
                     httpPrefix: str, projectVersion: str,
                     YTReplacementDomain: str) -> str:
    """Show an rss feed for a hashtag
    """
    if hashtag.startswith('#'):
        hashtag = hashtag[1:]
    hashtag = urllib.parse.unquote(hashtag)
    hashtagIndexFile = baseDir + '/tags/' + hashtag + '.txt'
    if not os.path.isfile(hashtagIndexFile):
        if hashtag != hashtag.lower():
            hashtag = hashtag.lower()
            hashtagIndexFile = baseDir + '/tags/' + hashtag + '.txt'
    if not os.path.isfile(hashtagIndexFile):
        print('WARN: hashtag file not found ' + hashtagIndexFile)
        return None

    # check that the directory for the nickname exists
    if nickname:
        if not os.path.isdir(baseDir + '/accounts/' +
                             nickname + '@' + domain):
            nickname = None

    # read the index
    lines = []
    with open(hashtagIndexFile, "r") as f:
        lines = f.readlines()
    if not lines:
        return None

    domainFull = domain
    if port:
        if port != 80 and port != 443:
            domainFull = domain + ':' + str(port)

    maxFeedLength = 10
    hashtagFeed = \
        rss2TagHeader(hashtag, httpPrefix, domainFull)
    for index in range(len(lines)):
        postId = lines[index].strip('\n').strip('\r')
        if '  ' not in postId:
            nickname = getNicknameFromActor(postId)
            if not nickname:
                index += 1
                if index >= maxFeedLength:
                    break
                continue
        else:
            postFields = postId.split('  ')
            if len(postFields) != 3:
                index += 1
                if index >= maxFeedLength:
                    break
                continue
            nickname = postFields[1]
            postId = postFields[2]
        postFilename = locatePost(baseDir, nickname, domain, postId)
        if not postFilename:
            index += 1
            if index >= maxFeedLength:
                break
            continue
        postJsonObject = loadJson(postFilename)
        if postJsonObject:
            if not isPublicPost(postJsonObject):
                index += 1
                if index >= maxFeedLength:
                    break
                continue
            # add to feed
            if postJsonObject['object'].get('content') and \
               postJsonObject['object'].get('attributedTo') and \
               postJsonObject['object'].get('published'):
                published = postJsonObject['object']['published']
                pubDate = datetime.strptime(published, "%Y-%m-%dT%H:%M:%SZ")
                rssDateStr = pubDate.strftime("%a, %d %b %Y %H:%M:%S UT")
                hashtagFeed += '     <item>'
                hashtagFeed += \
                    '         <author>' + \
                    postJsonObject['object']['attributedTo'] + \
                    '</author>'
                if postJsonObject['object'].get('summary'):
                    hashtagFeed += \
                        '         <title>' + \
                        postJsonObject['object']['summary'] + \
                        '</title>'
                description = postJsonObject['object']['content']
                description = firstParagraphFromString(description)
                hashtagFeed += \
                    '         <description>' + description + '</description>'
                hashtagFeed += \
                    '         <pubDate>' + rssDateStr + '</pubDate>'
                if postJsonObject['object'].get('attachment'):
                    for attach in postJsonObject['object']['attachment']:
                        if not attach.get('url'):
                            continue
                        hashtagFeed += \
                            '         <link>' + attach['url'] + '</link>'
                hashtagFeed += '     </item>'
        index += 1
        if index >= maxFeedLength:
            break

    return hashtagFeed + rss2TagFooter()