Module:Commons link

 require('strict')

 -- Module to find commons galleries and categories based on wikidata entries
 localgetArgs=require('Module:Arguments').getArgs
 localp={}

 -- Check if string is a valid QID
 -- Argument: QID to check
 -- Returns: valid (bool)
 localfunction_validQID(qid)
 returnqidandmw.ustring.find(qid,"^[Qq]%d+$")
 end

 -- Check if string is a valid wikidata property string
 -- Argument: property string to check
 -- Returns: valid (bool)
 localfunction_validProp(prop)
 returnpropandmw.ustring.find(prop,"^[Pp]%d+$")
 end

 localfunction_lcfirst(s)
 returnmw.ustring.lower(mw.ustring.sub(s,1,1))..mw.ustring.sub(s,2)
 end

 -- Format displayed linktext
 -- Arguments:
 -- s = string to display
 -- formatting = formatting table:
 -- formatting.linktext = if defined, override s
 -- formatting.lcfirst = lower case the first letter in display
 -- formatting.bold = whether to bold the display
 -- formatting.italic = whether to italicize the display
 -- formatting.nowrap = set nowrapping
 -- Returns:
 -- formatted string
 localfunction_formatResult(s,formatting)
 localresultVal=formatting.linktextors
 ifformatting.lcfirstthen
 resultVal=_lcfirst(resultVal)
 end
 localstyle=""
 ifformatting.italicthenstyle="font-style:italic; "end
 ifformatting.boldthenstyle=style.."font-weight:bold; "end
 ifformatting.nowrapthenstyle=style.."white-space:nowrap; "end
 ifstyle~=""then
 resultVal='<span style="'..mw.text.trim(style)..'">'..resultVal..'</span>'
 end
 returnresultVal
 end

 -- Get title, namespace, and QID for current page
 -- Arguments:
 -- qid = testing only: get title of alternative page with QID=qid
 -- nsQid = whether to return the ns of the qid page or current
 -- Returns:
 -- title, namespace (string), qid of current page (or test page)
 localfunction_getTitleQID(qid,nsQid)
 localtitleObject=mw.title.getCurrentTitle()
 -- look up qid for current page (if not testing)
 localnsText=string.gsub(titleObject.nsText,"_"," ")-- [[phab:T369784]]
 ifnot_validQID(qid)then
 qid=mw.wikibase.getEntityIdForCurrentPage()
 returntitleObject.text,nsText,qid
 end
 -- testing-only path: given a qid, determine title
 -- always use namespace from current page (to suppress tracking cat)
 qid=qid:upper()
 localtitle=mw.wikibase.getSitelink(qid)or""
 -- strip any namespace from sitelink
 localfirstColon=mw.ustring.find(title,':',1,true)
 localqidNsText=""
 iffirstColonthen
 qidNsText=mw.ustring.sub(title,1,firstColon-1)
 title=mw.ustring.sub(title,firstColon+1)
 end
 ifnsQidthen
 returntitle,qidNsText,qid
 end
 returntitle,nsText,qid
 end

 -- Lookup Commons gallery in Wikidata
 -- Arguments:
 -- qid = QID of current article
 -- fetch = whether to lookup Commons sitelink (bool)
 -- commonsSitelink = default value for Commons sitelink
 -- Returns:
 -- categoryLink = name of Commons category, nil if nothing is found
 -- consistent = multiple wikidata fields are examined: are they consistent?
 -- commonsSitelink = commons sitelink for current article
 localfunction_lookupGallery(qid,fetch,commonsSitelink)
 ifnot_validQID(qid)then
 returnnil,true,nil
 end
 qid=qid:upper()
 localgalleryLink=nil
 localconsistent=true
 -- look up commons sitelink for article, use if not category
 iffetchthen
 commonsSitelink=mw.wikibase.getSitelink(qid,"commonswiki")orcommonsSitelink
 end
 ifcommonsSitelinkandmw.ustring.sub(commonsSitelink,1,9)~="Category:"then
 galleryLink=commonsSitelink
 end
 -- P935 is the "commons gallery" property for this article
 localP935=mw.wikibase.getBestStatements(qid,"P935")[1]
 ifP935andP935.mainsnak.datavaluethen
 localgallery=P935.mainsnak.datavalue.value
 ifgalleryLinkandgalleryLink~=gallerythen
 consistent=false
 else
 galleryLink=gallery
 end
 end
 returngalleryLink,consistent,commonsSitelink
 end

 -- Find fallback category by looking up Commons sitelink of different page
 -- Arguments:
 -- qid = QID for current article
 -- property = property that refers to other article whose sitelink to return
 -- Returns: either category-stripped name of article, or nil
 localfunction_lookupFallback(qid,property)
 ifnot_validQID(qid)ornot_validProp(property)then
 returnnil
 end
 qid=qid:upper()
 property=property:upper()
 -- If property exists on current article, get value (other article qid)
 localvalue=mw.wikibase.getBestStatements(qid,property)[1]
 ifvalueandvalue.mainsnak.datavalueandvalue.mainsnak.datavalue.value.idthen
 -- Look up Commons sitelink of other article
 localsitelink=mw.wikibase.getSitelink(value.mainsnak.datavalue.value.id,"commonswiki")
 -- Check to see if it starts with "Category:". If so, strip it and return
 ifsitelinkandmw.ustring.sub(sitelink,1,9)=="Category:"then
 returnmw.ustring.sub(sitelink,10)
 end
 end
 returnnil
 end

 -- Find Commons category by looking in wikidata
 -- Arguments:
 -- qid = QID of current article
 -- fetch = whether to lookup Commons sitelink (bool)
 -- commonsSitelink = default value for Commons sitelink
 -- Returns:
 -- categoryLink = name of Commons category, nil if nothing is found
 -- consistent = multiple wikidata fields are examined: are they consistent?
 -- commonsSitelink = commons sitelink for current article
 localfunction_lookupCategory(qid,fetch,commonsSitelink)
 ifnot_validQID(qid)then
 returnnil,true,nil
 end
 qid=qid:upper()
 localcategoryLink=nil
 localconsistent=true
 -- look up commons sitelink for article, use if starts with "Category:"
 iffetchthen
 commonsSitelink=mw.wikibase.getSitelink(qid,"commonswiki")orcommonsSitelink
 end
 ifcommonsSitelinkandmw.ustring.sub(commonsSitelink,1,9)=="Category:"then
 categoryLink=mw.ustring.sub(commonsSitelink,10)
 end
 -- P910 is the "topic's main category". Look for commons sitelink there
 localfallback=_lookupFallback(qid,"P910")
 iffallbackthen
 ifcategoryLinkandcategoryLink~=fallbackthen
 consistent=false
 qid=nil
 else
 categoryLink=fallback
 end
 end
 -- P1754 is the "list's main category". Look for commons sitelink there
 fallback=_lookupFallback(qid,"P1754")
 iffallbackthen
 ifcategoryLinkandcategoryLink~=fallbackthen
 consistent=false
 qid=nil
 else
 categoryLink=fallback
 end
 end
 -- P373 is the "commons category" property for this article. This is
 -- a low-quality field, so should only be used as a last resort.
 ifcategoryLink==niland_validQID(qid)then
 localP373=mw.wikibase.getBestStatements(qid,"P373")[1]
 ifP373andP373.mainsnak.datavaluethen
 categoryLink=P373.mainsnak.datavalue.value
 consistent=true-- P373 is never used if anything else is available
 end
 end
 returncategoryLink,consistent,commonsSitelink
 end

 -- Does the article have a Commons gallery, and is it consistent?
 -- Arguments:
 -- qid = QID to lookup in wikidata (for testing only)
 -- Returns:
 -- filename at Commons, bool: is wikidata consistent for this article?
 functionp._hasGalleryConsistent(qid)
 localwp_title,wp_ns
 wp_title,wp_ns,qid=_getTitleQID(qid)
 return_lookupGallery(qid,true)
 end

 -- Does the article have a corresponding Commons gallery?
 -- Arguments:
 -- qid = QID to lookup in wikidata (for testing only)
 -- Returns:
 -- filename at Commons if so, false if not
 functionp._hasGallery(qid)
 localgalleryLink,consistent=p._hasGalleryConsistent(qid)
 returnconsistentandgalleryLink
 end

 -- Does the article have a Commons category? Is wikidata consistent for that?
 -- Arguments:
 -- qid = QID to lookup in wikidata (for testing only)
 -- prefix = whether to add "Category:" to return string (default true)
 -- Returns:
 -- filename at Commons, bool: consistent
 functionp._hasCategoryConsistent(qid,prefix)
 ifprefix==nilthen
 prefix=true
 end
 localwp_title,wp_ns
 wp_title,wp_ns,qid=_getTitleQID(qid)
 localcategoryLink,consistent=_lookupCategory(qid,true)
 ifcategoryLinkandprefixthen
 categoryLink="Category:"..categoryLink
 end
 returncategoryLink,consistent
 end

 -- Does the article have a corresponding Commons category?
 -- Arguments:
 -- qid = QID to lookup in wikidata (for testing only)
 -- prefix = whether to add "Category:" to return string (default true)
 -- Returns:
 -- filename at Commons if so, blank if not
 functionp._hasCategory(qid,prefix)
 localcategoryLink,consistent=p._hasCategoryConsistent(qid,prefix)
 returnconsistentandcategoryLink
 end

 -- Create Commons link corresponding to current article
 -- Arguments:
 -- namespace = namespace in Commons ("" for galleries)
 -- default = use as Commons link, don't access wikidata
 -- search = string to search for
 -- fallback = string to search for if wikidata fails
 -- formatting = formatting parameters
 -- qid = QID to lookup in wikidata (for testing only)
 -- Returns:
 -- formatted wikilink to Commons in specified namespace
 functionp._getCommons(namespace,default,search,fallback,formatting,qid)
 localnsColon
 ifnotnamespaceornamespace==""then
 nsColon=""
 else
 nsColon=namespace..":"
 end
 ifdefaultthen
 return"[[Commons:"..nsColon..default.."|".._formatResult(default,formatting).."]]"
 end
 ifsearchthen
 return"[[Commons:Special:Search/"..nsColon..search.."|".._formatResult(search,formatting).."]]"
 end
 localwp_title,wp_ns
 wp_title,wp_ns,qid=_getTitleQID(qid)
 localcommonsLink=nil
 localconsistent=true
 ifnsColon==""then
 commonsLink,consistent=_lookupGallery(qid,true)
 elseifnamespace:lower()=="category"then
 commonsLink,consistent=_lookupCategory(qid,true)
 end
 -- use wikidata if consistent
 ifcommonsLinkandconsistentthen
 return"[[Commons:"..nsColon..commonsLink.."|".._formatResult(commonsLink,formatting).."]]"
 end
 -- if not consistent, fall back to search and add to tracking cat
 -- construct default result (which searches for title)
 localsearchResult="[[Commons:Special:Search/"..nsColon..(fallbackorwp_title)
 .."|".._formatResult(fallbackorwp_title,formatting).."]]"
 ifnotconsistentandwp_ns==""then
 localfriendlyNS
 ifnsColon==""then
 friendlyNS="gallery"
 else
 friendlyNS=namespace:lower()
 end
 searchResult=searchResult.."[[Category:Inconsistent wikidata for Commons "..friendlyNS.."]]"
 end
 returnsearchResult
 end

 -- Returns "best" Commons link: first look for gallery, then try category
 -- Arguments:
 -- default = use as Commons link, don't access wikidata
 -- search = string to search for
 -- fallback = string to search for if wikidata lookup fails
 -- formatting = formatting parameters
 -- qid = QID to lookup in wikidata (for testing only)
 -- Returns:
 -- formatted wikilink to Commons "best" landing page
 functionp._getGalleryOrCategory(default,search,fallback,formatting,qid)
 ifdefaultthen
 return"[[Commons:"..default.."|".._formatResult(default,formatting).."]]"
 end
 ifsearchthen
 return"[[Commons:Special:Search/"..search.."|".._formatResult(search,formatting).."]]"
 end
 localwp_title,wp_ns
 wp_title,wp_ns,qid=_getTitleQID(qid)
 localtrackingCats=""
 localgalleryLink,consistent,commonsSitelink=_lookupGallery(qid,true)
 -- use wikidata if either sitelink or P935 exist, and they both agree
 ifgalleryLinkandconsistentthen
 return"[[Commons:"..galleryLink.."|".._formatResult(galleryLink,formatting).."]]"
 end
 ifnotconsistentandwp_ns==""then
 trackingCats="[[Category:Inconsistent wikidata for Commons gallery]]"
 end
 -- if gallery is not good, fall back looking for category
 localcategoryLink
 categoryLink,consistent=_lookupCategory(qid,false,commonsSitelink)
 ifcategoryLinkandconsistentthen
 return"[[Commons:Category:"..categoryLink.."|".._formatResult(categoryLink,formatting).."]]"..trackingCats
 end
 ifnotconsistentandwp_ns==""then
 trackingCats=trackingCats.."[[Category:Inconsistent wikidata for Commons category]]"
 end
 -- return search result looking for title as last attempt
 return"[[Commons:Special:Search/"..(fallbackorwp_title)..
 "|".._formatResult(fallbackorwp_title,formatting).."]]"..trackingCats
 end

 -- Return link(s) Commons gallery, or category, or both from wikidata
 -- Arguments:
 -- defaultGallery = default gallery link to use, instead of wikidata
 -- defaultCategory = default category link to use, instead of wikidata
 -- categoryText = if both gallery and category, text to use in category link ("category" by default)
 -- oneSearch = only emit one search result
 -- formatting = formatting parameters
 -- qid = qid of page to lookup in wikidata (testing only)
 functionp._getGalleryAndCategory(defaultGallery,defaultCategory,
 categoryText,oneSearch,formatting,qid
 )
 localwp_title,wp_ns
 wp_title,wp_ns,qid=_getTitleQID(qid)
 categoryText=categoryTextor"category"
 localtrackingCats=""
 localgalleryLink,galleryConsistent
 localcommonsSitelink=nil
 ifdefaultGallerythen
 galleryLink=defaultGallery
 galleryConsistent=true
 else
 galleryLink,galleryConsistent,commonsSitelink=_lookupGallery(qid,true)
 end
 localgalleryGood=galleryLinkandgalleryConsistent
 ifnotgalleryConsistentandwp_ns==""then
 trackingCats="[[Category:Inconsistent wikidata for Commons gallery]]"
 end
 localcategoryLink,categoryConsistent
 ifdefaultCategorythen
 categoryLink=defaultCategory
 categoryConsistent=true
 else
 categoryLink,categoryConsistent=_lookupCategory(qid,defaultGallery,commonsSitelink)
 end
 localcategoryGood=categoryLinkandcategoryConsistent
 ifnotcategoryConsistentandwp_ns==""then
 trackingCats=trackingCats.."[[Category:Inconsistent wikidata for Commons category]]"
 end
 localfirstLink
 -- construct default result (which searches for title)
 localsearchResult="[[Commons:Special:Search/"..wp_title.."|".._formatResult(wp_title,formatting).."]]"
 ifnotoneSearchthen
 searchResult=searchResult.." ([[Commons:Special:Search/Category:"..wp_title.."|"..categoryText.."]])"
 end
 locallinkText=nil
 ifgalleryGoodthen
 firstLink=galleryLink
 linkText=galleryLink
 elseifcategoryGoodthen
 firstLink="Category:"..categoryLink
 linkText=categoryLink
 else
 returnsearchResult..trackingCats
 end
 localresultVal="[[Commons:"..firstLink.."|".._formatResult(linkText,formatting).."]]"
 ifgalleryGoodandcategoryGoodthen
 resultVal=resultVal.." ([[Commons:Category:"..categoryLink.."|"..categoryText.."]])"
 end
 returnresultVal..trackingCats
 end

 -- Compare two titles with their namespaces stripped
 localfunctiontitleMatch(s1,s2)
 s1=s1or""
 s2=s2or""
 s1=mw.ustring.gsub(s1,"^[^:]+:","")
 s2=mw.ustring.gsub(s2,"^[^:]+:","")
 returns1==s2
 end

 localgalleryTrackingCats={
 commons_link_on_wikidata='[[Category:Commons link is on Wikidata]]',
 commons_link_defined_as_pagename='[[Category:Commons link is defined as the pagename]]',
 commons_link_locally_defined='[[Category:Commons link is locally defined]]',
 commons_link_from_wikidata='[[Category:Commons link from Wikidata]]',
 commons_link_is_pagename='[[Category:Commons link is the pagename]]',
 inconsistent='[[Category:Inconsistent wikidata for Commons gallery]]'
 }

 localcategoryTrackingCats={
 commons_link_on_wikidata='[[Category:Commons category link is on Wikidata]]',
 commons_link_defined_as_pagename='[[Category:Commons category link is defined as the pagename]]',
 commons_link_locally_defined='[[Category:Commons category link is locally defined]]',
 commons_link_from_wikidata='[[Category:Commons category link from Wikidata]]',
 commons_link_is_pagename='[[Category:Commons category link is the pagename]]',
 inconsistent='[[Category:Inconsistent wikidata for Commons category]]'
 }

 localfunctionselectTrackingCat(trackingCats,wikidata,consistent,default,title)
 ifnotconsistentthen
 returntrackingCats.inconsistent
 end
 ifdefaultthen
 -- construct warning message
 ifdefault==wikidatathen
 returntrackingCats.commons_link_on_wikidata
 end
 localwarning=""
 ifwikidatathen
 localgenerateWarning=require('Module:If preview')._warning
 warning=generateWarning({
 "Commons link does not match Wikidata – [[Template:Commons_category#Resolving_discrepancies|please check]]"
 })
 end
 iftitleMatch(default,title)then
 returntrackingCats.commons_link_defined_as_pagename..warning
 end
 returntrackingCats.commons_link_locally_defined..warning
 end
 ifwikidatathen
 returntrackingCats.commons_link_from_wikidata
 end
 returntrackingCats.commons_link_is_pagename
 end

 -- Figure out tracking categories and editor warnings
 -- Arguments:
 -- default = Commons link argument passed to template
 -- fetchGallery = whether to fetch a gallery from Wikidata
 -- fetchCategory = whether to fetch a category from Wikidata
 -- qid = force a qid for testing
 -- Returns:
 -- tracking category and possible user warning
 --
 -- Note: the logic for the tracking is quite different than the logic
 -- for generating Commons links (above). Thus, it is separated into another
 -- function for code clarity and maintainability. This should not seriously 
 -- affect performance: server time is dominated by fetching wikidata entities,
 -- and those entities should be cached and shared between the Commons generating
 -- code and this tracking code.
 functionp._tracking(default,fetchGallery,fetchCategory,qid)
 localtitle,wp_ns,wp_qid=_getTitleQID(qid,true)
 ifwp_ns~=""then
 title=wp_ns..":"..title
 end
 -- only track if test or namespace=article or namespace=category
 ifnot(qidorwp_ns==""orwp_ns=="Category")then
 return""
 end

 -- determine title and namespace of wikidata and wp article
 localwikidata=nil
 localconsistent=nil
 -- Tracking code works for all 4 cases of states of fetchGallery/Category
 -- fetchGallery takes precedence
 iffetchGallerythen
 wikidata,consistent=p._hasGalleryConsistent(qid)
 ifdefaultornotfetchCategoryor(consistentandwikidata)then
 returnselectTrackingCat(galleryTrackingCats,wikidata,consistent,
 default,title)
 end
 end
 iffetchCategorythen
 localcat_wikidata,cat_consistent=p._hasCategoryConsistent(qid,true)
 ifnotfetchGalleryor(cat_consistentandcat_wikidata)then
 returnselectTrackingCat(categoryTrackingCats,cat_wikidata,
 cat_consistent,default,title)
 end
 returnselectTrackingCat(galleryTrackingCats,wikidata,consistent,
 default,title)
 end
 return""-- nothing fetched, nothing tracked
 end

 localfunction_createFormatting(args)
 localformatting={}
 formatting.linktext=args.linktext
 localyesNo=require('Module:Yesno')
 formatting.lcfirst=yesNo(args.lcfirst)
 formatting.bold=yesNo(args.bold)
 formatting.italic=yesNo(args.italic)
 formatting.nowrap=yesNo(args.nowrap)
 returnformatting
 end

 -- Testing-only entry point for _getTitleQID
 functionp.getTitleQID(frame)
 localargs=getArgs(frame,{frameOnly=true,parentOnly=false,parentFirst=false})
 localtext,ns,qid=_getTitleQID(args[1],args[2])
 returntext..","..ns..","..(qidor"nil")
 end

 -- Testing-only entry point for _lookupFallback
 functionp.lookupFallback(frame)
 localargs=getArgs(frame,{frameOnly=true,parentOnly=false,parentFirst=false})
 localfallback=_lookupFallback(args[1],args[2])
 returnfallbackor"nil"
 end

 -- Find the Commons gallery page associated with article
 functionp.getGallery(frame)
 localargs=getArgs(frame,{frameOnly=true,parentOnly=false,parentFirst=false})
 returnp._getCommons("",args[1],args.search,args.fallback,_createFormatting(args),args.qid)
 end

 -- Find the Commons category page associated with article
 functionp.getCategory(frame)
 localargs=getArgs(frame,{frameOnly=true,parentOnly=false,parentFirst=false})
 localretval=p._getCommons("Category",args[1],
 args.search,args.fallback,_createFormatting(args),args.qid
 )
 ifargs.trackingthen
 localdefault=nil
 ifargs[1]then
 default="Category:"..args[1]
 end
 retval=retval..p._tracking(default,false,true,args.qid)
 end
 returnretval
 end

 functionp.getGalleryOrCategory(frame)
 localargs=getArgs(frame,{frameOnly=true,parentOnly=false,parentFirst=false})
 localretval=p._getGalleryOrCategory(
 args[1],args.search,args.fallback,_createFormatting(args),args.qid
 )
 ifargs.trackingthen
 retval=retval..p._tracking(args[1],true,true,args.qid)
 end
 returnretval
 end

 functionp.hasGallery(frame)
 localargs=getArgs(frame,{frameOnly=true,parentOnly=false,parentFirst=false})
 returnp._hasGallery(args.qid)or""
 end

 functionp.hasCategory(frame)
 localargs=getArgs(frame,{frameOnly=true,parentOnly=false,parentFirst=false})
 returnp._hasCategory(args.qid)or""
 end

 functionp.hasGalleryOrCategory(frame)
 localargs=getArgs(frame,{frameOnly=true,parentOnly=false,parentFirst=false})
 returnp._hasGallery(args.qid)orp._hasCategory(args.qid)or""
 end

 functionp.getGalleryAndCategory(frame)
 localargs=getArgs(frame,{frameOnly=true,parentOnly=false,parentFirst=false})
 returnp._getGalleryAndCategory(args[1],args[2],
 args.categoryText,args.oneSearch,_createFormatting(args),args.qid)
 end

 functionp.tracking(frame)
 localargs=getArgs(frame,{frameOnly=true,parentOnly=false,parentFirst=false})
 returnp._tracking(args[1],args.fetchGallery,args.fetchCategory,args.qid)
 end

 returnp