Module:Wikidata

local i18n = {
    ["errors"] = {
        ["property-param-not-provided"] = "Property parameter not provided.",
        ["entity-not-found"] = "Entity not found.",
        ["unknown-claim-type"] = "Unknown claim type.",
        ["unknown-snak-type"] = "Unknown snak type.",
        ["unknown-datavalue-type"] = "Unknown datavalue type.",
        ["unknown-entity-type"] = "Unknown entity type.",
        ["unknown-value-module"] = "You must set both value-module and value-function parameters.",
        ["value-module-not-found"] = "The module pointed by value-module not found.",
        ["value-function-not-found"] = "The function pointed by value-function not found."
    },
    ["somevalue"] = "''unknown value''",
    ["novalue"] = "''no value''"
}

function getEntityFromId( id )
    return mw.wikibase.getEntity() --TODO support for getting other entities
end

function getEntityIdFromValue( value )
    if value['entity-type'] == 'item' then
        return 'q' .. value['numeric-id']
    elseif value['entity-type'] == 'property' then
        return 'p' .. value['numeric-id']
    else
        return formatError( 'unknown-entity-type' )
    end
end

function getSitelink( options)
	entity = getEntityFromId( )
	lang = options.lang
	if options.item then 
		item = options.item
	else 
		item = entity.id
	end
	if entity.sitelinks and entity.sitelinks[lang .. 'wiki'] then
		return entity.sitelinks[lang .. 'wiki']['title']
	else 
		return nil
	end
end
function formatError( key )
    return '<span class="error">' .. i18n.errors[key] .. '</span>'
end


function formatStatements( options )
    if not options.property then
        return formatError( 'property-param-not-provided' )
    end

    --Get entity
    local entity = nil
    if options.entity and type( options.entity ) == "table" then
        entity = options.entity
    else
        entity = getEntityFromId( options.entityId )
    end

    if not entity then
        return '' --TODO error?
    end

    if not entity.claims or not entity.claims[string.lower(options.property)] then
        return '' --TODO error?
    end

    --Format statement and concat them cleanly
    local formattedStatements = {}
    for i, statement in pairs( entity.claims[options.property:lower()] ) do
        if options.rank == 'one' then
            return formatStatement( statement, options ) --Output only one value
        else
            table.insert( formattedStatements, formatStatement( statement, options ) )
        end
    end
    return mw.text.listToText( formattedStatements, options.separator, options.conjunction )
end

function formatStatement( statement, options )
    if not statement.type or statement.type ~= 'statement' then
        return formatError( 'unknown-claim-type' )
    end

    return formatSnak( statement.mainsnak, options )
    --TODO reference and qualifiers
end

function formatSnak( snak, options )
    if snak.snaktype == 'somevalue' then
        return i18n['somevalue']
    elseif snak.snaktype == 'novalue' then
        return i18n['novalue']
    elseif snak.snaktype == 'value' then
        return formatDatavalue( snak.datavalue, options )
    else
        return formatError( 'unknown-snak-type' )
    end
end

function formatDatavalue( datavalue, options )
    --Use the customize handler if provided
    if options['value-module'] or options['value-function'] then
        if not options['value-module'] or not options['value-function'] then
            return formatError( 'unknown-value-module' )
        end
        local formatter = require ('Module:' .. options['value-module'])
        if not formatter then
            return formatError( 'value-module-not-found' )
        end
        local fun = formatter[options['value-function']]
        if not fun then
            return formatError( 'value-function-not-found' )
        end
        return fun( datavalue.value, options )
    end

    --Default formatters
    if datavalue.type == 'wikibase-entityid' then
        return formatEntityId( getEntityIdFromValue( datavalue.value ), options )
    elseif datavalue.type == 'string' then
        if options.pattern and options.pattern ~= '' then
            return formatFromPattern( datavalue.value, options )
        else
            return datavalue.value
        end
    else
        return formatError( 'unknown-datavalue-type' )
    end
end

function formatEntityId( entityId, options )
    local label = mw.wikibase.label( entityId )
    local link = mw.wikibase.sitelink( entityId )
    if link then
        if label then
            return '[[' .. link .. '|' .. label .. ']]'
        else
            return '[[' .. link .. ']]'
        end
    else
        return label --TODO what if no links and label + fallback language?
    end
end

function formatFromPattern( str, options )
    return mw.ustring.gsub( options.pattern, '$1', str ) .. '' --Hack to get only the first result of the function
end

local p = {}

function p.formatStatements( frame )
    local args = frame.args

    --If a value if already set, use it
    if args.value and args.value ~= '' then
        return args.value
    end
    return formatStatements( frame.args )
end

function p.translationTable(frame) -- translation tables that are so common on Commons
	entity = getEntityFromId( )
    if not entity then
        return '' --TODO error?
    end
    id = entity.id
	if not entity.labels then 
		return ''
	end
	labeltable = {}
	for lang, content in pairs(entity.labels) do
		link= ''
		label = content.value
		if entity.sitelinks then
			if entity.sitelinks[lang .. 'wiki'] then
				link = lang .. ':' .. entity.sitelinks[lang .. 'wiki'].title
			end
		end
		if link == '' then 
			link = "wikidata:" .. entity.id 
		end
		link = '[[:' .. link .. '|' .. label .. ']]'
		table.insert(labeltable, {lang= lang, link = link})
	end
	text = ''
	for i, j in pairs(labeltable) do
		langname = j['lang'] --  frame:callParserFunction{name = 'language', args= {j['lang']}}
		text = text .. langname .. ': ' .. j['link'] .. ' '
	end 
	return text
end

function p.formatStatementsFromLua( options )
    --If a value if already set, use it
    if options.value and options.value ~= '' then
        return options.value
    end
    return formatStatements( options )
end

function p.getSitelink(frame)
	return getSitelink(frame.args)
end

return p