--[[
This module provides the core functionality to a set of templates used to
display a list of taxon name/authority pairs, with the taxon names optionally
italicized, wikilinked and/or emboldened. Such lists are usually part of
taxoboxes.
]]

-- use a function from Module:TaxonItalics to italicize a taxon name
local TaxonItalics = require("Module:TaxonItalics")
local IfPreview = require([[Module:If preview]])

local p = {}

--[[=========================================================================
Utility function to strip off any initial † present to mark the taxon as
extinct. The † must not be italicized, emboldened, or included in the
wikilinked text, so needs to be added back afterwards.
† is assumed to be present as one of:
* the unicode character †
* the HTML entity †
* the output of {{extinct}} – this will have been expanded before reaching this
  module and is assumed to have the form '<span ... </span>'
The function returns two values: the taxon name with any † before it removed
and either '†' if it was present or the empty string if not.
=============================================================================]]
function p.stripDagger(taxonName)
	local dagger = ''
	if mw.ustring.sub(taxonName,1,1) == '†' then
		taxonName = mw.ustring.sub(taxonName,2,#taxonName)
		dagger = '†'
	else 
		if string.sub(taxonName,1,8) == '&dagger;' then
			taxonName = string.sub(taxonName,9,#taxonName)
			dagger = '†'
		else
			-- did the taxon name originally have {{extinct}} before it?
			if (string.sub(taxonName,1,5) == '<abbr') and mw.ustring.find(taxonName, '†') then
				taxonName = string.gsub(taxonName, '^.*</abbr>', '', 1)
				dagger = '†'
			end
		end
	end
	return taxonName, dagger
end

--[[=========================================================================
Utility function to do the following:

1. Strip off any initial † present to mark the taxon as extinct. We outsource
to p.stripDagger() for this.

2. Strip off any double quotation marks present to mark the taxon as invalid.
The double-quotation marks, too, should not be formatted.

3. Strip off any Candidatus or Ca. to mark the taxon as Candidatus.

The function returns four values:
* the taxon name with all of the three modifiers removed
* either '†' if it was present or the empty string if not
* either a single dquote if it was present in a pair or the empty string if not
* either italicized "Candidatus " or "Ca. " if it was present or the empty string if not

The function can error in case of an unpaired quotation mark. In that case, a
IfPreview._warning() is mixed into the first return.
=============================================================================]]
function p.parseName(taxonName)
	local name, dagger = p.stripDagger(taxonName)
	local dquote = ''
	if string.sub(name,1,1) == '"' then
		name = string.sub(name,2)
		dquote = '"'
		if string.sub(name,#name) == '"' then
			name = string.sub(name,1,#name-1)
		else
			name = '|' .. IfPreview._warning({'"' .. name .. ' has an unpaired double quote.'})
		end
	end

	local candidatus = ''
	if string.sub(name,1,11) == 'Candidatus ' then
		name = string.sub(name,12)
		candidatus = "''Candidatus'' "
	elseif string.sub(name,1,4) == 'Ca. ' then
		name = string.sub(name,5)
		candidatus = "''Ca.'' "
	end

	return name, dagger, dquote, candidatus
end

--[[=========================================================================
The function returns a list of taxon names and authorities, appropriately
formatted.
Usage:
{{#invoke:TaxonList|main
|italic = yes - to italicize the taxon name
|linked = yes - to wikilink the taxon name
|bold = yes - to emboldent the taxon name
|incomplete = yes - to output "(incomplete)" at the end of the list
}}
The template that transcludes the invoking template must supply an indefinite
even number of arguments in the format
|Name1|Author1 |Name2|Author2| ... |NameN|AuthorN
=============================================================================]]
function p.main(frame)
	local italic = frame.args['italic'] == 'yes'
	local bold = frame.args['bold'] == 'yes'
	local linked = frame.args['linked'] == 'yes'
	if bold then linked = false end -- must not have bold and wikilinked
	local abbreviated = frame.args['abbreviated'] == 'yes'
	local incomplete = frame.args['incomplete'] == 'yes'
	local taxonArgs = frame:getParent().args
	local result = ''
	-- iterate over unnamed variables
	local taxonName
	local dagger
	local dquote
	local candidatus
	local first = true -- is this the first of a taxon name/author pair?
	for param, value in pairs(taxonArgs) do
		if tonumber(param) then
			if first then
				taxonName = mw.text.trim(value)
				-- if necessary separate any initial modifier
				taxonName, dagger, dquote, candidatus = p.parseName(taxonName)
				if linked and not (italic and candidatus == '') then
					taxonName = '[[' .. taxonName .. ']]'
				end
				if italic and candidatus == '' then
					taxonName = TaxonItalics.italicizeTaxonName(taxonName, linked, abbreviated)
				end
				taxonName = candidatus .. taxonName
				if bold then
					taxonName = '<b>' .. taxonName .. '</b>'
				end
				result = result .. '<li>' .. dagger .. dquote .. taxonName .. dquote
			else
				result = result .. ' <small>' .. value .. '</small></li>'
			end
			first = not first
		end
	end
	if incomplete then
		result = result .. '<small>(incomplete list)</small>'
	end
	return '<ul class="taxonlist">' .. result .. '</ul>'
end

return p