--[[=========================================================================
Italicize a taxon name appropriately by invoking italicizeTaxonName.
The algorithm used is:
* If the name has italic markup at the start or the end, do nothing.
* Else
  * Remove (internal) italic markup.
  * If the name is made up of four words and the third word is a
    botanical connecting term, de-italicize the connecting term and add italic
    markup to the outside of the name.
  * Else if the name is made up of three words and the second word is a
    botanical connecting term or a variant of "cf.", de-italicize the
    connecting term and add italic markup to the outside of the name.
  * Else just add italic markup to the outside of the name.
=============================================================================]]

local p = {}

local cTerms3 = {
    subspecies = "subsp.",
    ["subsp."] = "subsp.",
    subsp = "subsp.",
    ["ssp."] = "subsp.",
    ssp = "subsp.",
    varietas = "var.",
    ["var."] = "var.",
    var = "var.",
    subvarietas = "subvar.",
    ["subvar."] = "subvar.",
    subvar = "subvar.",
    forma = "f.",
    ["f."] = "f.",
    f = "f.",
    subforma = "subf.",
    ["subf."] = "subf.",
    subf = "subf."
    }
local cTerms2 = {
    subgenus = "subg.",
    ["subg."] = "subg.",
    subg = "subg.",
    section = "sect.",
    ["sect."] = "sect.",
    subsection = "subsect.",
    subsect = "subsect.",
    ["subsect."] = "subsect.",
    series = "ser.",
    ser = "ser.",
    ["ser."] = "ser.",
    subseries = "subser.",
    subser = "subser.",
    ["subser."] = "subser.",
    ["cf."] = "cf.",
    cf = "cf.",
    ["c.f."] = "cf."
    }

--[[=========================================================================
Italicize a taxon name appropriately.
=============================================================================]]
function p.main(frame)
    local name = frame.args[1] or ''
    local linked = frame.args['linked'] == 'yes'
    return p.italicizeTaxonName(name, linked)
end

function p.italicizeTaxonName(name, linked)
    local italMarker = "''"
    -- trim the name and replace any use of the HTML italic tags by Wikimedia markup
    name = string.gsub(mw.text.trim(name), "</?i>", italMarker)
    local result = name
    if name ~= '' then
        if string.sub(name, 1, 2) == "''" or string.sub(name, -2) == "''" then
            -- do nothing if the name already has italic markers at the start or end
        else
            name = string.gsub(name, "''", "") -- first remove internal italics
            local words = mw.text.split(name, " ", true)
            if #words == 4 then
                -- test for the third word of a four word name being a connecting term
                if cTerms3[words[3]] then
                    -- de-italicize the connecting term by adding internal italic markup
                    result = words[1] .. " " .. words[2] .. italMarker .. " " .. cTerms3[words[3]] .. " " .. italMarker .. words[4]
                end
            elseif #words == 3 then
                -- test for the second word of a three word name being a connecting term
                if cTerms2[words[2]] then
                    -- de-italicize the connecting term by adding internal italic markup
                    result = words[1] .. italMarker .. " " .. cTerms2[words[2]] .. " " .. italMarker .. words[3]
                end
            else
                -- do nothing
                result = name
            end
            -- deal with any hybrid symbol as it should not be italicized
            result = string.gsub(result, "×", '<span style="font-style:normal;">×</span>')
            result = string.gsub(result, "&times;", '<span style="font-style:normal;">×</span>')
            result = string.gsub(result, "&#215;", '<span style="font-style:normal;">×</span>')
            -- add outside markup
            if linked then
                if result ~= name then
                    result = "[[" .. name .. "|" .. italMarker .. result .. italMarker .. "]]"
                else
                    result = italMarker .. "[[" .. name .. "]]" .. italMarker
                end
            else
                result = italMarker .. result .. italMarker
            end
        end
    end
    return result
end

return p