Module:Conversion

local math_mod = require "Module:Math"
local params = mw.loadData("Module:Conversion/Données")
local linguistic = require "Module:Linguistique"

local p = {}

local i18n = {
 invalidunitcat = 'Page avec une unité de mesure non prise en charge',
 invalidsourceunit = '$1 (unité non prise en charge)',
 invalidtargetunit = 'unité cible non prise en charge $1',
 typemismatch = 'impossible de convertir $1 en $2'
}

local function convert(value, sourceunitdata, targetunitdata) -- convertir une valeur numérique en son équivalent dans une autre unité de mesure
 if not value then
  return nil
 end
 if type(value) ~= 'number' then
  return error("bad datatype: " .. type(value))
 end
 if (not sourceunitdata) or (not targetunitdata) then
  return value
 end
 return value * sourceunitdata[2] / targetunitdata[2]
end

function p.displayvalue(val, sourceunit, displayformat, complement) -- affiche une valeur formatée)
 
 -- préparation des paramètres
 local numval = tonumber(val)
 if not numval then -- si les données sont inhabituelles, on laisse la fonction appelante se débrouiller
  return val
 end
 
 if not displayformat or type(displayformat) ~= 'table' then
  displayformat = {}
 end
 local showunit, showlink, targetunit = displayformat.showunit, displayformat.showlink, displayformat.targetunit
 if showlink == 'true' then
  showlink = true
 end
 local rounding = displayformat.rounding or 2
 -- récupération des donnnées concernant les unités
 if sourceunit and not targetunit then
  targetunit = sourceunit
 end
 local sourceunitdata, targetunitdata = sourceunit, targetunit
 if type(sourceunitdata) ~= 'table' then
  sourceunitdata = params.units[sourceunit] or params.units[params.redirects[sourceunit]]
 end
 if type(targetunitdata) ~= 'table' then 
  targetunitdata = params.units[targetunit] or params.units[params.redirects[targetunit]]
 end
 local suffix = {'', '', ''}

 local maintenancestr = ""

 
 -- conversion

 local function invalidsourcefallback(val, sourceunit) -- text to be shown when source unit is not supported
  local str = tostring(val)
  if sourceunit:match('Q%d+') or sourceunit:match('q%d+') then -- wikidata item
   sourceunit = mw.wikibase.label(sourceunit)
  end
  return val .. ' ' .. i18n['invalidsourceunit']:gsub('$1', sourceunit) .. '[[Category:' .. i18n.invalidunitcat .. '|' .. sourceunit .. ']]'
 end


 -- escape if source unit is invalid
 if (sourceunit and targetunit) and (targetunit~= sourceunit) and (not sourceunitdata or not sourceunitdata[1]) then
  return invalidsourcefallback(val, sourceunit)
 end

 if sourceunit and (not sourceunitdata) then 
  local label = sourceunit
  local item = sourceunit:match('q%d+') or sourceunit:match('Q%d+')
  local link
  local symbol
  if item then
   label = mw.wikibase.label(item)
   link = mw.wikibase.sitelink(item)
   if showunit and (showunit ~= 'long') then -- symbole retrieved only if needed (somewhat expensive)
    for _,statement in pairs(mw.wikibase.getBestStatements(item, 'P5061')) do
     if statement['mainsnak']['snaktype'] == 'value' and (statement['mainsnak']['datavalue']['value']['language'] == 'fr' or statement['mainsnak']['datavalue']['value']['language'] == 'mul') then
      symbol = statement['mainsnak']['datavalue']['value']['text']
     end
    end
   end
  end
  sourceunitdata = {nil, 1, symbol or label, item, link, label, label}
  targetunit, targetunitdata  = sourceunit, sourceunitdata 
 end
 
 -- warn if targetunit is unknown
 if targetunit and (not targetunitdata) then
  targetunit, targetunitdata = sourceunit, sourceunitdata
  maintenancestr = maintenancestr .. " "  .. i18n['invalidtargetunit']:gsub('$1', targetunit) .. '[[Category:' .. i18n.invalidunitcat .. '|' .. targetunit .. ']]'
 end

 -- check for type mismatch
 if (sourceunitdata and targetunitdata) and (targetunitdata[1] ~= sourceunitdata[1]) then
  local errmsg = i18n.typemismatch
  errmsg = errmsg:gsub('$1', sourceunit)
  errmsg = errmsg:gsub('$2', targetunit)
  maintenancestr = maintenancestr .. '(' .. errmsg .. ')'
  targetunit, targetunitdata = sourceunit, sourceunitdata
 end

 -- convert if needed
 if (sourceunit and targetunit) and (sourceunit ~= targetunit) then
  numval = convert(numval, sourceunitdata, targetunitdata)
 end
 
 if rounding then
  numval = math_mod._round( numval, rounding )
 end
 
 if displayformat.raw == true then -- nombre non formaté chaîne convertible en nombre sauf si catégorie de maintenance
  return (tostring(numval) or "") .. maintenancestr
 end
 
 if not displayformat.rounding then
  if (math.abs(numval) > 1E9) then
   numval = math_mod._round( numval / 1E9, 1 )
   suffix = {"milliard ", "milliards ", "<abbr title=\"milliard\">G</abbr> "}
  elseif (math.abs(numval) > 1E6) then
   numval = math_mod._round( numval / 1E6, 1 )
   suffix = {"million ", "millions ", "<abbr title=\"million\">M</abbr> "}
  end
 end
 
 local numstr = mw.getContentLanguage():formatNum(numval)

 -- showlink
 if not targetunitdata then -- pour éviter les bugs
  targetunitdata = {}
 end
 local link
 if showlink == '-' then
  link = nil
 elseif type(showlink) == 'string' then
  link = showlink
 elseif showlink then
  link = targetunitdata[5]
 end
 
 -- affichage de l'unité
 local unitstr, suffixstr
 if showunit == 'long' then -- format long = montrer l'unité en entier
  if math.abs(numval or 0) >= 2 then
   unitstr = targetunitdata[7]
  else
   unitstr = targetunitdata[6]
  end
  if ((unitstr ~= '') and link) then
   unitstr = '[[' .. link .. '|' .. unitstr .. ']]'
  end
  if (unitstr ~= '') and ((suffix[1] ~= '') or (((numval or 0) > 999999) and ( (numval or 0)% 1000000 == 0))) then
   unitstr = linguistic.of(unitstr) -- 10 000 000 "de" tonnes
  end
  if math.abs(numval or 0) >= 2 then
   suffixstr = suffix[2]
  else
   suffixstr = suffix[1]
  end
   
 elseif showunit and (showunit ~= '-') then
  unitstr = targetunitdata[3]
  if string.find(unitstr, "^%a") then -- 8 G$ mais 8 G CHF
   suffixstr = suffix[3]
  else
   suffixstr = mw.text.trim(suffix[3])
  end
  if ((unitstr ~= '') and link) then
   unitstr = '[[' .. link .. '|' .. unitstr .. ']]'
  end
 else
  suffixstr = suffix[3]
 end
 
 local str = numstr .. ' ' .. (suffixstr or '') .. (unitstr or '')
 str = mw.text.trim(str) .. maintenancestr
 if complement then
  if sourceunit then
   str = str .. " " .. linguistic.of(complement) -- "10 kg de bambous"
  else
   str = str .. " " .. complement -- "3000 véhicules"
  end
 end
 return str

end

function p.display(frame)
 local args = frame.args
 local value, origunit, targetunit = args[1], args[2], args[3]
 local rounding = args.rounding
 local showlink, showunit =  args.showlink, args.showunit
 displayformat = {showunit = showunit, showlink = showlink, rounding = rounding, targetunit = targetunit}
 return p.displayvalue(value, origunit, displayformat)
end
return p