-- Module:ChartFieldTitles (name it whatever fits your conventions)
local TabUtils = require('Module:TabUtils')

-- Field-name → extra title translations. Only fills in languages
-- that aren't already set on the .tab file, so nothing gets overwritten.
local fieldTitles = {
    populatie = {
        eu = 'Biztanleria',
        es = 'Población',
        fr = 'Population',
        en = 'Population',
        it = 'Popolazione',
        de = 'Bevölkerung',
        pt = 'População',
        ca = 'Població',
        gl = 'Poboación',
        nl = 'Bevolking',
        pl = 'Ludność',
        cs = 'Obyvatelstvo',
        sv = 'Befolkning',
        da = 'Befolkning',
        nb = 'Befolkning',
        fi = 'Väestö',
        hu = 'Népesség',
        el = 'Πληθυσμός',
        ru = 'Население',
        ja = '人口',
        zh = '人口',
        ro = 'Populație',  -- native language of this dataset, kept as a fallback
    },
    an = {
        eu = 'Urtea',
        es = 'Año',
        fr = 'Année',
        en = 'Year',
        it = 'Anno',
        de = 'Jahr',
        pt = 'Ano',
        ca = 'Any',
        gl = 'Ano',
        nl = 'Jaar',
        pl = 'Rok',
        cs = 'Rok',
        sv = 'År',
        da = 'År',
        nb = 'År',
        fi = 'Vuosi',
        hu = 'Év',
        el = 'Έτος',
        ru = 'Год',
        ja = '年',
        zh = '年',
        ro = 'An',
    },
}

local p = {}

function p.select(tab, args)
    tab = TabUtils.select(tab, args)
    for _, field in ipairs(tab.schema.fields) do
        local extra = fieldTitles[field.name]
        if extra then
            field.title = field.title or {}
            for lang, label in pairs(extra) do
                if not field.title[lang] then
                    field.title[lang] = label
                end
            end
        end
    end
    return tab
end

return p