local p = {}

-- ============================
-- SITELEN KALAMA INVENTORY
-- ============================
local sitelen_kalama = {
    ka=true, kan=true, ke=true, ken=true, ki=true, kin=true,
    ko=true, kon=true, ku=true, kun=true,
    la=true, lan=true, le=true, len=true, li=true, lin=true,
    lo=true, lon=true, lu=true, lun=true,
    ma=true, man=true, me=true, men=true, mi=true, min=true,
    mo=true, mon=true, mu=true, mun=true,
    na=true, nan=true, ne=true, nen=true, ni=true, nin=true,
    no=true, non=true, nu=true, nun=true,
    pa=true, pan=true, pe=true, pen=true, pi=true, pin=true,
    po=true, pon=true, pu=true, pun=true,
    sa=true, san=true, se=true, sen=true, si=true, sin=true,
    so=true, son=true, su=true, sun=true,
    ta=true, tan=true, te=true, ten=true, ti=true, tin=true,
    to=true, ton=true, tu=true, tun=true,
    wa=true, wan=true, we=true, wen=true, wi=true, win=true,
    wo=true, won=true, wu=true, wun=true,
    xa=true, xan=true, xe=true, xen=true, xi=true, xin=true,
    xo=true, xon=true, xu=true, xun=true,
    ya=true, yan=true, ye=true, yen=true, yi=true, yin=true,
    yo=true, yon=true, yu=true, yun=true,
}

-- ============================
-- BOOLEAN HELPERS
-- ============================
local function isFalse(v)
    if not v then return false end
    v = mw.ustring.lower(v)
    return (v == "false" or v == "0" or v == "no" or v == "off")
end

local function isTrue(v)
    if not v then return false end
    v = mw.ustring.lower(v)
    return (v == "true" or v == "1" or v == "yes" or v == "on")
end

-- ============================
-- KALAMA NORMALIZER
-- ============================
-- x- prefix indicates no onset consonant (A → xa, AN → xan, etc)
local function kalama_key_for(lower)
    if sitelen_kalama[lower] then
        return lower
    end

    if lower:match("^[aeiou]") then
        local with_x = "x" .. lower
        if sitelen_kalama[with_x] then
            return with_x
        end
    end

    return nil
end

-- ============================
-- FILENAME SELECTOR
-- ============================
local function filename_for(word, usePona)
    -- ALL CAPS = sitelen pona sound symbol
    if word:match("^%u+$") then
        local lower = mw.ustring.lower(word)
        local key = kalama_key_for(lower) or lower
        return "File:Sitelen kalama pona - " .. key .. ".svg"
    end

    local lower = mw.ustring.lower(word)

    -- Sitelen sitelen word symbols
    if not usePona then
        local cap = lower:sub(1,1):upper() .. lower:sub(2)
        return "File:" .. cap .. " - sitelen sitelen word symbol.svg"
    end

    -- Sitelen pona (seli-kiwen set)
    return "File:Sitelen-seli-kiwen-" .. lower .. ".svg"
end

-- ============================
-- MAIN
-- ============================
function p.main(frame)
    local invokeArgs = frame.args
    local parent = frame:getParent()
    local tplArgs = parent and parent.args or {}

    local ponaParam   = invokeArgs.pona   or tplArgs.pona
    local inlineParam = invokeArgs.inline or tplArgs.inline

    local usePona = not isFalse(ponaParam)
    local inline  = isTrue(inlineParam)

    -- gather positional args
    local words = {}
    local i = 1
    while invokeArgs[i] ~= nil do
        local v = invokeArgs[i]
        if v ~= nil and v ~= "" then
            table.insert(words, v)
        end
        i = i + 1
    end

    local files = {}
    for _, w in ipairs(words) do
        table.insert(files, filename_for(w, usePona))
    end

    -- INLINE MODE
    if inline then
        local out = {}
        for _, fn in ipairs(files) do
            table.insert(out,
                string.format('[[%s|25x25px|class=skin-invert-image]]', fn)
            )
        end
        return table.concat(out, " ")
    end

    -- GALLERY MODE
    local gallery = {}
    for _, fn in ipairs(files) do
        table.insert(gallery, fn .. '|class=skin-invert-image')
    end

    return '<gallery widths="30" heights="30">\n'
        .. table.concat(gallery, "\n")
        .. '\n</gallery>'
end

return p