local S = minetest.get_translator(minetest.get_current_modname())

local extrabuttons = {}
i3_extrabuttons = {}

-- API-kompatibel: optionale priv/privs
function i3_extrabuttons.new_tab(name, def)
    extrabuttons[#extrabuttons+1] = {
        name = name,
        def = def,
    }
end

local function has_required_priv(player, def)
    -- Einzelnes Privileg
    if def.priv then
        return minetest.check_player_privs(player, { [def.priv] = true })
    end
    -- Liste von Privs (alle müssen erfüllt sein)
    if def.privs then
        for _, priv in ipairs(def.privs) do
            if not minetest.check_player_privs(player, { [priv] = true }) then
                return false
            end
        end
        return true
    end
    -- Kein Priv, immer anzeigen
    return true
end

local function extras_formspec(player, data, fs)
    -- Alphabetisch sortiert nach sichtbarer Beschriftung ("description" oder "name")
    table.sort(extrabuttons, function(a, b)
        local ad = a.def.description or a.name
        local bd = b.def.description or b.name
        return ad:lower() < bd:lower()
    end)

    local max_per_col = 10
    local btn_width = 4
    local btn_height = 0.8
    local col_space = 7
    local x_left = 1
    local x_right = x_left + col_space

    local btn_idx = 0
    for _, tab in ipairs(extrabuttons) do
        -- PRÜFUNG auf Rechte für diese Button-Definition:
        if has_required_priv(player, tab.def) then
            btn_idx = btn_idx + 1
            local desc = tab.def.description or tab.name
            local col = math.floor((btn_idx-1) / max_per_col)
            local row = (btn_idx-1) % max_per_col
            local x = (col == 0) and x_left or x_right
            local y = 1 + row * (btn_height + 0.3)
            fs(string.format(
                'image_button[%.1f,%.1f;%.1f,%.1f;i3_extrabuttons_blank.png;extrabtn_%s;%s;;i3_extrabuttons_button_hover.png]',
                x, y, btn_width, btn_height,
                tab.name, minetest.formspec_escape(desc)
            ))
        end
    end
end

local function extras_fields(player, data, fields)
    for _, tab in ipairs(extrabuttons) do
        if fields["extrabtn_"..tab.name] and tab.def.fields then
            return tab.def.fields(player, data, fields)
        elseif fields["extrabtn_"..tab.name] and tab.def.formspec then
            i3.set_tab(player, "inventory")
            tab.def.formspec(player, data, function(...) end)
            return
        end
    end
end

-- Tabs registrieren (wie gehabt)
if i3 then
    i3.new_tab("i3_extrabuttons", {
        description = S("Extras"),
        formspec = extras_formspec,
        fields = extras_fields,
    })
end

_G.i3_extrabuttons = i3_extrabuttons