rgt_inv = {}
local ns = rgt_inv

Inventory = setmetatable({
    new = function(p)
        local e = setmetatable({
            player = p,
            state = {
                proximate_machines = {}
            }
        }, {
            __index = Inventory,
            -- Setting a value on the Inventory instance directly will
            -- automatically update the player's inventory formspec.
            -- `inv.state` should be used in cases where this is not desirable.
            __newindex = function(e, k, v)
                e.state[k] = v
                e:rebuild()
            end
        })
        e:rebuild()
        return e
    end,
    rebuild = function(e)
        local fs = {"\
            formspec_version[10]\
            size[12,10]\
            style_type[button,image_button;border=false]\
        "}
        for x = 0, 7 do
            for y = 0, 3 do
                fs[#fs +1] = "\
                image["..(x *1.25 +1.125 -0.0625)..","..(y *1.25 +4.5 -0.0625)..";1.14,1.14;rgt_other_button_bg.png;8,8]\
                "
            end
        end
        fs[#fs +1] = "\
        style_type[image_button;noclip=true;bgimg=rgt_button_bg.png;bgimg_middle=8,8]\
        "
        local i = 0
        for _, x in ipairs(e.state.proximate_machines) do
            local y = i > 11 and 10.5 or -1
            fs[#fs +1] = "image_button["..(i %11 +0.125)..","..y..";0.75,0.75;rgt_stone.png;blah;]"
            i = i +1
        end
        fs[#fs +1] = "\
            list[current_player;main;1.125,4.5;8,4;]\
            list[current_player;craft;3,0.5;3,3;]\
            listring[]\
            list[current_player;craftpreview;7,1;1,1;]\
        "
        e.player:set_inventory_formspec(table.concat(fs))
    end,
    on_action = function(e, data)
        
    end
}, {
    __call = function(_, ...)
        return Inventory.new(...)
    end
})

local last_time = 0
minetest.register_globalstep(function()
    local time = minetest.get_us_time()
    -- Scan for machines every second.
    if time -last_time > 1000000 then
        for name, m in pairs(rgt.players) do
            local pm = {}
            local machines = minetest.find_nodes_in_area(m.pos:offset(-7, -7, -7), m.pos:offset(7, 7, 7), "group:rgt_machine", true)
            for type, positions in pairs(machines) do
                pm[#pm +1] = {
                    type = type,
                    pos = positions[math.random(1, #positions)]
                }
            end
            if not (#pm <= 0 and #m.inv.state.proximate_machines <= 0) then
                -- Give the machines list a predictable order by sorting it alphabetically prior to submission.
                table.sort(pm, function(a, b) return a.type < b.type end)
                m.inv.proximate_machines = pm
            end
        end
        last_time = time
    end
end)


minetest.register_chatcommand("/lua", {
    privs = {server = true},
    func = function(name, args)
        xpcall(function()
            loadstring(args)()
        end, say)
    end
})