local modname = minetest.get_current_modname()
local ci = {}
ci.blocks = {all = {}, nodes = {}, tools = {}, items = {}}
ci.pages = {}
ci.searches = {}

-- Layout-Einstellungen
local columns = 15
local rows = 10 
local nodes_per_page = columns * rows

minetest.register_privilege("ci", {
    description = "Allows the player to use the ci command",
    give_to_singleplayer = false
})

local function has_permission(player_name)
    return minetest.check_player_privs(player_name, {ci=true})
end

-- Deep Scan mit Kategorisierung
minetest.register_on_mods_loaded(function()
    minetest.after(1, function()
        ci.blocks = {all = {}, nodes = {}, tools = {}, items = {}}
        local added = {}

        local function add_to_list(name, def)
            if not name or name == "" or added[name] or not def then return end
            
            local d = name
            if def.description and def.description ~= "" then
                d = def.description:split("\n")[1]
            end
            
            local entry = {name = name, desc = d}
            
            if def.type == "node" then
                table.insert(ci.blocks.nodes, entry)
            elseif def.type == "tool" then
                table.insert(ci.blocks.tools, entry)
            else
                table.insert(ci.blocks.items, entry)
            end
            table.insert(ci.blocks.all, entry)
            added[name] = true
        end

        for name, def in pairs(minetest.registered_items) do
            add_to_list(name, def)
        end
        for name, target in pairs(minetest.registered_aliases) do
            local def = minetest.registered_items[target]
            if def then add_to_list(name, def) end
        end

        local function sort_func(a, b) 
            local val_a = a.desc or a.name or ""
            local val_b = b.desc or b.name or ""
            return val_a:lower() < val_b:lower() 
        end

        table.sort(ci.blocks.all, sort_func)
        table.sort(ci.blocks.nodes, sort_func)
        table.sort(ci.blocks.tools, sort_func)
        table.sort(ci.blocks.items, sort_func)
        
        print("[ci] Scan fertig. " .. #ci.blocks.all .. " Items bereit.")
    end)
end)

function ci.get_filtered_list(player_name)
    local state = ci.pages[player_name]
    local category = state.tab or "all"
    local raw_list = ci.blocks[category] or ci.blocks.all
    local search_term = ci.searches[player_name]
    
    if not search_term or search_term == "" then return raw_list end

    local filtered = {}
    local term = search_term:lower()
    for i=1, #raw_list do
        local entry = raw_list[i]
        if entry.name:lower():find(term, 1, true) or entry.desc:lower():find(term, 1, true) then
            table.insert(filtered, entry)
        end
    end
    return filtered
end

function ci.get_formspec(player)
    local player_name = player:get_player_name()
    if not ci.pages[player_name] then
        ci.pages[player_name] = {page = 1, quantity = 1, tab = "all"}
    end
    
    local state = ci.pages[player_name]
    local filtered = ci.get_filtered_list(player_name)
    local total_pages = math.max(1, math.ceil(#filtered / nodes_per_page))
    
    if state.page > total_pages then state.page = total_pages end

    local tabs = {"all", "nodes", "tools", "items"}
    local tab_labels = {"Alle", "Blöcke", "Werkzeuge", "Gegenstände"}
    local current_tab_idx = 1
    for i, t in ipairs(tabs) do if t == state.tab then current_tab_idx = i end end

    local formspec = "size[17.5,14.2]" ..
        "background[0,0;17.5,14.2;gui_formbg.png;true]" ..
        "tabheader[0,0;tab;" .. table.concat(tab_labels, ",") .. ";" .. current_tab_idx .. ";true;false]"

    -- 1. Controls oben
    local search = ci.searches[player_name] or ""
    formspec = formspec ..
        "field[0.75,0.8;5.5,1;search;Suche im Tab:;" .. minetest.formspec_escape(search) .. "]" ..
        "button[6.1,0.45;1.5,1;do_search;Suchen]" ..
        "button[7.6,0.45;0.8,1;reset_search;X]" ..
        "field[13.0,0.8;4,1;quantity;Anzahl:;" .. state.quantity .. "]"

    -- 2. Item-Grid
    local start_idx = (state.page - 1) * nodes_per_page + 1
    local end_idx = math.min(state.page * nodes_per_page, #filtered)

    for i = start_idx, end_idx do
        local entry = filtered[i]
        local rel = i - start_idx
        local x = 0.5 + (rel % columns) * 1.1
        local y = 1.8 + math.floor(rel / columns) * 1.1

        local name_esc = minetest.formspec_escape(entry.name)
        local desc_esc = minetest.formspec_escape(entry.desc or entry.name)

        formspec = formspec .. "box[" .. x .. "," .. y .. ";1,1;#33333355]" ..
            "item_image_button[" .. x .. "," .. y .. ";1,1;" .. name_esc .. ";add_" .. name_esc .. ";]" ..
            "tooltip[add_" .. name_esc .. ";" .. desc_esc .. "\n" .. name_esc .. " ]"
    end

    -- 3. Navigation
    local footer_y = 13.5
    
    -- Label ÜBER den Buttons
    formspec = formspec ..
        "label[7.5," .. (footer_y - 0.75) .. ";Seite " .. state.page .. " von " .. total_pages .. " (" .. #filtered .. " Items)]"

    if state.page > 1 then 
        formspec = formspec .. "button[6.0," .. (footer_y - 0.2) .. ";1.2,0.8;prev;<<]" 
    end
    if state.page < total_pages then 
        formspec = formspec .. "button[10.3," .. (footer_y - 0.2) .. ";1.2,0.8;next;>>]" 
    end

    formspec = formspec .. "button_exit[15.0," .. (footer_y - 0.2) .. ";2,0.8;exit;Schließen]"

    return formspec
end

minetest.register_chatcommand("ci", {
    description = "Kreativ-Inventar öffnen",
    privs = {ci=true},
    func = function(name)
        local player = minetest.get_player_by_name(name)
        if player then 
            if not ci.pages[name] then ci.pages[name] = {page = 1, quantity = 1, tab = "all"} end
            minetest.show_formspec(name, modname .. ":form", ci.get_formspec(player)) 
        end
        return true
    end,
})

minetest.register_on_player_receive_fields(function(player, formname, fields)
    if formname ~= modname .. ":form" then return end
    local name = player:get_player_name()
    local state = ci.pages[name]
    if not state then return end

    if fields.tab then
        local tabs = {"all", "nodes", "tools", "items"}
        state.tab = tabs[tonumber(fields.tab)] or "all"
        state.page = 1
        minetest.show_formspec(name, modname .. ":form", ci.get_formspec(player))
        return
    end

    if fields.quantity then state.quantity = tonumber(fields.quantity) or 1 end

    if fields.do_search or (fields.key_enter_field == "search") then
        ci.searches[name] = fields.search
        state.page = 1
        minetest.show_formspec(name, modname .. ":form", ci.get_formspec(player))
        return
    elseif fields.reset_search then
        ci.searches[name] = nil
        state.page = 1
        minetest.show_formspec(name, modname .. ":form", ci.get_formspec(player))
        return
    end

    if fields.next then
        state.page = state.page + 1
        minetest.show_formspec(name, modname .. ":form", ci.get_formspec(player))
    elseif fields.prev then
        state.page = math.max(1, state.page - 1)
        minetest.show_formspec(name, modname .. ":form", ci.get_formspec(player))
    end

    for field, _ in pairs(fields) do
        if field:sub(1, 4) == "add_" then
            local item = field:sub(5)
            local inv = player:get_inventory()
            inv:add_item("main", item .. " " .. state.quantity)
            local def = minetest.registered_items[item]
            local desc = (def and def.description and def.description ~= "") and def.description:split("\n")[1] or item
            minetest.chat_send_player(name, "Hinzugefügt: " .. state.quantity .. "x " .. desc .. " [" .. item .. "]")
            minetest.show_formspec(name, modname .. ":form", ci.get_formspec(player))
            return
        end
    end
end)

minetest.after(0, function()
  if minetest.global_exists("i3_extrabuttons") then
    i3_extrabuttons.new_tab("cinventory", {
      description = "Kreativ-Inventar",
      priv = "ci",
      formspec = function(player, data, fs) end,
      fields = function(player, data, fields)
        i3.set_tab(player, "inventory")
        minetest.show_formspec(player:get_player_name(), modname .. ":form", ci.get_formspec(player))
      end,
    })
  end
end)