class TINV_GuiSlotGrid {

    var SubInventory;
    var Slots = { }; // Gui slots
    var Items = { }; // Gui items

    /*
        Init
    */
    function Init() {
        self:__new();

        this:SetSize(64, 64);
    }

    /*
        Setup
    */
    function Setup(subInventory) {
        this.SubInventory = subInventory;

        if(!this.SubInventory)
            error("TINV Error: Gui slot not initialized properly! SubInventory is null.");

        // Create slots
        for(var x = 1; x <= this.SubInventory.Width; x++) {
            this.Slots[x] = { };
            for(var y = 1; y <= this.SubInventory.Height; y++) {
                this.Slots[x][y] = this:Add("TINVGuiSlot");
                this.Slots[x][y]:Setup(this.SubInventory, x, y);
                this.Slots[x][y].DrawnLast = x == this.SubInventory.Width || y == this.SubInventory.Height;
            }
        }

        this:Populate();
        this:PerformLayout();
    }

    /*
        Paint
    */
    function PaintOver(w, h) {
        if(IsValid(TINV.HoverItem)) {
            var screenX, screenY = this:LocalToScreen(0, 0);
            var hoverX, hoverY = TINV.HoverItem:GetPos();
            var startPosX = math.floor((hoverX - screenX) / this.Slots[1][1]:GetWide() + 0.5);
            var startPosY = math.floor((hoverY - screenY) / this.Slots[1][1]:GetTall() + 0.5);

            draw.RoundedBox(0, startPosX * this.Slots[1][1]:GetWide(), startPosY * this.Slots[1][1]:GetTall(),
                this.Slots[1][1]:GetWide() * TINV.HoverItem.Item.Width, this.Slots[1][1]:GetTall()  * TINV.HoverItem.Item.Height, Color(200, 255, 255, 10));
        }
    }

    function Paint() { }

    /*
        Slot clicking
    */
    function SlotClick(slot, x, y) {
        LocalPlayer():ChatPrint("Slot clicked! " .. x .. " " .. y);

        var item = Enumerable(this.Items):First(i => (x >= i.Item.SlotX) && (y >= i.Item.SlotY) && (x <= i.Item.SlotX + i.Item.Width - 1) && (y <= i.Item.SlotY + i.Item.Height - 1));

        // Handle hovering item place or change
        if(IsValid(TINV.HoverItem)) {
            if(item) {
                LocalPlayer():ChatPrint("You're trying to swap items " .. item.Item.Model);
            }
            else {
                /*if(this.SubInventory:HasPlaceOn(x, y, TINV.HoverItem.Item.Width,  TINV.HoverItem.Item.Height)) {
                    LocalPlayer():ChatPrint("Place free");
                }
                else
                    LocalPlayer():ChatPrint("No place for item");*/


                // Real size and position calculation

                var screenX, screenY = this:LocalToScreen(0, 0);
                var hoverX, hoverY = TINV.HoverItem:GetPos();
                var startPosX = math.floor((hoverX - screenX) / this.Slots[1][1]:GetWide() + 0.5) + 1;
                var startPosY = math.floor((hoverY - screenY) / this.Slots[1][1]:GetTall() + 0.5) + 1;

                LocalPlayer():ChatPrint("" .. startPosX .. " " .. startPosY);

                // Higlights the occupied area
                //for(var slotX = startPosX; slotX <= (startPosX + TINV.HoverItem.Item.Width - 1) && (slotX > 0) && (slotX <= this.SubInventory.Width); slotX++)
                //  for(var slotY = startPosY; slotY <= (startPosY + TINV.HoverItem.Item.Height - 1) && (slotY > 0) && (slotY <= this.SubInventory.Height); slotY++)
                //      if(this.Slots[slotX][slotY])
                //          this.Slots[slotX][slotY]:HighlightRed(2);

                if(this.SubInventory:HasPlaceOn(startPosX, startPosY, TINV.HoverItem.Item.Width, TINV.HoverItem.Item.Height)) {
                    LocalPlayer():ChatPrint("There's place");
                    TINV.HoverItem.Item.SlotX, TINV.HoverItem.Item.SlotY = startPosX, startPosY;
                    this.SubInventory.Items[#this.SubInventory.Items + 1] = TINV.HoverItem.Item;
                    this.SubInventory:UpdateSlots();
                    TINV.HoverItem:SetParent(this);
                    this.Items[#this.Items + 1] = TINV.HoverItem;
                    if(TINV.MaterialSounds[TINV.HoverItem.Item.MaterialType]) // Material sound playing
                        surface.PlaySound(table.Random(TINV.MaterialSounds[TINV.HoverItem.Item.MaterialType]));
                    TINV.HoverItem:SetHover(false);
                    TINV.Place(this.SubInventory, startPosX, startPosY);
                }
                else {
                    LocalPlayer():ChatPrint("There's no place :(");
                }
            }

            return;
        }

        // Item grabbing
        if(item) {
            LocalPlayer():ChatPrint("You clicked on item: " .. item.Item.Model);
            table.RemoveByValue(this.SubInventory.Items, item.Item);
            this.SubInventory:UpdateSlots();
            table.RemoveByValue(this.Items, item);
            item:SetHover(true);
            TINV.Grab(this.SubInventory, x, y);
            if(TINV.MaterialSounds[TINV.HoverItem.Item.MaterialType]) // Material sound playing
                surface.PlaySound(table.Random(TINV.MaterialSounds[TINV.HoverItem.Item.MaterialType]));
        }
    }

    /*
        Populate - creates gui items
    */
    function Populate() {
        foreach(var k, v in this.Items) {
            v:Remove();
            this.Items[k] = null;
        }

        foreach(var item in this.SubInventory.Items) {
            var i = this:Add("TINVGuiItem");
            i:Setup(item);
            this.Items[#this.Items+1] = i;
        }
    }

    /*
        Layout
    */
    function PerformLayout() {
        // Calculate size for single slot
        var sizeX, sizeY = this:GetWide() / this.SubInventory.Width, this:GetTall() / this.SubInventory.Height;

        // Size a position each slot
        for(var x = 0; x < this.SubInventory.Width; x++)
            for(var y = 0; y < this.SubInventory.Height; y++) {
                this.Slots[x+1][y+1]:SetSize(math.floor(sizeX), math.floor(sizeY));
                this.Slots[x+1][y+1]:SetPos(math.floor(x*sizeX), math.floor(y*sizeY));
            }

        // Gui items
        foreach(var item in this.Items) {
            item:SetPos(sizeX * (item.Item.SlotX-1), sizeY * (item.Item.SlotY-1));
            item:SetSize(sizeX * item.Item.Width, sizeY * item.Item.Height);
        }
    }
}

CTINV_GuiSlotGrid.__index = null; // This is required for derma inheritance ;(
derma.DefineControl("TINVGuiSlotGrid", "Tetris Inventory Slot Grid", CTINV_GuiSlotGrid, "DPanel");

if(TINV.Test)
    TINV.Test();