local Textbox = require("textbox")

local HUD = {}
HUD.__index = HUD

HUD.slots = {
    { enabled = false },
    { enabled = false },
    { enabled = false },
    { enabled = false },
}

local SLOT_SIZE = 16
local SLOT_SPACING = 8
local LOREM = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua."

local function createMissingTexture()
    local size = SLOT_SIZE
    local half = size / 2
    local imgData = love.image.newImageData(size, size)
    for y = 0, size - 1 do
        for x = 0, size - 1 do
            local inBlack = (x < half and y < half) or (x >= half and y >= half)
            if inBlack then
                imgData:setPixel(x, y, 0, 0, 0, 1)
            else
                imgData:setPixel(x, y, 1, 0, 1, 1)
            end
        end
    end
    local img = love.graphics.newImage(imgData)
    img:setFilter("nearest", "nearest")
    return img
end

function HUD:new()
    local self = setmetatable({}, HUD)
    self.missingTexture = createMissingTexture()
    self.textbox = Textbox:new()
    self.hoveredSlot = nil
    self.slotRects = {}
    self.screenW = 0
    self.screenH = 0
    self.drawScale = 1
    return self
end

function HUD:computeSlotRects(screenW, screenH, drawScale)
    local slotW = SLOT_SIZE * drawScale
    local slotH = SLOT_SIZE * drawScale
    local spacing = SLOT_SPACING * drawScale
    local totalW = 4 * slotW + 3 * spacing
    local startX = math.floor((screenW - totalW) / 2)
    local startY = math.floor(screenH / 2 - slotH / 2)
    local rects = {}
    for i = 1, 4 do
        rects[i] = {
            x = startX + (i - 1) * (slotW + spacing),
            y = startY,
            w = slotW,
            h = slotH,
        }
    end
    return rects
end

function HUD:update(dt, screenW, screenH, drawScale)
    self.screenW = screenW
    self.screenH = screenH
    self.drawScale = drawScale
    self.slotRects = self:computeSlotRects(screenW, screenH, drawScale)

    local mx, my = love.mouse.getPosition()
    local prevHovered = self.hoveredSlot
    self.hoveredSlot = nil
    for i, rect in ipairs(self.slotRects) do
        if mx >= rect.x and mx < rect.x + rect.w
           and my >= rect.y and my < rect.y + rect.h then
            self.hoveredSlot = i
            break
        end
    end

    if self.hoveredSlot and self.hoveredSlot ~= prevHovered then
        local rect = self.slotRects[self.hoveredSlot]
        local centerX = screenW / 2
        local topY = rect.y + rect.h + 8 * drawScale
        self.textbox:show(LOREM, { centerX, topY, "center" }, "show", {
            fontSize = 16,
            centeredText = true,
            wrapToFit = true,
            maxChars = 40,
        })
        self.textbox.y = topY + self.textbox.height / 2
    elseif not self.hoveredSlot and prevHovered then
        self.textbox:hide()
    end

    self.textbox:update(dt)
end

function HUD:mousepressed(mx, my, button)
    if button ~= 1 then return end
    for i, rect in ipairs(self.slotRects) do
        if mx >= rect.x and mx < rect.x + rect.w
           and my >= rect.y and my < rect.y + rect.h then
            HUD.slots[i].enabled = not HUD.slots[i].enabled
            break
        end
    end
end

function HUD:draw()
    local screenW = self.screenW
    local screenH = self.screenH
    local drawScale = self.drawScale

    love.graphics.setColor(0, 0, 0, 0.4)
    love.graphics.rectangle("fill", 0, 0, screenW, screenH)

    for i, rect in ipairs(self.slotRects) do
        love.graphics.setColor(1, 1, 1, 1)
        love.graphics.draw(self.missingTexture, rect.x, rect.y, 0, drawScale, drawScale)

        if HUD.slots[i].enabled then
            love.graphics.setColor(0, 1, 0, 0.3)
            love.graphics.rectangle("fill", rect.x, rect.y, rect.w, rect.h)
        end

        if self.hoveredSlot == i then
            love.graphics.setColor(1, 1, 0, 1)
            love.graphics.setLineWidth(2)
        else
            love.graphics.setColor(1, 1, 1, 0.5)
            love.graphics.setLineWidth(1)
        end
        love.graphics.rectangle("line", rect.x, rect.y, rect.w, rect.h)
    end

    love.graphics.setLineWidth(1)
    love.graphics.setColor(1, 1, 1, 1)

    self.textbox:draw()
end

return HUD