local Textbox = require("textbox")

local HUD = {}
HUD.__index = HUD

HUD.slots = {
    { enabled = false, object = "key", name = "Key" },
    { enabled = false, object = "dbljump", name = "Double Jump" },
    { enabled = false },
    { enabled = false },
}

local SLOT_SIZE = 16
local SLOT_SPACING = 8

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
    self.player = nil

    for _, slot in ipairs(HUD.slots) do
        if slot.object == "key" then
            slot.image = love.graphics.newImage("assets/misc/key.png")
            slot.image:setFilter("nearest", "nearest")
        elseif slot.object == "dbljump" then
            slot.image = love.graphics.newImage("assets/misc/dbljump.png")
            slot.image:setFilter("nearest", "nearest")
        end
    end

    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, player)
    self.screenW = screenW
    self.screenH = screenH
    self.drawScale = drawScale
    self.player = player
    self.slotRects = self:computeSlotRects(screenW, screenH, drawScale)

    if player and player.pickups then
        for _, slot in ipairs(HUD.slots) do
            if slot.object then
                slot.enabled = (player.pickups[slot.object] or 0) > 0
            end
        end
    end

    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 slot = HUD.slots[self.hoveredSlot]
        local text = "Planned feature that didn't make it into the game ;("
        if slot.name then
            local count = 0
            if player and player.pickups and slot.object then
                count = player.pickups[slot.object] or 0
            end
            text = slot.name .. " x" .. count
        end
        local rect = self.slotRects[self.hoveredSlot]
        local centerX = screenW / 2
        local topY = rect.y + rect.h + 8 * drawScale
        self.textbox:show(text, { 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
        local slot = HUD.slots[i]
        local img = slot.image or self.missingTexture

        if slot.enabled then
            love.graphics.setColor(1, 1, 1, 1)
        else
            love.graphics.setColor(1, 1, 1, 0.25)
        end
        love.graphics.draw(img, rect.x, rect.y, 0, drawScale, drawScale)

        if slot.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