local world = require("world")
local gfx = love.graphics

---@generic T
---@param shape T | fun()
---@param process fun(entity: T, dt: number, system: System) | nil
---@return System | { entities: T[] }
local function drawSystem(name, shape, process)
    local system = world:filteredSystem(name, shape, process, function(_, a, b)
        if a.z ~= nil and b.z ~= nil then
            return a.z < b.z
        end
        if a.z ~= nil then
            return true
        end
        return false
    end)
    system.isDrawSystem = true
    return system
end

local spriteDrawSystem = drawSystem(
    "drawSprites",
    { position = T.XyPair, drawAsSprite = T.Drawable, rotation = Maybe(T.number) },
    function(e)
        if not e.drawAsSprite then
            return
        end
        gfx.draw(e.drawAsSprite, e.position.x, e.position.y)
    end
)

function spriteDrawSystem:preProcess()
    gfx.setColor(1, 1, 1)
end

local margin = 8

drawSystem(
    "drawText",
    { position = T.XyPair, drawAsText = { text = T.str, style = Maybe(T.str), font = Maybe(T.FontData) } },
    function(e)
        local font
        if e.drawAsText.font ~= nil then
            font = e.drawAsText.font
            gfx.setFont(font)
        else
            font = gfx.getFont()
        end
        local textHeight = font:getHeight()
        local textWidth = font:getWidth(e.drawAsText.text)

        local bgLeftEdge = e.position.x - margin -- - (textWidth / 2)
        local bgTopEdge = e.position.y - 2
        local bgWidth, bgHeight = textWidth + (margin * 2), textHeight + 2

        if e.drawAsText.style == TextStyle.Inverted then
            gfx.setColor(1, 1, 1)
            gfx.rectangle("fill", bgLeftEdge, bgTopEdge, textWidth + margin, textHeight + 2)
            gfx.setColor(0, 0, 0)
        elseif e.drawAsText.style == TextStyle.Bordered then
            gfx.setColor(0, 0, 0)
            gfx.rectangle("fill", bgLeftEdge, bgTopEdge, bgWidth, bgHeight)

            gfx.setColor(1, 1, 1)
            gfx.rectangle("line", bgLeftEdge, bgTopEdge, bgWidth, bgHeight)
        end

        gfx.print(e.drawAsText.text, bgLeftEdge + margin, bgTopEdge + margin)
    end
)

drawSystem("drawRectangles", { position = T.XyPair, drawAsRectangle = { size = T.XyPair } }, function(e, _, _)
    gfx.setColor(1, 1, 1, 0.5)
    local mode = e.drawAsRectangle.mode or "line" -- (e.highlighted and "fill" or "line")
    gfx.rectangle(mode, e.position.x, e.position.y, e.drawAsRectangle.size.x, e.drawAsRectangle.size.y)
end)