--- @class Render
--- @field shadowLayer love.Canvas
--- @field spriteLayer love.Canvas
--- @field floorLayer love.Canvas
--- @field overlayLayer love.Canvas
local render = {}
render.__index = render

function render:clear()
    love.graphics.setCanvas(self.shadowLayer)
    love.graphics.clear()
    love.graphics.setCanvas(self.spriteLayer)
    love.graphics.clear()
    love.graphics.setCanvas(self.floorLayer)
    love.graphics.clear()
    love.graphics.setCanvas(self.overlayLayer)
    love.graphics.clear()
end

--- TODO: это используется для блюра, должно кэшироваться и поддерживать ресайз
local tmp1 = love.graphics.newCanvas(1280, 720)
local tmp2 = love.graphics.newCanvas(1280, 720)
local function applyBlur(input, radius)
    local blurShader = Tree.assets.files.shaders.blur

    -- Горизонтальный проход
    blurShader:send("direction", { 1.0, 0.0 })
    blurShader:send("radius", radius)

    tmp1:renderTo(function()
        love.graphics.clear()
        love.graphics.setShader(blurShader)
        love.graphics.draw(input)
        love.graphics.setShader()
    end)

    -- Вертикальный проход
    tmp2:renderTo(
        function()
            love.graphics.clear()
            love.graphics.setShader(blurShader)
            blurShader:send("direction", { 0.0, 1.0 })
            love.graphics.draw(tmp1)
            love.graphics.setShader()
        end
    )
    return tmp2
end

function render:draw()
    -- пол -> тени -> спрайты -> оверлей
    love.graphics.draw(self.floorLayer)
    love.graphics.push()

    local blurred = applyBlur(self.shadowLayer, 2)
    local wc, hc = love.graphics.getWidth() / 2, love.graphics.getHeight() / 2
    love.graphics.translate(wc, hc)

    love.graphics.scale(Tree.level.camera.scale, Tree.level.camera.scale)
    love.graphics.translate(-Tree.level.camera.position.x * Tree.level.camera.pixelsPerMeter,
        -Tree.level.camera.position.y * Tree.level.camera.pixelsPerMeter)
    love.graphics.draw(blurred)
    love.graphics.pop()
    love.graphics.draw(self.spriteLayer)

    love.graphics.draw(self.overlayLayer)
end

local function new()
    return setmetatable({
        shadowLayer = love.graphics.newCanvas(1280, 720),
        spriteLayer = love.graphics.newCanvas(1280, 720),
        floorLayer = love.graphics.newCanvas(1280, 720),
        overlayLayer = love.graphics.newCanvas(1280, 720),
    }, render)
end

return { new = new }