local easing = require "lib.utils.easing"
--- @class ShadowcasterBehavior : Behavior
local behavior = {}
behavior.id = "shadowcaster"
behavior.__index = behavior

function behavior.new() return setmetatable({}, behavior) end

function behavior:draw()
    local sprite = self.owner:has(Tree.behaviors.sprite)
    local positioned = self.owner:has(Tree.behaviors.positioned)
    if not positioned then return end

    local ppm = Tree.level.camera.pixelsPerMeter
    local position = positioned.position + Vec3 { 0.5, 0.5 }

    local lightIds = Tree.level.lightGrid:query(position, 5)
    --- @type Character[]
    local lights = {}
    for _, id in ipairs(lightIds) do
        table.insert(lights, Tree.level.characters[id])
    end

    Tree.level.camera:attach()
    love.graphics.setCanvas(Tree.level.render.textures.shadowLayer)
    love.graphics.push()
    love.graphics.setColor(0, 0, 0, 1)
    love.graphics.translate(position.x, position.y)
    love.graphics.ellipse("fill", 0, 0, 0.2, 0.2 * math.cos(math.pi / 4))
    love.graphics.pop()

    if not sprite then
        love.graphics.setCanvas()
        return
    end

    love.graphics.setCanvas(Tree.level.render.textures.spriteLightLayer)
    love.graphics.setBlendMode("add")
    for _, light in ipairs(lights) do
        local lightPos = light:has(Tree.behaviors.positioned).position
        local lightVec = lightPos - position

        local lightColor = light:has(Tree.behaviors.light).color
        if lightPos.y > position.y then
            love.graphics.setColor(lightColor.x, lightColor.y, lightColor.z,
                1 - 0.3 * lightVec:length())
        elseif position.y - lightPos.y < 3 then
            love.graphics.setColor(lightColor.x, lightColor.y, lightColor.z,
                (1 - easing.easeInSine((position.y - lightPos.y))) - 0.3 * lightVec:length())
        end

        sprite.animationTable[sprite.state]:draw(Tree.assets.files.sprites.character[sprite.state],
            position.x,
            position.y, nil, 1 / ppm * sprite.side, 1 / ppm, 38, 47)
    end
    love.graphics.setBlendMode("alpha")

    Tree.level.camera:detach()
    love.graphics.setColor(1, 1, 1)
    love.graphics.setCanvas()
end

return behavior