local FVector = import "Vector"
local FVector2D = import "Vector2D"
local Reactive = require "Core.Reactive"
local BusyActorManagerSubSystem = import("BusyActorManagerSubSystem")


local Movement = {
    proxy = {},
}

function Movement:ReceiveComponentBeginPlay()
    self.proxy = Reactive.ReactiveProperty({
        isIdle = true,
        direction = {X = 0, Y = 0},
        destination = {X = 0, Y = 0}
    })
end

function Movement:ReceiveComponentTick(delta_time)
    local proxy = self.proxy
    if proxy.isIdle then return end
    local new_pos = FVector()
    local owner = self:GetOwner()
    local curr_pos = owner:K2_GetActorLocation()
    new_pos.Z = curr_pos.Z

    local move_distance = delta_time * owner:GetSpeed()
    local distance_x = proxy.destination.X - curr_pos.X
    local distance_y = proxy.destination.Y - curr_pos.Y

    if move_distance^2 >= distance_x^2 + distance_y^2 then
        proxy.isIdle = true
        new_pos.X = proxy.destination.X
        new_pos.Y = proxy.destination.Y
        proxy.direction = FVector2D()
    else
        new_pos.X = curr_pos.X + proxy.direction.X * move_distance
        new_pos.Y = curr_pos.Y + proxy.direction.Y * move_distance
    end
    owner:K2_SetActorLocation(new_pos, true, nil, false)
end



function Movement:SetDestination(x, y)
    local direction = FVector2D()
    local destination = FVector2D()

    local owner = self:GetOwner()
    local curr_pos = owner:K2_GetActorLocation()
    local delta_x = x - curr_pos.X
    local delta_y = y - curr_pos.Y
    -- 计算方向向量
    local length = math.sqrt(delta_x ^ 2 + delta_y ^ 2)
    if length > 0 then
        direction.X, direction.Y = delta_x / length, delta_y / length
    else
        direction.X, direction.Y = 0, 0
    end
    destination.X , destination.Y = x, y

    self.proxy.isIdle = false
    self.proxy.direction = direction
    self.proxy.destination = destination
end

function Movement:Stop()
    self.proxy.isIdle = true
end

function Movement:BackBonfire()
    local sub_system = BusyActorManagerSubSystem.Get(self)
    local bonfire = sub_system:GetNearestBonfire()
    local position = bonfire:K2_GetActorLocation()
    self:SetDestination(position.X, position.Y)
end

return Class(nil, nil, Movement)