local Animation = {}
local ERoleState = import("EBusyRoleState")
local ERoleMoveDirection = import("ERoleMoveDirection")
local Reactive = require("Core.Reactive")


local direction_mapping = {
    [0] = ERoleMoveDirection.Move_Right,
    [1] = ERoleMoveDirection.Move_Left,
}


local function GetAnimationIndex(direction, N)
    -- 使用自定义 atan2 计算角度
    local angle = math.atan(direction.Y, direction.X)
    -- 转换为 [0, 2π) 范围
    if angle < 0 then angle = angle + 2 * math.pi end

    -- 调整角度：使 Y 轴负方向 (0,-1) 成为 0°（第一份的中心）
    local adjusted_angle = (angle  + math.pi / N) % (2 * math.pi)
    -- local adjusted_angle = (angle + math.pi / 2 + math.pi / N) % (2 * math.pi)

    -- 计算每份的角度大小
    local theta = 2 * math.pi / N
    -- -- 计算所属区间的索引（1-based）
    local index = math.floor(adjusted_angle / theta)
    -- 处理边界情况（adjusted_angle = 2π 时归到第 1 份）
    if index > N then index = 0 end
    return index
end

function Animation:ReceiveLuaBeginPlay()
    self.prev_direction = nil
    self.watcher = Reactive.Watcher(function() self:UpdateMoveAnimation() end)
end

function Animation:UpdateMoveAnimation()
    local owner = self:GetOwner()
    local movement_proxy = owner.Movement.proxy

    local index = 0

    if owner.proxy.state == ERoleState.Picking then
        return
    end

    if movement_proxy.isIdle then
        if self.prev_direction ~= nil then
            index = GetAnimationIndex(self.prev_direction, ERoleMoveDirection.Move_All_Cnt)
        end
        self:SetIdleAnimation(direction_mapping[index])
    else
        local direction = movement_proxy.direction
        if direction.X ~= 0 and direction.Y ~= 0 then
            index = GetAnimationIndex(direction, ERoleMoveDirection.Move_All_Cnt)
        end
        self:SetMoveAnimation(direction_mapping[index])
        self.prev_direction = {X = direction.X, Y = direction.Y}
    end
end

function Animation:GetMoveDirection()
    local index = GetAnimationIndex(self.prev_direction, ERoleMoveDirection.Move_All_Cnt)
    return direction_mapping[index]
end


return Class(nil, nil, Animation)