---@alias Vec2Like { x: number, y: number}

---@class Vector2
---@field x number
---@field y number

---@operator add: Vector2
---@operator sub: Vector2

local Vector2 = {}
Vector2.__index = Vector2

---@param x number
---@param y number
---@return Vector2
function Vector2.new(x, y)
  return setmetatable({ x = x or 0, y = y or 0 }, Vector2)
end

---@return Vector2
function Vector2:copy()
  return Vector2.new(self.x, self.y)
end

---@return string
function Vector2:__tostring()
  return string.format("Vector2(%.3f, %.3f)", self.x, self.y)
end

---@param v Vector2 | Vec2Like
---@return Vector2
function Vector2:add(v)
  return Vector2.new(self.x + v.x, self.y + v.y)
end

---@param v Vector2 | Vec2Like
---@return Vector2
function Vector2:sub(v)
  return Vector2.new(self.x - v.x, self.y - v.y)
end

---@param scalar number
---@return Vector2
function Vector2:mul(scalar)
  return Vector2.new(self.x * scalar, self.y * scalar)
end

---@param scalar number | Vec2Like
---@return Vector2
function Vector2:div(scalar)
  return Vector2.new(self.x / scalar, self.y / scalar)
end

---@param self Vector2 | Vec2Like
---@param v Vector2 | Vec2Like
---@return Vector2
function Vector2.__add(self, v)
  return Vector2.new(self.x + v.x, self.y + v.y)
end

---@param self Vector2 | Vec2Like
---@param v Vector2 | Vec2Like
---@return Vector2
function Vector2.__sub(self, v)
  return Vector2.new(self.x - v.x, self.y - v.y)
end

---@return number
function Vector2:length()
  return math.sqrt(self.x^2 + self.y^2)
end

---@return number
function Vector2:lengthSq()
  return self.x^2 + self.y^2
end

---@param dx number
---@return Vector2
function Vector2:addX(dx)
    self.x = self.x + dx
    return self
end

---@param dy number
---@return Vector2
function Vector2:addY(dy)
    self.y = self.y + dy
    return self
end

---@return Vector2
function Vector2:normalize()
  local len = self:length()
  if len == 0 then return Vector2.new(0, 0) end
  return Vector2.new(self.x / len, self.y / len)
end

---@param v Vector2 | Vec2Like
---@return number
function Vector2:dot(v)
  return self.x * v.x + self.y * v.y
end

---@param v Vector2 | Vec2Like
---@return number
function Vector2:distanceTo(v)
  return (self:sub(v)):length()
end

---@param v Vector2 | Vec2Like
---@return number
function Vector2:distanceToSq(v)
  return (self:sub(v)):lengthSq()

end


---@param v Vector2 | Vec2Like
---@param epsilon number
---@return boolean
function Vector2:equals(v, epsilon)
  epsilon = epsilon or 1e-5
  return math.abs(self.x - v.x) < epsilon and
         math.abs(self.y - v.y) < epsilon
end

---@param func function
---@return Vector2
function Vector2:map(func)
  return Vector2.new(func(self.x), func(self.y))
end

---@return Vec2Like
function Vector2:toTable()
  return { x = self.x, y = self.y }
end

---@param tbl Vec2Like
---@return Vector2
function Vector2.fromTable(tbl)
  return Vector2.new(tbl.x, tbl.y)
end

---@param tbl table
---@return Vector2
function Vector2.fromArray(tbl)
  return Vector2.new(tbl[1], tbl[2])
end

---@return table
function Vector2:toArray()
    return {self.x, self.y}
end

---@return number
---@return number
function Vector2:unpack()
    return self.x, self.y
end

return Vector2