---@alias Vec3Like { x: number, y: number, z: number }
---@alias Vec3 Vec3Like

---@class Vector3
---@field x number
---@field y number
---@field z number

---@operator add: Vector3
---@operator sub: Vector3

local Vector3 = {}
Vector3.__index = Vector3


---@param x number
---@param y number
---@param z number
---@return Vector3
function Vector3.new(x, y, z)
  return setmetatable({ x = x or 0, y = y or 0, z = z or 0 }, Vector3)
end

---@return Vector3
function Vector3:copy()
  return Vector3.new(self.x, self.y, self.z)
end

---@return string
function Vector3:__tostring()
  return string.format("Vector3(%.3f, %.3f, %.3f)", self.x, self.y, self.z)
end

---@param v Vector3 | Vec3Like
---@return Vector3
function Vector3:add(v)
  return Vector3.new(self.x + v.x, self.y + v.y, self.z + v.z)
end

---@param v Vector3 | Vec3Like
---@return Vector3
function Vector3:sub(v)
  return Vector3.new(self.x - v.x, self.y - v.y, self.z - v.z)
end

---@param scalar number
---@return Vector3
function Vector3:mul(scalar)
  return Vector3.new(self.x * scalar, self.y * scalar, self.z * scalar)
end

---@param scalar number
---@return Vector3
function Vector3:div(scalar)
  return Vector3.new(self.x / scalar, self.y / scalar, self.z / scalar)
end

---@param self Vector3 | Vec3Like
---@param v Vector3 | Vec3Like
---@return Vector3
function Vector3.__add(self, v)
  return Vector3.new(self.x + v.x, self.y + v.y, self.z + v.z)
end

---@param self Vector3 | Vec3Like
---@param v Vector3 | Vec3Like
---@return Vector3
function Vector3.__sub(self, v)
  return Vector3.new(self.x - v.x, self.y - v.y, self.z - v.z)
end

---@return number
function Vector3:length()
  return math.sqrt(self.x^2 + self.y^2 + self.z^2)
end

---@return number
function Vector3:lengthSq()
  return self.x^2 + self.y^2 + self.z^2
end

---@return Vector3
function Vector3:normalize()
  local len = self:length()
  if len == 0 then return Vector3.new(0, 0, 0) end
  return Vector3.new(self.x / len, self.y / len, self.z / len)
end

---@param v Vector3 | Vec3Like
---@return number
function Vector3:dot(v)
  return self.x * v.x + self.y * v.y + self.z * v.z
end

---@param v Vector3 | Vec3Like
---@return Vector3
function Vector3:cross(v)
  return Vector3.new(
    self.y * v.z - self.z * v.y,
    self.z * v.x - self.x * v.z,
    self.x * v.y - self.y * v.x
  )
end

---@param v Vector3 | Vec3Like
---@return number
function Vector3:distanceTo(v)
  return (self:sub(v)):length()
end

---@param v Vector3 | Vec3Like
---@return number
function Vector3:distanceToSq(v)
  return (self:sub(v)):lengthSq()
end

---@param v Vector3 | Vec3Like
---@param epsilon number
---@return boolean
function Vector3:equals(v, epsilon)
  epsilon = epsilon or 1e-5
  return math.abs(self.x - v.x) < epsilon and
         math.abs(self.y - v.y) < epsilon and
         math.abs(self.z - v.z) < epsilon
end

---@param func function
---@return Vector3
function Vector3:map(func)
  return Vector3.new(func(self.x), func(self.y), func(self.z))
end

---@return table
function Vector3:toTable()
  return { x = self.x, y = self.y, z = self.z }
end

---@param tbl Vec3Like | Vector3
---@return Vector3
function Vector3.fromTable(tbl)
  return Vector3.new(tbl.x, tbl.y, tbl.z)
end

---@param tbl table
---@return Vector3
function Vector3.fromArray(tbl)
  return Vector3.new(tbl[1], tbl[2], tbl[3])
end

---@return number
---@return number
---@return number
function Vector3:unpack()
  return self.x, self.y, self.z
end

---@return Vec3Like
function Vector3:toArray()
  return {self.x, self.y, self.z}
end

---@return Vec3Like
function Vector3:projectXZ()
    return Vector3.new(self.x, 0, self.z)
end

return Vector3