Files
component-system/lib/components_elixir/inventory/storage_location.ex
2025-09-14 15:20:25 +02:00

134 lines
4.2 KiB
Elixir

defmodule ComponentsElixir.Inventory.StorageLocation do
@moduledoc """
Schema for storage locations with hierarchical organization.
Storage locations can be nested (shelf -> drawer -> box) and each
has a unique QR code for quick scanning and identification.
"""
use Ecto.Schema
import Ecto.Changeset
alias ComponentsElixir.Inventory.{StorageLocation, Component}
schema "storage_locations" do
field :name, :string
field :description, :string
field :qr_code, :string
field :is_active, :boolean, default: true
# Computed/virtual fields - not stored in database
field :level, :integer, virtual: true
field :path, :string, virtual: true
# Only parent relationship is stored
belongs_to :parent, StorageLocation
has_many :children, StorageLocation, foreign_key: :parent_id
has_many :components, Component
timestamps()
end
@doc false
def changeset(storage_location, attrs) do
storage_location
|> cast(attrs, [:name, :description, :parent_id, :is_active])
|> validate_required([:name])
|> validate_length(:name, min: 1, max: 100)
|> validate_length(:description, max: 500)
|> foreign_key_constraint(:parent_id)
|> validate_no_circular_reference()
|> put_qr_code()
end
# Prevent circular references (location being its own ancestor)
defp validate_no_circular_reference(changeset) do
case get_change(changeset, :parent_id) do
nil -> changeset
parent_id ->
location_id = changeset.data.id
if location_id && would_create_cycle?(location_id, parent_id) do
add_error(changeset, :parent_id, "cannot be a descendant of this location")
else
changeset
end
end
end
defp would_create_cycle?(location_id, parent_id) do
# Check if parent_id is the same as location_id or any of its descendants
location_id == parent_id or
(parent_id && is_descendant_of?(parent_id, location_id))
end
defp is_descendant_of?(potential_descendant, ancestor_id) do
case ComponentsElixir.Repo.get(StorageLocation, potential_descendant) do
nil -> false
%{parent_id: nil} -> false
%{parent_id: ^ancestor_id} -> true
%{parent_id: parent_id} -> is_descendant_of?(parent_id, ancestor_id)
end
end
@doc """
Returns the full hierarchical path as a human-readable string.
"""
def full_path(storage_location) do
storage_location.path
|> String.split("/")
|> Enum.join("")
end
@doc """
Returns the QR code format for this storage location.
Format: SL:{level}:{qr_code}:{parent_qr_or_ROOT}
"""
def qr_format(storage_location, parent \\ nil) do
parent_code = if parent, do: parent.qr_code, else: "ROOT"
"SL:#{storage_location.level}:#{storage_location.qr_code}:#{parent_code}"
end
# Private functions for changeset processing
defp put_qr_code(changeset) do
case get_field(changeset, :qr_code) do
nil -> put_change(changeset, :qr_code, generate_qr_code())
_ -> changeset
end
end
# Compute the hierarchy level based on parent chain
def compute_level(%StorageLocation{parent_id: nil}), do: 0
def compute_level(%StorageLocation{parent: %StorageLocation{} = parent}) do
compute_level(parent) + 1
end
def compute_level(%StorageLocation{parent_id: parent_id}) when not is_nil(parent_id) do
# Parent not loaded, fetch it
parent = ComponentsElixir.Inventory.get_storage_location!(parent_id)
compute_level(parent) + 1
end
# Compute the full path based on parent chain
def compute_path(%StorageLocation{name: name, parent_id: nil}), do: name
def compute_path(%StorageLocation{name: name, parent: %StorageLocation{} = parent}) do
"#{compute_path(parent)}/#{name}"
end
def compute_path(%StorageLocation{name: name, parent_id: parent_id}) when not is_nil(parent_id) do
# Parent not loaded, fetch it
parent = ComponentsElixir.Inventory.get_storage_location!(parent_id)
"#{compute_path(parent)}/#{name}"
end
defp generate_qr_code do
# Generate a unique 6-character alphanumeric code
chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
1..6
|> Enum.map(fn _ ->
chars
|> String.graphemes()
|> Enum.random()
end)
|> Enum.join()
end
end