neiam /gitgud

defmodule GitGud.Issues.Issue do
  use Ecto.Schema
  import Ecto.Changeset

  alias GitGud.Accounts.User
  alias GitGud.Issues.IssueComment
  alias GitGud.Repositories.Repository

  @valid_states ~w(open closed)

  schema "issues" do
    field :number, :integer
    field :title, :string
    field :body, :string
    field :state, :string, default: "open"
    field :closed_at, :utc_datetime

    field :moderated_at, :utc_datetime
    field :moderation_note, :string
    field :original_body, :string

    belongs_to :repository, Repository
    belongs_to :author, User
    belongs_to :moderated_by, User

    has_many :comments, IssueComment

    timestamps(type: :utc_datetime)
  end

  @doc """
  Creation changeset. `repository_id`, `author_id`, and `number` are set by
  the context — never via user input.
  """
  def create_changeset(issue, attrs) do
    issue
    |> cast(attrs, [:title, :body])
    |> validate_required([:title])
    |> validate_length(:title, min: 1, max: 255)
    |> validate_length(:body, max: 65_535)
  end

  def update_changeset(issue, attrs) do
    issue
    |> cast(attrs, [:title, :body])
    |> validate_required([:title])
    |> validate_length(:title, min: 1, max: 255)
    |> validate_length(:body, max: 65_535)
  end

  def state_changeset(issue, state) when state in @valid_states do
    change(issue, %{
      state: state,
      closed_at: if(state == "closed", do: DateTime.utc_now(:second))
    })
  end

  def valid_states, do: @valid_states

  @doc "Replace the body with a moderator note, preserving the original."
  def moderate_changeset(target, moderator, note) do
    original = target.original_body || target.body

    change(target, %{
      original_body: original,
      body: "",
      moderation_note: note,
      moderated_by_id: moderator.id,
      moderated_at: DateTime.utc_now(:second)
    })
  end

  @doc "Reverse a previous moderation: restore the original body."
  def restore_changeset(target) do
    change(target, %{
      body: target.original_body || target.body,
      original_body: nil,
      moderation_note: nil,
      moderated_by_id: nil,
      moderated_at: nil
    })
  end

  def moderated?(%__MODULE__{moderated_at: nil}), do: false
  def moderated?(%__MODULE__{}), do: true
end