defmodule AshGraphql.Resource.Query do
  @moduledoc "Represents a configured query on a resource"
  defstruct [
    :name,
    :action,
    :type,
    :identity,
    :allow_nil?,
    :modify_resolution,
    as_mutation?: false,
    relay?: false
  ]

  @get_schema [
    name: [
      type: :atom,
      doc: "The name to use for the query.",
      default: :get
    ],
    action: [
      type: :atom,
      doc: "The action to use for the query.",
      required: true
    ],
    identity: [
      type: :atom,
      doc: "The identity to use for looking up the record. Pass `false` to not use an identity.",
      required: false
    ],
    allow_nil?: [
      type: :boolean,
      default: true,
      doc: "Whether or not the action can return nil."
    ],
    modify_resolution: [
      type: :mfa,
      doc: """
      An MFA that will be called with the resolution, the query, and the result of the action as the first three arguments (followed by the arguments in the mfa).
      Must return a new absinthe resolution. This can be used to implement things like setting cookies based on resource actions. A method of using resolution context
      for that is documented here: https://hexdocs.pm/absinthe_plug/Absinthe.Plug.html#module-before-send

      *Important* if you are modifying the context, then you should also set `as_mutation?` to true and represent
      this in your graphql as a mutation. See `as_mutation?` for more.
      """
    ],
    as_mutation?: [
      type: :boolean,
      default: false,
      doc: """
      Places the query in the `mutations` key instead. The use cases for this are likely very minimal.

      If you have a query that needs to modify the graphql context using `modify_resolution`, then you
      should likely set this as well. A simple example might be a `log_in`, which could be a read
      action on the user that accepts an email/password, and should then set some context in the graphql
      inside of `modify_resolution`. Once in the context, you can see the guide referenced in `modify_resolution`
      for more on setting the session or a cookie with an auth token.
      """
    ]
  ]

  @read_one_schema [
    name: [
      type: :atom,
      doc: "The name to use for the query.",
      default: :read_one
    ],
    action: [
      type: :atom,
      doc: "The action to use for the query.",
      required: true
    ],
    allow_nil?: [
      type: :boolean,
      default: true,
      doc: "Whether or not the action can return nil."
    ]
  ]

  @list_schema [
    name: [
      type: :atom,
      doc: "The name to use for the query.",
      default: :list
    ],
    action: [
      type: :atom,
      doc: "The action to use for the query.",
      required: true
    ],
    relay?: [
      type: :boolean,
      default: false,
      doc: """
      If true, the graphql queries/resolvers for this resource will be built to honor the [relay specification](https://relay.dev/graphql/connections.htm).

      The two changes that are made currently are:

      * the type for the resource will implement the `Node` interface
      * pagination over that resource will behave as a Connection.
      """
    ]
  ]

  def get_schema, do: @get_schema
  def read_one_schema, do: @read_one_schema
  def list_schema, do: @list_schema
end