def deps do
  [
    {:open_api_spex, "~> 3.21"}
  ]
end

defmodule MyAppWeb.ApiSpec do
  alias OpenApiSpex.{Components, Info, OpenApi, Paths, Server}
  alias MyAppWeb.{Endpoint, Router}
  @behaviour OpenApi

  @impl OpenApi
  def spec do
    %OpenApi{
      servers: [
        # Populate the Server info from a phoenix endpoint
        Server.from_endpoint(Endpoint)
      ],
      info: %Info{
        title: "My App",
        version: "1.0"
      },
      # Populate the paths from a phoenix router
      paths: Paths.from_router(Router)
    }
    |> OpenApiSpex.resolve_schema_modules() # Discover request/response schemas from path specs
  end
end

info: %Info{
  title: to_string(Application.spec(:my_app, :description)),
  version: to_string(Application.spec(:my_app, :vsn))
}

components: %Components{
  securitySchemes: %{"authorization" => %SecurityScheme{type: "http", scheme: "bearer"}}
}

security: [%{"authorization" => []}]

defmodule MyAppWeb.UserController do
  use MyAppWeb, :controller
  use OpenApiSpex.ControllerSpecs

  alias MyAppWeb.Schemas.{UserParams, UserResponse}

  tags ["users"]
  security [%{}, %{"petstore_auth" => ["write:users", "read:users"]}]

  operation :update,
    summary: "Update user",
    parameters: [
      id: [in: :path, description: "User ID", type: :integer, example: 1001]
    ],
    request_body: {"User params", "application/json", UserParams},
    responses: [
      ok: {"User response", "application/json", UserResponse}
    ]

  def update(conn, %{"id" => id}) do
    json(conn, %{
      data: %{
        id: id,
        name: "joe user",
        email: "joe@gmail.com"
      }
    })
  end
end

[
  import_deps: [:open_api_spex]
]

operation :create, false

defmodule MyAppWeb.Schemas do
  alias OpenApiSpex.Schema

  defmodule User do
    require OpenApiSpex

    OpenApiSpex.schema(%{
      # The title is optional. It defaults to the last section of the module name.
      # So the derived title for MyApp.User is "User".
      title: "User",
      description: "A user of the app",
      type: :object,
      properties: %{
        id: %Schema{type: :integer, description: "User ID"},
        name: %Schema{type: :string, description: "User name", pattern: ~r/[a-zA-Z][a-zA-Z0-9_]+/},
        email: %Schema{type: :string, description: "Email address", format: :email},
        birthday: %Schema{type: :string, description: "Birth date", format: :date},
        inserted_at: %Schema{
          type: :string,
          description: "Creation timestamp",
          format: :"date-time"
        },
        updated_at: %Schema{type: :string, description: "Update timestamp", format: :"date-time"}
      },
      required: [:name, :email],
      example: %{
        "id" => 123,
        "name" => "Joe User",
        "email" => "joe@gmail.com",
        "birthday" => "1970-01-01T12:34:55Z",
        "inserted_at" => "2017-09-12T12:34:55Z",
        "updated_at" => "2017-09-13T10:11:12Z"
      }
    })
  end

  defmodule UserResponse do
    require OpenApiSpex

    OpenApiSpex.schema(%{
      title: "UserResponse",
      description: "Response schema for single user",
      type: :object,
      properties: %{
        data: User
      },
      example: %{
        "data" => %{
          "id" => 123,
          "name" => "Joe User",
          "email" => "joe@gmail.com",
          "birthday" => "1970-01-01T12:34:55Z",
          "inserted_at" => "2017-09-12T12:34:55Z",
          "updated_at" => "2017-09-13T10:11:12Z"
        }
      }
    })
  end
end

pipeline :api do
  plug OpenApiSpex.Plug.PutApiSpec, module: MyAppWeb.ApiSpec
end

scope "/api" do
  pipe_through :api
  resources "/users", MyAppWeb.UserController, only: [:create, :index, :show]
  get "/openapi", OpenApiSpex.Plug.RenderSpec, []
end

# config/dev.exs
config :open_api_spex, :cache_adapter, OpenApiSpex.Plug.NoneCache

  %OpenApi{
    info: %Info{
      title: "Phoenix App",
      version: "1.0"
    },
    # Replace this 👇
    servers: [OpenApiSpex.Server.from_endpoint(MyAppWeb.Endpoint)],
    # With this 👇
    servers: [%OpenApiSpex.Server{url: "https://yourapi.example.com"}],
  }

def deps do
  [
    {:ymlr, "~> 2.0"}
  ]
end

scope "/" do
  pipe_through :browser # Use the default browser stack

  get "/", MyAppWeb.PageController, :index
  get "/swaggerui", OpenApiSpex.Plug.SwaggerUI, path: "/api/openapi"
end

scope "/api" do
  pipe_through :api

  resources "/users", MyAppWeb.UserController, only: [:create, :index, :show]
  get "/openapi", OpenApiSpex.Plug.RenderSpec, []
end

# Importing an existing JSON encoded schema
open_api_spec_from_json = "encoded_schema.json"
  |> File.read!()
  |> Jason.decode!()
  |> OpenApiSpex.OpenApi.Decode.decode()

# Importing an existing YAML encoded schema
open_api_spec_from_yaml = "encoded_schema.yaml"
  |> YamlElixir.read_all_from_file!()
  |> List.first()
  |> OpenApiSpex.OpenApi.Decode.decode()

{:ok, _} = OpenApiSpex.cast_and_validate(
  open_api_spec_from_json, # or open_api_spec_from_yaml
  spec.paths["/some_path"].post,
  test_conn
)

# Phoenix
plug OpenApiSpex.Plug.CastAndValidate, json_render_error_v2: true
# Plug
plug OpenApiSpex.Plug.CastAndValidate, json_render_error_v2: true, operation_id: "UserController.create"

defmodule MyAppWeb.UserController do
  use MyAppWeb, :controller
  use OpenApiSpex.ControllerSpecs

  alias MyAppWeb.Schemas.{UserParams, UserResponse}

  plug OpenApiSpex.Plug.CastAndValidate, json_render_error_v2: true

  operation :update,
    summary: "Update user",
    description: "Updates with the given params.\nThis is another line of text in the description.",
    parameters: [
      id: [in: :path, type: :integer, description: "user ID"],
      vsn: [in: :query, type: :integer, description: "API version number"],
      "api-version": [in: :header, type: :integer, description: "API version number"]
    ],
    request_body: {"The user attributes", "application/json", UserParams},
    responses: %{
      201 => {"User", "application/json", UserResponse},
      422 => OpenApiSpex.JsonErrorResponse.response()
    }
  def update(
        conn = %{
          body_params: %UserParams{
            name: name,
            email: email,
            birthday: %Date{} = birthday
          }
        },
        %{id: id}
      ) do
    # conn.body_params cast to UserRequest struct
    # conn.params combines path params, query params and header params
    # conn.params.id cast to integer
    # conn.params.vsn cast to integer
    # conn.params[:"api-version"] cast to integer
    # params is the same as conn.params
    # params.id cast to integer

    # Note: Using pattern-matching in the action function's arguments can
    # cause Dialyzer to complain. This is because Dialyzer expects the
    # `conn` and `params` arguments to have string keys, not atom keys.
    # To resolve this, fetch the `:body_params` with
    # `body_params = Map.get(conn, :body_params)`.
  end
end

plug OpenApiSpex.Plug.CastAndValidate, render_error: MyErrorRendererPlug

defmodule MyErrorRendererPlug do
  @behaviour Plug

  alias Plug.Conn
  alias OpenApiSpex.OpenApi

  @impl Plug
  def init(errors), do: errors

  @impl Plug
  def call(conn, errors) when is_list(errors) do
    response = %{
      errors: Enum.map(errors, &to_string/1)
    }

    json = OpenApi.json_encoder().encode!(response)

    conn
    |> Conn.put_resp_content_type("application/json")
    |> Conn.send_resp(422, json)
  end
end

use MyAppWeb.ConnCase

test "create/2", %{conn: conn} do
  request_body = OpenApiSpex.Schema.example(MyAppWeb.Schemas.UserRequest.schema())

  json =
    conn
    |> post(user_path(conn), request_body)
    |> json_response(200)
end

use ExUnit.Case
import OpenApiSpex.TestAssertions

test "UsersResponse example matches schema" do
  api_spec = MyAppWeb.ApiSpec.spec()
  schema = MyAppWeb.Schemas.UsersResponse.schema()
  assert_schema(schema.example, "UsersResponse", api_spec)
end

use MyAppWeb.ConnCase
import OpenApiSpex.TestAssertions

test "UserController produces a UsersResponse", %{conn: conn} do
  json =
    conn
    |> get(user_path(conn, :index))
    |> json_response(200)

  api_spec = MyAppWeb.ApiSpec.spec()
  assert_schema(json, "UsersResponse", api_spec)
end