defmodule TribeOne.TribesPlugin.SupertestWeb.APIPlug do
  @moduledoc """
  Local-only JSON API used by the infra supertest runner.
  """

  import Plug.Conn

  def init(opts), do: opts

  def call(conn, _opts) do
    if loopback?(conn.remote_ip) do
      dispatch(conn, supertest_path(conn.path_info), conn.method)
    else
      send_json(conn, 403, %{ok: false, error: "local-only"})
    end
  end

  defp dispatch(conn, ["health"], "GET") do
    conn |> send_result(TribeOne.TribesPlugin.Supertest.API.health())
  end

  defp dispatch(conn, ["schema"], "GET") do
    conn |> send_result(TribeOne.TribesPlugin.Supertest.API.schema())
  end

  defp dispatch(conn, ["reset"], "POST") do
    conn |> send_result(TribeOne.TribesPlugin.Supertest.API.reset(conn.body_params))
  end

  defp dispatch(conn, ["cases"], "POST") do
    conn |> send_result(TribeOne.TribesPlugin.Supertest.API.create_case(conn.body_params))
  end

  defp dispatch(conn, ["cases", id, "increment"], "POST") do
    conn
    |> send_result(
      TribeOne.TribesPlugin.Supertest.API.increment_case(Map.put(conn.body_params, "id", id))
    )
  end

  defp dispatch(conn, ["events"], "POST") do
    conn |> send_result(TribeOne.TribesPlugin.Supertest.API.create_event(conn.body_params))
  end

  defp dispatch(conn, ["cluster-pubsub", "broadcast"], "POST") do
    conn
    |> send_result(TribeOne.TribesPlugin.Supertest.API.broadcast_cluster_pubsub(conn.body_params))
  end

  defp dispatch(conn, ["cluster-pubsub", "reset"], "POST") do
    conn
    |> send_result(TribeOne.TribesPlugin.Supertest.API.reset_cluster_pubsub(conn.body_params))
  end

  defp dispatch(conn, ["cluster-pubsub", "received"], "GET") do
    conn
    |> send_result(TribeOne.TribesPlugin.Supertest.API.received_cluster_pubsub(conn.query_params))
  end

  defp dispatch(conn, ["metrics", "probe"], "POST") do
    conn |> send_result(TribeOne.TribesPlugin.Supertest.API.emit_metrics_probe(conn.body_params))
  end

  defp dispatch(conn, ["scheduler", "probes"], "POST") do
    conn
    |> send_result(TribeOne.TribesPlugin.Supertest.API.start_scheduler_probe(conn.body_params))
  end

  defp dispatch(conn, ["scheduler", "probes", run_id], "GET") do
    conn
    |> send_result(TribeOne.TribesPlugin.Supertest.API.scheduler_probe(%{"run_id" => run_id}))
  end

  defp dispatch(conn, ["scheduler", "probes", run_id, "stop"], "POST") do
    conn
    |> send_result(
      TribeOne.TribesPlugin.Supertest.API.stop_scheduler_probe(%{"run_id" => run_id})
    )
  end

  defp dispatch(conn, ["state"], "GET") do
    conn |> send_result(TribeOne.TribesPlugin.Supertest.API.state(conn.query_params))
  end

  defp dispatch(conn, _path, _method) do
    send_json(conn, 404, %{ok: false, error: "not-found"})
  end

  defp send_result(conn, {:ok, payload}), do: send_json(conn, 200, payload)

  defp send_result(conn, {:error, reason}) do
    send_json(conn, 422, %{ok: false, error: inspect(reason)})
  end

  defp send_json(conn, status, payload) do
    body = Jason.encode!(payload)

    conn
    |> put_resp_content_type("application/json")
    |> send_resp(status, body)
    |> halt()
  end

  defp supertest_path(["plugins-api", "tribe-one-supertest" | rest]), do: rest
  defp supertest_path(["tribe-one-supertest" | rest]), do: rest
  defp supertest_path(path), do: path

  defp loopback?({127, _second, _third, _fourth}), do: true
  defp loopback?({0, 0, 0, 0, 0, 0, 0, 1}), do: true
  defp loopback?({0, 0, 0, 0, 0, 65_535, high, _low}) when high in 0x7F00..0x7FFF, do: true
  defp loopback?(_remote_ip), do: false
end