neiam /gitgud

defmodule GitGudWeb.Api.Mobile.WikiController do
  @moduledoc """
  Wiki viewer.

  Read-only: the wiki is a git repository of markdown files, and editing
  one on a phone means resolving conflicts on a phone. The page list
  walks the wiki repo's HEAD tree, so a repo whose wiki was never
  initialized returns an empty list rather than a 404 — "no pages yet"
  is a state the client renders, not an error.
  """
  use GitGudWeb, :controller

  import GitGudWeb.Api.Mobile.Helpers

  alias GitGud.Wikis
  alias GitGudWeb.Api.Mobile.Auth
  alias GitGudWeb.Api.Mobile.JSON

  def index(conn, %{"owner" => owner, "name" => name}) do
    with {:ok, user} <- Auth.require_scope(conn, "wiki:read"),
         {:ok, repo} <- fetch_repo(conn, user, owner, name) do
      json(conn, %{
        "pages" => repo |> Wikis.list_pages() |> Enum.map(&JSON.wiki_page_meta/1),
        "initialized" => Wikis.initialized?(repo)
      })
    else
      {:error, conn} -> conn
    end
  end

  def show(conn, %{"owner" => owner, "name" => name, "slug" => slug}) do
    with {:ok, user} <- Auth.require_scope(conn, "wiki:read"),
         {:ok, repo} <- fetch_repo(conn, user, owner, name),
         body when is_binary(body) <- Wikis.get_page(repo, slug) do
      json(conn, %{
        "slug" => slug,
        "title" => slug,
        "body" => body,
        "body_html" => to_string(GitGud.Markdown.to_html(body, repo: repo))
      })
    else
      {:error, conn} -> conn
      nil -> send_error(conn, 404, "no wiki page '#{slug}'")
    end
  end
end