module Agents
  class DropboxFileUrlAgent < Agent
    include DropboxConcern

    cannot_be_scheduled!
    no_bulk_receive!
    can_dry_run!

    description <<~MD
      The _DropboxFileUrlAgent_ is used to work with Dropbox. It takes a file path (or multiple files paths) and emits events with either [temporary links](https://www.dropbox.com/developers/core/docs#media) or [permanent links](https://www.dropbox.com/developers/core/docs#shares).

      #{'## Include the `dropbox-api` and `omniauth-dropbox` gems in your `Gemfile` and set `DROPBOX_OAUTH_KEY` and `DROPBOX_OAUTH_SECRET` in your environment to use Dropbox Agents.' if dependencies_missing?}

      The incoming event payload needs to have a `paths` key, with a comma-separated list of files you want the URL for. For example:

          {
            "paths": "first/path, second/path"
          }

      __TIP__: You can use the _Event Formatting Agent_ to format events before they come in. Here's an example configuration for formatting an event coming out of a _Dropbox Watch Agent_:

          {
            "instructions": {
              "paths": "{{ added | map: 'path' | join: ',' }}"
            },
            "matchers": [],
            "mode": "clean"
          }

      An example of usage would be to watch a specific Dropbox directory (with the _DropboxWatchAgent_) and get the URLs for the added or updated files. You could then, for example, send emails with those links.

      Set `link_type` to `'temporary'` if you want temporary links, or to `'permanent'` for permanent ones.

    MD

    event_description do
      "Events will looks like this:\n\n    " +
        Utils.pretty_print(
          if options['link_type'] == 'permanent'
            {
              url: "https://www.dropbox.com/s/abcde3/example?dl=1",
              ".tag": "file",
              id: "id:abcde3",
              name: "hi",
              path_lower: "/huginn/hi",
              link_permissions: {
                resolved_visibility: { ".tag": "public" },
                requested_visibility: { ".tag": "public" },
                can_revoke: true
              },
              client_modified: "2017-10-14T18:38:39Z",
              server_modified: "2017-10-14T18:38:45Z",
              rev: "31db0615354b",
              size: 0
            }
          else
            {
              url: "https://dl.dropboxusercontent.com/apitl/1/somelongurl",
              metadata: {
                name: "hi",
                path_lower: "/huginn/hi",
                path_display: "/huginn/hi",
                id: "id:abcde3",
                client_modified: "2017-10-14T18:38:39Z",
                server_modified: "2017-10-14T18:38:45Z",
                rev: "31db0615354b",
                size: 0,
                content_hash: "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
              }
            }
          end
        )
    end

    def default_options
      {
        'link_type' => 'temporary'
      }
    end

    def working?
      !recent_error_logs?
    end

    def receive(events)
      events.flat_map { |e| e.payload['paths'].split(',').map(&:strip) }
        .each do |path|
          create_event payload: (options['link_type'] == 'permanent' ? permanent_url_for(path) : temporary_url_for(path))
        end
    end

    private

    def temporary_url_for(path)
      dropbox.find(path).direct_url.response.tap do |response|
        response['url'] = response.delete('link')
      end
    end

    def permanent_url_for(path)
      dropbox.find(path).share_url.response.tap do |response|
        response['url'].gsub!('?dl=0', '?dl=1')
      end
    end
  end
end