request limiter

config/config.exs

@@ -1,6 +1,7 @@
 import Config
 
 config :plantid_discord_bot,
-  start_time: DateTime.utc_now()
+  start_time: DateTime.utc_now(),
+  image_folder: "priv/static"
 
 import_config "#{config_env()}.exs"

config/dev.exs

@@ -1,10 +1,10 @@
 import Config
 
 config :plantid_discord_bot,
+  guild_request_limit_per_day: 20,
   guild_ids: [1_002_507_312_159_797_318],
   plantnet_api_key: System.get_env("PLANTNET_API_KEY"),
   plantnet_api_base_url: "https://my-api.plantnet.org/v2",
-  image_folder: "priv/static",
   fileserver_url: "http://localhost:4321",
   port: 4321,
   source: "https://github.com/TheRealOwenRees/plantid-discord-bot",

config/prod.exs

@@ -1,10 +1,10 @@
 import Config
 
 config :plantid_discord_bot,
+  guild_request_limit_per_day: 20,
   guild_ids: [],
   plantnet_api_key: System.get_env("PLANTNET_API_KEY"),
   plantnet_api_base_url: "https://my-api.plantnet.org/v2",
-  image_folder: "priv/static",
   fileserver_url: "http://localhost:4321",
   port: 4321,
   source: "https://github.com/TheRealOwenRees/plantid-discord-bot",

config/runtime.exs

@@ -4,7 +4,6 @@ config :plantid_discord_bot,
   guild_ids: [1_002_507_312_159_797_318],
   plantnet_api_key: System.get_env("PLANTNET_API_KEY"),
   plantnet_api_base_url: "https://my-api.plantnet.org/v2",
-  image_folder: "priv/static",
   fileserver_url: "http://localhost:4321",
   port: 4321,
   source: "https://github.com/TheRealOwenRees/plantid-discord-bot",

config/test.exs

@@ -1,10 +1,10 @@
 import Config
 
 config :plantid_discord_bot,
+  guild_request_limit_per_day: 20,
   guild_ids: [1_002_507_312_159_797_318],
   plantnet_api_key: System.get_env("PLANTNET_API_KEY"),
   plantnet_api_base_url: "https://my-api.plantnet.org/v2",
-  image_folder: "priv/static",
   fileserver_url: "http://localhost:4321",
   port: 4321,
   source: "https://github.com/TheRealOwenRees/plantid-discord-bot",

lib/application.ex

@@ -6,7 +6,8 @@ defmodule PlantIdDiscordBot.Application do
   @impl true
   def start(_type, _args) do
     children = [
-      PlantIdDiscordBot
+      PlantIdDiscordBot.Consumer,
+      PlantIdDiscordBot.RateLimiter
     ]
 
     opts = [strategy: :one_for_one, name: PlantIdDiscordBot.Supervisor]

lib/plantid_discord_bot.ex

@@ -1,4 +1,4 @@
-defmodule PlantIdDiscordBot do
+defmodule PlantIdDiscordBot.Consumer do
   @moduledoc """
   A Discord bot that identifies plants from photos of their organs.
   """
@@ -30,39 +30,17 @@ defmodule PlantIdDiscordBot do
     Api.create_guild_application_command(1_002_507_312_159_797_318, @global_application_commands)
   end
 
-  # Handle /source command
-  def handle_event({:INTERACTION_CREATE, %{data: %{name: "source"}} = interaction, _ws_state}) do
-    Cog.Info.source(interaction)
+  # Handle application commands
+  def handle_event({:INTERACTION_CREATE, %{data: %{name: command}} = interaction, _ws_state}) do
+    case command do
+      "source" -> Cog.Info.source(interaction)
+      "invite" -> Cog.Info.invite(interaction)
+      "help" -> Cog.Info.help(interaction)
+      "info" -> Cog.Info.info(interaction)
+      "stats" -> Cog.Info.stats(interaction)
+      "status" -> Cog.Info.status(interaction)
+      "servers" -> Cog.Info.servers(interaction)
+      "id" -> Cog.PlantNet.id(interaction)
     end
-
-  # Handle /invite command
-  def handle_event({:INTERACTION_CREATE, %{data: %{name: "invite"}} = interaction, _ws_state}) do
-    Cog.Info.invite(interaction)
   end
-
-  # Handle /help command
-  def handle_event({:INTERACTION_CREATE, %{data: %{name: "help"}} = interaction, _ws_state}) do
-    Cog.Info.help(interaction)
-  end
-
-  # Handle /info command
-  def handle_event({:INTERACTION_CREATE, %{data: %{name: "info"}} = interaction, _ws_state}) do
-    Cog.Info.info(interaction)
-  end
-
-  # def handle_event({:INTERACTION_CREATE, %{data: %{name: "stats"}} = interaction, _ws_state}) do
-  #   Cog.Info.info(interaction)
-  # end
-
-  def handle_event({:INTERACTION_CREATE, %{data: %{name: "status"}} = interaction, _ws_state}) do
-    Cog.Info.status(interaction)
-  end
-
-  # def handle_event({:INTERACTION_CREATE, %{data: %{name: "servers"}} = interaction, _ws_state}) do
-  #   Cog.Info.info(interaction)
-  # end
-
-  # def handle_event({:INTERACTION_CREATE, %{data: %{name: "id"}} = interaction, _ws_state}) do
-  #   Cog.Info.info(interaction)
-  # end
 end

lib/plantid_discord_bot/cogs/info.ex

@@ -63,15 +63,16 @@ defmodule PlantIdDiscordBot.Cog.Info do
     embed =
       %Nostrum.Struct.Embed{}
       |> put_title(app_info.name)
-      |> put_description("Stats etc.")
-      |> put_color(0x1AAAE5)
-      |> put_field("Server Count", app_info.approximate_guild_count, true)
-      |> put_field("Uptime", Utils.get_uptime(), true)
-      |> put_field("Latency", Utils.get_shard_latency(), true)
+      |> put_description("This bot is designed to help you identify plants")
+      |> put_color(0x41C03F)
+      |> put_field("/info", "Show this message", true)
+      |> put_field("/help", "Gives detailed help on the plant ID bot", true)
+      |> put_field("/stats", "Bot stats", true)
+      |> put_field("/invite", "Invite the bot to your server", true)
+      |> put_field("/source", "Link to the source code", true)
       |> put_footer("Made by #{app_info.owner.username}")
 
-    response = %{type: 4, data: %{embeds: [embed]}}
-    @api.create_interaction_response(interaction, response)
+    @api.create_interaction_response(interaction, %{type: 4, data: %{embeds: [embed]}})
   end
 
   @doc """
@@ -89,4 +90,42 @@ defmodule PlantIdDiscordBot.Cog.Info do
 
     @api.create_interaction_response(interaction, %{type: 4, data: %{content: message}})
   end
+
+  @doc """
+  Bot stats.
+  """
+  def stats(interaction) do
+    {:ok, app_info} = @api.get_application_information()
+
+    embed =
+      %Nostrum.Struct.Embed{}
+      |> put_title(app_info.name)
+      |> put_description("Stats etc.")
+      |> put_color(0x1AAAE5)
+      |> put_field("Server Count", app_info.approximate_guild_count, true)
+      |> put_field("Uptime", Utils.get_uptime(), true)
+      |> put_field("Latency", Utils.get_shard_latency(), true)
+      |> put_footer("Made by #{app_info.owner.username}")
+
+    @api.create_interaction_response(interaction, %{type: 4, data: %{embeds: [embed]}})
+  end
+
+  @doc """
+  List all servers the bot is connected to.
+  """
+  def servers(interaction) do
+    {:ok, %{owner: owner}} = @api.get_application_information()
+
+    guilds = PlantIdDiscordBot.Utils.get_guilds_names()
+    guilds_string = Enum.join(guilds, "\n")
+
+    embed =
+      %Nostrum.Struct.Embed{}
+      |> put_title("Connected on #{length(guilds)} server(s):")
+      |> put_description(guilds_string)
+      |> put_color(0x1AAAE5)
+      |> put_footer("Made by #{owner.username}")
+
+    @api.create_interaction_response(interaction, %{type: 4, data: %{embeds: [embed]}})
+  end
 end

lib/plantid_discord_bot/cogs/plantnet.ex

@@ -1,3 +1,49 @@
 defmodule PlantIdDiscordBot.Cog.PlantNet do
   use Nostrum.Consumer
+  alias PlantIdDiscordBot.RateLimiter
+
+  @api Application.compile_env(:plantid_discord_bot, :api)
+
+  @doc """
+  ID a plant from up to 5 images of organs.
+  """
+  def id(interaction) do
+    guild_id = interaction.guild_id
+
+    case RateLimiter.check_limit(guild_id) do
+      {:limit_exceeded, value} ->
+        @api.create_interaction_response(interaction, %{
+          type: 4,
+          data: %{
+            content:
+              "This server has exceeded its allowed requests in 24 hours. Please try again tomorrow."
+          }
+        })
+
+      {:ok, _} ->
+        do_identification(interaction)
+    end
+
+    # TODO increase on success (failed id or otherwise)
+    # RateLimiter.increase_counter(guild_id)
+  end
+
+  defp do_identification(interaction) do
+    attachment_urls = get_attachment_urls(interaction)
+    original_images = get_original_images(attachment_urls)
+
+    @api.create_interaction_response(interaction, %{
+      type: 4,
+      data: %{content: "This command is not yet implemented." <> "\n#{original_images}"}
+    })
+  end
+
+  defp get_attachment_urls(interaction) do
+    interaction.data.resolved.attachments
+    |> Map.values()
+    |> Enum.map(& &1.url)
+  end
+
+  @spec get_original_images([String.t()]) :: String.t()
+  defp get_original_images(attachment_urls), do: Enum.join(attachment_urls, "\n")
 end

lib/rate_limiter.ex

@@ -0,0 +1,52 @@
+defmodule PlantIdDiscordBot.RateLimiter do
+  use GenServer
+
+  @request_limit Application.compile_env(:plantid_discord_bot, :guild_request_limit_per_day)
+
+  def start_link(_) do
+    GenServer.start_link(__MODULE__, nil, name: __MODULE__)
+  end
+
+  @impl GenServer
+  def init(_) do
+    :ets.new(__MODULE__, [:named_table, :public, write_concurrency: true])
+    {:ok, nil}
+  end
+
+  defp put(key, value) do
+    :ets.insert(__MODULE__, {key, value})
+  end
+
+  defp get(key) do
+    case :ets.lookup(__MODULE__, key) do
+      [{^key, value}] -> {:ok, value}
+      [] -> {:error, nil}
+    end
+  end
+
+  @doc """
+  Check if the number of requests for a guild exceeds the limit.
+  """
+  @spec check_limit(String.t()) :: {:ok, integer()} | {:limit_exceeded, integer()}
+  def check_limit(guild_id) do
+    case get(guild_id) do
+      {:ok, value} ->
+        if value >= @request_limit do
+          {:limit_exceeded, value}
+        else
+          {:ok, value}
+        end
+
+      {:error, _} ->
+        put(guild_id, 0)
+        {:ok, 0}
+    end
+  end
+
+  @doc """
+  Increase the counter for the number of requests for a guild by one.
+  """
+  def increase_counter(guild_id) do
+    :ets.update_counter(__MODULE__, guild_id, 1)
+  end
+end

lib/utils.ex

@@ -12,4 +12,8 @@ defmodule PlantIdDiscordBot.Utils do
     |> to_string()
     |> Kernel.<>("ms")
   end
+
+  def get_guilds_names() do
+    Nostrum.Cache.GuildCache.fold([], fn %{name: name}, acc -> [name | acc] end)
+  end
 end

test/commands/stats_test.exs

@@ -0,0 +1,9 @@
+defmodule PlantIdDiscordBotTest.Cog.Stats do
+  use ExUnit.Case
+
+  test "/stats" do
+    {:ok, response} = PlantIdDiscordBot.Cog.Info.info(%{data: %{name: "stats"}})
+    [embed] = response[:data][:embeds]
+    assert match?(%Nostrum.Struct.Embed{}, embed)
+  end
+end