defmodule Pleroma.LoadTesting.Generator do
  use Pleroma.LoadTesting.Helper
  alias Pleroma.Web.CommonAPI

  def generate_like_activities(user, posts) do
    count_likes = Kernel.trunc(length(posts) / 4)
    IO.puts("Starting generating #{count_likes} like activities...")

    {time, _} =
      :timer.tc(fn ->
        Task.async_stream(
          Enum.take_random(posts, count_likes),
          fn post -> {:ok, _, _} = CommonAPI.favorite(post.id, user) end,
          max_concurrency: 10,
          timeout: 30_000
        )
        |> Stream.run()
      end)

    IO.puts("Inserting like activities take #{to_sec(time)} sec.\n")
  end

  def generate_users(opts) do
    IO.puts("Starting generating #{opts[:users_max]} users...")
    {time, users} = :timer.tc(fn -> do_generate_users(opts) end)

    IO.puts("Inserting users take #{to_sec(time)} sec.\n")
    users
  end

  defp do_generate_users(opts) do
    max = Keyword.get(opts, :users_max)

    Task.async_stream(
      1..max,
      &generate_user_data(&1),
      max_concurrency: 10,
      timeout: 30_000
    )
    |> Enum.to_list()
  end

  defp generate_user_data(i) do
    remote = Enum.random([true, false])

    user = %User{
      name: "Test テスト User #{i}",
      email: "user#{i}@example.com",
      nickname: "nick#{i}",
      password_hash:
        "$pbkdf2-sha512$160000$bU.OSFI7H/yqWb5DPEqyjw$uKp/2rmXw12QqnRRTqTtuk2DTwZfF8VR4MYW2xMeIlqPR/UX1nT1CEKVUx2CowFMZ5JON8aDvURrZpJjSgqXrg",
      bio: "Tester Number #{i}",
      local: remote
    }

    user_urls =
      if remote do
        base_url =
          Enum.random(["https://domain1.com", "https://domain2.com", "https://domain3.com"])

        ap_id = "#{base_url}/users/#{user.nickname}"

        %{
          ap_id: ap_id,
          follower_address: ap_id <> "/followers",
          following_address: ap_id <> "/following"
        }
      else
        %{
          ap_id: User.ap_id(user),
          follower_address: User.ap_followers(user),
          following_address: User.ap_following(user)
        }
      end

    user = Map.merge(user, user_urls)

    Repo.insert!(user)
  end

  def generate_activities(user, users) do
    do_generate_activities(user, users)
  end

  defp do_generate_activities(user, users) do
    IO.puts("Starting generating 20000 common activities...")

    {time, _} =
      :timer.tc(fn ->
        Task.async_stream(
          1..20_000,
          fn _ ->
            do_generate_activity([user | users])
          end,
          max_concurrency: 10,
          timeout: 30_000
        )
        |> Stream.run()
      end)

    IO.puts("Inserting common activities take #{to_sec(time)} sec.\n")

    IO.puts("Starting generating 20000 activities with mentions...")

    {time, _} =
      :timer.tc(fn ->
        Task.async_stream(
          1..20_000,
          fn _ ->
            do_generate_activity_with_mention(user, users)
          end,
          max_concurrency: 10,
          timeout: 30_000
        )
        |> Stream.run()
      end)

    IO.puts("Inserting activities with menthions take #{to_sec(time)} sec.\n")

    IO.puts("Starting generating 10000 activities with threads...")

    {time, _} =
      :timer.tc(fn ->
        Task.async_stream(
          1..10_000,
          fn _ ->
            do_generate_threads([user | users])
          end,
          max_concurrency: 10,
          timeout: 30_000
        )
        |> Stream.run()
      end)

    IO.puts("Inserting activities with threads take #{to_sec(time)} sec.\n")
  end

  defp do_generate_activity(users) do
    post = %{
      "status" => "Some status without mention with random user"
    }

    CommonAPI.post(Enum.random(users), post)
  end

  def generate_power_intervals(opts \\ []) do
    count = Keyword.get(opts, :count, 20)
    power = Keyword.get(opts, :power, 2)
    IO.puts("Generating #{count} intervals for a power #{power} series...")
    counts = Enum.map(1..count, fn n -> :math.pow(n, power) end)
    sum = Enum.sum(counts)

    densities =
      Enum.map(counts, fn c ->
        c / sum
      end)

    densities
    |> Enum.reduce(0, fn density, acc ->
      if acc == 0 do
        [{0, density}]
      else
        [{_, lower} | _] = acc
        [{lower, lower + density} | acc]
      end
    end)
    |> Enum.reverse()
  end

  def generate_tagged_activities(opts \\ []) do
    tag_count = Keyword.get(opts, :tag_count, 20)
    users = Keyword.get(opts, :users, Repo.all(User))
    activity_count = Keyword.get(opts, :count, 200_000)

    intervals = generate_power_intervals(count: tag_count)

    IO.puts(
      "Generating #{activity_count} activities using #{tag_count} different tags of format `tag_n`, starting at tag_0"
    )

    Enum.each(1..activity_count, fn _ ->
      random = :rand.uniform()
      i = Enum.find_index(intervals, fn {lower, upper} -> lower <= random && upper > random end)
      CommonAPI.post(Enum.random(users), %{"status" => "a post with the tag #tag_#{i}"})
    end)
  end

  defp do_generate_activity_with_mention(user, users) do
    mentions_cnt = Enum.random([2, 3, 4, 5])
    with_user = Enum.random([true, false])
    users = Enum.shuffle(users)
    mentions_users = Enum.take(users, mentions_cnt)
    mentions_users = if with_user, do: [user | mentions_users], else: mentions_users

    mentions_str =
      Enum.map(mentions_users, fn user -> "@" <> user.nickname end) |> Enum.join(", ")

    post = %{
      "status" => mentions_str <> "some status with mentions random users"
    }

    CommonAPI.post(Enum.random(users), post)
  end

  defp do_generate_threads(users) do
    thread_length = Enum.random([2, 3, 4, 5])
    actor = Enum.random(users)

    post = %{
      "status" => "Start of the thread"
    }

    {:ok, activity} = CommonAPI.post(actor, post)

    Enum.each(1..thread_length, fn _ ->
      user = Enum.random(users)

      post = %{
        "status" => "@#{actor.nickname} reply to thread",
        "in_reply_to_status_id" => activity.id
      }

      CommonAPI.post(user, post)
    end)
  end

  def generate_remote_activities(user, users) do
    do_generate_remote_activities(user, users)
  end

  defp do_generate_remote_activities(user, users) do
    IO.puts("Starting generating 10000 remote activities...")

    {time, _} =
      :timer.tc(fn ->
        Task.async_stream(
          1..10_000,
          fn i ->
            do_generate_remote_activity(i, user, users)
          end,
          max_concurrency: 10,
          timeout: 30_000
        )
        |> Stream.run()
      end)

    IO.puts("Inserting remote activities take #{to_sec(time)} sec.\n")
  end

  defp do_generate_remote_activity(i, user, users) do
    actor = Enum.random(users)
    %{host: host} = URI.parse(actor.ap_id)
    date = Date.utc_today()
    datetime = DateTime.utc_now()

    map = %{
      "actor" => actor.ap_id,
      "cc" => [actor.follower_address, user.ap_id],
      "context" => "tag:mastodon.example.org,#{date}:objectId=#{i}:objectType=Conversation",
      "id" => actor.ap_id <> "/statuses/#{i}/activity",
      "object" => %{
        "actor" => actor.ap_id,
        "atomUri" => actor.ap_id <> "/statuses/#{i}",
        "attachment" => [],
        "attributedTo" => actor.ap_id,
        "bcc" => [],
        "bto" => [],
        "cc" => [actor.follower_address, user.ap_id],
        "content" =>
          "<p><span class=\"h-card\"><a href=\"" <>
            user.ap_id <>
            "\" class=\"u-url mention\">@<span>" <> user.nickname <> "</span></a></span></p>",
        "context" => "tag:mastodon.example.org,#{date}:objectId=#{i}:objectType=Conversation",
        "conversation" =>
          "tag:mastodon.example.org,#{date}:objectId=#{i}:objectType=Conversation",
        "emoji" => %{},
        "id" => actor.ap_id <> "/statuses/#{i}",
        "inReplyTo" => nil,
        "inReplyToAtomUri" => nil,
        "published" => datetime,
        "sensitive" => true,
        "summary" => "cw",
        "tag" => [
          %{
            "href" => user.ap_id,
            "name" => "@#{user.nickname}@#{host}",
            "type" => "Mention"
          }
        ],
        "to" => ["https://www.w3.org/ns/activitystreams#Public"],
        "type" => "Note",
        "url" => "http://#{host}/@#{actor.nickname}/#{i}"
      },
      "published" => datetime,
      "to" => ["https://www.w3.org/ns/activitystreams#Public"],
      "type" => "Create"
    }

    Pleroma.Web.ActivityPub.ActivityPub.insert(map, false)
  end

  def generate_dms(user, users, opts) do
    IO.puts("Starting generating #{opts[:dms_max]} DMs")
    {time, _} = :timer.tc(fn -> do_generate_dms(user, users, opts) end)
    IO.puts("Inserting dms take #{to_sec(time)} sec.\n")
  end

  defp do_generate_dms(user, users, opts) do
    Task.async_stream(
      1..opts[:dms_max],
      fn _ ->
        do_generate_dm(user, users)
      end,
      max_concurrency: 10,
      timeout: 30_000
    )
    |> Stream.run()
  end

  defp do_generate_dm(user, users) do
    post = %{
      "status" => "@#{user.nickname} some direct message",
      "visibility" => "direct"
    }

    CommonAPI.post(Enum.random(users), post)
  end

  def generate_long_thread(user, users, opts) do
    IO.puts("Starting generating long thread with #{opts[:thread_length]} replies")
    {time, activity} = :timer.tc(fn -> do_generate_long_thread(user, users, opts) end)
    IO.puts("Inserting long thread replies take #{to_sec(time)} sec.\n")
    {:ok, activity}
  end

  defp do_generate_long_thread(user, users, opts) do
    {:ok, %{id: id} = activity} = CommonAPI.post(user, %{"status" => "Start of long thread"})

    Task.async_stream(
      1..opts[:thread_length],
      fn _ -> do_generate_thread(users, id) end,
      max_concurrency: 10,
      timeout: 30_000
    )
    |> Stream.run()

    activity
  end

  defp do_generate_thread(users, activity_id) do
    CommonAPI.post(Enum.random(users), %{
      "status" => "reply to main post",
      "in_reply_to_status_id" => activity_id
    })
  end

  def generate_non_visible_message(user, users) do
    IO.puts("Starting generating 1000 non visible posts")

    {time, _} =
      :timer.tc(fn ->
        do_generate_non_visible_posts(user, users)
      end)

    IO.puts("Inserting non visible posts take #{to_sec(time)} sec.\n")
  end

  defp do_generate_non_visible_posts(user, users) do
    [not_friend | users] = users

    make_friends(user, users)

    Task.async_stream(1..1000, fn _ -> do_generate_non_visible_post(not_friend, users) end,
      max_concurrency: 10,
      timeout: 30_000
    )
    |> Stream.run()
  end

  defp make_friends(_user, []), do: nil

  defp make_friends(user, [friend | users]) do
    {:ok, _} = User.follow(user, friend)
    {:ok, _} = User.follow(friend, user)
    make_friends(user, users)
  end

  defp do_generate_non_visible_post(not_friend, users) do
    post = %{
      "status" => "some non visible post",
      "visibility" => "private"
    }

    {:ok, activity} = CommonAPI.post(not_friend, post)

    thread_length = Enum.random([2, 3, 4, 5])

    Enum.each(1..thread_length, fn _ ->
      user = Enum.random(users)

      post = %{
        "status" => "@#{not_friend.nickname} reply to non visible post",
        "in_reply_to_status_id" => activity.id,
        "visibility" => "private"
      }

      CommonAPI.post(user, post)
    end)
  end
end