defmodule Mix.Tasks.GenerateConfig do
  use Mix.Task

  @moduledoc """
  Generate a new config

  ## Usage
  ``mix generate_config``

  This mix task is interactive, and will overwrite the config present at ``config/generated_config.exs``.
  """

  def run(_) do
    IO.puts("Answer a few questions to generate a new config\n")
    IO.puts("--- THIS WILL OVERWRITE YOUR config/generated_config.exs! ---\n")
    domain = IO.gets("What is your domain name? (e.g. pleroma.soykaf.com): ") |> String.trim()
    name = IO.gets("What is the name of your instance? (e.g. Pleroma/Soykaf): ") |> String.trim()
    email = IO.gets("What's your admin email address: ") |> String.trim()

    secret = :crypto.strong_rand_bytes(64) |> Base.encode64() |> binary_part(0, 64)
    dbpass = :crypto.strong_rand_bytes(64) |> Base.encode64() |> binary_part(0, 64)

    resultSql = EEx.eval_file("lib/mix/tasks/sample_psql.eex", dbpass: dbpass)

    {web_push_public_key, web_push_private_key} = :crypto.generate_key(:ecdh, :prime256v1)

    result =
      EEx.eval_file(
        "lib/mix/tasks/sample_config.eex",
        domain: domain,
        email: email,
        name: name,
        secret: secret,
        dbpass: dbpass,
        web_push_public_key: Base.url_encode64(web_push_public_key, padding: false),
        web_push_private_key: Base.url_encode64(web_push_private_key, padding: false)
      )

    IO.puts(
      "\nWriting config to config/generated_config.exs.\n\nCheck it and configure your database, then copy it to either config/dev.secret.exs or config/prod.secret.exs"
    )

    File.write("config/generated_config.exs", result)

    IO.puts(
      "\nWriting setup_db.psql, please run it as postgre superuser, i.e.: sudo su postgres -c 'psql -f config/setup_db.psql'"
    )

    File.write("config/setup_db.psql", resultSql)
  end
end