defmodule Mix.Tasks.Blog.Server do
  @shortdoc "Run the blog preview and Micropub editing servers"
  @moduledoc """
  Starts two Bandit servers from a single supervisor:

  * **Preview server** on port 4000 — serves the built `_site/` directory
    for local browser preview.
  * **API server** on port 4010 — Micropub + XML-RPC endpoint for MarsEdit.

      mix blog.server [--api-port 4010] [--preview-port 4000]

  Ports default to 4000 (preview) and 4010 (API) but can be set in config:

      config :static_blog, :preview_port, 4000
      config :static_blog, :api_port, 4010

  Command-line flags override config values.

  Before running, set a bearer token in the environment. The environment
  variable name defaults to `BLOG_TOKEN` but can be overridden via
  `config :static_blog, :auth_token_env_var, "MY_TOKEN"`.

  Press `Ctrl+C` twice to stop.

  """
  use Mix.Task

  alias StaticBlog.Web.Server

  @impl Mix.Task
  def run(argv) do
    {options, _, _} =
      OptionParser.parse(argv, switches: [api_port: :integer, preview_port: :integer])

    default_api_port = Application.get_env(:static_blog, :api_port, 4010)
    default_preview_port = Application.get_env(:static_blog, :preview_port, 4000)
    api_port = Keyword.get(options, :api_port, default_api_port)
    preview_port = Keyword.get(options, :preview_port, default_preview_port)

    token_var = Application.get_env(:static_blog, :auth_token_env_var, "BLOG_TOKEN")

    unless System.get_env(token_var) do
      Mix.raise("""
      #{token_var} is not set.

      Generate a long random string and export it before running the server:

          export #{token_var}=$(openssl rand -hex 32)
          mix blog.server
      """)
    end

    Mix.Task.run("app.start")
    Application.ensure_all_started(:bandit)

    micropub_url = "http://localhost:#{api_port}/micropub"
    Application.put_env(:static_blog, :micropub_url, micropub_url)

    Mix.shell().info([:cyan, "→ Rebuilding _site/ with local micropub URL…"])
    {:ok, _} = StaticBlog.Generator.build("_site", StaticBlog.RuntimePosts.all())

    children = Server.child_specs(api_port, preview_port)

    {:ok, _pid} =
      Supervisor.start_link(children, strategy: :one_for_one)

    Mix.shell().info([
      :green,
      "✓ Preview   ",
      :reset,
      "http://localhost:#{preview_port}/"
    ])

    Mix.shell().info([
      :green,
      "✓ Micropub  ",
      :reset,
      micropub_url
    ])

    Mix.shell().info("Press Ctrl+C twice to stop.")
    Process.sleep(:infinity)
  end
end