defmodule CCXT.Exchanges do
  @moduledoc """
  Compile-time generator for all exchange modules.

  Reads the spec manifest and generates one module per exchange
  (e.g., `CCXT.Bybit`, `CCXT.Binance`) at compile time via `Module.create/3`.

  New exchange = new spec file in `priv/specs/json/output/`, zero Elixir code.

  ## How it works

  The manifest lists all exchange IDs. For each ID, this module calls
  `CCXT.Exchange.prepare_generate_data/1` to build the AST, then creates
  the module directly — same pipeline as `use CCXT.Exchange`, but without
  needing individual stub files.
  """

  @manifest_path CCXT.Spec.manifest_path()
  @external_resource @manifest_path

  @exchange_ids CCXT.Spec.load_manifest!()["exchanges"]

  for id <- @exchange_ids do
    module_name = Module.concat(CCXT, Macro.camelize(id))
    data = CCXT.Exchange.prepare_generate_data(id)
    display_name = data.exchange_name
    body = CCXT.Exchange.build_module_body(data, moduledoc: "#{display_name} exchange — generated from spec.")

    Module.create(module_name, body, Macro.Env.location(__ENV__))
  end
end