let usage =
  {|coollang toolchain

사용법:
  cool check <file.cool>...   타입/effect/capability 검사 (fast path)
  cool run <file.cool>        typed IR 인터프리터로 실행
  cool tokens <file.cool>     토큰 덤프 (렉서 디버깅)
  cool ast <file.cool>        구문 트리 덤프 (파서 디버깅)
  cool version                버전 출력
|}

let report_errors errors =
  List.iter (fun e -> prerr_endline (Coollang.Driver.string_of_error e)) errors;
  1

let report = function Ok () -> 0 | Error errors -> report_errors errors

let dump_tokens file =
  match Coollang.Driver.tokens file with
  | Error errors -> report_errors errors
  | Ok tokens ->
      List.iter (fun t -> print_endline (Coollang.Token.show t)) tokens;
      0

let dump_ast file =
  match Coollang.Driver.ast file with
  | Error errors -> report_errors errors
  | Ok m ->
      List.iter
        (fun it -> print_endline (Coollang.Ast.show_item it))
        m.Coollang.Ast.items;
      0

let () =
  let argv = Array.to_list Sys.argv in
  let code =
    match List.tl argv with
    | "check" :: files -> report (Coollang.Driver.check files)
    | [ "run"; file ] -> report (Coollang.Driver.run file)
    | [ "tokens"; file ] -> dump_tokens file
    | [ "ast"; file ] -> dump_ast file
    | [ "version" ] ->
        print_endline Coollang.Version.string;
        0
    | [] | [ "help" ] | [ "--help" ] | [ "-h" ] ->
        print_string usage;
        0
    | cmd :: _ ->
        Printf.eprintf "알 수 없는 명령: %s\n\n%s" cmd usage;
        2
  in
  exit code