#!/usr/bin/env swipl

:- initialization(main, main).

:- consult(log).
:- consult(parser).
:- consult(types).

main(Args) :-
    log:set_verbosity(1), % Default verbosity, can be adjusted
    ( Args = [FilePath | VerbosityArgs] ->
        ( VerbosityArgs = [VerbosityArg | _], atom_string(VerbosityAtom, VerbosityArg), atom_number(VerbosityAtom, VLevel) ->
            log:set_verbosity(VLevel),
            format(user_error, 'Verbosity set to ~w from command line.~n', [VLevel])
        ; format(user_error, 'Using default verbosity 1. Add a number (0-2) after filepath to change.~n', [])
        ),
        type_check_file(FilePath)
    ; writeln(user_error, 'Usage: type_check_file.pl <filepath> [verbosity_level]'),
      halt(1)
    ).

type_check_file(FilePath) :-
    ( exists_file(FilePath) ->
        read_file_to_string(FilePath, CodeString, []),
        format(user_output, "--- Type Checking File: ~w ---~n", [FilePath]),
        format(user_output, "Code:~n~s~n~n", [CodeString]),
        ( parser:parse(CodeString, AST) ->
            format(user_output, "Parsed AST: ~w~n", [AST]),
            types:initial_env(EmptyEnv),
            ( catch(types:infer_type(AST, EmptyEnv, InferredType), Error, (
                log:log(error, caught_error_in_type_check_file(Error)),
                log:explain_error(Error, Explanation),
                format(user_output, "Type Inference Error: ~w~n", [Explanation]),
                InferredType = error(Error) % Represent error
                )) -> true
            ; InferredType = 'inference_failed_silently_in_type_check_file'
            ),
            format(user_output, "~n--- Inferred Type for the whole expression ---~n~w~n~n", [InferredType]),
            ( InferredType = error(_) ; InferredType = 'inference_failed_silently_in_type_check_file' ->
                halt(1)
            ; halt(0)
            )
        ; format(user_error, "Parse FAILED for file: ~w~n", [FilePath]),
          halt(1)
        )
    ; format(user_error, "File not found: ~w~n", [FilePath]),
      halt(1)
    ).