(* This Source Code Form is subject to the terms of the Mozilla Public License,
  v. 2.0. If a copy of the MPL was not distributed with this file, You can
  obtain one at https://mozilla.org/MPL/2.0/. *)
program;

from FIO import Close, IsNoError, File, OpenToRead, OpenToWrite, StdErr, StdOut, WriteLine, WriteString;
from M2RTS import HALT, ExitOnHalt;

from Lexer import Lexer, lexer_destroy, lexer_initialize;
from Transpiler import transpile;
from CommandLineInterface import CommandLine, parse_command_line;
from Parser import AstModule, parse;
from Strings import Length;

var
  command_line: ^CommandLine;

proc compile_from_stream();
var
  lexer: Lexer;
  source_input: File;
  source_output: File;
  ast_module: ^AstModule;
begin
  source_input := OpenToRead(command_line^.input);

  if IsNoError(source_input) = false then
    WriteString(StdErr, 'Fatal error: failed to read the input file "');
    WriteString(StdErr, command_line^.input);
    WriteString(StdErr, '".');
    WriteLine(StdErr);

    ExitOnHalt(2)
  end;
  source_output := nil;

  if Length(command_line^.output) > 0 then
    source_output := OpenToWrite(command_line^.output);

    if IsNoError(source_output) = false then
      WriteString(StdErr, 'Fatal error: failed to create the output file "');
      WriteString(StdErr, command_line^.output);
      WriteString(StdErr, '".');
      WriteLine(StdErr);
     
      ExitOnHalt(2)
    end
  end;

  if IsNoError(source_input) then
    lexer_initialize(@lexer, source_input);

    ast_module := parse(@lexer);
    transpile(ast_module, StdOut, source_output, command_line^.input);

    lexer_destroy(@lexer);

    Close(source_output);
    Close(source_input)
  end
end;

begin
  ExitOnHalt(0);
  command_line := parse_command_line();

  if command_line <> nil then
    compile_from_stream()
  end;
  if command_line = nil then
    ExitOnHalt(1)
  end;
  HALT()
end.