#include "interpreter.hh"
#include "error_handler.hh"
#include "tokenizer.hh"
#include "parser.hh"
#include <cstdint>
#include <fstream>
#include <iostream>
#include <optional>
#include <sysexits.h>

#define PROMPT "> "

extern ErrorHandler error_handler;

void run_file(const char *path);
void run_prompt();
void run(const std::string &code);

void run_interpreter(int argc, char *argv[]) {
  if (argc == 2) {
    run_file(argv[1]);
  } else {
    run_prompt();
  }
}

void run_file(const char *path) {
  if (std::ifstream source_code{path, std::ios::ate}) {
    uint64_t size = source_code.tellg();
    std::string code(size, '\0');
    source_code.seekg(0);
    source_code.read(&code[0], size);

    run(code);
    if (error_handler.had_error) {
      exit(EX_DATAERR);
    }
  }
}

void run_prompt() {
  std::string line{};
  std::cout << PROMPT;
  while (std::getline(std::cin, line)) {
    run(line);
    std::cout << PROMPT;
    error_handler.had_error = false;
  }
}

void run(const std::string &code) {
  Scanner scanner{code};
  std::vector<Token> tokens = scanner.scan_tokens();

  Parser parser{tokens};
  std::optional<Expr> expression = parser.parse();

  if (expression) {
    AstPrinter printer{};
    std::cout << printer.print(*expression) << '\n';
  }
}