#include "token.hh"
#include "scanner.hh"
#include <iostream>
#include <fstream>
#include <string>
#include <sysexits.h>
#include <cstdint>
#include <vector>

#define PROMPT "> "

static bool had_error = false;

void run_file(const char *path);
void run_prompt();
void run(const std::string &code);
void error(int line, const std::string &message);
void report(int line, const std::string &where, const std::string &message);

int main(int argc, char *argv[]) {
  if (argc > 2) {
    std::cout << "Usage: cclox [script]\n";
    exit(EX_USAGE);
  }

  if (argc == 2) {
    run_file(argv[1]);
  } else {
    run_prompt();
  }

  return 0;
}

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 (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;
    had_error = false;
  }
}

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

  for (auto token : tokens) {
    std::cout << token << '\n';
  }
}

void error(int line, const std::string &message) {
  report(line, "", message);
}

void report(int line, const std::string &where, const std::string &message) {
  std::cout << "[line " << line << "] Error" << where << ": " << message << '\n';
  had_error = true;
}