#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>

#include "lexer.h"

int read_file(const char * filename, uint8_t ** buf)
{
  FILE * file = fopen(filename, "rb");
  if (file == NULL) {
    fprintf(stderr, "fopen(\"%s\", \"rb\"): %s\n", filename, strerror(errno));
    return -1;
  }

  int ret;
  ret = fseek(file, 0L, SEEK_END);
  if (ret < 0) {
    fprintf(stderr, "fseek(SEEK_END)");
    return -1;
  }

  int offset = ftell(file);
  if (offset < 0) {
    fprintf(stderr, "ftell");
    return -1;
  }
  int size = offset;

  ret = fseek(file, 0L, SEEK_SET);
  if (ret < 0) {
    fprintf(stderr, "fseek(SEEK_SET)");
    return -1;
  }

  fprintf(stderr, "read_file: %s size %d\n", filename, size);
  *buf = (uint8_t *)malloc(size);
  int fread_size = fread(*buf, 1, size, file);
  if (fread_size != size) {
    fprintf(stderr, "fread `%s` short read: %d ; expected: %d\n", filename, fread_size, size);
    return -1;
  }

  ret = fclose(file);
  if (ret < 0) {
    fprintf(stderr, "fclose");
    return -1;
  }

  return size;
}

const char * token_str[] = {
  [TOKEN_INVALID] = "TOKEN_INVALID",
  [TOKEN_EOF] = "TOKEN_EOF",
  [TOKEN_IDENTIFIER] = "TOKEN_IDENTIFIER",
  [TOKEN_CONSTANT] = "TOKEN_CONSTANT",
  [TOKEN_INT] = "TOKEN_INT",
  [TOKEN_VOID] = "TOKEN_VOID",
  [TOKEN_RETURN] = "TOKEN_RETURN",
  [TOKEN_LPAREN] = "TOKEN_LPAREN",
  [TOKEN_RPAREN] = "TOKEN_RPAREN",
  [TOKEN_LBRACE] = "TOKEN_LBRACE",
  [TOKEN_RBRACE] = "TOKEN_RBRACE",
  [TOKEN_SEMICOLON] = "TOKEN_SEMICOLON",
};

int main(int argc, char * argv[])
{
  if (argc != 3) {
    fprintf(stderr, "argc != 3 %d %s\n", argc, argv[1]);
    return EXIT_FAILURE;
  }

  // --lex
  // --parse
  // --codegen

  uint8_t * buf;
  int size = read_file(argv[2], &buf);
  if (size < 0) {
    return EXIT_FAILURE;
  }

  struct lexer_state lexer_state;
  lexer_state.buf = buf;
  lexer_state.offset = 0;
  lexer_state.size = size;

  while (true) {
    struct token token = lexer_next_token(&lexer_state);
    printf("%s\n", token_str[token.type]);
    if (token.type == TOKEN_INVALID)
      return EXIT_FAILURE;
    if (token.type == TOKEN_EOF)
      break;
  }
  return EXIT_SUCCESS;
}