#if 0
gcc -fsanitize=address,undefined,leak gen_inl.c -o gen_inl && ./gen_inl
exit
#endif

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

char *HEADERS[] = { "source/kit/types.h",
                    "source/kit/status.h",
                    "source/kit/allocator.h",
                    "source/kit/thread_defs.h",
                    "source/kit/thread.h",
                    "source/kit/atomic.h",
                    "source/kit/mutex.h",
                    "source/kit/condition_variable.h",
                    "source/kit/array_ref.h",
                    "source/kit/string_ref.h",
                    "source/kit/dynamic_array.h",
                    "source/kit/lower_bound.h",
                    "source/kit/move_back.h",
                    "source/kit/bigint.h",
                    "source/kit/input_stream.h",
                    "source/kit/input_buffer.h",
                    "source/kit/async_function.h",
                    "source/kit/file.h",
                    "source/kit/mersenne_twister_64.h",
                    "source/kit/secure_random.h",
                    "source/kit/sha256.h",
                    "source/kit/sockets.h" };

char *IMPL[] = { "source/kit/allocator.c",
                 "source/kit/thread.posix.c",
                 "source/kit/thread.win32.c",
                 "source/kit/atomic.win32.c",
                 "source/kit/mutex.c",
                 "source/kit/condition_variable.c",
                 "source/kit/dynamic_array.c",
                 "source/kit/input_stream.c",
                 "source/kit/input_buffer.c",
                 "source/kit/file.c",
                 "source/kit/mersenne_twister_64.c",
                 "source/kit/secure_random.c",
                 "source/kit/sha256.c" };

char *repeat(int n, char c) {
  static char buf[200];
  for (int i = 0; i < n && i < 199; i++) buf[i] = c;
  buf[n] = '\0';
  return buf;
}

int skip_whitespaces(char *line, int i) {
  while (line[i] == ' ') i++;
  return i;
}

int skip(char *line, int i, char *s) {
  int j = 0;
  while (s[j] != '\0') {
    if (line[i] != s[j])
      return -1;
    i++;
    j++;
  }
  return i;
}

int is_local_include(char *line) {
  if (line[0] != '#')
    return 0;
  int i = skip_whitespaces(line, 1);
  i     = skip(line, i, "include");
  if (i == -1)
    return 0;
  i = skip_whitespaces(line, i);
  if (line[i] != '"')
    return 0;
  return 1;
}

int is_empty_line(char *line) {
  int i = skip_whitespaces(line, 0);
  return line[i] == '\0' || line[i] == '\n';
}

int write_file(FILE *out, char *source) {
  assert(out != NULL);
  assert(source != NULL);

  FILE *in = fopen(source, "rt");

  if (in == NULL) {
    fprintf(stderr, "File not found: %s\n", source);
    return 1;
  }

  fprintf(out, "/*%s*\n", repeat(67, '*'));
  fprintf(out, " *%s*\n", repeat(67, ' '));
  fprintf(out, " *    File:   %s%s*\n", source,
          repeat(55 - strlen(source), ' '));
  fprintf(out, " *%s*\n", repeat(67, ' '));
  fprintf(out, " *%s*/\n", repeat(67, '*'));

  char line[200];
  char buf[400];

  while (fgets(line, 199, in) != NULL) {
    if (is_empty_line(line) || is_local_include(line))
      continue;

    int j = 0;
    for (int i = 0; line[i] != '\0'; i++) {
      if (line[i] == '\t') {
        buf[j++] = ' ';
        buf[j++] = ' ';
      } else if (line[i] != '\n' && line[i] != '\r')
        buf[j++] = line[i];
    }
    buf[j] = '\0';
    fprintf(out, "%s\n", buf);
  }

  fclose(in);
  return 0;
}

int main(int argc, char **argv) {
  char *out_file = "./include/kit.inl.h";
  FILE *out      = fopen(out_file, "wt");

  if (out == NULL) {
    fprintf(stderr, "Can't write: %s\n", out_file);
    return 1;
  }

  fprintf(out, "#ifndef KIT_INL_H\n");
  fprintf(out, "#define KIT_INL_H\n");

  for (int i = 0; i < sizeof HEADERS / sizeof *HEADERS; i++)
    if (write_file(out, HEADERS[i]) != 0) {
      fclose(out);
      return 1;
    }

  fprintf(out, "#ifdef KIT_IMPLEMENTATION\n");

  for (int i = 0; i < sizeof IMPL / sizeof *IMPL; i++)
    if (write_file(out, IMPL[i]) != 0) {
      fclose(out);
      return 1;
    }

  fprintf(out, "#endif\n");
  fprintf(out, "#endif\n");

  fclose(out);
  return 0;
}