/*
 * *****************************************************************************
 *
 * Copyright 2018 Gavin D. Howard
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 *
 * *****************************************************************************
 *
 * Generates a const array from a bc script.
 *
 */

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

#include <libgen.h>

const char *bc_gen_usage = "usage: gen bc_script output [header]\n";

#define INVALID_PARAMS (1)
#define MALLOC_FAIL (2)
#define INVALID_INPUT_FILE (3)
#define INVALID_OUTPUT_FILE (4)
#define INVALID_HEADER_FILE (5)
#define IO_ERR (6)

#define MAX_WIDTH (74)

int main(int argc, char *argv[]) {

  FILE *in;
  FILE *out;
  FILE *header;
  char *header_name;
  char *header_buf;
  int c;
  int count;
  char *buffer;
  size_t len, read;
  char *buf;
  char *base;
  int err;
  int slashes;

  err = 0;

  if (argc < 3) {
    printf("%s", bc_gen_usage);
    return INVALID_PARAMS;
  }

  buf = malloc(strlen(argv[1]) + 1);

  if (!buf) return MALLOC_FAIL;

  strcpy(buf, argv[1]);

  base = basename(buf);

  in = fopen(argv[1], "r");

  if (!in) {
    err = INVALID_INPUT_FILE;
    goto in_err;
  }

  out = fopen(argv[2], "w");

  if (!out) {
    err = INVALID_OUTPUT_FILE;
    goto out_err;
  }

  if (argc >= 4) header_name = argv[3];
  else header_name = "lib/header.c";

  header = fopen(header_name, "r");

  if (!header) {
    err = INVALID_HEADER_FILE;
    goto header_err;
  }

  fseek(header, 0, SEEK_END);
  len = ftell(header);
  fseek(header, 0, SEEK_SET);

  buffer = malloc(len + 1);

  if (!buffer) {
    err = MALLOC_FAIL;
    goto buffer_err;
  }

  read = fread(buffer, 1, len, header);

  if (read != len) {
    err = IO_ERR;
    goto header_buf_err;
  }

  buffer[len] = '\0';

  header_buf = malloc(len + strlen(base) + 1);

  if (!header_buf) {
    err= MALLOC_FAIL;
    goto header_buf_err;
  }

  if (sprintf(header_buf, buffer, base) < 0) {
    err = IO_ERR;
    goto error;
  }

  count = 0;

  if (fputs(header_buf, out) == EOF) {
    err = IO_ERR;
    goto error;
  }

  if (fprintf(out, "const char *bc_lib_name = \"%s\";\n\n", base) < 0) {
    err = IO_ERR;
    goto error;
  }

  if (fprintf(out, "const char bc_lib[] = {\n") < 0) {
    err = IO_ERR;
    goto error;
  }

  slashes = 0;

  while (slashes < 2 && (c = fgetc(in)) >= 0) {
    if (slashes == 1 && c == '/' && fgetc(in) == '\n') ++slashes;
    if (!slashes && c == '/' && fgetc(in) == '*') ++slashes;
  }

  if (c < 0) {
    err = INVALID_INPUT_FILE;
    goto error;
  }

  while ((c = fgetc(in)) >= 0) {

    int val;

    if (!count) {
      if (fprintf(out, "  ") < 0) {
        err = IO_ERR;
        goto error;
      }
    }

    val = fprintf(out, "%d,", c);

    if (val < 0) {
      err = IO_ERR;
      goto error;
    }

    count += val;

    if (count > MAX_WIDTH) {

      count = 0;

      if (fputc('\n', out) == EOF) {
        err = IO_ERR;
        goto error;
      }
    }
  }

  if (!count) {
    if (fputc(' ', out) == EOF || fputc(' ', out) == EOF) {
      err = IO_ERR;
      goto error;
    }
  }
  if (fprintf(out, "0\n};\n") < 0) {
    err = IO_ERR;
    goto error;
  }

error:

  free(header_buf);

header_buf_err:

  free(buffer);

buffer_err:

  fclose(header);

header_err:

  fclose(out);

out_err:

  fclose(in);

in_err:

  free(buf);

  return err;
}