#include <sys/stat.h>

#include <errno.h>

#include <fcntl.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include "jv.h"

#include "jv_unicode.h"

jv jv_load_file(const char* filename, int raw) {

  struct stat sb;

  int fd = open(filename, O_RDONLY);

  if (fd == -1) {

    return jv_invalid_with_msg(jv_string_fmt("Could not open %s: %s",

                                             filename,

                                             strerror(errno)));

  }

  if (fstat(fd, &sb) == -1 || S_ISDIR(sb.st_mode)) {

    close(fd);

    return jv_invalid_with_msg(jv_string_fmt("Could not open %s: %s",

                                             filename,

                                             "It's a directory"));

  }

  FILE* file = fdopen(fd, "r");

  struct jv_parser* parser = NULL;

  jv data;

  if (!file) {

    close(fd);

    return jv_invalid_with_msg(jv_string_fmt("Could not open %s: %s",

                                             filename,

                                             strerror(errno)));

  }

  if (raw) {

    data = jv_string("");

  } else {

    data = jv_array();

    parser = jv_parser_new(0);

  }

  // To avoid mangling UTF-8 multi-byte sequences that cross the end of our read

  // buffer, we need to be able to read the remainder of a sequence and add that

  // before appending.

  const int max_utf8_len = 4;

  char buf[4096+max_utf8_len];

  while (!feof(file) && !ferror(file)) {

    size_t n = fread(buf, 1, sizeof(buf)-max_utf8_len, file);

    int len = 0;

    if (n == 0)

      continue;

    if (jvp_utf8_backtrack(buf+(n-1), buf, &len) && len > 0 &&

        !feof(file) && !ferror(file)) {

      n += fread(buf+n, 1, len, file);

    }

    if (raw) {

      data = jv_string_append_buf(data, buf, n);

    } else {

      jv_parser_set_buf(parser, buf, n, !feof(file));

      jv value;

      while (jv_is_valid((value = jv_parser_next(parser))))

        data = jv_array_append(data, value);

      if (jv_invalid_has_msg(jv_copy(value))) {

        jv_free(data);

        data = value;

        break;

      }

    }

  }

  if (!raw)

      jv_parser_free(parser);

  int badread = ferror(file);

  if (fclose(file) != 0 || badread) {

    jv_free(data);

    return jv_invalid_with_msg(jv_string_fmt("Error reading from %s",

                                             filename));

  }

  return data;

}