native_json_config.c

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/**
 * @file
 * @brief Provides lightweight JSON and conf value extraction helpers for manifests and config files.
 */
 
#include "native_json_config.h"
 
#include "native_support.h"
 
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
#ifdef _WIN32
#define pharos_json_strdup _strdup
#else
#define pharos_json_strdup strdup
#endif
 
char *json_find_string_after(const char *text, const char *key, const char *start_at) {
  char pattern[256];
  const char *cursor;
  const char *colon;
  const char *open_quote;
  const char *end_quote;
  size_t key_len;
  if (text == NULL || key == NULL) {
    return NULL;
  }
  snprintf(pattern, sizeof(pattern), "\"%s\"", key);
  cursor = strstr(start_at != NULL ? start_at : text, pattern);
  if (cursor == NULL) {
    return NULL;
  }
  key_len = strlen(pattern);
  colon = strchr(cursor + key_len, ':');
  if (colon == NULL) {
    return NULL;
  }
  open_quote = strchr(colon, '"');
  if (open_quote == NULL) {
    return NULL;
  }
  open_quote++;
  end_quote = open_quote;
  while (*end_quote != '\0') {
    if (*end_quote == '"' && end_quote[-1] != '\\') {
      break;
    }
    end_quote++;
  }
  if (*end_quote != '"') {
    return NULL;
  }
  return dup_range(open_quote, (size_t)(end_quote - open_quote));
}
 
char *json_find_string(const char *text, const char *key) {
  return json_find_string_after(text, key, text);
}
 
char *json_find_string_in_section(const char *text, const char *section, const char *key) {
  char pattern[256];
  const char *cursor;
  const char *brace;
  if (text == NULL || section == NULL || key == NULL) {
    return NULL;
  }
  snprintf(pattern, sizeof(pattern), "\"%s\"", section);
  cursor = strstr(text, pattern);
  if (cursor == NULL) {
    return NULL;
  }
  brace = strchr(cursor, '{');
  if (brace == NULL) {
    return NULL;
  }
  return json_find_string_after(text, key, brace);
}
 
char *json_extract_array_in_section(const char *text, const char *section, const char *key) {
  char section_pattern[256];
  char key_pattern[256];
  const char *section_cursor;
  const char *brace;
  const char *key_cursor;
  const char *colon;
  const char *open_bracket;
  const char *close_bracket;
  int depth;
  size_t len;
  char *result;
  if (text == NULL || section == NULL || key == NULL) {
    return NULL;
  }
  snprintf(section_pattern, sizeof(section_pattern), "\"%s\"", section);
  section_cursor = strstr(text, section_pattern);
  if (section_cursor == NULL) {
    return NULL;
  }
  brace = strchr(section_cursor, '{');
  if (brace == NULL) {
    return NULL;
  }
  snprintf(key_pattern, sizeof(key_pattern), "\"%s\"", key);
  key_cursor = strstr(brace, key_pattern);
  if (key_cursor == NULL) {
    return NULL;
  }
  colon = strchr(key_cursor + strlen(key_pattern), ':');
  if (colon == NULL) {
    return NULL;
  }
  open_bracket = strchr(colon, '[');
  if (open_bracket == NULL) {
    return NULL;
  }
  depth = 1;
  for (close_bracket = open_bracket + 1; *close_bracket != '\0' && depth > 0; close_bracket++) {
    if (*close_bracket == '[') {
      depth++;
    } else if (*close_bracket == ']') {
      depth--;
    }
  }
  if (depth != 0) {
    return NULL;
  }
  len = (size_t)(close_bracket - open_bracket);
  result = (char *)malloc(len + 1);
  if (result == NULL) {
    return NULL;
  }
  memcpy(result, open_bracket, len);
  result[len] = '\0';
  return result;
}
 
char *conf_lookup_value_in_text(const char *text, const char *key) {
  const char *cursor;
  size_t key_len;
  if (text == NULL || key == NULL) {
    return NULL;
  }
  key_len = strlen(key);
  cursor = text;
  while (*cursor != '\0') {
    const char *line_end = strchr(cursor, '\n');
    size_t line_len = line_end != NULL ? (size_t)(line_end - cursor) : strlen(cursor);
    char *line = dup_range(cursor, line_len);
    char *eq;
    char *value_copy;
    if (line == NULL) {
      return NULL;
    }
    trim_in_place(line);
    if (line[0] != '\0' && line[0] != '#') {
      eq = strchr(line, '=');
      if (eq != NULL) {
        *eq = '\0';
        trim_in_place(line);
        trim_in_place(eq + 1);
        if (strlen(line) == key_len && strcmp(line, key) == 0) {
          value_copy = pharos_json_strdup(eq + 1);
          free(line);
          return value_copy;
        }
      }
    }
    free(line);
    if (line_end == NULL) {
      break;
    }
    cursor = line_end + 1;
  }
  return NULL;
}
 
char *conf_lookup_value(const char *path, const char *key) {
  char *text;
  char *value;
  if (path == NULL || key == NULL) {
    return NULL;
  }
  text = read_file_text(path);
  if (text == NULL) {
    return NULL;
  }
  value = conf_lookup_value_in_text(text, key);
  free(text);
  return value;
}