// json.h #pragma once #include "cJSON.h" #include #include #include // The `nspanel_ha_blueprint` namespace encapsulates utility functions for JSON manipulation // tailored for the NSPanel Home Assistant Blueprint project. namespace nspanel_ha_blueprint { /** * Compares the string value of a cJSON object with a target C-string. * * This function checks if the given cJSON object is not NULL, is a string type, * and its value matches the target string provided. * * @param json_item The cJSON object whose string value is to be compared. * @param target_str The target C-string to compare against the cJSON object's value. * @return True if the cJSON object's string value matches the target string, false otherwise. */ bool json_cmp_string(const cJSON* json_item, const char* target_str) { if (json_item != NULL && cJSON_IsString(json_item) && json_item->valuestring != NULL) { return strcmp(json_item->valuestring, target_str) == 0; } return false; } /** * Compares the integer value of a cJSON object with a target unsigned integer. * * This function checks if the given cJSON object is not NULL, represents a number, * and its integer value matches the target unsigned integer provided. It's particularly * useful for JSON fields that are expected to contain numeric boolean values (e.g., 0 or 1) * or other unsigned integer values. * * @param json_item The cJSON object whose integer value is to be compared. * @param target_uint The target unsigned integer to compare against the cJSON object's value. * @return True if the cJSON object's integer value matches the target unsigned integer, false otherwise. */ bool json_cmp_uint(const cJSON* json_item, unsigned int target_uint) { if (json_item != NULL && cJSON_IsNumber(json_item)) { return (unsigned int)json_item->valueint == target_uint; } return false; } /** * Retrieves a string value from a cJSON item or returns a default value if the item is not a string. * * @param json_item The cJSON item from which to retrieve the string value. * @param default_value The default value to return if the cJSON item is not a string. Defaults to "". * @return The string value of the cJSON item, or the default value if the item is not a string. */ const char* json_get_text(const cJSON* json_item, const char* default_value = "") { if (json_item != NULL && cJSON_IsString(json_item) && json_item->valuestring != NULL) { return json_item->valuestring; } return default_value; } /** * Retrieves a floating-point value from a cJSON object. * * @param json_item The cJSON object from which to retrieve the value. * @return The floating-point value of the cJSON object if it is a number, NaN otherwise. */ float json_get_float(const cJSON* json_item) { if (json_item != NULL && cJSON_IsNumber(json_item)) { return static_cast(json_item->valuedouble); } return std::nan(""); // Return NaN if not a valid number } /** * Extracts RGB color values from a cJSON array. * * This function is designed to extract an array of integers from a given cJSON array object, * specifically targeting RGB color values. It expects the array to contain exactly three integers, * each representing the red, green, and blue components of a color, in that order. * * @param value The cJSON array object from which to extract the RGB values. This object * should be an array containing exactly three elements, each of which should * be an integer between 0 and 255. * @return A dynamically allocated array of three integers, representing the RGB color * values extracted from the JSON array. The caller is responsible for freeing * this memory using `free()` once the array is no longer needed. If the input * does not meet the expected format (not an array, not exactly three elements, * or contains non-integer values), the function returns NULL. * * Example JSON input: {"page": "light", "component": "rgb_color", "value": [127, 255, 159]} * In this example, the function would return an int array containing {127, 255, 159}. * * Note: This function performs dynamic memory allocation for the returned array. * It's crucial to free the allocated memory using `free()` when done with the array * to prevent memory leaks. */ int* json_extract_rgb_array(const cJSON* value) { if (!cJSON_IsArray(value) || cJSON_GetArraySize(value) != 3) { return NULL; // Ensures the array exists and contains exactly 3 elements } int* rgb = (int*)malloc(3 * sizeof(int)); // Allocate space for 3 integers if (!rgb) { return NULL; // Allocation failed } for (int i = 0; i < 3; ++i) { cJSON* item = cJSON_GetArrayItem(value, i); if (!cJSON_IsNumber(item)) { free(rgb); return NULL; // Ensures all elements are numbers } rgb[i] = item->valueint; } return rgb; } /** * Converts a JSON integer percentage value to a string representing a floating-point number between 0.00 and 1.00. * * @param json_item The cJSON object containing the integer percentage value. * @return A string representation of the floating-point number, or an empty string if the input is invalid. */ std::string json_percentage_to_float_string(const cJSON* json_item) { // Ensure the item is a valid number if (json_item != NULL && cJSON_IsNumber(json_item)) { // Convert the integer percentage to a float between 0.00 and 1.00 float percentage = static_cast(json_item->valueint) / 100.0f; // Buffer to hold the formatted string, large enough for "0.00" plus null terminator char buffer[8]; // Format the floating-point number with two decimal places snprintf(buffer, sizeof(buffer), "%.2f", percentage); // Return the formatted string return std::string(buffer); } // Return an empty string to indicate invalid input or non-numeric JSON item return ""; } } // namespace nspanel_ha_blueprint