blinky-esp/main/presets.cpp

static const char *TAG = "presets";
#include <esp_log.h>

#include <cJSON.h>

#include "presets.hpp"
#include "utils.hpp"


namespace Presets {

/* Preset Map */

std::map <std::string, const Pattern*> map;

const Pattern* find(const std::string &name) {
    auto e = map.find(name);
    return e == map.end() ? NULL : e->second;
}

std::map<std::string, const Pattern*>::const_iterator map_begin() {
    return map.begin();
}

std::map<std::string, const Pattern*>::const_iterator map_end() {
    return map.end();
}

static inline cJSON* load_json(const char *path) {
    return cJSON_Parse(read_file(path).c_str());
}


/* Preset Loader */

static Color json_raw_color(cJSON *json) {
    if (json->type != cJSON_Array) {
        ESP_LOGE(TAG, "Not an array: %s", json->string);
        return {0, 0, 0};
    }
    int count = cJSON_GetArraySize(json);
    if (count != 3) {
        ESP_LOGE(TAG, "Wrong size for %s: %d", json->string, count);
        return {0, 0, 0};
    }
    // TODO: Number checks for array elements?
    return Color{
        (uint8_t)cJSON_GetArrayItem(json, 0)->valueint,
        (uint8_t)cJSON_GetArrayItem(json, 1)->valueint,
        (uint8_t)cJSON_GetArrayItem(json, 2)->valueint
    };
}

static Color json_color(cJSON *json, const std::map <std::string, Color> &colors) {
    if (json->type == cJSON_Array) return json_raw_color(json);
    if (json->type != cJSON_String) {
        ESP_LOGE(TAG, "Not a string: %s", json->string);
        return {0, 0, 0};
    }
    auto iter = colors.find(json->valuestring);
    if (iter == colors.end()) {
        ESP_LOGE(TAG, "Not a color: %s", json->valuestring);
        return {0, 0, 0};
    }
    return iter->second;
}

static Pattern* json_pattern(cJSON *json, const std::map <std::string, Color> &colors) {
    if (json->type != cJSON_Object) {
        ESP_LOGE(TAG, "Not an object: %s", json->string);
        return NULL;
    }

    cJSON *pattern = json->child;
    std::string type(pattern->string);

    if (type == "gradient") {
        if (pattern->type != cJSON_Object) {
            ESP_LOGE(TAG, "Not an object: %s", pattern->type);
            return NULL;
        }
        cJSON *jcolors = cJSON_GetObjectItem(pattern, "colors");
        if (!jcolors) {
            ESP_LOGE(TAG, "No colors for %s", json->string);
            return NULL;
        }
        if (jcolors->type != cJSON_Array) {
            ESP_LOGE(TAG, "Not an array: %s", jcolors->string);
            return NULL;
        }
        Gradient *gradient = Gradient::make(cJSON_GetArraySize(jcolors));
        int i = 0;
        cJSON *jcolor;
        cJSON_ArrayForEach(jcolor, jcolors) {
            Color color = json_color(jcolor, colors);
            gradient->colors[i++] = color;
        }
        return new GradientPattern(gradient);

    } else {
        ESP_LOGE(TAG, "Unknown pattern type: %s", type.c_str());
    }

    return NULL;
}

void reload() {
    std::map <std::string, Color> colors;
    cJSON *jcolors = load_json("/spiffs/colors.json");
    if (!jcolors) {
        ESP_LOGW(TAG, "No preset colors!");
    } else {
        cJSON *jcolor;
        cJSON_ArrayForEach(jcolor, jcolors) {
            Color color = json_color(jcolor, colors);
            colors[jcolor->string] = color;
        }
        cJSON_Delete(jcolors);
    }

    for (const auto &k_v : map) delete k_v.second;
    map.clear();

    cJSON *jpresets = load_json("/spiffs/presets.json");
    if (!jpresets) {
        ESP_LOGE(TAG, "No preset patterns!");
    } else {
        cJSON *jpreset;
        cJSON_ArrayForEach(jpreset, jpresets) {
            Pattern *pattern = json_pattern(jpreset, colors);
            if (pattern) {
                ESP_LOGI(TAG, "Creating preset: %s", jpreset->string);
                map[jpreset->string] = pattern;
            }
        }
        cJSON_Delete(jpresets);
    }
}

} // Presets