blinky-esp/main/presets.cpp

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

#include <cJSON.h>

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


/* Sadly, need to define these here */

extern Pattern* json_gradient_pattern(cJSON *pattern, const Presets::ColorMap &colors);
extern Pattern* json_random_pattern(cJSON *pattern, const Presets::ColorMap &colors);
extern Pattern* json_sparkle_pattern(cJSON *pattern, const Presets::ColorMap &colors);

namespace Presets {

/* Factory */

typedef Pattern* (*PatternGenerator)(cJSON*, const Presets::ColorMap&);

static const std::map <std::string, PatternGenerator> generators {
    {"gradient", json_gradient_pattern},
    {"random",   json_random_pattern},
    {"sparkle",   json_sparkle_pattern},
};


/* 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
    };
}

Color json_color(cJSON *json, const ColorMap &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 ColorMap &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);

    auto iter = generators.find(type);
    if (iter == generators.end()) {
        ESP_LOGE(TAG, "Unknown pattern type: %s", type.c_str());
        return NULL;
    }

    return iter->second(pattern, colors);
}

void reload() {
    if (generators.empty()) {
        ESP_LOGE(TAG, "No pattern generators defined!");
        return;
    }

    ColorMap 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