#include "config.h"
#include "log.h"

#ifdef ESP32

#include <nvs_flash.h>
#include <Preferences.h>

Preferences config;

void configSetup() {
  config.begin("config", false);
  const String &stored = config.getString("HOSTNAME", "");
  if (!stored.equals(HOSTNAME)) {
    error(R"([WARNING] Stored config hostname mismatch: "%s" != "%s" [WARNING])", stored.c_str(), HOSTNAME);
  }
}

void configReset() {
  info("[CONFIG RESET]");
  config.end();
  nvs_flash_erase();
  nvs_flash_init();
  config.begin("config", false);
  config.putString("HOSTNAME", HOSTNAME);
  configLoaded();
}

String configGetString(const char *name, const char *fallback, bool allowEmpty) {
  if (!config.isKey(name)) {
    return fallback;
  }
  String value = config.getString(name);
  if (!allowEmpty && value.isEmpty()) {
    return fallback;
  }
  return value;
}

bool configPutString(const char *name, const char *value) {
  return config.putString(name, value) == strlen(value);
}

double configGetDouble(const char *name, double fallback) {
  if (!config.isKey(name)) {
    return fallback;
  }
  return config.getDouble(name);
}

bool configPutDouble(const char *name, double value) {
  return config.value(name, value) == 0;
}

#else

#include <EEPROM.h>
#include <ArduinoJson.h>

JsonDocument json;

bool configRead();

bool configWrite();

size_t configWriteBytes(int *address, uint8_t *data, size_t size);

size_t configReadBytes(int *address, uint8_t *data, size_t size);

void configSetup() {
  configRead();
}

void configReset() {
  json.clear();
  json["HOSTNAME"] = HOSTNAME;
  configWrite();
}

String configGetString(const char *name, const char *fallback, bool allowEmpty) {
  if (!json.containsKey(name)) {
    return fallback;
  }
  String value = json[name];
  if (!allowEmpty && value.isEmpty()) {
    return fallback;
  }
  return value;
}

bool configPutString(const char *name, const char *value) {
  json[name] = value;
  return configWrite();
}

double configGetDouble(const char *name, double fallback) {
  if (!json.containsKey(name)) {
    return fallback;
  }
  return json[name];
}

bool configPutDouble(const char *name, double value) {
  json[name] = value;
  return configWrite();
}

bool configRead() {
  size_t length;
  char buffer[512];

  bool ok = true;
  int address = 0;
  EEPROM.begin(512);
  ok &= configReadBytes(&address, reinterpret_cast<uint8_t *>(&length), sizeof length);
  ok &= configReadBytes(&address, reinterpret_cast<uint8_t *>(buffer), length);
  ok &= EEPROM.end();

  if (ok) {
    JsonDocument tmp;
    deserializeJson(tmp, buffer);
    if (tmp.is<JsonObject>() && !tmp.isNull() && tmp.containsKey("HOSTNAME")) {
      info("Config loaded");
      json = tmp;
      return true;
    } else {
      error("Failed to parse config JSON");
    }
  } else {
    error("Failed to load config from EEPROM");
  }
  return false;
}

bool configWrite() {
  char buffer[512];
  size_t length = serializeJson(json, buffer, sizeof buffer);

  bool ok = true;
  int address = 0;
  EEPROM.begin(512);
  ok &= configWriteBytes(&address, reinterpret_cast<uint8_t *>(&length), sizeof length);
  ok &= configWriteBytes(&address, reinterpret_cast<uint8_t *>(buffer), length);
  ok &= EEPROM.end();
  return ok;
}

size_t configWriteBytes(int *address, uint8_t *data, size_t size) {
  uint8_t *b = data;
  for (; b < data + size; b++) {
    EEPROM.write((*address)++, *b);
    if (*address >= EEPROM.length()) {
      error("END OF EEPROM!!!");
      break;
    }
  }
  return b - data;
}

size_t configReadBytes(int *address, uint8_t *data, size_t size) {
  uint8_t *b = data;
  for (; b < data + size; b++) {
    *b = EEPROM.read((*address)++);
    if (*address >= EEPROM.length()) {
      error("END OF EEPROM!!!");
      break;
    }
  }
  return b - data;
}

#endif