#include <Arduino.h>
#include <OneWire.h>
#include <DallasTemperature.h>

#include "config.h"
#include "sensors.h"
#include "app_config.h"

SensorData sensors;

OneWire oneWire(ONEWIRE_PIN);
DallasTemperature ds18b20(&oneWire);

DeviceAddress sensorAddresses[MAX_TEMP_SENSORS];
String sensorAddressStrings[MAX_TEMP_SENSORS];
int sensorCount = 0;

float cToF(float c) {
    return (c * 9.0 / 5.0) + 32.0;
}

bool validTempC(float tempC) {
    return tempC != DEVICE_DISCONNECTED_C && tempC > -55 && tempC < 125;
}

String addressToString(DeviceAddress address) {
    String output = "";

    for (uint8_t i = 0; i < 8; i++) {
        if (address[i] < 16) output += "0";
        output += String(address[i], HEX);
        if (i < 7) output += ":";
    }

    output.toUpperCase();
    return output;
}

void printAddress(DeviceAddress address) {
    Serial.print(addressToString(address));
}

bool addressMatches(DeviceAddress address, const String& expected) {
    if (expected.length() == 0) {
        return false;
    }

    String actual = addressToString(address);
    String normalizedExpected = expected;
    normalizedExpected.toUpperCase();

    return actual == normalizedExpected;
}

void clearSensorRuntimeData() {
    for (int i = 0; i < MAX_TEMP_SENSORS; i++) {
        sensors.tempsF[i] = -127.0;
        sensors.online[i] = false;
    }
}

int scanTempSensors() {
    ds18b20.begin();

    sensorCount = ds18b20.getDeviceCount();

    if (sensorCount > MAX_TEMP_SENSORS) {
        sensorCount = MAX_TEMP_SENSORS;
    }

    for (int i = 0; i < MAX_TEMP_SENSORS; i++) {
        sensorAddressStrings[i] = "";
    }

    for (int i = 0; i < sensorCount; i++) {
        if (ds18b20.getAddress(sensorAddresses[i], i)) {
            sensorAddressStrings[i] = addressToString(sensorAddresses[i]);
        }
    }

    return sensorCount;
}

int getTempScanResultCount() {
    return sensorCount;
}

String getTempScanResultAddress(int index) {
    if (index < 0 || index >= sensorCount) {
        return "";
    }

    return sensorAddressStrings[index];
}

void printSensorAddresses() {
    Serial.println("DS18B20 Sensors Found:");

    for (int i = 0; i < sensorCount; i++) {
        Serial.print(i + 1);
        Serial.print(") ");
        Serial.println(sensorAddressStrings[i]);
    }

    if (sensorCount == 0) {
        Serial.println("No DS18B20 sensors found.");
    } else {
        Serial.println("Use: assign temp <slot> <number>");
    }
}

void initSensors() {
    clearSensorRuntimeData();
    scanTempSensors();
    printSensorAddresses();
}

void updateSensors() {
    clearSensorRuntimeData();

    ds18b20.requestTemperatures();

    for (int configIndex = 0; configIndex < MAX_TEMP_SENSORS; configIndex++) {
        if (!appConfig.tempSensors[configIndex].enabled) {
            continue;
        }

        String configuredAddress = appConfig.tempSensors[configIndex].address;

        if (configuredAddress.length() == 0) {
            // Backward-compatible behavior:
            // if no address is assigned, use physical scan order.
            if (configIndex < sensorCount) {
                float tempC = ds18b20.getTempC(sensorAddresses[configIndex]);

                if (validTempC(tempC)) {
                    sensors.tempsF[configIndex] = cToF(tempC);
                    sensors.online[configIndex] = true;
                }
            }

            continue;
        }

        for (int physicalIndex = 0; physicalIndex < sensorCount; physicalIndex++) {
            if (!addressMatches(sensorAddresses[physicalIndex], configuredAddress)) {
                continue;
            }

            float tempC = ds18b20.getTempC(sensorAddresses[physicalIndex]);

            if (validTempC(tempC)) {
                sensors.tempsF[configIndex] = cToF(tempC);
                sensors.online[configIndex] = true;
            }

            break;
        }
    }
}

bool assignTempSensorByIndex(int configIndex, int scanIndex) {
    if (configIndex < 0 || configIndex >= MAX_TEMP_SENSORS) {
        return false;
    }

    if (scanIndex < 0 || scanIndex >= sensorCount) {
        return false;
    }

    String selectedAddress = sensorAddressStrings[scanIndex];

    for (int i = 0; i < MAX_TEMP_SENSORS; i++) {
        if (i == configIndex) {
            continue;
        }

        if (appConfig.tempSensors[i].address == selectedAddress) {
            appConfig.tempSensors[i].address = "";
            appConfig.tempSensors[i].enabled = false;
            sensors.tempsF[i] = -127.0;
            sensors.online[i] = false;
        }
    }

    appConfig.tempSensors[configIndex].address = selectedAddress;
    appConfig.tempSensors[configIndex].enabled = true;

    return true;
}

bool clearTempSensor(int configIndex) {
    if (configIndex < 0 || configIndex >= MAX_TEMP_SENSORS) {
        return false;
    }

    appConfig.tempSensors[configIndex].address = "";
    appConfig.tempSensors[configIndex].enabled = false;
    appConfig.tempSensors[configIndex].weather = false;
    sensors.tempsF[configIndex] = -127.0;
    sensors.online[configIndex] = false;

    return true;
}