#include <Arduino.h>
#include <avr/boot.h>
#include <avr/eeprom.h>
#include <avr/pgmspace.h>

#include <firmware_runtime.h>
#include <hardware_seam.h>

#include "board_profile.h"

static_assert(F_CPU == meCoffee::hardware::board::kClockFrequency, "Clock frequency does not match the board profile");
static_assert(meCoffee::hardware::board::kAdcPrescaler == 128, "ADC register configuration requires prescaler 128");

// Optional start-up padding that lines this image up with the original's start-up time in
// differential runs. Zero in the default build.
#ifndef MECOFFEE_CONSTRUCTION_ALIGNMENT_MICROSECONDS
#define MECOFFEE_CONSTRUCTION_ALIGNMENT_MICROSECONDS 0
#endif
#ifndef MECOFFEE_SETUP_ALIGNMENT_MICROSECONDS
#define MECOFFEE_SETUP_ALIGNMENT_MICROSECONDS 0
#endif
#include <mains_events.h>
#include <pulse_tick.h>

namespace meCoffee::hardware {

void beginSerialLink(uint32_t baudRate) {
#if MECOFFEE_SETUP_ALIGNMENT_MICROSECONDS > 0
    static bool isFirstCall = true;
    if (isFirstCall) {
        isFirstCall = false;
        delayMicroseconds(MECOFFEE_SETUP_ALIGNMENT_MICROSECONDS);
    }
#endif
    Serial.begin(baudRate);
}

void writeSerialByte(uint8_t byteToTransmit) { Serial.write(byteToTransmit); }

int readSerialByte() { return Serial.read(); }

void waitForSerialTransmitCompletion() { Serial.flush(); }

uint32_t readMillisecondCounter() { return millis(); }

uint32_t readMicrosecondCounter() { return micros(); }

void blockForMilliseconds(uint32_t durationInMilliseconds) { delay(durationInMilliseconds); }

uint8_t readPersistentByte(uint16_t persistentAddress) {
    return eeprom_read_byte(reinterpret_cast<const uint8_t*>(persistentAddress));
}

void writePersistentByte(uint16_t persistentAddress, uint8_t byteToStore) {
    eeprom_write_byte(reinterpret_cast<uint8_t*>(persistentAddress), byteToStore);
}

uint8_t readProgramMemoryByte(const void* programMemoryAddress) { return pgm_read_byte(programMemoryAddress); }

uint8_t readDeviceSignatureByte(uint8_t signatureByteIndex) {
    // The signature read must complete within a few cycles of the control write.
    const uint8_t savedStatusRegister = SREG;
    cli();
    const uint8_t signatureByte = boot_signature_byte_get(signatureByteIndex);
    SREG = savedStatusRegister;
    return signatureByte;
}

void configureLogicalPin(uint8_t logicalPin, PinConfiguration configuration) {
    const uint8_t physicalPin = board::physicalPin(logicalPin);
    switch (configuration) {
        case PinConfiguration::Input: pinMode(physicalPin, INPUT); break;
        case PinConfiguration::InputWithPullUp: pinMode(physicalPin, INPUT_PULLUP); break;
        case PinConfiguration::Output: pinMode(physicalPin, OUTPUT); break;
    }
}

void writeLogicalPin(uint8_t logicalPin, bool isHigh) { digitalWrite(board::physicalPin(logicalPin), isHigh ? HIGH : LOW); }

bool readLogicalPin(uint8_t logicalPin) { return digitalRead(board::physicalPin(logicalPin)) != LOW; }

void selectAnalogChannel(uint8_t channelNumber) { ADMUX = static_cast<uint8_t>(0xc0 | (board::analogChannel(channelNumber) & 0x0f)); }

void startAnalogConversion() { ADCSRA |= _BV(ADSC); }

bool isAnalogConversionRunning() { return (ADCSRA & _BV(ADSC)) != 0; }

uint16_t readAnalogConversionResult() {
    const uint8_t lowByte = ADCL;
    const uint8_t highByte = ADCH;
    return static_cast<uint16_t>(lowByte | (highByte << 8));
}

void clearPulseOutputPins() {
#if MECOFFEE_ARDUINO_16MHZ
    PORTD &= static_cast<uint8_t>(~(_BV(PD3) | _BV(PD4) | _BV(PD5)));
#else
    PORTB &= static_cast<uint8_t>(~(_BV(PB1) | _BV(PB2)));
    PORTD &= static_cast<uint8_t>(~_BV(PD3));
#endif
}

void writeRangeIndicatorPin(uint8_t rangeSelector, bool isHigh) {
#if MECOFFEE_ARDUINO_16MHZ
    const uint8_t rangeMask = rangeSelector == 0 ? _BV(PC2) : _BV(PC3);
    if (isHigh) {
        PORTC |= rangeMask;
    } else {
        PORTC &= static_cast<uint8_t>(~rangeMask);
    }
#else
    if (rangeSelector == 0) {
        if (isHigh) {
            PORTB |= _BV(PB7);
        } else {
            PORTB &= static_cast<uint8_t>(~_BV(PB7));
        }
    } else if (isHigh) {
        PORTD |= _BV(PD7);
    } else {
        PORTD &= static_cast<uint8_t>(~_BV(PD7));
    }
#endif
}

void writeGenerationParityPin(bool isHigh) {
#if MECOFFEE_ARDUINO_16MHZ
    if (isHigh) {
        PORTB |= _BV(PB3);
    } else {
        PORTB &= static_cast<uint8_t>(~_BV(PB3));
    }
#else
    if (isHigh) {
        PORTC |= _BV(PC0);
    } else {
        PORTC &= static_cast<uint8_t>(~_BV(PC0));
    }
#endif
}

void startPulseTimerAndMainsInterrupt() {
    // Mains edge: logical pin 2 (INT0), no pull-up, both edges.
    pinMode(2, INPUT);
    EICRA = static_cast<uint8_t>((EICRA & ~(_BV(ISC01) | _BV(ISC00))) | _BV(ISC00));
    EIMSK |= _BV(INT0);

    // Output pins that follow the sensor range flags and generation parity.
#if MECOFFEE_ARDUINO_16MHZ
    DDRC |= _BV(PC2) | _BV(PC3);
    PORTC &= static_cast<uint8_t>(~(_BV(PC2) | _BV(PC3)));
    DDRB |= _BV(PB3);
    PORTB |= _BV(PB3);
#else
    DDRB |= _BV(PB7);
    PORTB &= static_cast<uint8_t>(~_BV(PB7));
    DDRC |= _BV(PC0);
    PORTC |= _BV(PC0);
#endif

    // Pulse timer: Timer 1, CTC, no prescaling, compare interrupt every 16.125 microseconds.
    TCCR1A = 0;
    TCCR1B = 0;
    TCNT1 = 0;
    OCR1A = board::kPulseTimerCompare;
    TCCR1B = _BV(WGM12) | _BV(CS10);
    TIMSK1 = _BV(OCIE1A);

    // Analog converter: internal reference, first temperature channel, prescaler 128.
    selectAnalogChannel(3);
    ADCSRA = _BV(ADEN) | _BV(ADPS2) | _BV(ADPS1) | _BV(ADPS0);
}

void disableInterrupts() { cli(); }

void enableInterrupts() { sei(); }

uint8_t readOscillatorCalibrationRegister() { return OSCCAL; }

void writeOscillatorCalibrationRegister(uint8_t calibrationValue) {
    if (!board::kUsesExternalClock) {
        OSCCAL = calibrationValue;
    }
}

}  // namespace meCoffee::hardware

ISR(TIMER1_COMPA_vect) {
    const meCoffee::PulseTickResult tickResult = meCoffee::advancePulseTick(&meCoffee::firmwareStateStorage);
    if ((tickResult.toggleMask & 0x01) != 0) {
        PIND = _BV(PD3);
    }
    if ((tickResult.toggleMask & 0x02) != 0) {
#if MECOFFEE_ARDUINO_16MHZ
        PIND = _BV(PD4);
#else
        PINB = _BV(PB2);
#endif
    }
    if ((tickResult.toggleMask & 0x04) != 0) {
#if MECOFFEE_ARDUINO_16MHZ
        PIND = _BV(PD5);
#else
        PINB = _BV(PB1);
#endif
    }
    if (tickResult.shouldStartConversion) {
        ADCSRA |= _BV(ADSC);
    }
}

ISR(INT0_vect) { meCoffee::processMainsEdge(&meCoffee::firmwareStateStorage); }

namespace {

// Mirrors the original's static constructors: settings are restored before the
// Arduino runtime starts its millisecond timer.
struct ConstructionTimeInitializer {
    ConstructionTimeInitializer() {
        meCoffee::initializeAtConstruction();
#if MECOFFEE_CONSTRUCTION_ALIGNMENT_MICROSECONDS > 0
        delayMicroseconds(MECOFFEE_CONSTRUCTION_ALIGNMENT_MICROSECONDS);
#endif
    }
};

const ConstructionTimeInitializer constructionTimeInitializer;

}  // namespace