#ifndef HAL_H
#define HAL_H

#include <stdint.h>

// Pin modes (match Arduino constants)
#ifndef INPUT
#define INPUT  0x0
#define OUTPUT 0x1
#define INPUT_PULLUP 0x2
#endif

#ifndef LOW
#define LOW  0x0
#define HIGH 0x1
#endif

// LED_BUILTIN for host builds
#ifndef LED_BUILTIN
#define LED_BUILTIN 13
#endif

/*
 * Hardware Abstraction Layer
 *
 * Abstract interface over GPIO, timing, serial, and I2C. Sketch logic
 * depends on this interface only -- never on Arduino.h directly.
 *
 * Two implementations:
 *   hal_arduino.h  -- real hardware (included by .ino files)
 *   mock_hal.h     -- Google Mock (included by test files)
 */
class Hal {
public:
    virtual ~Hal() = default;

    // -- GPIO ---------------------------------------------------------------
    virtual void pinMode(uint8_t pin, uint8_t mode) = 0;
    virtual void digitalWrite(uint8_t pin, uint8_t value) = 0;
    virtual uint8_t digitalRead(uint8_t pin) = 0;
    virtual int analogRead(uint8_t pin) = 0;
    virtual void analogWrite(uint8_t pin, int value) = 0;

    // -- Timing -------------------------------------------------------------
    virtual unsigned long millis() = 0;
    virtual unsigned long micros() = 0;
    virtual void delay(unsigned long ms) = 0;
    virtual void delayMicroseconds(unsigned long us) = 0;

    // -- Serial -------------------------------------------------------------
    virtual void serialBegin(unsigned long baud) = 0;
    virtual void serialPrint(const char* msg) = 0;
    virtual void serialPrintln(const char* msg) = 0;
    virtual int serialAvailable() = 0;
    virtual int serialRead() = 0;

    // -- I2C ----------------------------------------------------------------
    virtual void i2cBegin() = 0;
    virtual void i2cBeginTransmission(uint8_t addr) = 0;
    virtual size_t i2cWrite(uint8_t data) = 0;
    virtual uint8_t i2cEndTransmission() = 0;
    virtual uint8_t i2cRequestFrom(uint8_t addr, uint8_t count) = 0;
    virtual int i2cAvailable() = 0;
    virtual int i2cRead() = 0;
};

#endif // HAL_H