#!/usr/bin/env python3
"""
Battery Monitor Example.

Demonstrates power monitoring with the INA219:
- Read voltage, current, and power
- Estimate battery percentage
- Calculate time remaining
- Detect charging status

This example requires actual INA219 hardware connected via I2C.
"""

import asyncio
import sys
import os

# Add src to path
sys.path.insert(0, os.path.join(os.path.dirname(__file__), '../src'))

from dreader_hal import EReaderDisplayHAL


async def main():
    """Main example function."""

    # Create HAL with power monitoring enabled
    hal = EReaderDisplayHAL(
        width=800,
        height=1200,
        virtual_display=True,  # Virtual display for testing
        enable_orientation=False,
        enable_rtc=False,
        enable_power_monitor=True,  # Enable power monitoring
        shunt_ohms=0.1,  # Shunt resistor value
        battery_capacity_mah=3000,  # Battery capacity
    )

    print("Initializing HAL with power monitoring...")
    try:
        await hal.initialize()
        print("HAL initialized!")
    except RuntimeError as e:
        print(f"Error: {e}")
        print("\nNote: This example requires INA219 hardware on I2C bus.")
        print("If testing without hardware, power monitor will be disabled.")
        return

    # Monitor battery stats
    print("\nMonitoring battery stats (Ctrl+C to exit)...\n")

    try:
        while True:
            # Get power statistics
            stats = await hal.get_power_stats()

            # Display stats
            print(f"\r"
                  f"Voltage: {stats.voltage:.2f}V | "
                  f"Current: {stats.current:.1f}mA | "
                  f"Power: {stats.power:.1f}mW | "
                  f"Battery: {stats.battery_percent:.0f}% | "
                  f"Charging: {'Yes' if stats.is_charging else 'No'} | "
                  f"Time remaining: {stats.time_remaining or 'N/A'} min",
                  end="", flush=True)

            # Check for low battery
            if await hal.is_low_battery(threshold=20.0):
                print("\n⚠️  LOW BATTERY WARNING!")

            # Wait 1 second
            await asyncio.sleep(1.0)

    except KeyboardInterrupt:
        print("\n\nStopped by user")

    finally:
        # Cleanup
        print("Cleaning up...")
        await hal.cleanup()
        print("Done!")


if __name__ == "__main__":
    asyncio.run(main())