#!/usr/bin/env python3
"""
RTC (Real-Time Clock) Demo.

Demonstrates PCF8523 RTC functionality:
- Read current date/time
- Set RTC time
- Sync with system time
- Set and monitor alarms
- Display continuous time updates

This example requires actual PCF8523 RTC hardware connected via I2C.
"""

import asyncio
import sys
import os
import time

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

from dreader_hal import EReaderDisplayHAL


def format_time(t: time.struct_time) -> str:
    """Format struct_time as readable string."""
    return time.strftime("%Y-%m-%d %H:%M:%S %A", t)


async def display_current_time(hal: EReaderDisplayHAL):
    """Display current RTC time continuously."""
    print("\nDisplaying current time (Ctrl+C to stop)...\n")

    try:
        while True:
            current = await hal.get_datetime()
            if current:
                print(f"\rCurrent time: {format_time(current)}", end="", flush=True)
            else:
                print("\rRTC not available", end="", flush=True)

            await asyncio.sleep(1.0)

    except KeyboardInterrupt:
        print("\n")


async def set_time_demo(hal: EReaderDisplayHAL):
    """Demonstrate setting RTC time."""
    print("\n=== Setting RTC Time ===")

    # Show current time
    current = await hal.get_datetime()
    if current:
        print(f"Current RTC time: {format_time(current)}")

    # Set to system time
    print("\nSetting RTC to current system time...")
    system_time = time.localtime()
    await hal.set_datetime(system_time)
    print(f"System time: {format_time(system_time)}")

    # Verify
    await asyncio.sleep(0.5)
    new_time = await hal.get_datetime()
    if new_time:
        print(f"New RTC time: {format_time(new_time)}")
        print("✓ Time updated successfully!")


async def alarm_demo(hal: EReaderDisplayHAL):
    """Demonstrate RTC alarm functionality."""
    print("\n=== RTC Alarm Demo ===")

    # Get current time
    current = await hal.get_datetime()
    if not current:
        print("Error: RTC not available")
        return

    print(f"Current time: {format_time(current)}")

    # Set alarm for 2 minutes from now
    alarm_minute = (current.tm_min + 2) % 60
    alarm_hour = current.tm_hour
    if alarm_minute < current.tm_min:
        alarm_hour = (alarm_hour + 1) % 24

    print(f"\nSetting alarm for {alarm_hour:02d}:{alarm_minute:02d}...")
    await hal.set_alarm(hour=alarm_hour, minute=alarm_minute)
    print("✓ Alarm set!")

    print("\nNote: Alarm functionality requires checking alarm status")
    print("via the low-level RTC driver (hal.rtc.check_alarm())")


async def interactive_menu(hal: EReaderDisplayHAL):
    """Interactive menu for RTC operations."""
    while True:
        print("\n" + "="*50)
        print("RTC Demo Menu")
        print("="*50)
        print("1. Display current time")
        print("2. Set time to system time")
        print("3. Set custom time")
        print("4. Set alarm")
        print("5. Display time continuously")
        print("6. Exit")
        print("="*50)

        choice = input("\nEnter choice (1-6): ").strip()

        if choice == "1":
            current = await hal.get_datetime()
            if current:
                print(f"\nCurrent RTC time: {format_time(current)}")
            else:
                print("\nRTC not available")

        elif choice == "2":
            await set_time_demo(hal)

        elif choice == "3":
            print("\nEnter date/time (or press Enter to cancel):")
            year = input("Year (YYYY): ").strip()
            if not year:
                continue

            try:
                year = int(year)
                month = int(input("Month (1-12): "))
                day = int(input("Day (1-31): "))
                hour = int(input("Hour (0-23): "))
                minute = int(input("Minute (0-59): "))
                second = int(input("Second (0-59): "))

                # Create struct_time (weekday and yearday are calculated)
                custom_time = time.struct_time((
                    year, month, day, hour, minute, second, 0, 0, -1
                ))

                print(f"\nSetting RTC to: {format_time(custom_time)}")
                await hal.set_datetime(custom_time)

                # Verify
                await asyncio.sleep(0.5)
                new_time = await hal.get_datetime()
                if new_time:
                    print(f"Verified: {format_time(new_time)}")
                    print("✓ Time updated successfully!")

            except (ValueError, OverflowError) as e:
                print(f"\nError: Invalid date/time - {e}")

        elif choice == "4":
            await alarm_demo(hal)

        elif choice == "5":
            await display_current_time(hal)

        elif choice == "6":
            print("\nExiting...")
            break

        else:
            print("\nInvalid choice. Please enter 1-6.")


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

    # Create HAL with RTC enabled
    hal = EReaderDisplayHAL(
        width=800,
        height=1200,
        virtual_display=True,  # Virtual display for testing
        enable_orientation=False,
        enable_rtc=True,  # Enable RTC
        enable_power_monitor=False,
    )

    print("="*50)
    print("DReader HAL - RTC Demo")
    print("="*50)
    print("\nInitializing HAL with RTC...")

    try:
        await hal.initialize()
        print("✓ HAL initialized!")

        if not hal.rtc:
            print("\n⚠️  Warning: RTC not available!")
            print("\nThis example requires PCF8523 RTC hardware on I2C bus.")
            print("RTC should be at address 0x68 on I2C bus 1.")
            print("\nCheck connections:")
            print("  - VCC → 3.3V (Pin 1)")
            print("  - GND → GND (Pin 6)")
            print("  - SDA → GPIO2 (Pin 3)")
            print("  - SCL → GPIO3 (Pin 5)")
            print("\nVerify with: i2cdetect -y 1")
            return

        print("✓ RTC initialized!")

        # Show initial time
        current = await hal.get_datetime()
        if current:
            print(f"\nCurrent RTC time: {format_time(current)}")
            system_time = time.localtime()
            print(f"System time:      {format_time(system_time)}")

            # Check if times differ
            time_diff = abs(time.mktime(current) - time.mktime(system_time))
            if time_diff > 2:  # More than 2 seconds difference
                print(f"\n⚠️  RTC differs from system time by {time_diff:.0f} seconds")

        # Run interactive menu
        await interactive_menu(hal)

    except RuntimeError as e:
        print(f"\n❌ Error: {e}")
        print("\nNote: This example requires PCF8523 RTC hardware on I2C bus.")
        return

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

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


if __name__ == "__main__":
    try:
        asyncio.run(main())
    except KeyboardInterrupt:
        print("\nExiting...")