#!/usr/bin/env python3
"""
Demo: Accelerometer-based Page Flipping

This example demonstrates how to use the accelerometer for hands-free
page turning by tilting the device forward or backward.

Features:
- Tilt device forward to advance to next page
- Tilt device backward to go to previous page
- Touch gestures still work normally
- Configurable tilt threshold and debounce time

Prerequisites:
1. Run calibration first: python examples/calibrate_accelerometer.py
2. This creates accelerometer_config.json with calibration data

Usage:
    python examples/demo_accelerometer_page_flip.py <epub_file>
"""

import asyncio
import sys
from pathlib import Path

# Add parent directory to path for imports
sys.path.insert(0, str(Path(__file__).parent.parent))

from dreader.hal_hardware import HardwareDisplayHAL
from dreader.application import EbookReader
from dreader.gesture import GestureType


class AccelerometerPageFlipDemo:
    """Demo application with accelerometer-based page flipping"""

    def __init__(self, epub_path: str):
        self.epub_path = epub_path

        # Create HAL with accelerometer enabled
        print("Initializing hardware HAL...")
        self.hal = HardwareDisplayHAL(
            width=1872,
            height=1404,
            enable_orientation=True,
            enable_rtc=False,
            enable_power_monitor=False,
            virtual_display=False  # Set to True for testing without hardware
        )

        # Create reader
        print("Creating ebook reader...")
        self.reader = EbookReader(
            page_size=(self.hal.width, self.hal.height),
            margin=60
        )

        self.running = False

    async def run(self):
        """Run the demo application"""
        print("\n" + "="*60)
        print("Accelerometer Page Flip Demo")
        print("="*60)

        # Initialize HAL
        await self.hal.initialize()

        # Load accelerometer calibration
        print("\nLoading accelerometer calibration...")
        calibrated = self.hal.load_accelerometer_calibration("accelerometer_config.json")

        if not calibrated:
            print("\nWARNING: Accelerometer not calibrated!")
            print("Please run: python examples/calibrate_accelerometer.py")
            print("\nProceeding with touch gestures only...\n")
        else:
            print("Accelerometer calibration loaded successfully!")
            print(f"  Up vector: {self.hal.accel_up_vector}")
            print(f"  Tilt threshold: {self.hal.accel_tilt_threshold:.2f} rad")
            print(f"  Debounce time: {self.hal.accel_debounce_time:.2f}s")

        # Load EPUB
        print(f"\nLoading EPUB: {self.epub_path}")
        success = self.reader.load_epub(self.epub_path)

        if not success:
            print(f"ERROR: Failed to load {self.epub_path}")
            await self.hal.cleanup()
            return

        print(f"Loaded: {self.reader.book_title}")
        print(f"Author: {self.reader.book_author}")

        # Display first page
        print("\nDisplaying first page...")
        img = self.reader.get_current_page()
        await self.hal.show_image(img)

        # Instructions
        print("\n" + "="*60)
        print("Controls:")
        print("  - Tilt FORWARD to go to next page")
        print("  - Tilt BACKWARD to go to previous page")
        print("  - Swipe LEFT for next page (touch)")
        print("  - Swipe RIGHT for previous page (touch)")
        print("  - Long press to exit")
        print("="*60 + "\n")

        # Main event loop
        self.running = True
        try:
            await self.event_loop()
        finally:
            await self.hal.cleanup()
            print("\nDemo finished!")

    async def event_loop(self):
        """Main event loop - poll for touch and accelerometer events"""
        accel_poll_interval = 0.05  # Check accelerometer every 50ms

        while self.running:
            # Check for touch events
            touch_event = await self.hal.get_touch_event()
            if touch_event:
                await self.handle_event(touch_event)

            # Check for accelerometer tilt events (if calibrated)
            if hasattr(self.hal, 'accel_up_vector'):
                tilt_event = await self.hal.get_tilt_gesture()
                if tilt_event:
                    await self.handle_event(tilt_event)

            # Small delay to avoid busy-waiting
            await asyncio.sleep(accel_poll_interval)

    async def handle_event(self, event):
        """Handle a gesture event (touch or accelerometer)"""
        gesture = event.gesture
        print(f"Gesture: {gesture.value}")

        # Navigation gestures
        if gesture in [GestureType.SWIPE_LEFT, GestureType.TILT_FORWARD]:
            await self.next_page()

        elif gesture in [GestureType.SWIPE_RIGHT, GestureType.TILT_BACKWARD]:
            await self.previous_page()

        # Exit on long press
        elif gesture == GestureType.LONG_PRESS:
            print("\nLong press detected - exiting...")
            self.running = False

        # Word tap
        elif gesture == GestureType.TAP:
            # You could implement word selection here
            print(f"  Tap at ({event.x}, {event.y})")

    async def next_page(self):
        """Go to next page"""
        img = self.reader.next_page()
        if img:
            progress = self.reader.get_reading_progress()
            chapter = self.reader.get_current_chapter_info()
            print(f"  -> Next page ({progress['percent']:.1f}% - {chapter['title']})")
            await self.hal.show_image(img)
        else:
            print("  -> At end of book")

    async def previous_page(self):
        """Go to previous page"""
        img = self.reader.previous_page()
        if img:
            progress = self.reader.get_reading_progress()
            chapter = self.reader.get_current_chapter_info()
            print(f"  -> Previous page ({progress['percent']:.1f}% - {chapter['title']})")
            await self.hal.show_image(img)
        else:
            print("  -> At start of book")


async def main():
    """Main entry point"""
    if len(sys.argv) < 2:
        print("Usage: python demo_accelerometer_page_flip.py <epub_file>")
        print("\nExample:")
        print("  python demo_accelerometer_page_flip.py ~/Books/mybook.epub")
        sys.exit(1)

    epub_path = sys.argv[1]

    # Check if file exists
    if not Path(epub_path).exists():
        print(f"ERROR: File not found: {epub_path}")
        sys.exit(1)

    # Run demo
    demo = AccelerometerPageFlipDemo(epub_path)
    await demo.run()


if __name__ == "__main__":
    try:
        asyncio.run(main())
    except KeyboardInterrupt:
        print("\nDemo interrupted by user")
        sys.exit(0)
    except Exception as e:
        print(f"\nError: {e}")
        import traceback
        traceback.print_exc()
        sys.exit(1)