"""
Pre-upload script that sends FLASH command to device before firmware upload.

This allows the firmware to display "Flashing firmware..." on the e-ink display
before the actual flash begins. The e-ink retains this message throughout the
flash process since it doesn't require power to maintain the display.

Protocol (Plan A - Simple timing):
1. Host opens serial port and sends "FLASH:version"
2. Host keeps port open briefly for device to receive and process
3. Device displays flash screen when it receives the command
4. Host proceeds with flash
"""

Import("env")
import serial
import time
from version_utils import get_version


def before_upload(source, target, env):
    """Send FLASH command to device before uploading firmware."""
    port = env.GetProjectOption("upload_port", None)

    if not port:
        import serial.tools.list_ports

        # Look for common ESP32-C3 USB serial port patterns
        ports = [
            p.device
            for p in serial.tools.list_ports.comports()
            if "usbmodem" in p.device.lower() or "ttyacm" in p.device.lower()
        ]
        port = ports[0] if ports else None

    if not port:
        print("[pre_flash] No serial port found, skipping notification")
        return

    try:
        version = get_version(env)
        ser = serial.Serial(port, 115200, timeout=1)
        ser.write(f"FLASH:{version}\n".encode())
        ser.flush()
        time.sleep(4.0)  # Keep port open for device to receive and complete full refresh (~2-3s)
        ser.close()
        print(f"[pre_flash] Flash notification sent to {port} (version {version})")
    except Exception as e:
        print(f"[pre_flash] Notification skipped: {e}")


env.AddPreAction("upload", before_upload)