#!/usr/bin/env python3
"""Copies a file to the Cardputer's SD card over the USB serial console (the `sd put` command).

Usage: scripts/sd_put.sh <file> [card path]
The card path defaults to /updates/<file name>, where Settings > Firmware finds Update Files.
The device acknowledges each chunk once it's on the card, checks the SHA-256 of the whole file,
and only then renames <card path>.part to <card path>.
"""
import glob
import hashlib
import os
import sys
import time

import serial

DEBUG = bool(os.environ.get("SD_PUT_DEBUG"))  # also show the console lines in between


def find_port():
    ports = sorted(glob.glob("/dev/serial/by-id/*Espressif*"))
    return os.path.realpath(ports[0]) if ports else None


def reply(port, timeout):
    """The next `sd put:` line from the device; everything else on the console is skipped."""
    deadline = time.time() + timeout
    while time.time() < deadline:
        line = port.readline().decode(errors="replace").strip()
        if line.startswith("sd put:"):
            return line[len("sd put:"):].strip()
        if line and DEBUG:
            print(f"\n  console: {line}", file=sys.stderr)
    return "error no answer from the device"


def fail(answer):
    print()
    sys.exit(f"device: {answer}")


def main():
    if len(sys.argv) < 2:
        sys.exit(__doc__)
    path = sys.argv[1]
    dest = sys.argv[2] if len(sys.argv) > 2 else "/updates/" + os.path.basename(path)
    port_name = find_port()
    if not port_name:
        sys.exit("No Cardputer found on USB")
    data = open(path, "rb").read()
    sha = hashlib.sha256(data).hexdigest()

    with serial.Serial(port_name, 115200, timeout=0.5) as port:
        port.reset_input_buffer()
        # The leading newline ends any half-typed command.
        port.write(f"\nsd put {dest} {len(data)} {sha}\n".encode())
        answer = reply(port, 10)
        if not answer.startswith("ready "):
            fail(answer)
        chunk = int(answer.split()[1])

        start, sent = time.time(), 0
        while sent < len(data):
            port.write(data[sent:sent + chunk])
            sent = min(sent + chunk, len(data))
            print(f"\rsending {sent * 100 // len(data):3d}%", end="", flush=True)
            if sent < len(data):
                answer = reply(port, 10)
                if answer != f"ok {sent}":
                    fail(answer)
        answer = reply(port, 15)
        if not answer.startswith("done "):
            fail(answer)
        seconds = time.time() - start
        print(f"\rdevice: {answer}, {seconds:.1f} s ({len(data) / 1024 / seconds:.0f} KB/s)")


if __name__ == "__main__":
    main()