#!/usr/bin/env python3
"""
CLI to send JSON over SPI to the ESP32-C3 SPI slave.

Examples:
  ./send_json.py --data '{"settings":{"pattern":"on","brightness":128}}'
  ./send_json.py --file payload.json
  ./send_json.py --brightness 180 --delay 30 --pattern wave
"""

import argparse
import json
import os
import sys

# Ensure we can import the local test helper
SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
if SCRIPT_DIR not in sys.path:
    sys.path.insert(0, SCRIPT_DIR)

from spi_master_test import SPIMasterTest  # noqa: E402


def build_payload_from_args(args: argparse.Namespace) -> dict:
    """Build a control payload matching led-bar's receiver format from args.

    Format:
      {"settings": { ... }, "save": false}
      Or raw passthrough if --data/--file is provided.
    """
    if args.data:
        try:
            return json.loads(args.data)
        except Exception as exc:
            print(f"Invalid JSON in --data: {exc}")
            sys.exit(2)

    if args.file:
        try:
            with open(args.file, "r", encoding="utf-8") as f:
                return json.load(f)
        except Exception as exc:
            print(f"Failed to read JSON file {args.file}: {exc}")
            sys.exit(2)

    # Build led-bar settings object
    settings: dict = {}

    if args.pattern:
        settings["pattern"] = args.pattern
    if args.brightness is not None:
        settings["brightness"] = int(args.brightness)
    if args.delay is not None:
        settings["delay"] = int(args.delay)

    # Optional numeric params if supported on led-bar side
    if args.n1 is not None:
        settings["n1"] = int(args.n1)
    if args.n2 is not None:
        settings["n2"] = int(args.n2)
    if args.n3 is not None:
        settings["n3"] = int(args.n3)

    payload: dict = {"settings": settings}

    # Optional: step tick control
    if args.step is not None:
        payload["step"] = int(args.step)

    # Allow override raw NAME JSON into settings directly if provided
    if args.name_value:
        try:
            name, value = args.name_value
            override = json.loads(value)
            # Merge override fields into settings
            if not isinstance(override, dict):
                raise ValueError("--name-value JSON must be an object")
            settings.update(override)
        except Exception as exc:
            print(f"Invalid --name-value: {exc}")
            sys.exit(2)

    # Default save=false; caller can include save in --data if desired
    payload.setdefault("save", False)

    if not settings and "step" not in payload:
        print("No settings specified to send.", file=sys.stderr)
        return {"settings": {}, "save": False}

    return payload


def parse_args() -> argparse.Namespace:
    p = argparse.ArgumentParser(description="Send JSON over SPI to ESP32-C3 (led-bar format)")
    src = p.add_mutually_exclusive_group()
    src.add_argument("--data", help="Raw JSON string to send (passthrough)")
    src.add_argument("--file", help="Path to JSON file to send (passthrough)")

    p.add_argument("--brightness", type=int, help="Brightness")
    p.add_argument("--delay", type=int, help="Delay (ms)")
    p.add_argument("--pattern", help="Pattern name")
    p.add_argument("--n1", type=int, help="n1 parameter")
    p.add_argument("--n2", type=int, help="n2 parameter")
    p.add_argument("--n3", type=int, help="n3 parameter")
    p.add_argument("--step", type=int, help="Pattern step override")
    p.add_argument("--name-value", nargs=2, metavar=("NAME", "JSON"), help="Merge JSON into settings (shortcut)")

    # SPI params
    p.add_argument("--bus", type=int, default=0, help="SPI bus (default 0)")
    p.add_argument("--device", type=int, default=0, help="SPI device/CE (default 0)")
    p.add_argument("--speed", type=int, default=1_000_000, help="SPI speed Hz (default 1MHz)")
    return p.parse_args()


def main() -> int:
    args = parse_args()
    payload = build_payload_from_args(args)

    spi = SPIMasterTest(bus=args.bus, device=args.device, max_speed_hz=args.speed)
    try:
        spi.send_json(payload)
    finally:
        spi.cleanup()
    return 0


if __name__ == "__main__":
    raise SystemExit(main())