#!/usr/bin/env python3
import argparse
import time
from pymodbus.client import ModbusTcpClient


def read_block(client, kind, start, count, unit):
    fn = client.read_holding_registers if kind == "holding" else client.read_input_registers

    try:
        rr = fn(address=start, count=count, device_id=unit)
    except Exception:
        return None

    if rr.isError():
        return None

    return rr.registers


def snapshot(client, unit):
    ranges = [
        ("holding", 0, 200),
        ("holding", 1000, 100),
        ("holding", 2000, 200),
        ("holding", 3000, 200),
        ("holding", 4000, 200),
        ("input", 0, 200),
        ("input", 1000, 100),
        ("input", 2000, 200),
        ("input", 3000, 200),
        ("input", 4000, 200),
    ]

    data = {}

    for kind, start, count in ranges:
        regs = read_block(client, kind, start, count, unit)
        if regs is None:
            continue

        for i, value in enumerate(regs):
            data[(kind, start + i)] = value

    return data


def u16_delta(before, after):
    return (after - before) & 0xFFFF


def u32(hi, lo):
    return ((hi & 0xFFFF) << 16) | (lo & 0xFFFF)


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument("--host", required=True)
    parser.add_argument("--unit", type=int, default=1)
    parser.add_argument("--expected", type=int, default=10)
    args = parser.parse_args()

    client = ModbusTcpClient(args.host, port=502, timeout=2)

    if not client.connect():
        raise RuntimeError("No conecta con WISE")

    try:
        print("Tomando snapshot inicial...")
        before = snapshot(client, args.unit)

        print(f"\nAhora pulsa DI1 exactamente {args.expected} veces.")
        input("Cuando termines, pulsa ENTER aquí...")

        time.sleep(0.5)

        print("Tomando snapshot final...")
        after = snapshot(client, args.unit)

        print("\nCambios 16-bit detectados:")
        changes = []

        for key, before_value in before.items():
            if key not in after:
                continue

            after_value = after[key]
            if after_value != before_value:
                delta = u16_delta(before_value, after_value)
                closeness = abs(delta - args.expected)
                changes.append((closeness, key, before_value, after_value, delta))

        for closeness, key, b, a, delta in sorted(changes, key=lambda x: x[0])[:40]:
            kind, addr = key
            print(f"{kind:7s} addr={addr:5d} before={b:6d} after={a:6d} delta={delta}")

        print("\nCambios 32-bit por parejas:")
        pair_changes = []

        keys = sorted(before.keys())

        for kind, addr in keys:
            key_hi = (kind, addr)
            key_lo = (kind, addr + 1)

            if key_lo not in before or key_hi not in after or key_lo not in after:
                continue

            before_u32 = u32(before[key_hi], before[key_lo])
            after_u32 = u32(after[key_hi], after[key_lo])

            if before_u32 != after_u32:
                delta = (after_u32 - before_u32) & 0xFFFFFFFF
                closeness = abs(delta - args.expected)
                pair_changes.append((closeness, kind, addr, before_u32, after_u32, delta))

        for closeness, kind, addr, b, a, delta in sorted(pair_changes, key=lambda x: x[0])[:40]:
            print(f"{kind:7s} addr={addr:5d}/{addr+1:5d} before={b} after={a} delta={delta}")

    finally:
        client.close()


if __name__ == "__main__":
    main()