#!/usr/bin/env python3
"""
Симуляция IR_DecoderRaw::tick() по CSV уровней (как Analyzer/raw/*_raw.txt).
Сверка с IR_DecoderRaw.cpp / IR_config.h — без Arduino, только логика декодера.
"""
from __future__ import annotations

import sys
from dataclasses import dataclass, field
from pathlib import Path

# IR_config.h
BIT_ACTIVE_TAKTS = 25
BIT_PAUSE_TAKTS = 12
CARRIER_HZ = 38000
CARRIER_PERIOD_US = 1_000_000 / CARRIER_HZ
BIT_TIME_US = int((BIT_ACTIVE_TAKTS + BIT_PAUSE_TAKTS) * CARRIER_PERIOD_US)
TOLERANCE_US = 300
SYNC_BITS = 3
BIT_PER_BYTE = 8
MSG_BYTES = 1
CRC_BYTES = 2
POLY1 = 0x31
POLY2 = 0x8C
DATA_BYTE_SIZE_MAX = 1 + 2 + 2 + 31 + 2
IR_MASK_MSG_INFO = 0x1F
PREAMB_FRONTS = 6  # preambPulse*2

RISE_MIN = BIT_TIME_US - TOLERANCE_US
RISE_MAX = BIT_TIME_US + TOLERANCE_US
IR_TIMEOUT = RISE_MAX * (8 + SYNC_BITS + 1)
# IR_config.h: IR_SHORT_LOW_GLITCH_REJECT (по умолчанию 1)
SHORT_LOW_GLITCH_REJECT = True
GLITCH_REJECT_PHASE_NUDGE = True
MICRO_GAP_RISE_REJECT = True
IN_MARK_DOUBLE_FALL_IGNORE = False  # как IR_config по умолчанию; True — меньше err_other, на разбор битов не влияет
# IR_RISE_INCLUSIVE_AROUND, IR_RISE_GRAY_SINGLE_BIT_FALLBACK
RISE_INCLUSIVE_AROUND = True
RISE_GRAY_SINGLE_BIT_FALLBACK = False  # как IR_config по умолчанию; True — только для экспериментов


def around_rise_period(rise_period: int, rise_sync: int) -> bool:
    lo = max(0, rise_sync - TOLERANCE_US)
    hi = rise_sync + TOLERANCE_US
    if RISE_INCLUSIVE_AROUND:
        return lo <= rise_period <= hi
    return lo < rise_period < hi


def rise_gray_single_bit_fallback(rise_period: int, rise_sync: int) -> bool:
    hi = rise_sync + TOLERANCE_US
    return rise_period > hi and rise_period <= 2 * rise_sync


def glitch_phase_nudge(edge_us: float, rise_sync: int, prev_rise: float) -> float:
    if not GLITCH_REJECT_PHASE_NUDGE:
        return prev_rise
    if edge_us <= rise_sync:
        return prev_rise
    nudged = edge_us - rise_sync
    if nudged > prev_rise and nudged < edge_us:
        return nudged
    return prev_rise


def ceil_div(val: int, div: int) -> int:
    ret = val // div
    if ((val << 4) // div - (ret << 4)) >= 8:
        ret += 1
    return ret


def crc8(data: bytes, start: int, end: int, poly: int) -> int:
    crc = 0xFF
    for i in range(start, end):
        crc ^= data[i]
        for _ in range(8):
            if crc & 0x80:
                crc = ((crc << 1) ^ poly) & 0xFF
            else:
                crc = (crc << 1) & 0xFF
    return crc


def crc_check(buf: bytearray, pack_size: int) -> bool:
    ln = pack_size - CRC_BYTES
    c1 = crc8(bytes(buf), 0, ln, POLY1)
    c2 = crc8(bytes(buf), 0, ln + 1, POLY2)
    crc = ((c1 << 8) & 0xFF00) | (c2 & 0xFF)
    return buf[ln] == ((crc >> 8) & 0xFF) and buf[ln + 1] == (crc & 0xFF)


def parse_raw_csv(path: Path) -> list[tuple[float, str, float]] | None:
    """None — файл не в формате уровней (например экспорт битов декодера)."""
    rows = []
    with path.open(encoding="utf-8", errors="replace") as f:
        header = f.readline()
        h = header.lower()
        if "duration" not in h and "level" not in h:
            if "bit_idx" in h or (len(header.split(",")) >= 3 and header.split(",")[1].strip() == "Type"):
                return None
        for line in f:
            line = line.strip()
            if not line:
                continue
            parts = line.split(",")
            if len(parts) < 4:
                continue
            t_s = float(parts[0])
            level = parts[1].strip()
            if level.upper() not in ("HIGH", "LOW"):
                return None
            dur_us = float(parts[3].replace(" us", "").strip())
            rows.append((t_s, level, dur_us))
    return rows


def segments_to_edges(rows: list[tuple[float, str, float]]) -> list[tuple[float, bool]]:
    """Фронты: (t_us, rising)."""
    edges: list[tuple[float, bool]] = []
    prev = None
    for t_s, level, _dur in rows:
        high = level.upper() == "HIGH"
        if prev is not None:
            rising = high
            edges.append((t_s * 1e6, rising))
        prev = high
    return edges


@dataclass
class SimState:
    prev_rise: float = 0.0
    prev_fall: float = 0.0
    rise_period: int = 0
    high_time: int = 0
    low_time: int = 0
    last_edge: float = 0.0
    preamb_front_counter: int = 0
    is_preamb: bool = False
    is_recive_raw: bool = False
    is_recive: bool = False
    is_wrong_pack: bool = False
    is_buffer_overflow: bool = False
    buf_bit_pos: int = 0
    is_data: bool = True
    i_data_buffer: int = 0
    next_control_bit: int = BIT_PER_BYTE
    i_sync_bit: int = 0
    err_sync_bit: int = 0
    pack_size: int = 0
    data_buffer: bytearray = field(default_factory=lambda: bytearray(DATA_BYTE_SIZE_MAX))
    err_low: int = 0
    err_high: int = 0
    err_other: int = 0
    high_count: int = 0
    low_count: int = 0
    all_count: int = 0
    packets: list[tuple[bool, int, bytes]] = field(default_factory=list)  # crc_ok, pack_size, raw bytes
    bits_log: list[tuple[float, str, int]] = field(default_factory=list)  # t_us, kind, bit


def first_rx(st: SimState) -> None:
    """IR_DecoderRaw::firstRX — сброс буфера; isRecive/isReciveRaw в прошивке здесь не меняются."""
    st.is_preamb = True
    st.is_wrong_pack = False
    st.is_buffer_overflow = False
    st.buf_bit_pos = 0
    st.is_data = True
    st.i_data_buffer = 0
    st.next_control_bit = BIT_PER_BYTE
    st.i_sync_bit = 0
    st.err_sync_bit = 0
    st.pack_size = 0
    st.data_buffer = bytearray(DATA_BYTE_SIZE_MAX)


def tick(
    st: SimState,
    t_us: float,
    rising: bool,
    rise_sync_time: int,
    *,
    trace_rise: list[dict] | None = None,
) -> None:
    """Один вызов tick — один фронт (как IR_DecoderRaw после pop)."""
    rise_min = max(0, rise_sync_time - TOLERANCE_US)
    rise_max = rise_sync_time + TOLERANCE_US
    irmax = IR_TIMEOUT  # упрощ.: без подстройки riseSyncTime в timeout

    # listenStart: обрыв незавершённого приёма
    if st.is_recive_raw and (t_us - st.prev_rise) > irmax * 2:
        st.is_recive_raw = False
        first_rx(st)

    st.last_edge = t_us
    skip_rest = False

    if rising:
        cand_rp = int(t_us - st.prev_rise)
        cand_ht = int(t_us - st.prev_fall)
        cand_lt = int(st.prev_fall - st.prev_rise)
        if SHORT_LOW_GLITCH_REJECT:
            short_low_glitch = (
                st.is_recive
                and not st.is_preamb
                and cand_ht < (rise_min // 8)
                and cand_lt >= rise_min
                and cand_rp >= rise_min
                and cand_rp <= IR_TIMEOUT
            )
            if short_low_glitch:
                st.err_other += 1
                if GLITCH_REJECT_PHASE_NUDGE:
                    st.prev_rise = glitch_phase_nudge(t_us, rise_sync_time, st.prev_rise)
                skip_rest = True
        if not skip_rest and MICRO_GAP_RISE_REJECT:
            lt_ok = (cand_lt >= rise_min) or (cand_lt >= (rise_min // 4) and cand_lt < rise_min)
            micro_gap = (
                st.is_recive
                and not st.is_preamb
                and cand_ht < (rise_min // 8)
                and lt_ok
                and cand_rp >= (rise_min // 4)
                and cand_rp < rise_min
                and cand_rp <= IR_TIMEOUT
            )
            if micro_gap:
                st.err_other += 1
                if GLITCH_REJECT_PHASE_NUDGE:
                    st.prev_rise = glitch_phase_nudge(t_us, rise_sync_time, st.prev_rise)
                skip_rest = True
        if not skip_rest and cand_rp <= rise_max / 4 and not st.high_count and not st.low_count:
            st.err_other += 1
            skip_rest = True
        if not skip_rest:
            # Как IR_DecoderRaw::tick: до обновления prev_rise, иначе (t_us - prev_rise) == 0 на подъёме.
            if cand_rp > irmax * 2 and not st.is_recive_raw:
                first_rx(st)
                st.preamb_front_counter = PREAMB_FRONTS - 1
                st.is_preamb = True
                st.is_recive = True
                st.is_recive_raw = True
                st.is_wrong_pack = False
            st.rise_period = cand_rp
            st.high_time = cand_ht
            st.low_time = cand_lt
            st.prev_rise = t_us
    else:
        if t_us - st.prev_fall > rise_min / 4:
            st.prev_fall = t_us
        else:
            skip_err = False
            if IN_MARK_DOUBLE_FALL_IGNORE:
                hi_since_rise = t_us - st.prev_rise
                mark_end_min = (rise_min * BIT_ACTIVE_TAKTS) // (
                    BIT_ACTIVE_TAKTS + BIT_PAUSE_TAKTS
                )
                skip_err = (
                    st.is_recive
                    and not st.is_preamb
                    and hi_since_rise < mark_end_min
                )
            if not skip_err:
                st.err_other += 1

    if skip_rest:
        return

    # Старт нового кадра после длинной паузы (в прошивке буфер обнуляется через available/таймаут;
    # для мульти-пакета в симуляции явно first_rx, иначе i_data_buffer залипает).
    if t_us > st.prev_rise and (t_us - st.prev_rise) > irmax * 2 and not st.is_recive_raw:
        first_rx(st)
        st.preamb_front_counter = PREAMB_FRONTS - 1
        st.is_preamb = True
        st.is_recive = True
        st.is_recive_raw = True
        st.is_wrong_pack = False

    if st.preamb_front_counter:
        if rising and st.rise_period < irmax:
            if st.rise_period < rise_min // 2:
                st.preamb_front_counter += 2
                st.err_other += 1
        st.preamb_front_counter -= 1
    else:
        if st.is_preamb:
            st.is_preamb = False
            st.prev_rise += st.rise_period / 2.0
            return

    if st.is_preamb:
        return

    if st.rise_period > irmax or st.is_buffer_overflow or st.rise_period < rise_min or st.is_wrong_pack:
        return

    if not rising:
        return

    st.high_count = st.low_count = st.all_count = 0
    invert_err = False

    def write_to_buffer(bit: bool, invert_fix: bool) -> None:
        if st.i_data_buffer > DATA_BYTE_SIZE_MAX * 8:
            st.is_buffer_overflow = True
        if st.is_buffer_overflow or st.is_preamb or st.is_wrong_pack:
            st.is_recive = False
            st.is_recive_raw = False
            return
        if st.buf_bit_pos == st.next_control_bit:
            st.next_control_bit += SYNC_BITS if st.is_data else BIT_PER_BYTE
            st.is_data = not st.is_data
            st.i_sync_bit = 0
            st.err_sync_bit = 0
        if st.is_data:
            bi = st.i_data_buffer
            st.data_buffer[bi // 8] |= (1 if bit else 0) << (7 - (bi % 8))
            st.i_data_buffer += 1
            st.buf_bit_pos += 1
            st.bits_log.append((t_us, "D", 1 if bit else 0))
        else:
            if st.i_sync_bit == 0:
                last_b = (st.data_buffer[((st.i_data_buffer - 1) // 8)] >> (7 - ((st.i_data_buffer - 1) % 8))) & 1
                if bit != bool(last_b):
                    st.buf_bit_pos += 1
                    st.i_sync_bit += 1
                    st.bits_log.append((t_us, "S", 1 if bit else 0))
                else:
                    st.i_sync_bit = 0
                    st.err_other += 1
                    st.err_sync_bit += 1
                    if st.err_sync_bit >= SYNC_BITS:
                        st.is_wrong_pack = True
            else:
                st.buf_bit_pos += 1
                st.i_sync_bit += 1
                st.bits_log.append((t_us, "S", 1 if bit else 0))
            st.is_wrong_pack = st.err_sync_bit >= SYNC_BITS
        if st.is_data and not st.is_wrong_pack:
            if st.i_data_buffer == 8 * MSG_BYTES:
                st.pack_size = st.data_buffer[0] & IR_MASK_MSG_INFO
            if st.pack_size and st.i_data_buffer == st.pack_size * BIT_PER_BYTE:
                ok = crc_check(st.data_buffer, st.pack_size)
                st.packets.append((ok, st.pack_size, bytes(st.data_buffer[: st.pack_size])))
                st.is_recive = False
                st.is_recive_raw = False
                # буфер не чистят здесь — как в IR_DecoderRaw; firstRX по listenStart

    if around_rise_period(st.rise_period, rise_sync_time):
        if st.high_time > st.low_time:
            write_to_buffer(True, False)
        else:
            write_to_buffer(False, False)
    elif RISE_GRAY_SINGLE_BIT_FALLBACK and rise_gray_single_bit_fallback(st.rise_period, rise_sync_time):
        st.err_other += 1
        if st.high_time > st.low_time:
            write_to_buffer(True, False)
        else:
            write_to_buffer(False, False)
    else:
        hc = ceil_div(min(st.high_time, 0xFFFF), rise_sync_time)
        lc = ceil_div(min(st.low_time, 0xFFFF), rise_sync_time)
        ac = ceil_div(min(st.rise_period, 0xFFFF), rise_sync_time)
        st.high_count = min(hc, 127)
        st.low_count = min(lc, 127)
        st.all_count = min(ac, 127)
        if st.high_count == 0 and st.high_time > rise_sync_time // 3:
            st.high_count += 1
            st.err_other += 1
        if st.low_count + st.high_count > st.all_count:
            if st.low_count > st.high_count:
                st.low_count = st.all_count - st.high_count
                st.err_low += st.low_count
            elif st.low_count < st.high_count:
                st.high_count = st.all_count - st.low_count
                st.err_high += st.high_count
            elif st.low_count == st.high_count:
                invert_err = True
                st.err_other += st.all_count
        if st.low_count < st.high_count:
            st.err_high += st.high_count
        else:
            st.err_low += st.low_count
        # Как IR_DecoderRaw.cpp / IrFoxDecoder: не более 8 LOW и 8 HIGH за один подъём (i < n && 8 - i).
        i = 0
        while i < st.low_count and (8 - i):
            if i == st.low_count - 1 and invert_err:
                invert_err = False
                write_to_buffer(True, True)
            else:
                write_to_buffer(False, False)
            i += 1
        i = 0
        while i < st.high_count and (8 - i):
            if i == st.high_count - 1 and invert_err:
                invert_err = False
                write_to_buffer(False, True)
            else:
                write_to_buffer(True, False)
            i += 1

    if trace_rise is not None and rising and not skip_rest:
        # После decode: залогировать только реальные записи битов (не преамбула, не ранний return выше)
        if (
            not st.is_preamb
            and st.rise_period <= irmax
            and not st.is_buffer_overflow
            and st.rise_period >= rise_min
        ):
            rec: dict = {
                "t_us": t_us,
                "rp": st.rise_period,
                "ht": st.high_time,
                "lt": st.low_time,
                "i_buf": st.i_data_buffer,
                "n_pkt": len(st.packets),
            }
            if around_rise_period(st.rise_period, rise_sync_time):
                rec["branch"] = "around"
                rec["bits_out"] = 1
            elif RISE_GRAY_SINGLE_BIT_FALLBACK and rise_gray_single_bit_fallback(
                st.rise_period, rise_sync_time
            ):
                rec["branch"] = "gray"
                rec["bits_out"] = 1
            else:
                rec["branch"] = "ceil"
                rec["hc"] = st.high_count
                rec["lc"] = st.low_count
                rec["ac"] = st.all_count
                rec["bits_out"] = st.low_count + st.high_count
            trace_rise.append(rec)


def run_file(path: Path, max_packets: int = 0) -> SimState | None:
    """max_packets=0 — обработать весь файл (для регрессии по всем пакетам)."""
    rows = parse_raw_csv(path)
    if rows is None:
        return None
    edges = segments_to_edges(rows)
    st = SimState()
    rise_sync = BIT_TIME_US
    for t_us, rising in edges:
        tick(st, t_us, rising, rise_sync)
        if max_packets and len(st.packets) >= max_packets:
            break
    return st


def main() -> None:
    root = Path(__file__).resolve().parents[1]
    default_set = [
        ("CAR", root / "Analyzer" / "raw" / "car_raw.txt"),
        ("POINT", root / "Analyzer" / "raw" / "point_raw.txt"),
        ("CARRAW3", root / "Analyzer" / "raw" / "carraw3.txt"),
        ("POINTRA3", root / "Analyzer" / "raw" / "pointraw_3.txt"),
    ]
    files = default_set
    if len(sys.argv) >= 2:
        files = [(Path(p).name, Path(p)) for p in sys.argv[1:]]

    for label, p in files:
        if not p.exists():
            print(f"skip {label}: {p} not found")
            continue
        st = run_file(p, max_packets=0)
        print(f"=== {label} {p.name} ===")
        if st is None:
            print(
                "  (skip: decoder trace CSV Type/bit_idx, or missing Level+Duration; need Saleae level like car_raw.txt)"
            )
            continue
        n_ok = sum(1 for x in st.packets if x[0])
        n_bad = len(st.packets) - n_ok
        print(
            f"  packets={len(st.packets)} crc_ok={n_ok} crc_bad={n_bad} "
            f"err_other={st.err_other} err_low={st.err_low} err_high={st.err_high}"
        )
        for i, (ok, psz, raw) in enumerate(st.packets[:12]):
            hx = raw.hex(" ")
            print(f"  pkt[{i}] crc_ok={ok} len={psz}  {hx}")
        if len(st.packets) > 12:
            print(f"  ... ({len(st.packets) - 12} more packets)")
        print(f"  first 24 bits: {st.bits_log[:24]}")

    car = root / "Analyzer" / "raw" / "car_raw.txt"
    point = root / "Analyzer" / "raw" / "point_raw.txt"
    if car.exists() and point.exists():
        sc = run_file(car, max_packets=1)
        sp = run_file(point, max_packets=1)
        if sc is None or sp is None:
            return
        print("\n=== First packet bit diff (D/S sequence) CAR vs POINT ===")
        for i, (a, b) in enumerate(zip(sc.bits_log, sp.bits_log)):
            if a != b:
                print(f"  idx {i}: CAR {a} vs POINT {b}")
                break
        else:
            if len(sc.bits_log) != len(sp.bits_log):
                print(f"  len CAR={len(sc.bits_log)} POINT={len(sp.bits_log)}")
            else:
                print("  identical bit logs for min(len)")


if __name__ == "__main__":
    main()