"""Čisté Deye konstanty a helpery pro control export."""

from __future__ import annotations

from datetime import datetime, timedelta, timezone
from zoneinfo import ZoneInfo

from services.control.models import InverterConfig

PRAGUE_TZ = ZoneInfo("Europe/Prague")

# Hodiny Deye 62-64: po zápisu sekundy na zařízení dál běží, verify musí být toleranční.
DEYE_CLOCK_VERIFY_MAX_DELTA_SEC = 120
# Řidší zápis: bez zápisu, pokud čas na invertoru neodbočí od Prahy víc než o tolik sekund.
DEYE_CLOCK_DRIFT_OK_SEC = 60
# A zároveň neuplynul tento interval od posledního syncu / potvrzení driftu.
DEYE_CLOCK_RESYNC_INTERVAL_HOURS = 24

# Deye LV baterie: převod výkon -> proud pro registry 108/109.
BATT_VOLTAGE_V = 51.2

# Reg 178 - bitové pole: bity 4-5 (peak shaving switch) a bity 0-1 (MI export cutoff).
REG178_SELL = 0b00100000
REG178_PASSIVE = 0b00110000
REG178_VERIFY_MASK = 0x0030
REG178_MI_EXPORT_MASK = 0x0003
REG178_MI_EXPORT_DISABLE = 0b10
REG178_MI_EXPORT_ENABLE = 0b11
REG178_VERIFY_MASK_COMBINED = REG178_VERIFY_MASK | REG178_MI_EXPORT_MASK

DEYE_CRITICAL_REGS_SELF_SUSTAIN = frozenset({108, 109, 142, 143, 145})
DEYE_TOU_POWER_REGS = frozenset(range(154, 160))
DEYE_LV_BATTERY_MAX_CHARGE_DISCHARGE_A = 350

# Neaktivní TOU bloky (3-6): Deye často 23:59 (2359) neuloží, 23:55 je stabilní.
DEYE_TOU_INACTIVE_HHMM = 2355

_DEYE_INACTIVE_TOU_REGISTERS: frozenset[int] = frozenset(
    [
        150,
        151,
        152,
        153,
        156,
        157,
        158,
        159,
        168,
        169,
        170,
        171,
        174,
        175,
        176,
        177,
    ]
)

DEYE_CLOCK_REGS: frozenset[int] = frozenset({62, 63, 64})

DEYE_REGISTER_NAMES: dict[int, str] = {
    108: "max_charge_a (max nabíjecí proud baterie)",
    109: "max_discharge_a (max vybíjecí proud baterie)",
    141: "energy_mode (0, EMS nemění)",
    142: "limit_control (0=selling first, 1=zero export to load, 2=zero export to CT)",
    143: "export_limit_w (max export do sítě)",
    145: "solar_sell (0=disabled, 1=enabled)",
    340: "max_solar_power_w (strop DC PV A v W; cap z fn_inverter_pv_a_max_w / deye_reg340_max_solar_w)",
    178: "control_board_special_1 (bits0-1: MI export cutoff disable=2 enable=3; bits4-5 peak shaving 32/48)",
    148: "time_point_1_time",
    149: "time_point_2_time",
    154: "time_point_1_power_w",
    155: "time_point_2_power_w",
    166: "time_point_1_soc_min_pct",
    167: "time_point_2_soc_min_pct",
    172: "time_point_1_grid_charge",
    173: "time_point_2_grid_charge",
    62: "system_time_year_month",
    63: "system_time_day_hour",
    64: "system_time_min_sec",
}
for _tp_i in range(6):
    _n = _tp_i + 1
    DEYE_REGISTER_NAMES.setdefault(148 + _tp_i, f"time_point_{_n}_time")
    DEYE_REGISTER_NAMES.setdefault(154 + _tp_i, f"time_point_{_n}_power_w")
    DEYE_REGISTER_NAMES.setdefault(166 + _tp_i, f"time_point_{_n}_soc_min_pct")
    DEYE_REGISTER_NAMES.setdefault(172 + _tp_i, f"time_point_{_n}_grid_charge")


def _deye_reg178_verify_match(expected_i: int, actual_i: int) -> bool:
    return (int(expected_i) & REG178_VERIFY_MASK_COMBINED) == (
        int(actual_i) & REG178_VERIFY_MASK_COMBINED
    )


def deye_reg_triggers_self_sustain_after_verify_exhaust(reg: int) -> bool:
    """True = po 3x mismatch přepnout lokalitu do SELF_SUSTAIN (kritický registr)."""
    return int(reg) in DEYE_CRITICAL_REGS_SELF_SUSTAIN


def _deye_tou_power_verify_match(
    expected_i: int, actual_i: int, inv: InverterConfig
) -> bool:
    """Firmware často clampne TOU power W na max z reg. 108/109 x 51.2 V."""
    if int(actual_i) == int(expected_i):
        return True
    max_w_charge = int(inv.max_charge_a * BATT_VOLTAGE_V)
    max_w_discharge = int(inv.max_discharge_a * BATT_VOLTAGE_V)
    a = int(actual_i)
    return a == max_w_charge or a == max_w_discharge


def _deye_reg178_verify_with_double_read(
    expected_i: int, actual_first: int, actual_second: int | None
) -> tuple[bool, int]:
    """
    Vrátí (shoda, hodnota_pro_journal).
    Druhé čtení použít jen když první neprojde maskou (RS485 / glitch).
    """
    if _deye_reg178_verify_match(expected_i, actual_first):
        return True, actual_first
    if actual_second is not None and _deye_reg178_verify_match(expected_i, actual_second):
        return True, int(actual_second)
    return False, actual_first


def watts_to_amps(power_w: int | None, phases: int = 3, voltage: int = 230) -> int:
    if not power_w or power_w <= 0:
        return 0
    return min(32, max(0, int(power_w / (phases * voltage))))


def battery_watts_to_amps(power_w: int, max_amps: int) -> int:
    """Proud z |výkonu| baterie; max_amps z DB."""
    derived = int(abs(power_w) / BATT_VOLTAGE_V)
    return min(max(0, max_amps), max(0, derived))


def current_slot_hhmm() -> int:
    """Začátek probíhajícího 15min slotu v Europe/Prague, formát HHMM."""
    now = datetime.now(PRAGUE_TZ)
    slot_min = (now.minute // 15) * 15
    return now.hour * 100 + slot_min


def next_slot_hhmm() -> int:
    """Začátek příštího 15min slotu v Europe/Prague, formát HHMM."""
    now = datetime.now(PRAGUE_TZ)
    minutes = now.minute
    slot_minutes = ((minutes // 15) + 1) * 15
    if slot_minutes >= 60:
        next_hour = (now.hour + 1) % 24
        next_min = 0
    else:
        next_hour = now.hour
        next_min = slot_minutes
    return next_hour * 100 + next_min


def compute_pv_a_reg340_max_solar_w(
    cap_w: int,
    forecast_w: int,
    curtail_w: int,
    *,
    min_w: int = 0,
) -> int:
    """Hodnota pro Deye reg 340 (max solar power, W) z capu a plánovaného curtailmentu pole A."""
    if curtail_w <= 0:
        raw = int(cap_w)
    else:
        raw = max(0, min(int(cap_w), int(forecast_w) - int(curtail_w)))
    if raw > 0 and int(min_w) > 0:
        return max(int(min_w), raw)
    return raw


def _prague_minute_start_utc() -> datetime:
    """UTC okamžik odpovídající začátku aktuální kalendářní minuty v Europe/Prague."""
    p = datetime.now(PRAGUE_TZ).replace(second=0, microsecond=0)
    return p.astimezone(timezone.utc)


def _deye_registers_to_prague_datetime(r62: int, r63: int, r64: int) -> datetime | None:
    """Dekódování reg 62-64 (Deye system time v Europe/Prague)."""
    try:
        year = (int(r62) >> 8) + 2000
        month = int(r62) & 0xFF
        day = int(r63) >> 8
        hour = int(r63) & 0xFF
        minute = int(r64) >> 8
        second = int(r64) & 0xFF
        if not (1 <= month <= 12 and 1 <= day <= 31 and 0 <= hour <= 23):
            return None
        if not (0 <= minute <= 59 and 0 <= second <= 59):
            return None
        return datetime(year, month, day, hour, minute, second, tzinfo=PRAGUE_TZ)
    except (ValueError, OverflowError):
        return None


def _deye_clock_registers_verify_match(
    w62: int,
    w63: int,
    w64: int,
    a62: int,
    a63: int,
    a64: int,
) -> bool:
    w_dt = _deye_registers_to_prague_datetime(w62, w63, w64)
    a_dt = _deye_registers_to_prague_datetime(a62, a63, a64)
    if w_dt is None or a_dt is None:
        return False
    return abs((a_dt - w_dt).total_seconds()) <= DEYE_CLOCK_VERIFY_MAX_DELTA_SEC


def _deye_should_skip_time_sync_after_read(
    inv: InverterConfig,
    r62: int,
    r63: int,
    r64: int,
) -> bool:
    """
    True = nezařazovat zápis 62-64: drift je malý a od posledního úspěšného zápisu
    nebo tolerančního ověření neuplynulo 24h.
    """
    dev = _deye_registers_to_prague_datetime(r62, r63, r64)
    if dev is None:
        return False
    wall = datetime.now(PRAGUE_TZ)
    drift = abs((wall - dev).total_seconds())
    if drift > DEYE_CLOCK_DRIFT_OK_SEC:
        return False
    last_write = inv.deye_last_system_time_sync_at
    if last_write is None:
        return False
    if last_write.tzinfo is None:
        last_write = last_write.replace(tzinfo=timezone.utc)
    else:
        last_write = last_write.astimezone(timezone.utc)
    age = datetime.now(timezone.utc) - last_write
    if age >= timedelta(hours=DEYE_CLOCK_RESYNC_INTERVAL_HOURS):
        return False
    return True