import re
from dataclasses import dataclass, field

from ..chat.base import Target
from ..chat.targets import valid_target
from ..globs import validate_glob
from .limits import (AI_HINT_MAX, DEFAULT_MIN_STATE, DELAY_MINUTES_RANGE, MIN_STATE_RANGE, NAME_MAX,
                     OUTPUT_CONTAINS_MAX, REMINDER_HOURS_RANGE, TARGET_MAX)
from .rules import ALL_KINDS

BACKENDS = ("telegram", "matrix")
CONTROL_RE = re.compile(r"[\x00-\x08\x0b-\x1f\x7f]")


@dataclass(frozen=True)
class RouteInput:
    name: str = ""
    match_host: str = ""
    match_service: str = ""
    min_state: int = DEFAULT_MIN_STATE
    kinds: tuple[str, ...] = ALL_KINDS
    stop_on_match: bool = False
    enabled: bool = True
    targets: tuple[Target, ...] = field(default_factory=tuple)
    delay_minutes: int | None = None
    output_contains: str = ""
    ai_enabled: bool = True
    ai_hint: str = ""
    reminder_hours: int | None = None
    loud: bool = True
    use_default_targets: bool = False


def _range_error(value: int | None, bounds: tuple[int, int], label: str, unit: str = "") -> list[str]:
    low, high = bounds
    if value is not None and not low <= value <= high:
        suffix = f" {unit}" if unit else ""
        return [f"{label} muss zwischen {low} und {high}{suffix} liegen."]
    return []


def validate_route(data: RouteInput) -> list[str]:
    errors = []
    if not data.name.strip():
        errors.append("Name fehlt.")
    elif len(data.name) > NAME_MAX:
        errors.append(f"Name ist zu lang (max. {NAME_MAX} Zeichen).")
    errors += validate_glob(data.match_host, "Host-Muster") + validate_glob(data.match_service, "Service-Muster")
    errors += _range_error(data.min_state, MIN_STATE_RANGE, "Mindest-Schweregrad")
    if not data.kinds or any(kind not in ALL_KINDS for kind in data.kinds):
        errors.append("Mindestens eine gültige Alarmart wählen.")
    errors += _range_error(data.delay_minutes, DELAY_MINUTES_RANGE, "Verzögerung", "Minuten")
    errors += _range_error(data.reminder_hours, REMINDER_HOURS_RANGE, "Erinnerung", "Stunden")
    if len(data.output_contains) > OUTPUT_CONTAINS_MAX:
        errors.append(f"Der Ausgabe-Text ist zu lang (max. {OUTPUT_CONTAINS_MAX} Zeichen).")
    if CONTROL_RE.search(data.output_contains):
        errors.append("Der Ausgabe-Text enthält Steuerzeichen.")
    if len(data.ai_hint) > AI_HINT_MAX:
        errors.append(f"Der KI-Hinweis ist zu lang (max. {AI_HINT_MAX} Zeichen).")
    if CONTROL_RE.search(data.ai_hint):
        errors.append("Der KI-Hinweis enthält Steuerzeichen.")
    for target in data.targets:
        if target.backend not in BACKENDS:
            errors.append(f"Unbekanntes Backend: {target.backend}")
        elif len(target.target) > TARGET_MAX or not valid_target(target.backend, target.target):
            errors.append(f"Ungültiges Ziel für {target.backend}.")
    return errors