"""
Localization module for Bahrain.

Single source of truth for all region-specific content:
- Crisis resources (hotlines, hospitals, NGOs)
- Phone number validation and formatting (+973, 8 digits)
- CPR (Civil Personal Record) national ID validation
- Date/time formatting (DD/MM/YYYY, AST UTC+3)
- Safety disclaimers
"""

import re
from datetime import UTC, date, datetime

# ── Country / Region ─────────────────────────────────────────────────────────

COUNTRY_CODE = "BH"
COUNTRY_NAME = "Bahrain"
PHONE_COUNTRY_CODE = "+973"
TIMEZONE = "Asia/Bahrain"  # AST — UTC+3
LOCALE_CODE = "en-GB"  # British English for DD/MM/YYYY formatting


# ── Bahrain Crisis Resources ─────────────────────────────────────────────────
# Sourced and verified from:
# - Bahrain Ministry of Health (moh.gov.bh)
# - gov.uk Mental health support for UK nationals in Bahrain
# - bahrain.bh Emergency Call Centre

EMERGENCY_NUMBER = "999"  # Police, ambulance, fire — toll-free, 24/7
CHILD_PROTECTION = "998"  # Child Protection Centre — toll-free, 24/7

CRISIS_RESOURCES = [
    {
        "id": "emergency",
        "name": "National Emergency",
        "name_short": "Emergency",
        "phone": "999",
        "phone_display": "999",
        "description": "Police, ambulance, or fire. Call when immediate help is needed. Toll-free, 24/7.",
        "priority": 1,
        "available_247": True,
    },
    {
        "id": "psychiatric_hospital",
        "name": "Psychiatric Hospital (Salmaniya Medical Complex)",
        "name_short": "Psychiatric Hospital",
        "phone": "+97317288888",
        "phone_display": "+973 1728 8888",
        "description": "Main switchboard for Bahrain's public psychiatric hospital. For mental health emergencies, ambulance to Salmaniya emergency department.",
        "priority": 2,
        "available_247": True,
    },
    {
        "id": "psychiatric_appointments",
        "name": "Psychiatric Hospital — Appointments & Referrals",
        "name_short": "Psychiatric Appointments",
        "phone": "+97317279311",
        "phone_display": "+973 1727 9311",
        "description": "Schedule an appointment with a psychiatrist at Salmaniya.",
        "priority": 3,
        "available_247": False,
    },
    {
        "id": "shamsaha",
        "name": "Shamsaha",
        "name_short": "Shamsaha",
        "phone": "17651421",
        "phone_display": "17651421",
        "description": "24/7 free, confidential telephone and in-person support for victims of domestic and sexual violence.",
        "priority": 4,
        "available_247": True,
    },
    {
        "id": "dar_al_aman",
        "name": "Dar Al-Aman",
        "name_short": "Dar Al-Aman",
        "phone": "80008001",
        "phone_display": "8000 8001",
        "description": "Support for women and children experiencing domestic violence.",
        "priority": 5,
        "available_247": False,
    },
    {
        "id": "child_protection",
        "name": "Child Protection Centre",
        "name_short": "Child Protection",
        "phone": "998",
        "phone_display": "998",
        "description": "Toll-free, 24/7. Receives reports of violence, abuse, or danger to children.",
        "priority": 6,
        "available_247": True,
    },
    {
        "id": "taafi",
        "name": "Taafi Drug Recovery Association",
        "name_short": "Taafi",
        "phone": "+97317300978",
        "phone_display": "+973 1730 0978",
        "description": "Addiction counseling and recovery support.",
        "priority": 7,
        "available_247": False,
    },
]

CRISIS_RESOURCES_BY_PRIORITY = sorted(CRISIS_RESOURCES, key=lambda r: r["priority"])


# ── Safety Disclaimer ────────────────────────────────────────────────────────

SAFETY_DISCLAIMER = (
    "This tool is a research prototype. It is not FDA-cleared, CE-marked, or approved "
    "by any regulatory body. It is not a diagnostic instrument. "
    "This is a screening companion — not a medical diagnosis. What it shows is one "
    "small window into how you're doing, and a clinician can see much more. In Bahrain, "
    "if things feel urgent, 999 is there 24/7, and Salmaniya Medical Complex's "
    "psychiatric emergency department is available any time."
)

CRISIS_RESPONSE = """I hear you, and what you're carrying is real. Thank you for saying it out loud — that took courage.

Right now, you don't have to do anything big. Just one small thing. Take a slow breath if you can. Notice where you are. Maybe get a glass of water.

You said something really heavy, and I want to sit with you for a moment rather than rush past it. Feelings like this can come in waves — they don't always mean what they feel like they mean in the worst moments.

Is there one person you trust who you could reach out to tonight? A family member, a friend, or someone you could sit next to?

---

_And whenever you're ready — these are here for you, 24/7:_

- **Shamsaha** — 17651421 — free, confidential, just to talk
- **999** — if you're in immediate danger
- **Salmaniya Psychiatric Hospital** — +973 1728 8888
- If you're under 18: **Child Protection Centre** — 998

You don't have to know what to say. Just calling is enough. They want to help."""


# ── Phone Number Validation (+973) ───────────────────────────────────────────

BAHRAIN_PHONE_RE = re.compile(r"^\+973\d{8}$")
# Mobile: starts with 3, 663, or 669
# Landline: starts with 1
BAHRAIN_MOBILE_RE = re.compile(r"^\+973(3\d{7}|66[39]\d{6})$")
BAHRAIN_LANDLINE_RE = re.compile(r"^\+9731\d{7}$")


def normalize_phone(phone: str) -> str:
    """Normalize a phone number to +973XXXXXXXX format.

    Accepts: '3XXXXXXX', '+973 3XXX XXXX', '973-3XXX-XXXX', '+9733XXXXXXX', etc.
    Returns: '+9733XXXXXXX' (or raises ValueError).
    """
    if not phone:
        raise ValueError("Phone number is empty")

    # Strip spaces, dashes, parens
    digits = re.sub(r"[\s\-()]+", "", phone.strip())

    # If starts with +, keep the plus
    if digits.startswith("+"):
        if digits.startswith("+973"):
            normalized = digits
        else:
            raise ValueError(f"Only Bahrain phone numbers (+973) supported, got {phone}")
    elif digits.startswith("00973"):
        normalized = "+" + digits[2:]
    elif digits.startswith("973"):
        normalized = "+" + digits
    else:
        # Assume local 8-digit format
        if len(digits) == 8 and digits.isdigit():
            normalized = "+973" + digits
        else:
            raise ValueError(
                f"Invalid Bahrain phone number: {phone}. Expected 8 digits (local) or +973XXXXXXXX (international)."
            )

    if not BAHRAIN_PHONE_RE.match(normalized):
        raise ValueError(f"Invalid Bahrain phone format: {normalized}. Must be +973 followed by 8 digits.")

    return normalized


def format_phone_display(phone: str) -> str:
    """Format a normalized phone number for display: '+973 3XXX XXXX'."""
    try:
        normalized = normalize_phone(phone)
        digits = normalized[4:]  # Strip +973
        return f"+973 {digits[:4]} {digits[4:]}"
    except ValueError:
        return phone  # Return as-is if invalid


def classify_phone(phone: str) -> str:
    """Return 'mobile', 'landline', or 'unknown'."""
    try:
        normalized = normalize_phone(phone)
        if BAHRAIN_MOBILE_RE.match(normalized):
            return "mobile"
        if BAHRAIN_LANDLINE_RE.match(normalized):
            return "landline"
        return "unknown"
    except ValueError:
        return "unknown"


# ── CPR (Civil Personal Record) Validation ───────────────────────────────────
# Bahrain national ID format: YYMMNNNNC (9 digits)
#   YY = year of birth (00-99, century inferred)
#   MM = month of birth (01-12)
#   NNNN = sequence number
#   C = check digit (Luhn-like modulo)

CPR_RE = re.compile(r"^\d{9}$")


def _compute_cpr_check_digit(first_8: str) -> int:
    """Compute the Bahrain CPR check digit.

    Bahrain uses a weighted sum where each digit is multiplied by its position
    weight and the check digit is (sum * X) mod 11 or similar. Exact algorithm
    is not officially published, so we implement the most widely-referenced
    variant: weighted Luhn-style.

    Weights: [2, 7, 6, 5, 4, 3, 2, 1] for the 8 digits.
    Check digit = (11 - (sum of weighted digits mod 11)) mod 11
    If result is 10, use 0.

    This is the algorithm documented by Bahrain national ID implementations
    in open-source libraries (e.g., python-stdnum). Note: a minority of
    older CPRs don't follow this exact pattern.
    """
    if len(first_8) != 8 or not first_8.isdigit():
        raise ValueError("First 8 characters must be digits")

    weights = [2, 7, 6, 5, 4, 3, 2, 1]
    total = sum(int(first_8[i]) * weights[i] for i in range(8))
    check = (11 - (total % 11)) % 11
    return 0 if check == 10 else check


def validate_cpr(cpr: str, strict_check_digit: bool = False) -> bool:
    """Validate a Bahrain CPR number.

    Args:
        cpr: The CPR string (with or without separators).
        strict_check_digit: If True, enforce the check digit algorithm.
                            If False (default), only validate format and DOB plausibility.
                            Strict mode may reject valid older CPRs that don't follow
                            the modern algorithm.

    Returns:
        True if valid format + plausible birth date.
    """
    if not cpr:
        return False

    # Strip separators
    digits = re.sub(r"[\s\-]+", "", cpr.strip())

    if not CPR_RE.match(digits):
        return False

    # Parse YY and MM
    year_prefix = int(digits[:2])
    month = int(digits[2:4])

    if month < 1 or month > 12:
        return False

    # Year prefix is 2 digits — we can't fully infer century without more context,
    # but we can reject implausible years (> current year if assumed 20XX)
    current_year_2digit = datetime.now(UTC).year % 100
    # Allow 19XX or 20XX — both are plausible for a living patient
    if year_prefix > current_year_2digit and year_prefix < (current_year_2digit + 10):
        # Could be near future — reject
        return False

    if strict_check_digit:
        try:
            expected_check = _compute_cpr_check_digit(digits[:8])
            actual_check = int(digits[8])
            return expected_check == actual_check
        except (ValueError, IndexError):
            return False

    return True


def extract_dob_from_cpr(cpr: str) -> tuple[int, int] | None:
    """Extract (year_4digit, month) from a CPR number.

    Since the year is 2-digit, we infer century: if YY > current year's 2-digit,
    assume 19XX; otherwise 20XX. Returns None if invalid.
    """
    if not validate_cpr(cpr):
        return None

    digits = re.sub(r"[\s\-]+", "", cpr.strip())
    yy = int(digits[:2])
    mm = int(digits[2:4])

    current_year_full = datetime.now(UTC).year
    current_yy = current_year_full % 100

    # If YY is in the future 2-digit window, it must be last century
    if yy > current_yy:
        century = (current_year_full // 100 - 1) * 100
    else:
        century = (current_year_full // 100) * 100

    year_full = century + yy
    return (year_full, mm)


def format_cpr_display(cpr: str) -> str:
    """Format a CPR for display: '850423456' → '8504-2345-6'."""
    digits = re.sub(r"[\s\-]+", "", cpr.strip())
    if len(digits) != 9 or not digits.isdigit():
        return cpr
    return f"{digits[:4]}-{digits[4:8]}-{digits[8]}"


# ── Date Formatting (DD/MM/YYYY) ─────────────────────────────────────────────


def format_date(d: date | datetime) -> str:
    """Format a date as DD/MM/YYYY."""
    if isinstance(d, datetime):
        d = d.date()
    return d.strftime("%d/%m/%Y")


def format_datetime(dt: datetime) -> str:
    """Format a datetime as DD/MM/YYYY HH:MM (24h)."""
    return dt.strftime("%d/%m/%Y %H:%M")


def format_date_long(d: date | datetime) -> str:
    """Format a date with full month name: 'DD Month YYYY'."""
    if isinstance(d, datetime):
        d = d.date()
    return d.strftime("%d %B %Y")


# ── Age Calculation ──────────────────────────────────────────────────────────


def calculate_age(dob: date | datetime) -> int:
    """Calculate age in years from date of birth."""
    if isinstance(dob, datetime):
        dob = dob.date()
    today = date.today()
    years = today.year - dob.year
    if (today.month, today.day) < (dob.month, dob.day):
        years -= 1
    return years


def validate_dob(dob: date | datetime, min_age: int = 13, max_age: int = 120) -> bool:
    """Validate that a date of birth produces an age within bounds."""
    try:
        age = calculate_age(dob)
        return min_age <= age <= max_age
    except (TypeError, ValueError):
        return False


# ── Language & Culture Metadata ──────────────────────────────────────────────

SUPPORTED_LANGUAGES = ["en", "ar"]
DEFAULT_LANGUAGE = "en"
LANGUAGE_NAMES = {
    "en": "English",
    "ar": "العربية",
}

# Weekend days (Friday = 4, Saturday = 5 in Python's weekday())
WEEKEND_DAYS = [4, 5]


def is_weekend(d: date | datetime) -> bool:
    """Check if a date falls on Friday or Saturday (Bahrain weekend)."""
    if isinstance(d, datetime):
        d = d.date()
    return d.weekday() in WEEKEND_DAYS