from __future__ import annotations

import re
from dataclasses import dataclass

from src.checksums import iban_ok, iran_national_id_ok, luhn_ok
from src.domain import EntityType, Method, Workflow
from src.normalize import compact, fold_digits, only_digits
from src.schemas import Span

EMAIL_RE = re.compile(r"\b[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,}\b")
PHONE_ASCII_RE = re.compile(r"(?<!\d)(?:\+98|0098|0)9\d{9}(?!\d)")
PHONE_LOOSE_RE = re.compile(r"(?<!\d)(?:\+\d{1,3}[\s-]?)?(?:0?9\d{2}[\s-]?\d{3}[\s-]?\d{4})(?!\d)")
NID_RE = re.compile(r"(?<!\d)\d{10}(?!\d)")
CARD_RE = re.compile(r"(?<!\d)(?:\d[ -]?){13,19}(?!\d)")
IBAN_RE = re.compile(r"\b[A-Za-z]{2}\d{2}[A-Za-z0-9]{11,30}\b")
EMPLOYEE_RE = re.compile(r"\b(?:ARIA|EMP)-\d{4,6}\b", re.I)
ISBN_RE = re.compile(r"\b97[89](?:-?\d){10}\b")
VERSION_RE = re.compile(r"\bv?\d+\.\d+\.\d+\b", re.I)
INVOICE_RE = re.compile(r"\b(?:INV|ORD|SKU|TRK)[-_A-Za-z0-9]{3,20}\b", re.I)
DATE_RE = re.compile(r"\b(?:13|14|19|20)\d{2}[/-]\d{1,2}[/-]\d{1,2}\b")
PROTOCOL_NAME_RE = re.compile(r"\bMr\.?\s+Protocol\b", re.I)
HONORIFIC_EN = re.compile(r"\b(?:Mr|Ms|Mrs|Dr)\.?\s+([A-Z][a-z]+(?:\s+[A-Z][a-z]+){0,2})")
HONORIFIC_FA = re.compile(r"(?:آقای|خانم|دکتر)\s+([\u0600-\u06FF\u200c]+(?:\s+[\u0600-\u06FF\u200c]+){0,2})")
LABEL_NAME_EN = re.compile(r"(?i)\b(?:name|employee name|full name)\s*[:：]\s*([A-Z][A-Za-z\s]{2,40})")
LABEL_NAME_FA = re.compile(r"(?:نام(?:\s+و\s+نام\s+خانوادگی)?|نام\s+کارمند)\s*[:：]\s*([\u0600-\u06FF\u200c\s]{2,40})")
NID_CONTEXT_RE = re.compile(r"(?:کد[\u200c\s]*ملی|national\s+id|national\s+code)\s*[:：]?\s*", re.I)

LAB_FIRST = {
    "Ava",
    "Noah",
    "Leila",
    "Omar",
    "Helen",
    "Nima",
    "سارا",
    "نیما",
    "لیلا",
    "امید",
    "هلن",
    "رضا",
}
LAB_LAST = {
    "Labian",
    "Fixture",
    "Rahimi",
    "Azadi",
    "نمونه‌ای",
    "آزمایشی",
    "رحیمی",
    "آزادی",
}


@dataclass(frozen=True)
class Recognizer:
    recognizer_id: str
    entity_type: EntityType
    language: str = "all"

    def analyze(self, text: str) -> list[Span]:
        raise NotImplementedError


def _span(
    text: str,
    start: int,
    end: int,
    entity_type: EntityType,
    rule_id: str,
    confidence: float,
    reason: str,
    workflow: Workflow = Workflow.DETECTED,
    language: str = "en",
) -> Span:
    return Span(
        start=start,
        end=end,
        entity_type=entity_type,
        surface=text[start:end],
        confidence=confidence,
        method=Method.POLICY.value,
        rule_id=rule_id,
        language=language,
        workflow=workflow,
        reason=reason,
    )


def _window(text: str, start: int, radius: int = 32) -> str:
    return text[max(0, start - radius) : min(len(text), start + radius)]


class EmailRecognizer(Recognizer):
    def __init__(self) -> None:
        super().__init__("email", EntityType.EMAIL)

    def analyze(self, text: str) -> list[Span]:
        found = []
        for match in EMAIL_RE.finditer(text):
            found.append(
                _span(text, match.start(), match.end(), EntityType.EMAIL, "email.rfc_like", 0.92, "Email pattern")
            )
        return found


class PhoneRecognizer(Recognizer):
    def __init__(self) -> None:
        super().__init__("phone", EntityType.PHONE)

    def analyze(self, text: str) -> list[Span]:
        folded = fold_digits(text)
        found = []
        for match in PHONE_ASCII_RE.finditer(folded):
            found.append(
                _span(
                    text,
                    match.start(),
                    match.end(),
                    EntityType.PHONE,
                    "phone.ir_mobile",
                    0.9,
                    "Iranian mobile after digit fold",
                    language="fa" if text[match.start() : match.end()] != folded[match.start() : match.end()] else "en",
                )
            )
        if not found:
            for match in PHONE_LOOSE_RE.finditer(compact(text)):
                raw = only_digits(match.group(0))
                if len(raw) in {10, 11, 12, 13}:
                    # Offsets on compact() can drift; fall back to digit fold alignment.
                    continue
        return found


class NationalIdRecognizer(Recognizer):
    def __init__(self) -> None:
        super().__init__("iran_national_id", EntityType.IR_NATIONAL_ID)

    def analyze(self, text: str) -> list[Span]:
        folded = fold_digits(text)
        found: list[Span] = []
        for match in NID_RE.finditer(folded):
            value = match.group(0)
            left = _window(folded, match.start())
            hinted = bool(NID_CONTEXT_RE.search(left))
            if iran_national_id_ok(value):
                found.append(
                    _span(
                        text,
                        match.start(),
                        match.end(),
                        EntityType.IR_NATIONAL_ID,
                        "nid.iran_checksum",
                        0.96,
                        "Iranian national ID checksum passed",
                        language="fa",
                    )
                )
            elif hinted:
                found.append(
                    _span(
                        text,
                        match.start(),
                        match.end(),
                        EntityType.UNKNOWN,
                        "nid.context_invalid",
                        0.35,
                        "National-ID context with failed checksum; left for review",
                        workflow=Workflow.REVIEW,
                        language="fa",
                    )
                )
        return found


class CardRecognizer(Recognizer):
    def __init__(self) -> None:
        super().__init__("credit_card", EntityType.CREDIT_CARD)

    def analyze(self, text: str) -> list[Span]:
        found = []
        for match in CARD_RE.finditer(fold_digits(text)):
            digits = only_digits(match.group(0))
            if digits.startswith(("978", "979")):
                continue
            if 13 <= len(digits) <= 19 and luhn_ok(digits):
                found.append(
                    _span(
                        text,
                        match.start(),
                        match.end(),
                        EntityType.CREDIT_CARD,
                        "card.luhn",
                        0.95,
                        "Luhn-valid laboratory PAN",
                    )
                )
        return found


class IbanRecognizer(Recognizer):
    def __init__(self) -> None:
        super().__init__("iban", EntityType.IBAN)

    def analyze(self, text: str) -> list[Span]:
        found = []
        folded = fold_digits(text)
        for match in IBAN_RE.finditer(folded):
            if iban_ok(match.group(0)):
                found.append(
                    _span(text, match.start(), match.end(), EntityType.IBAN, "iban.mod97", 0.95, "IBAN mod-97 passed")
                )
        return found


class EmployeeRecognizer(Recognizer):
    def __init__(self) -> None:
        super().__init__("employee_id", EntityType.EMPLOYEE_ID)

    def analyze(self, text: str) -> list[Span]:
        return [
            _span(text, match.start(), match.end(), EntityType.EMPLOYEE_ID, "employee.aria", 0.88, "Laboratory employee id")
            for match in EMPLOYEE_RE.finditer(text)
        ]


class PersonRecognizer(Recognizer):
    def __init__(self) -> None:
        super().__init__("person", EntityType.PERSON)

    def analyze(self, text: str) -> list[Span]:
        found: list[Span] = []
        if PROTOCOL_NAME_RE.search(text):
            # Explicit hard negative: software protocol, not a person.
            pass
        for match in HONORIFIC_EN.finditer(text):
            surface = match.group(0)
            if PROTOCOL_NAME_RE.search(surface):
                continue
            found.append(_span(text, match.start(), match.end(), EntityType.PERSON, "person.honorific_en", 0.72, "English honorific"))
        for match in HONORIFIC_FA.finditer(text):
            found.append(
                _span(
                    text,
                    match.start(),
                    match.end(),
                    EntityType.PERSON,
                    "person.honorific_fa",
                    0.74,
                    "Persian honorific",
                    language="fa",
                )
            )
        for match in LABEL_NAME_EN.finditer(text):
            start, end = match.start(1), match.end(1)
            found.append(_span(text, start, end, EntityType.PERSON, "person.label_en", 0.7, "Labeled English name"))
        for match in LABEL_NAME_FA.finditer(text):
            start, end = match.start(1), match.end(1)
            found.append(
                _span(text, start, end, EntityType.PERSON, "person.label_fa", 0.72, "Labeled Persian name", language="fa")
            )
        for first in LAB_FIRST:
            for last in LAB_LAST:
                needle = f"{first} {last}"
                start = 0
                while True:
                    index = text.find(needle, start)
                    if index < 0:
                        break
                    found.append(
                        _span(
                            text,
                            index,
                            index + len(needle),
                            EntityType.PERSON,
                            "person.lab_lexicon",
                            0.8,
                            "Laboratory name lexicon",
                            language="fa" if any(ord(ch) > 127 for ch in needle) else "en",
                        )
                    )
                    start = index + len(needle)
        return found


def hard_negative_surfaces(text: str) -> list[str]:
    surfaces: list[str] = []
    for pattern in (ISBN_RE, VERSION_RE, INVOICE_RE, DATE_RE, PROTOCOL_NAME_RE):
        surfaces.extend(match.group(0) for match in pattern.finditer(text))
    return surfaces


def default_recognizers() -> list[Recognizer]:
    return [
        EmailRecognizer(),
        PhoneRecognizer(),
        NationalIdRecognizer(),
        CardRecognizer(),
        IbanRecognizer(),
        EmployeeRecognizer(),
        PersonRecognizer(),
    ]