"""
Document check runner — two-pass L1/L2 logic.

Pass 1: Run all L1 checks ("Is it mentioned?")
Pass 2: Run L2 checks only where their L1 parent passed ("Is it correct?")
"""

import logging
import re

from .dse_checks import ART13_CHECKLIST
from .widerruf_checks import WIDERRUF_CHECKLIST
from .agb_checks import AGB_CHECKLIST
from .impressum_checks import IMPRESSUM_CHECKLIST
from .cookie_checks import COOKIE_CHECKLIST
from .social_media_checks import JOINT_CONTROLLER_CHECKLIST
from .dsfa_checks import DSFA_CHECKLIST

logger = logging.getLogger(__name__)

# Map doc_type strings to (checklist, label)
_CHECKLIST_MAP = {
    "dse": (ART13_CHECKLIST, "Art. 13 DSGVO"),
    "datenschutz": (ART13_CHECKLIST, "Art. 13 DSGVO"),
    "privacy": (ART13_CHECKLIST, "Art. 13 DSGVO"),
    "widerruf": (WIDERRUF_CHECKLIST, "§355 BGB"),
    "withdrawal": (WIDERRUF_CHECKLIST, "§355 BGB"),
    "cancellation": (WIDERRUF_CHECKLIST, "§355 BGB"),
    "agb": (AGB_CHECKLIST, "§305ff BGB"),
    "terms": (AGB_CHECKLIST, "§305ff BGB"),
    "nutzungsbedingungen": (AGB_CHECKLIST, "§305ff BGB"),
    "impressum": (IMPRESSUM_CHECKLIST, "§5 TMG / §18 MStV"),
    "imprint": (IMPRESSUM_CHECKLIST, "§5 TMG / §18 MStV"),
    "cookie": (COOKIE_CHECKLIST, "§25 TDDDG"),
    "social_media": (JOINT_CONTROLLER_CHECKLIST, "Art. 26 DSGVO"),
    "joint_controller": (JOINT_CONTROLLER_CHECKLIST, "Art. 26 DSGVO"),
    "dsfa": (DSFA_CHECKLIST, "Art. 35 DSGVO"),
}


def _match_patterns(patterns: list[str], text_lower: str):
    """Try each regex pattern against text, return first Match or None."""
    for p in patterns:
        m = re.search(p, text_lower)
        if m:
            return m
    return None


def _extract_context(text_lower: str, match) -> str:
    """Extract ~30 chars around a match for evidence display."""
    if not match:
        return ""
    start = max(0, match.start() - 30)
    end = min(len(text_lower), match.end() + 30)
    return text_lower[start:end].strip()


def check_document_completeness(
    text: str,
    doc_type: str,
    doc_title: str,
    doc_url: str,
) -> list[dict]:
    """Check a legal document against its type-specific requirements.

    Two-pass approach:
      L1 — Is the mandatory field mentioned at all?
      L2 — Is it correct/complete? (only checked if L1 parent passed)

    Returns a list of findings (summary + missing items).
    """
    findings = []
    text_lower = text.lower()

    if not text or len(text) < 50:
        findings.append({
            "code": f"DSI-EMPTY-{doc_type.upper()}",
            "severity": "HIGH",
            "text": f"Dokument '{doc_title}' ist leer oder zu kurz fuer eine Pruefung.",
            "doc_title": doc_title, "doc_url": doc_url, "doc_type": doc_type,
        })
        return findings

    word_count = len(text.split())
    if word_count < 200 and doc_type == "dse":
        findings.append({
            "code": f"DSI-SCORE-{doc_type.upper()}",
            "severity": "LOW",
            "text": (
                f"'{doc_title}': Kurzhinweis ({word_count} Woerter) — zu kurz fuer "
                f"eine vollstaendige Art. 13 DSGVO Pruefung. Kein eigenstaendiges DSI-Dokument."
            ),
            "doc_title": doc_title, "doc_url": doc_url, "doc_type": doc_type,
            "all_checks": [],
        })
        return findings

    entry = _CHECKLIST_MAP.get(doc_type, (ART13_CHECKLIST, "Art. 13 DSGVO"))
    checklist, label = entry

    l1_checks = [c for c in checklist if c.get("level", 1) == 1]
    l2_checks = [c for c in checklist if c.get("level", 1) == 2]

    # ── Pass 1: L1 checks ────────────────────────────────────────────
    passed_l1_ids: set[str] = set()
    all_checks: list[dict] = []
    l1_present = 0

    for check in l1_checks:
        match = _match_patterns(check["patterns"], text_lower)
        passed = match is not None
        if passed:
            passed_l1_ids.add(check["id"])
            l1_present += 1
        else:
            findings.append({
                "code": f"DSI-MISSING-{check['id'].upper()}",
                "severity": check.get("severity", "MEDIUM"),
                "text": (
                    f"'{doc_title}': Pflichtangabe '{check['label']}' nicht gefunden. "
                    f"Erforderlich nach {label}."
                ),
                "doc_title": doc_title, "doc_url": doc_url,
                "doc_type": doc_type, "check_id": check["id"],
            })
        all_checks.append({
            "id": check["id"], "label": check["label"],
            "passed": passed, "severity": check.get("severity", "MEDIUM"),
            "matched_text": _extract_context(text_lower, match),
            "level": 1, "parent": None, "skipped": False,
            "hint": check.get("hint", ""),
        })

    # ── Pass 2: L2 checks (only if parent L1 passed) ─────────────────
    l2_total = 0
    l2_passed = 0

    for check in l2_checks:
        parent = check.get("parent")
        skipped = parent not in passed_l1_ids
        passed = False
        matched_text = ""

        if not skipped:
            l2_total += 1
            match = _match_patterns(check["patterns"], text_lower)
            passed = match is not None
            if passed:
                l2_passed += 1
                matched_text = _extract_context(text_lower, match)
            else:
                findings.append({
                    "code": f"DSI-DETAIL-{check['id'].upper()}",
                    "severity": check.get("severity", "MEDIUM"),
                    "text": (
                        f"'{doc_title}': Detailpruefung '{check['label']}' "
                        f"nicht bestanden. Empfohlen nach {label}."
                    ),
                    "doc_title": doc_title, "doc_url": doc_url,
                    "doc_type": doc_type, "check_id": check["id"],
                })

        all_checks.append({
            "id": check["id"], "label": check["label"],
            "passed": passed, "severity": check.get("severity", "MEDIUM"),
            "matched_text": matched_text,
            "level": 2, "parent": parent, "skipped": skipped,
            "hint": check.get("hint", ""),
        })

    # ── Summary ───────────────────────────────────────────────────────
    l1_total = len(l1_checks)
    completeness_pct = round(l1_present / l1_total * 100) if l1_total else 0
    correctness_pct = round(l2_passed / l2_total * 100) if l2_total else 0

    severity = (
        "OK" if completeness_pct == 100
        else "LOW" if completeness_pct >= 80
        else "MEDIUM" if completeness_pct >= 50
        else "HIGH"
    )

    summary_text = (
        f"'{doc_title}': {l1_present}/{l1_total} Pflichtangaben vorhanden "
        f"({completeness_pct}%)."
    )
    if completeness_pct < 100:
        summary_text += f" Fehlend: {l1_total - l1_present} Angaben nach {label}."
    if l2_total > 0:
        summary_text += (
            f" Detailpruefung: {l2_passed}/{l2_total} bestanden "
            f"({correctness_pct}%)."
        )

    findings.insert(0, {
        "code": f"DSI-SCORE-{doc_type.upper()}",
        "severity": severity,
        "text": summary_text,
        "doc_title": doc_title, "doc_url": doc_url, "doc_type": doc_type,
        "all_checks": all_checks,
        "completeness_pct": completeness_pct,
        "correctness_pct": correctness_pct,
    })

    return findings


def classify_document_type(title: str, url: str) -> str:
    """Classify a document by its title/URL into a legal document type."""
    combined = f"{title} {url}".lower()

    if any(kw in combined for kw in ["datenschutzfolge", "dsfa", "risikoanalyse für nutzung"]):
        return "dsfa"
    if any(kw in combined for kw in ["social media", "facebook", "instagram", "linkedin", "fanpage"]):
        if any(kw in combined for kw in ["datenschutzerkl", "datenschutz für", "datenschutzinformation"]):
            return "social_media"
    if any(kw in combined for kw in ["datenschutz", "privacy", "dsgvo", "data protection", "données"]):
        return "dse"
    if any(kw in combined for kw in ["widerruf", "withdrawal", "rétractation", "desistimiento"]):
        return "widerruf"
    if any(kw in combined for kw in ["agb", "allgemeine geschäftsbedingungen", "terms",
                                       "nutzungsbedingungen", "conditions"]):
        return "agb"
    if any(kw in combined for kw in ["cookie", "slapuk", "evästeet", "kakor"]):
        return "cookie"
    if any(kw in combined for kw in ["impressum", "imprint", "legal notice", "mentions légales"]):
        return "impressum"
    return "other"