"""
P105 — IAB TCF Vendor-Liste als externe Authority.

Die IAB TCF v2.2 Global Vendor List (https://vendor-list.consensu.org/v3/
vendor-list.json) ist die DSGVO-Authoritaet fuer Werbe-Vendoren: jeder
gelistete Vendor hat verbindliche IAB-Purposes:
  Purpose 1 — Speichern + Zugriff (essential)
  Purpose 2 — Auswahl Werbung (functional/marketing)
  Purpose 3 — Personalisierte Werbeprofile (marketing)
  Purpose 4 — Personalisierte Werbung (marketing)
  Purpose 5 — Personalisierte Inhaltsprofile (marketing/personalization)
  Purpose 6 — Personalisierte Inhalte (marketing/personalization)
  Purpose 7 — Werbe-Performance-Messung (statistics)
  Purpose 8 — Inhalts-Performance-Messung (statistics)
  Purpose 9 — Marktforschung (statistics)
  Purpose 10 — Produkt-Verbesserung (statistics)

Wenn ein Vendor in der TCF-Liste mit Purpose 3/4 registriert ist und die
Site ihn als "Funktional" deklariert → eindeutiger Verstoss (eine externe
Authority widerspricht der Deklaration).

Ingest-Mode: idempotenter Fetch + Upsert in compliance.tcf_vendors_v2.
Lookup-Mode: by_vendor_name + by_cookie_owner.
"""

from __future__ import annotations

import logging
from typing import Iterable

import httpx
from sqlalchemy import text as sa_text
from sqlalchemy.orm import Session

logger = logging.getLogger(__name__)


_TCF_URL = "https://vendor-list.consensu.org/v3/vendor-list.json"

# IAB-Purpose → BreakPilot-Kategorie
_PURPOSE_TO_CATEGORY = {
    1: "essential",
    2: "marketing",
    3: "marketing",
    4: "marketing",
    5: "personalization",
    6: "personalization",
    7: "statistics",
    8: "statistics",
    9: "statistics",
    10: "statistics",
    11: "marketing",
}


def _category_for_purposes(purposes: Iterable[int]) -> str:
    """Aggregiert Purposes zu der STRENGSTEN Kategorie (Marketing > stats
    > personalization > essential). Wenn ein Vendor sowohl essential als
    auch marketing nutzt, ist die rechtlich verbindliche Kategorie
    Marketing (Einwilligungspflicht)."""
    cats = {_PURPOSE_TO_CATEGORY.get(p, "marketing") for p in purposes}
    if "marketing" in cats:
        return "marketing"
    if "statistics" in cats:
        return "statistics"
    if "personalization" in cats:
        return "personalization"
    return "essential"


async def fetch_and_ingest_tcf_vendors(db: Session) -> dict:
    """Idempotenter Ingest. Schema-Migration vermeiden — nutzt nur
    bestehende cookie_library-Tabelle und kennzeichnet TCF-Source via
    vendor_name='[TCF] <name>'."""
    async with httpx.AsyncClient(timeout=60.0) as client:
        resp = await client.get(_TCF_URL)
        resp.raise_for_status()
        data = resp.json()

    vendors = data.get("vendors") or {}
    if not vendors:
        return {"error": "no vendors in TCF response", "n_vendors": 0}

    # Erst alte TCF-Eintraege weg (kein UNIQUE-Index auf cookie_name,
    # daher kein ON CONFLICT moeglich → idempotent via DELETE+INSERT).
    db.execute(sa_text(
        "DELETE FROM compliance.cookie_library WHERE source_name='iab_tcf_v2'"
    ))
    db.commit()
    inserted = 0
    skipped = 0
    for vid, v in vendors.items():
        name = (v.get("name") or "").strip()
        if not name:
            continue
        purposes = v.get("purposes") or []
        leg_purposes = v.get("legIntPurposes") or []
        all_purposes = list(set(purposes) | set(leg_purposes))
        category = _category_for_purposes(all_purposes)
        privacy_url = (v.get("policyUrl") or "").strip()[:500] or None

        # Cookie-Names die der Vendor laut TCF setzt sind nicht in der
        # GVL — wir kennzeichnen nur den Vendor-Eintrag mit ID + Purposes.
        marker = f"_tcf_v{vid}"
        try:
            db.execute(sa_text(
                """
                INSERT INTO compliance.cookie_library
                       (cookie_name, domain_pattern, vendor_name,
                        vendor_privacy_url, actual_category,
                        purpose_en, source_name, source_url, confidence)
                VALUES (:n, :dp, :v, :pu, :cat, :purp, 'iab_tcf_v2',
                        'https://vendor-list.consensu.org/v3/vendor-list.json',
                        0.99)
                """
            ), {"n": marker, "dp": "*",
                "v": f"[TCF-{vid}] {name}",
                "pu": privacy_url, "cat": category,
                "purp": f"IAB TCF v2 Purposes: {sorted(all_purposes)}"})
            db.commit()  # Per-Vendor-Commit damit ein Fehler nicht
                         # die naechsten Eintraege blockt.
            inserted += 1
        except Exception as e:
            logger.warning("TCF vendor %s insert failed: %s", vid, e)
            skipped += 1
            db.rollback()  # frische Transaktion fuer den naechsten Insert
    return {"n_vendors_in_gvl": len(vendors), "inserted": inserted,
            "skipped": skipped}


def lookup_tcf_authority(
    db: Session,
    vendor_name: str | None,
) -> dict | None:
    """Liefert TCF-Authority-Daten fuer einen Vendor-Namen, wenn er
    in der TCF-Liste registriert ist. Returns {tcf_id, name, category}
    oder None.

    Fuzzy-Match: 'Google' matched '[TCF-755] Google Advertising Products'.
    """
    if not vendor_name:
        return None
    nl = vendor_name.lower().strip()
    try:
        rows = db.execute(sa_text(
            """
            SELECT cookie_name, actual_category, vendor_name
            FROM compliance.cookie_library
            WHERE source = 'iab_tcf_v2'
              AND LOWER(vendor_name) LIKE :pat
            LIMIT 5
            """
        ), {"pat": f"%{nl}%"}).fetchall()
        for r in rows:
            tcf_name = r[2]  # '[TCF-755] Google ...'
            if tcf_name and "]" in tcf_name:
                tcf_id = tcf_name.split("]")[0].lstrip("[TCF-")
                clean = tcf_name.split("]", 1)[1].strip()
                return {"tcf_id": tcf_id, "name": clean,
                         "category": r[1]}
    except Exception as e:
        logger.warning("TCF lookup failed: %s", e)
    return None


def cross_reference_with_tcf(
    db: Session,
    declared_vendors: list[dict],
) -> list[dict]:
    """Liefert pro Vendor mit Discrepancy ein Finding-dict.

    Eingang: list[{name, category}] aus cmp_vendors.
    Ausgang: list[{vendor, declared_category, tcf_category, severity}]
    """
    out: list[dict] = []
    for v in (declared_vendors or []):
        if not isinstance(v, dict):
            continue
        name = (v.get("name") or "").strip()
        declared_cat = (v.get("category") or "").lower().strip()
        if not name or not declared_cat:
            continue
        tcf = lookup_tcf_authority(db, name)
        if not tcf:
            continue
        if tcf["category"] == declared_cat:
            continue
        # Marketing/Statistics vs Functional/Essential ist die kritische
        # Diskrepanz. functional + personalization sind weicher.
        severity = "HIGH" if (tcf["category"] == "marketing"
                              and declared_cat in ("essential",
                                                    "functional",
                                                    "necessary")) else "MEDIUM"
        out.append({
            "vendor":            name,
            "tcf_id":            tcf["tcf_id"],
            "tcf_name":          tcf["name"],
            "declared_category": declared_cat,
            "tcf_category":      tcf["category"],
            "severity":          severity,
        })
    return out


def build_tcf_authority_block_html(findings: list[dict]) -> str:
    if not findings:
        return ""
    items: list[str] = []
    for f in findings[:30]:
        sev_color = "#dc2626" if f["severity"] == "HIGH" else "#d97706"
        items.append(
            f'<li style="margin-bottom:6px;font-size:11px;line-height:1.5">'
            f'<strong style="color:{sev_color}">{f["vendor"]}</strong> '
            f'<span style="color:#64748b">— deklariert als</span> '
            f'<strong>{f["declared_category"]}</strong>, '
            f'<span style="color:#64748b">IAB TCF v2 (Vendor-ID '
            f'{f["tcf_id"]}) listet als</span> '
            f'<strong style="color:{sev_color}">'
            f'{f["tcf_category"]}</strong>'
            f'</li>'
        )
    return (
        '<div style="font-family:-apple-system,BlinkMacSystemFont,sans-serif;'
        'max-width:760px;margin:0 auto 16px;padding:14px 18px;'
        'background:#fef2f2;border:1px solid #fecaca;border-radius:8px">'
        '<div style="font-size:11px;color:#991b1b;text-transform:uppercase;'
        'letter-spacing:1.2px;margin-bottom:4px;font-weight:600">'
        'IAB TCF v2 Authority-Check — Vendor-Kategorie-Diskrepanz</div>'
        f'<h3 style="margin:0 0 6px;font-size:14px;color:#1e293b">'
        f'{len(findings)} Vendor{"en" if len(findings) != 1 else ""} '
        'mit Kategorie-Widerspruch zur offiziellen IAB-Liste</h3>'
        '<p style="margin:0 0 10px;font-size:11px;color:#475569;'
        'line-height:1.5">'
        'Die IAB Transparency &amp; Consent Framework v2 Global Vendor List '
        'ist die rechtliche Authoritaet fuer die Klassifizierung von '
        'Werbe-Vendoren in der EU. Wenn ein Vendor dort als "Marketing" '
        'gefuehrt ist, kann die Site ihn nicht als "Funktional" einstufen '
        '— das ist eine externe, durchgesetzte Klassifikation.</p>'
        '<ul style="margin:0 0 0 18px;padding:0">'
        + "".join(items) +
        '</ul>'
        '<p style="margin:8px 0 0;font-size:10px;color:#94a3b8;'
        'font-style:italic">Quelle: '
        'https://vendor-list.consensu.org/v3/vendor-list.json — '
        'die TCF-Liste ist verbindlich fuer alle CMP-Tools die IAB-TCF v2 '
        'implementieren (Cookiebot, OneTrust, Usercentrics, Sourcepoint, …).</p>'
        '</div>'
    )