"""Cloudflare DNS records for domain management (read-only)."""

from __future__ import annotations

import os
from typing import Any

import httpx

CF_API = "https://api.cloudflare.com/client/v4"

EMAIL_PURPOSES = frozenset({"mx", "spf", "dkim", "dmarc", "mail-host", "autodiscover", "mail-alias"})


def _tokens() -> list[str]:
    raw = os.getenv("CLOUDFLARE_API_TOKENS") or os.getenv("CLOUDFLARE_API_TOKEN") or ""
    return [t.strip() for t in raw.replace(";", ",").split(",") if t.strip()]


def _parent_candidates(domain: str) -> list[str]:
    domain = domain.lower().strip().rstrip(".")
    parts = domain.split(".")
    if len(parts) < 2:
        return [domain] if domain else []
    return [".".join(parts[i:]) for i in range(len(parts) - 1)]


def _headers(token: str) -> dict[str, str]:
    return {"Authorization": f"Bearer {token}", "Content-Type": "application/json"}


def _classify_record(name: str, rtype: str, content: str) -> str:
    n = (name or "").lower().rstrip(".")
    c = (content or "").lower()
    if rtype == "MX":
        return "mx"
    if rtype == "TXT":
        if "v=spf1" in c:
            return "spf"
        if "_domainkey" in n or "v=dkim1" in c:
            return "dkim"
        if "_dmarc" in n or "v=dmarc1" in c:
            return "dmarc"
    if n.startswith("mail.") and rtype in ("A", "AAAA", "CNAME"):
        return "mail-host"
    if "autodiscover" in n or "autoconfig" in n:
        return "autodiscover"
    if rtype == "CNAME" and ("mail" in n or "autodiscover" in n):
        return "mail-alias"
    return "other"


def _record_belongs(name: str, domain: str) -> bool:
    rn = (name or "").lower().rstrip(".")
    d = domain.lower().strip().rstrip(".")
    return rn == d or rn.endswith(f".{d}")


def _normalize_record(raw: dict, domain: str) -> dict[str, Any]:
    name = raw.get("name", "")
    rtype = raw.get("type", "")
    content = raw.get("content", "")
    purpose = _classify_record(name, rtype, content)
    return {
        "id": raw.get("id"),
        "type": rtype,
        "name": name.rstrip("."),
        "content": content,
        "priority": raw.get("priority"),
        "proxied": raw.get("proxied"),
        "ttl": raw.get("ttl"),
        "purpose": purpose,
        "email_related": purpose in EMAIL_PURPOSES,
        "modified_on": raw.get("modified_on"),
        "created_on": raw.get("created_on"),
    }


async def _find_zone(client: httpx.AsyncClient, token: str, domain: str) -> dict | None:
    for candidate in _parent_candidates(domain):
        res = await client.get(
            f"{CF_API}/zones",
            headers=_headers(token),
            params={"name": candidate, "status": "active"},
        )
        if res.status_code != 200:
            continue
        data = res.json()
        if not data.get("success"):
            continue
        zones = data.get("result") or []
        if zones:
            z = zones[0]
            return {"id": z.get("id"), "name": z.get("name"), "status": z.get("status")}
    return None


async def _list_zone_records(client: httpx.AsyncClient, token: str, zone_id: str) -> list[dict]:
    records: list[dict] = []
    page = 1
    while page <= 10:
        res = await client.get(
            f"{CF_API}/zones/{zone_id}/dns_records",
            headers=_headers(token),
            params={"per_page": 100, "page": page},
        )
        if res.status_code != 200:
            break
        data = res.json()
        if not data.get("success"):
            break
        batch = data.get("result") or []
        records.extend(batch)
        info = data.get("result_info") or {}
        if page >= (info.get("total_pages") or 1):
            break
        page += 1
    return records


async def fetch_domain_dns(domain: str, *, email_service: bool | None = None) -> dict[str, Any]:
    domain = domain.lower().strip().rstrip(".")
    tokens = _tokens()
    if not tokens:
        return {
            "domain": domain,
            "zone": None,
            "email_service": bool(email_service),
            "service_type": "email_server" if email_service else None,
            "records": [],
            "email_records": [],
            "summary": {"total": 0, "email_related": 0},
            "error": "CLOUDFLARE_API_TOKEN não configurado no servidor",
        }

    async with httpx.AsyncClient(timeout=20.0) as client:
        zone = None
        token_used = None
        for token in tokens:
            zone = await _find_zone(client, token, domain)
            if zone:
                token_used = token
                break

        if not zone or not token_used:
            return {
                "domain": domain,
                "zone": None,
                "email_service": bool(email_service),
                "service_type": "email_server" if email_service else None,
                "records": [],
                "email_records": [],
                "summary": {"total": 0, "email_related": 0},
                "error": f"Zona Cloudflare não encontrada para {domain}",
            }

        raw_records = await _list_zone_records(client, token_used, zone["id"])
        scoped = [_normalize_record(r, domain) for r in raw_records if _record_belongs(r.get("name", ""), domain)]
        scoped.sort(key=lambda r: (0 if r["email_related"] else 1, r["type"], r["name"]))

        email_records = [r for r in scoped if r["email_related"]]
        is_email = email_service if email_service is not None else len(email_records) > 0

        purposes: dict[str, int] = {}
        for r in scoped:
            purposes[r["purpose"]] = purposes.get(r["purpose"], 0) + 1

        return {
            "domain": domain,
            "zone": zone,
            "email_service": is_email,
            "service_type": "email_server" if is_email else "other",
            "records": scoped,
            "email_records": email_records,
            "summary": {
                "total": len(scoped),
                "email_related": len(email_records),
                "by_purpose": purposes,
            },
            "error": None,
        }