"""HMRC Individual Tax API v1.1 wrapper.

One method per endpoint we consume. Every request attaches the full fraud-
prevention header set built by `fraud_headers.build_headers()`.

Individual Tax API v1.1 returns tax-paid + income-breakdown figures per
employment per tax year — exactly the ground-truth data we reconcile
against the payslip-ingest monthly aggregate.
"""
from __future__ import annotations

import logging
import time
from dataclasses import dataclass
from typing import Any

import httpx

from hmrc_sync.fraud_headers import SessionContext, build_headers

log = logging.getLogger(__name__)

PROD_BASE = "https://api.service.hmrc.gov.uk"
INDIVIDUAL_TAX_VERSION = "application/vnd.hmrc.1.1+json"


@dataclass
class HmrcResponse:
    status_code: int
    body: dict[str, Any]
    duration_ms: int
    request_id: str | None
    correlation_id: str | None
    fraud_headers_sent: dict[str, str]


class HmrcClient:

    def __init__(self,
                 access_token: str,
                 session: SessionContext,
                 connection_method: str = "BATCH_PROCESS_DIRECT",
                 base_url: str = PROD_BASE):
        self._access_token = access_token
        self._session = session
        self._connection_method = connection_method
        self._base_url = base_url.rstrip("/")

    async def individual_tax_summary(self, utr: str, tax_year: str) -> HmrcResponse:
        """GET /individuals/tax/sa/{utr}/summary/{taxYear}

        `utr` is the 10-digit Self Assessment reference; tax_year format
        is `YYYY-YY` (e.g. `2024-25`).
        """
        path = f"/individuals/tax/sa/{utr}/summary/{tax_year}"
        return await self._get(path)

    async def _get(self, path: str) -> HmrcResponse:
        fraud = build_headers(self._session, self._connection_method)
        headers = {
            "Accept": INDIVIDUAL_TAX_VERSION,
            "Authorization": f"Bearer {self._access_token}",
        }
        headers.update(fraud)
        started = time.perf_counter()
        async with httpx.AsyncClient(timeout=30.0) as client:
            resp = await client.get(f"{self._base_url}{path}", headers=headers)
        duration_ms = int((time.perf_counter() - started) * 1000)
        body: dict[str, Any]
        try:
            body = resp.json() if resp.content else {}
        except ValueError:
            body = {"raw": resp.text[:2000]}
        log.info("hmrc %s status=%s duration=%dms", path, resp.status_code, duration_ms)
        return HmrcResponse(
            status_code=resp.status_code,
            body=body,
            duration_ms=duration_ms,
            request_id=resp.headers.get("x-request-id"),
            correlation_id=resp.headers.get("x-correlation-id"),
            fraud_headers_sent=fraud,
        )