"""iconectiv 8YY Query Report adapter.

Parses the monthly 8YY query-counts-and-revenue report produced by
iconectiv (formerly Ericsson / Somos toll-free number administration).
The report drives the database-query component of 8YY originating access
charges — each query to the 8YY routing database is billable at a
tariff-specified per-query rate.

Supported layouts
-----------------
* **XML** (default, `.xml`): ``<QueryReport>`` root with a single
  ``<Period year="YYYY" month="MM"/>`` followed by N ``<Query>`` elements,
  each containing ``<OCN>``, ``<CarrierName>`` (optional), ``<Queries>``
  (integer count), and ``<Revenue>`` (decimal USD).

* **QRY pipe-delimited** (`.qry`): one record per line, fields separated
  by ``|``: ``OCN|QUERIES|REVENUE|PERIOD`` where PERIOD is ``YYYYMM``.
  Header row ``OCN|QUERIES|REVENUE|PERIOD`` is tolerated and skipped.

Output
------
Every record yields ``icc_category='8yy_orig_access'``,
``minutes_of_use=None`` (8YY database queries are discrete events, not
duration), ``counterparty_country='US'``. Reporting quarter is derived
from the record's period month.

Deferred
--------
* XML schema validation / multiple ``<Period>`` blocks per file
* Multi-currency revenue (assumes USD)
* Query-type breakdown (POTS Dip vs LRN Dip) — treated as one category
"""

from __future__ import annotations

import csv
import logging
import os
from typing import Iterator

from .common import BaseICCAdapter, IccRevenueLine, ValidationError

logger = logging.getLogger(__name__)

try:
    from lxml import etree as _etree          # pragma: no cover
    _USE_LXML = True
except ImportError:
    import xml.etree.ElementTree as _etree
    _USE_LXML = False


class IconectivQRYAdapter(BaseICCAdapter):
    SOURCE_FORMAT = "8yy_qry"

    @staticmethod
    def _month_to_quarter(month: int) -> int | None:
        if 1 <= month <= 3:
            return 1
        if 4 <= month <= 6:
            return 2
        if 7 <= month <= 9:
            return 3
        if 10 <= month <= 12:
            return 4
        return None

    def iter_rows(self, local_path: str) -> Iterator[IccRevenueLine]:
        ext = os.path.splitext(local_path)[1].lower()
        if ext in (".xml",):
            yield from self._iter_xml(local_path)
            return
        # Sniff by content when extension is unknown
        with open(local_path, "rb") as fh:
            head = fh.read(256).lstrip()
        if head.startswith(b"<"):
            yield from self._iter_xml(local_path)
        else:
            yield from self._iter_pipe(local_path)

    # ------------------------------------------------------------------
    # XML layout
    # ------------------------------------------------------------------

    def _iter_xml(self, local_path: str) -> Iterator[IccRevenueLine]:
        try:
            tree = _etree.parse(local_path)
        except Exception as exc:
            raise ValidationError("bad_xml", f"could not parse XML: {exc}") from exc
        root = tree.getroot()
        period_el = root.find(".//Period")
        period_year = self.reporting_year
        period_month: int | None = None
        if period_el is not None:
            try:
                period_year = int(period_el.get("year") or self.reporting_year)
            except ValueError:
                period_year = self.reporting_year
            try:
                pm = period_el.get("month")
                period_month = int(pm) if pm else None
            except ValueError:
                period_month = None
        quarter = self._month_to_quarter(period_month) if period_month else None

        lineno = 0
        for q in root.iter("Query"):
            lineno += 1
            ocn_el = q.find("OCN")
            rev_el = q.find("Revenue")
            queries_el = q.find("Queries")
            name_el = q.find("CarrierName")
            ocn = (ocn_el.text or "").strip() if ocn_el is not None else ""
            revenue_text = (rev_el.text or "").strip() if rev_el is not None else ""
            queries_text = (queries_el.text or "").strip() if queries_el is not None else ""
            name = (name_el.text or "").strip() if name_el is not None else ""
            if not ocn and not name:
                raise ValidationError("missing_ocn", f"Query row {lineno} has no OCN or CarrierName")
            try:
                revenue_cents = self.parse_cents(revenue_text)
                query_count = self.parse_int(queries_text) if queries_text else None
            except ValidationError:
                raise
            yield IccRevenueLine(
                profile_id=self.profile_id,
                reporting_year=period_year,
                reporting_quarter=quarter,
                icc_category="8yy_orig_access",
                counterparty_legal_name=name or ocn,
                counterparty_ocn=ocn or None,
                counterparty_country="US",
                revenue_cents=revenue_cents,
                minutes_of_use=None,
                source_line_no=lineno,
                raw_row={
                    "ocn": ocn,
                    "name": name,
                    "queries": query_count,
                    "revenue_raw": revenue_text,
                    "period_year": period_year,
                    "period_month": period_month,
                },
            )

    # ------------------------------------------------------------------
    # Pipe-delimited layout
    # ------------------------------------------------------------------

    def _iter_pipe(self, local_path: str) -> Iterator[IccRevenueLine]:
        with open(local_path, "r", encoding="utf-8", errors="replace", newline="") as fh:
            reader = csv.reader(fh, delimiter="|")
            for i, row in enumerate(reader, start=1):
                if not row or not any(cell.strip() for cell in row):
                    continue
                # Skip the header row
                if i == 1 and row[0].strip().upper() == "OCN":
                    continue
                if len(row) < 4:
                    raise ValidationError(
                        "bad_row",
                        f"8yy QRY row {i} has {len(row)} fields, expected 4",
                    )
                ocn = row[0].strip()
                queries_raw = row[1].strip()
                revenue_raw = row[2].strip()
                period_raw = row[3].strip()
                period_year = self.reporting_year
                period_month: int | None = None
                if len(period_raw) >= 6:
                    try:
                        period_year = int(period_raw[:4])
                        period_month = int(period_raw[4:6])
                    except ValueError:
                        pass
                quarter = self._month_to_quarter(period_month) if period_month else None
                yield IccRevenueLine(
                    profile_id=self.profile_id,
                    reporting_year=period_year,
                    reporting_quarter=quarter,
                    icc_category="8yy_orig_access",
                    counterparty_legal_name=ocn,
                    counterparty_ocn=ocn or None,
                    counterparty_country="US",
                    revenue_cents=self.parse_cents(revenue_raw),
                    minutes_of_use=None,
                    source_line_no=i,
                    raw_row={
                        "ocn": ocn,
                        "queries_raw": queries_raw,
                        "revenue_raw": revenue_raw,
                        "period_raw": period_raw,
                    },
                )