"""FreeSWITCH CDR adapter.

Handles the standard ``mod_cdr_csv`` output format:

    "caller_id_name","caller_id_number","destination_number","context",
    "start_stamp","answer_stamp","end_stamp","duration","billsec",
    "hangup_cause","uuid","bleg_uuid","accountcode"

Billed amount is populated via ``mod_nibblebill`` when installed — the
additional columns ``nibble_total_billed`` / ``nibble_bill_amount`` /
``nibble_rate`` land in the same CSV. We pick them up when present.

``uuid`` is FreeSWITCH's unique call identifier and makes a perfect
natural key for dedup.
"""

from __future__ import annotations

import csv
import logging
from typing import Iterator

from .base import BaseCDRAdapter, CDRRow, ValidationError

logger = logging.getLogger(__name__)


class FreeSWITCHAdapter(BaseCDRAdapter):
    FORMAT_SLUG = "freeswitch"

    # Columns we check for per-call billed amount (mod_nibblebill output)
    _BILLED_COLUMNS = (
        "nibble_total_billed",
        "nibble_bill_amount",
        "billed_amount",
        "total_charge",
        "charge",
    )

    def iter_rows(self, local_path: str) -> Iterator[CDRRow]:
        with open(local_path, "r", encoding="utf-8", errors="replace", newline="") as fh:
            reader = csv.DictReader(fh)
            for i, raw in enumerate(reader, start=1):
                try:
                    start_raw = raw.get("start_stamp") or raw.get("answer_stamp")
                    start = self.parse_ts(start_raw)
                    duration_raw = raw.get("billsec") or raw.get("duration") or "0"
                    duration = self.parse_duration(duration_raw)
                    caller = (raw.get("caller_id_number") or "").strip()
                    called = (raw.get("destination_number") or "").strip()
                    uuid = (raw.get("uuid") or "").strip()

                    billed_cents = None
                    for col in self._BILLED_COLUMNS:
                        if raw.get(col):
                            billed_cents = self.parse_cents(raw[col])
                            if billed_cents is not None:
                                break

                    row = CDRRow(
                        start_time=start,
                        caller_number=caller,
                        called_number=called,
                        duration_sec=duration,
                        billed_amount_cents=billed_cents,
                        billed_currency=("USD" if billed_cents is not None else None),
                        trunk_group_id=(raw.get("context") or "").strip() or None,
                        customer_account_id=(raw.get("accountcode") or "").strip() or None,
                        disposition=(raw.get("hangup_cause") or "").strip().lower() or None,
                        natural_key=uuid or f"{caller}|{called}|{start.isoformat()}|{duration}",
                        source_file=local_path,
                        source_row=i,
                        raw=dict(raw),
                    )
                    self.validate_row(row)
                    yield row
                except ValidationError:
                    raise
                except Exception as exc:
                    raise ValidationError("unparseable_row", str(exc)) from exc