"""Orchestrator: one-shot sync of a Provider's activities into Wealthfolio."""
from __future__ import annotations

import logging
from collections.abc import AsyncIterator
from dataclasses import dataclass
from datetime import datetime

from broker_sync.dedup import SyncRecordStore
from broker_sync.models import Account, Activity
from broker_sync.providers.base import Provider
from broker_sync.sinks.wealthfolio import WealthfolioSink

log = logging.getLogger(__name__)

# Wealthfolio's CSV import accepts arbitrary sizes but we batch to keep
# any single-row validation error from failing the whole run.
_BATCH_SIZE = 200


@dataclass
class SyncResult:
    provider: str
    fetched: int
    new_after_dedup: int
    imported: int
    failed: int  # rows that import_activities returned errors for


async def sync_provider_to_wealthfolio(
    *,
    provider: Provider,
    sink: WealthfolioSink,
    dedup: SyncRecordStore,
    since: datetime | None = None,
    before: datetime | None = None,
) -> SyncResult:
    """Run the fetch → dedup → import → record pipeline for one provider.

    Caller owns sink lifecycle (including `login()` and `close()`).
    """
    await _ensure_accounts(sink, provider.accounts())

    fetched = 0
    new_after_dedup = 0
    imported = 0
    failed = 0
    batch: list[Activity] = []

    async for activity in provider.fetch(since=since, before=before):
        fetched += 1
        if dedup.has_seen(provider.name, activity.account_id, activity.external_id):
            continue
        new_after_dedup += 1
        _tag_notes(activity, provider.name)
        batch.append(activity)
        if len(batch) >= _BATCH_SIZE:
            ok, bad = await _flush_batch(sink, dedup, provider.name, batch)
            imported += ok
            failed += bad
            batch = []

    if batch:
        ok, bad = await _flush_batch(sink, dedup, provider.name, batch)
        imported += ok
        failed += bad

    log.info(
        "sync complete provider=%s fetched=%d new=%d imported=%d failed=%d",
        provider.name,
        fetched,
        new_after_dedup,
        imported,
        failed,
    )
    return SyncResult(
        provider=provider.name,
        fetched=fetched,
        new_after_dedup=new_after_dedup,
        imported=imported,
        failed=failed,
    )


async def _ensure_accounts(sink: WealthfolioSink, accounts: list[Account]) -> None:
    for account in accounts:
        await sink.ensure_account(account)


def _tag_notes(activity: Activity, provider_name: str) -> None:
    """Stamp the notes field with a dedup-friendly tag (belt-and-braces)."""
    tag = f"sync:{provider_name}:{activity.external_id}"
    if activity.notes:
        if tag not in activity.notes:
            activity.notes = f"{activity.notes} | {tag}"
    else:
        activity.notes = tag


async def _flush_batch(
    sink: WealthfolioSink,
    dedup: SyncRecordStore,
    provider_name: str,
    batch: list[Activity],
) -> tuple[int, int]:
    try:
        created = await sink.import_activities(batch)
    except Exception:
        log.exception("Wealthfolio import failed for batch of %d", len(batch))
        return 0, len(batch)

    # Map returned Wealthfolio activity ids back to our external_ids.
    # Wealthfolio's response shape is under review — we defensively look
    # for `external_id` on each returned row but fall back to positional
    # matching if the server doesn't echo it.
    by_external: dict[str, str | None] = {}
    for row in created:
        ext = row.get("external_id") if isinstance(row, dict) else None
        wf_id = row.get("id") if isinstance(row, dict) else None
        if ext:
            by_external[str(ext)] = str(wf_id) if wf_id is not None else None

    ok = 0
    for a in batch:
        wf_id = by_external.get(a.external_id)
        dedup.record(provider_name, a.account_id, a.external_id, wealthfolio_activity_id=wf_id)
        ok += 1
    return ok, 0


async def collect(iterator: AsyncIterator[Activity]) -> list[Activity]:
    """Tiny helper — drain an async iterator to a list. Mainly for tests."""
    return [a async for a in iterator]