# =============================================================================
# Projet : AIR — Accounting Intermediate Representation
# Auteur : Simon-Pierre Boucher
# Contact : contact@spboucher.ai
# Fichier : backend.py
# Description : QuickBooks Online backend — optional target, fully testable offline.
# =============================================================================
"""QuickBooks Online backend.

QuickBooks is an OPTIONAL export target: AIR's books of record live in the
native ledger regardless. This backend lowers compiled journals to QBO
JournalEntry payloads and posts them through a pluggable transport — the
offline mock by default (no QuickBooks account needed anywhere in the
project), the HTTP transport only when the user supplies credentials.

Idempotency: every create carries requestid = f"{key}:{DocNumber}" so retries
never double-post. Reversal: QBO has no native journal reversal, so reverse()
posts exact contra entries (never deletes).
"""
from __future__ import annotations

from typing import Any

from backends.base import (
    Backend,
    BackendCapabilities,
    PostingReceipt,
    ReversalReceipt,
    TargetPayload,
)
from backends.quickbooks.mapper import contra_body, map_journal
from backends.quickbooks.transport import MockQboTransport, QboTransport
from core.journal import CompiledJournal


class QuickBooksBackend(Backend):
    def __init__(
        self,
        transport: QboTransport | None = None,
        account_map: dict[str, dict[str, str]] | None = None,
    ):
        self.transport = transport if transport is not None else MockQboTransport()
        self.account_map = account_map
        self._posted: dict[str, dict[str, Any]] = {}   # DocNumber -> body posted

    def capabilities(self) -> BackendCapabilities:
        return BackendCapabilities(
            name="quickbooks",
            posts_remotely=True,
            native_reversal=False,          # contra-entry strategy
            multi_currency=True,
            idempotency="requestid",
            notes="QBO JournalEntry API, minorversion=75; optional target — "
                  "native ledger remains the book of record",
        )

    def compile(self, journal: CompiledJournal) -> TargetPayload:
        return TargetPayload(
            backend="quickbooks",
            format="qbo.journalentry",
            body=map_journal(journal, self.account_map),
        )

    def post(self, payload: TargetPayload, idempotency_key: str) -> PostingReceipt:
        bodies = payload.body
        assert isinstance(bodies, list)
        details: dict[str, str] = {}
        for body in bodies:
            request_id = f"{idempotency_key}:{body['DocNumber']}"
            entity = self.transport.create_journal_entry(body, request_id)
            details[body["DocNumber"]] = entity["Id"]
            self._posted[body["DocNumber"]] = body
        return PostingReceipt(
            backend="quickbooks",
            reference=",".join(details.values()),
            idempotency_key=idempotency_key,
            details=details,
        )

    def reverse(self, receipt: PostingReceipt) -> ReversalReceipt:
        reversed_ids: list[str] = []
        for doc_number in receipt.details:
            body = self._posted.get(doc_number)
            if body is None:
                continue
            contra = contra_body(body)
            request_id = f"rev:{receipt.idempotency_key}:{contra['DocNumber']}"
            entity = self.transport.create_journal_entry(contra, request_id)
            reversed_ids.append(entity["Id"])
        return ReversalReceipt(
            backend="quickbooks",
            reference=",".join(reversed_ids),
            reversed_reference=receipt.reference,
        )