from __future__ import annotations

import json
from dataclasses import dataclass

from app.models import (
    ApplicationCreate,
    ApplicationRecord,
    ApplicationStatus,
    ExternalSyncStatus,
)
from app.repositories.applications import ApplicationRepository
from app.services.external_client import ExternalTicketClient


@dataclass(slots=True)
class CreateOutcome:
    application: ApplicationRecord | None
    created_local: bool
    sent_external: bool
    external_error: str | None = None


class ApplicationService:
    def __init__(
        self,
        repo: ApplicationRepository,
        external_client: ExternalTicketClient,
        channel_local_enabled: bool = True,
        channel_external_enabled: bool = True,
    ) -> None:
        self._repo = repo
        self._external_client = external_client
        self._channel_local_enabled = channel_local_enabled
        self._channel_external_enabled = channel_external_enabled

    @property
    def channel_local_enabled(self) -> bool:
        return self._channel_local_enabled

    @property
    def channel_external_enabled(self) -> bool:
        return self._channel_external_enabled

    async def create_application(
        self,
        customer_id: int | None,
        customer_name: str,
        chat_id: int | None,
        category: str,
        description: str,
        attachments: list[dict],
        source: str = "bot",
    ) -> CreateOutcome:
        if not self._channel_local_enabled and not self._channel_external_enabled:
            raise ValueError("Both creation channels are disabled.")

        application: ApplicationRecord | None = None
        if self._channel_local_enabled:
            application = self._repo.create(
                ApplicationCreate(
                    customer_id=customer_id,
                    customer_name=customer_name,
                    chat_id=chat_id,
                    category=category,
                    description=description,
                    attachments_json=json.dumps(attachments, ensure_ascii=False),
                    source=source,
                )
            )
        elif self._channel_external_enabled:
            # Локальный канал выключен: создаем "виртуальную" сущность без записи в БД.
            # Для v1 это только транспорт в внешнюю систему.
            application = ApplicationRecord(
                id=0,
                customer_id=customer_id,
                customer_name=customer_name,
                chat_id=chat_id,
                category=category,
                description=description,
                attachments_json=json.dumps(attachments, ensure_ascii=False),
                status=ApplicationStatus.NEW.value,
                external_sync_status=ExternalSyncStatus.NOT_SENT.value,
                external_id=None,
                external_error=None,
                source=source,
                created_at="",
                updated_at="",
            )

        if not self._channel_external_enabled:
            if application and self._channel_local_enabled:
                self._repo.update_external_sync(
                    application_id=application.id,
                    sync_status=ExternalSyncStatus.DISABLED.value,
                    external_id=None,
                    external_error="external_channel_disabled",
                )
                application = self._repo.get(application.id)
            return CreateOutcome(
                application=application,
                created_local=self._channel_local_enabled,
                sent_external=False,
            )

        if not self._external_client.enabled:
            if application and self._channel_local_enabled:
                self._repo.update_external_sync(
                    application_id=application.id,
                    sync_status=ExternalSyncStatus.FAILED.value,
                    external_id=None,
                    external_error="external_url_not_configured",
                )
                application = self._repo.get(application.id)
            return CreateOutcome(
                application=application,
                created_local=self._channel_local_enabled,
                sent_external=False,
                external_error="external_url_not_configured",
            )

        assert application is not None
        result = await self._external_client.create_ticket(application)
        if result.ok:
            if self._channel_local_enabled and application.id > 0:
                self._repo.update_external_sync(
                    application_id=application.id,
                    sync_status=ExternalSyncStatus.SENT.value,
                    external_id=result.external_id,
                    external_error=None,
                )
                application = self._repo.get(application.id)
            return CreateOutcome(
                application=application,
                created_local=self._channel_local_enabled,
                sent_external=True,
            )

        if self._channel_local_enabled and application.id > 0:
            self._repo.update_external_sync(
                application_id=application.id,
                sync_status=ExternalSyncStatus.FAILED.value,
                external_id=None,
                external_error=result.error,
            )
            application = self._repo.get(application.id)

        return CreateOutcome(
            application=application,
            created_local=self._channel_local_enabled,
            sent_external=False,
            external_error=result.error,
        )

    def list_applications(self, status: str | None = None, search: str | None = None) -> list[ApplicationRecord]:
        return self._repo.list(status=status, search=search)

    def get_application(self, application_id: int) -> ApplicationRecord | None:
        return self._repo.get(application_id)

    def get_events(self, application_id: int):
        return self._repo.get_events(application_id)

    def update_status(self, application_id: int, status: str, actor: str, reason: str | None = None):
        return self._repo.update_status(application_id, status, actor=actor, reason=reason)