import hashlib
import json
import secrets
from datetime import datetime
from typing import Any, NoReturn

from sqlalchemy.exc import IntegrityError
from sqlalchemy.ext.asyncio import AsyncSession

from common.vo import CrudResponseModel, PageModel
from exceptions.exception import PermissionException, ServiceException
from module_admin.entity.vo.user_vo import CurrentUserModel
from module_business.dao.access_dao import AccessDao
from module_business.dao.inventory_dao import InventoryDao
from module_business.dao.master_dao import MasterDao
from module_business.dao.operation_dao import OperationDao
from module_business.domain.enums import PalletEventType, PalletFlowState
from module_business.domain.pallet_state_machine import PalletStateMachine
from module_business.domain.test_batch_scope import TestBatchScope
from module_business.entity.do.master_do import BizPallet, BizStrain
from module_business.entity.do.operation_do import BizFillingRecord, BizPalletEvent, BizPalletInventory
from module_business.entity.vo.master_vo import StrainPageQueryModel
from module_business.entity.vo.operation_vo import (
    BusinessOptionModel,
    FillingCreateModel,
    FillingModel,
    FillingPageQueryModel,
    PalletScanResponseModel,
)
from module_business.service.access_service import AccessService
from module_business.service.test_batch_access_service import TestBatchAccessService


class FillingService:
    """仓库内单托盘即时装填服务层。"""

    @staticmethod
    def _current_identity(current_user: CurrentUserModel) -> tuple[int, str]:
        user = current_user.user
        if user is None or user.user_id is None or user.user_id <= 0 or not user.user_name:
            raise ServiceException(message='当前用户信息无效')
        return user.user_id, user.user_name

    @staticmethod
    def _is_admin(current_user: CurrentUserModel) -> bool:
        return bool(current_user.user and current_user.user.admin)

    @staticmethod
    def _record_value(record: Any, field: str) -> Any:
        if not isinstance(record, dict):
            return getattr(record, field)
        if field in record:
            return record[field]
        words = field.split('_')
        alias = words[0] + ''.join(word.capitalize() for word in words[1:])
        return record.get(alias)

    @staticmethod
    def _build_request_hash(page_object: FillingCreateModel) -> str:
        payload = json.dumps(
            {
                'qr_token': page_object.qr_token.strip(),
                'warehouse_id': page_object.warehouse_id,
                'strain_id': page_object.strain_id,
                'batch_no': page_object.batch_no.strip(),
                'package_spec': page_object.package_spec.strip(),
                'initial_packages': page_object.initial_packages,
            },
            sort_keys=True,
            separators=(',', ':'),
        ).encode()
        return hashlib.sha256(payload).hexdigest()

    @classmethod
    async def _warehouse_scope(
        cls,
        query_db: AsyncSession,
        current_user: CurrentUserModel,
    ) -> list[int] | None:
        if cls._is_admin(current_user):
            return None
        user_id, _ = cls._current_identity(current_user)
        return sorted(set(await AccessDao.list_user_warehouse_ids(query_db, user_id)))

    @classmethod
    def _raise_filling_not_accessible(cls, current_user: CurrentUserModel) -> NoReturn:
        if cls._is_admin(current_user):
            raise ServiceException(message='装填记录不存在')
        raise PermissionException(data='', message='无权访问该装填记录')

    @classmethod
    def _raise_pallet_not_accessible(
        cls,
        current_user: CurrentUserModel,
        admin_message: str = '托盘不存在',
    ) -> NoReturn:
        if cls._is_admin(current_user):
            raise ServiceException(message=admin_message)
        raise PermissionException(data='', message='无权访问该托盘')

    @classmethod
    async def _assert_pallet_warehouse_access(
        cls,
        query_db: AsyncSession,
        current_user: CurrentUserModel,
        warehouse_id: int,
        *,
        for_update: bool = False,
    ) -> None:
        try:
            if for_update:
                await AccessService.assert_warehouse_access(
                    query_db,
                    current_user,
                    warehouse_id,
                    for_update=True,
                )
            else:
                await AccessService.assert_warehouse_access(query_db, current_user, warehouse_id)
        except PermissionException:
            if cls._is_admin(current_user):
                raise
            cls._raise_pallet_not_accessible(current_user)

    @staticmethod
    def _validate_empty_warehouse_pallet(
        pallet: BizPallet,
        inventory: BizPalletInventory,
        warehouse_id: int,
        qr_token: str,
    ) -> None:
        if pallet.pallet_id != inventory.pallet_id or pallet.qr_token != qr_token:
            raise ServiceException(message='托盘二维码与库存不一致')
        if pallet.asset_status != '0':
            raise ServiceException(message='托盘资产已停用，不允许装填')
        if (
            inventory.flow_state != PalletFlowState.EMPTY_IN_WAREHOUSE.value
            or inventory.warehouse_id != warehouse_id
            or inventory.site_id is not None
            or inventory.current_line_id is not None
            or inventory.active_filling_id is not None
            or inventory.remaining_packages != 0
        ):
            raise ServiceException(message='托盘不符合仓库空托盘装填条件')
        if type(inventory.version) is not int or inventory.version < 0:
            raise ServiceException(message='托盘库存版本无效')

    @staticmethod
    def _validate_package_count(initial_packages: int, pallet: BizPallet) -> None:
        if type(initial_packages) is not int or initial_packages <= 0:
            raise ServiceException(message='装填包数必须为正整数')
        if initial_packages > pallet.capacity_packages:
            raise ServiceException(message='装填包数不能超过托盘容量')

    @staticmethod
    def _validate_active_strain(strain: BizStrain | None) -> BizStrain:
        if strain is None:
            raise ServiceException(message='菌种不存在')
        if strain.status != '0':
            raise ServiceException(message='菌种已停用')
        return strain

    @staticmethod
    def _is_exact_idempotent_result(
        filling: BizFillingRecord,
        page_object: FillingCreateModel,
        request_hash: str,
    ) -> bool:
        return (
            filling.idempotency_key == page_object.idempotency_key
            and filling.warehouse_id == page_object.warehouse_id
            and filling.request_hash == request_hash
        )

    @staticmethod
    def _success(filling_id: int) -> CrudResponseModel:
        return CrudResponseModel(is_success=True, message='装填成功', result=filling_id)

    @classmethod
    async def get_filling_list_services(
        cls,
        query_db: AsyncSession,
        query_object: FillingPageQueryModel,
        current_user: CurrentUserModel,
        test_scope: TestBatchScope,
        is_page: bool = True,
    ) -> PageModel | list[FillingModel]:
        warehouse_ids = await cls._warehouse_scope(query_db, current_user)
        if (
            warehouse_ids is not None
            and query_object.warehouse_id is not None
            and query_object.warehouse_id not in warehouse_ids
        ):
            raise PermissionException(data='', message='无权访问该仓库')
        result = await OperationDao.get_filling_list(
            query_db,
            query_object,
            warehouse_ids=warehouse_ids,
            scope=test_scope,
            is_page=is_page,
        )
        rows = result.rows if isinstance(result, PageModel) else result
        models = [FillingModel.model_validate(record) for record in rows]
        if isinstance(result, PageModel):
            return result.model_copy(update={'rows': models})
        return models

    @classmethod
    async def filling_detail_services(
        cls,
        query_db: AsyncSession,
        filling_id: int,
        current_user: CurrentUserModel,
        test_scope: TestBatchScope,
    ) -> FillingModel:
        warehouse_ids = await cls._warehouse_scope(query_db, current_user)
        filling = await OperationDao.get_filling_by_id(
            query_db,
            filling_id,
            test_scope,
            warehouse_ids=warehouse_ids,
        )
        if filling is None:
            cls._raise_filling_not_accessible(current_user)
        return FillingModel.model_validate(filling)

    @classmethod
    async def get_strain_options_services(
        cls,
        query_db: AsyncSession,
        current_user: CurrentUserModel,
        test_scope: TestBatchScope,
    ) -> list[BusinessOptionModel]:
        cls._current_identity(current_user)
        strains = await MasterDao.list_strain(
            query_db,
            StrainPageQueryModel(status='0'),
            test_scope,
            False,
        )
        options = [
            BusinessOptionModel(
                id=cls._record_value(strain, 'strain_id'),
                code=cls._record_value(strain, 'strain_code'),
                name=cls._record_value(strain, 'strain_name'),
            )
            for strain in strains
            if cls._record_value(strain, 'status') == '0'
        ]
        return sorted(options, key=lambda option: option.id)

    @classmethod
    async def scan_filling_pallet_services(
        cls,
        query_db: AsyncSession,
        qr_token: str,
        current_user: CurrentUserModel,
        test_scope: TestBatchScope,
    ) -> PalletScanResponseModel:
        pallet = await InventoryDao.get_pallet_by_qr_token(query_db, qr_token, test_scope)
        if pallet is None:
            cls._raise_pallet_not_accessible(current_user)
        inventory = await MasterDao.get_pallet_inventory(query_db, pallet.pallet_id, test_scope)
        if inventory is None:
            cls._raise_pallet_not_accessible(current_user, '托盘库存不存在')
        if inventory.warehouse_id is None:
            cls._raise_pallet_not_accessible(current_user, '托盘不在仓库')
        await cls._assert_pallet_warehouse_access(
            query_db,
            current_user,
            inventory.warehouse_id,
        )
        cls._validate_empty_warehouse_pallet(
            pallet,
            inventory,
            inventory.warehouse_id,
            qr_token,
        )
        return PalletScanResponseModel(
            pallet_id=pallet.pallet_id,
            pallet_code=pallet.pallet_code,
            flow_state=PalletFlowState.EMPTY_IN_WAREHOUSE,
            warehouse_id=inventory.warehouse_id,
            site_id=None,
            current_line_id=None,
            active_filling_id=None,
            strain_id=None,
            strain_code=None,
            strain_name=None,
            batch_no=None,
            package_spec=None,
            capacity_packages=pallet.capacity_packages,
            remaining_packages=0,
            allowed_actions=['filling'],
        )

    @classmethod
    async def _recover_integrity_error(
        cls,
        query_db: AsyncSession,
        page_object: FillingCreateModel,
        request_hash: str,
        current_user: CurrentUserModel,
        test_scope: TestBatchScope,
    ) -> CrudResponseModel:
        try:
            await TestBatchAccessService.lock_active_batch(query_db, test_scope)
            warehouse_ids = await cls._warehouse_scope(query_db, current_user)
            if warehouse_ids is not None and page_object.warehouse_id not in warehouse_ids:
                raise PermissionException(data='', message='无权访问该仓库')
            recovered = await OperationDao.get_filling_by_idempotency_key(
                query_db,
                page_object.idempotency_key,
                test_scope,
                warehouse_ids=[page_object.warehouse_id],
            )
            if recovered is None:
                raise ServiceException(message='装填失败，数据冲突')
            await AccessService.assert_warehouse_access(
                query_db,
                current_user,
                recovered.warehouse_id,
            )
            if not cls._is_exact_idempotent_result(recovered, page_object, request_hash):
                raise ServiceException(message='装填失败，幂等键已被其他请求使用')
            return cls._success(recovered.filling_id)
        finally:
            await query_db.rollback()

    @classmethod
    async def fill_pallet_services(  # noqa: PLR0912, PLR0915
        cls,
        query_db: AsyncSession,
        page_object: FillingCreateModel,
        current_user: CurrentUserModel,
        test_scope: TestBatchScope,
    ) -> CrudResponseModel:
        recovery_transaction_ended = False
        try:
            await TestBatchAccessService.lock_active_batch(query_db, test_scope)
            request_hash = cls._build_request_hash(page_object)
            user_id, user_name = cls._current_identity(current_user)
            warehouse_ids = await cls._warehouse_scope(query_db, current_user)
            if warehouse_ids is not None and page_object.warehouse_id not in warehouse_ids:
                raise PermissionException(data='', message='无权访问该仓库')

            existing = await OperationDao.get_filling_by_idempotency_key(
                query_db,
                page_object.idempotency_key,
                test_scope,
                warehouse_ids=[page_object.warehouse_id],
            )
            if existing is not None:
                await AccessService.assert_warehouse_access(
                    query_db,
                    current_user,
                    existing.warehouse_id,
                )
                if not cls._is_exact_idempotent_result(existing, page_object, request_hash):
                    raise ServiceException(message='装填失败，幂等键已被其他请求使用')
                filling_id = existing.filling_id
                await query_db.rollback()
                return cls._success(filling_id)

            await AccessService.assert_warehouse_access(
                query_db,
                current_user,
                page_object.warehouse_id,
            )

            scanned_pallet = await InventoryDao.get_pallet_by_qr_token(
                query_db,
                page_object.qr_token,
                test_scope,
            )
            if scanned_pallet is None:
                cls._raise_pallet_not_accessible(current_user)

            inventory = await InventoryDao.get_inventory_for_update(
                query_db,
                scanned_pallet.pallet_id,
                test_scope,
            )
            if inventory is None:
                cls._raise_pallet_not_accessible(current_user, '托盘库存不存在')
            if inventory.warehouse_id is None:
                cls._raise_pallet_not_accessible(current_user, '托盘不在仓库')
            await cls._assert_pallet_warehouse_access(
                query_db,
                current_user,
                inventory.warehouse_id,
            )
            locked_pallets = await InventoryDao.get_pallets_by_ids(
                query_db,
                [scanned_pallet.pallet_id],
                test_scope,
            )
            if len(locked_pallets) != 1 or locked_pallets[0].pallet_id != scanned_pallet.pallet_id:
                cls._raise_pallet_not_accessible(current_user)
            pallet = locked_pallets[0]

            if inventory.active_filling_id is not None:
                concurrent = await OperationDao.get_active_filling_for_update(
                    query_db,
                    inventory.active_filling_id,
                    test_scope,
                )
                if concurrent is not None and concurrent.idempotency_key == page_object.idempotency_key:
                    # 结束首次非锁定读取建立的 RR 快照，再按最新数据范围恢复并发成功结果。
                    await query_db.rollback()
                    recovery_transaction_ended = True
                    return await cls._recover_integrity_error(
                        query_db,
                        page_object,
                        request_hash,
                        current_user,
                        test_scope,
                    )

            warehouse = await MasterDao.get_warehouse(
                query_db,
                inventory.warehouse_id,
                test_scope,
                for_update=True,
            )
            if warehouse is None:
                raise ServiceException(message='仓库不存在')
            if warehouse.status != '0':
                raise ServiceException(message='仓库已停用')
            await cls._assert_pallet_warehouse_access(
                query_db,
                current_user,
                inventory.warehouse_id,
                for_update=True,
            )
            strain = cls._validate_active_strain(
                await MasterDao.get_strain(
                    query_db,
                    page_object.strain_id,
                    test_scope,
                    for_update=True,
                )
            )

            cls._validate_empty_warehouse_pallet(
                pallet,
                inventory,
                page_object.warehouse_id,
                page_object.qr_token,
            )
            cls._validate_package_count(page_object.initial_packages, pallet)
            PalletStateMachine.ensure_transition(
                PalletFlowState(inventory.flow_state),
                PalletFlowState.FILLED_IN_WAREHOUSE,
            )

            current_time = datetime.now()
            filling = BizFillingRecord(
                filling_no=f'FL-{secrets.token_hex(16)}',
                pallet_id=pallet.pallet_id,
                warehouse_id=inventory.warehouse_id,
                strain_id=strain.strain_id,
                strain_code_snapshot=strain.strain_code,
                strain_name_snapshot=strain.strain_name,
                batch_no=page_object.batch_no.strip(),
                package_spec=page_object.package_spec.strip(),
                initial_packages=page_object.initial_packages,
                active_slot='ACTIVE',
                idempotency_key=page_object.idempotency_key,
                request_hash=request_hash,
                operator_id=user_id,
                operated_at=current_time,
                create_by=user_name,
                create_time=current_time,
                update_by=user_name,
                update_time=current_time,
                test_batch_id=test_scope.batch_id,
            )
            filling = await OperationDao.add_filling_record(query_db, filling)
            filling_id = filling.filling_id

            before_state = inventory.flow_state
            before_warehouse_id = inventory.warehouse_id
            before_site_id = inventory.site_id
            before_line_id = inventory.current_line_id
            before_remaining_packages = inventory.remaining_packages
            inventory.active_filling_id = filling_id
            inventory.remaining_packages = page_object.initial_packages
            inventory.flow_state = PalletFlowState.FILLED_IN_WAREHOUSE.value
            inventory.version += 1
            inventory.updated_at = current_time
            event = BizPalletEvent(
                pallet_id=inventory.pallet_id,
                event_type=PalletEventType.FILLING_CONFIRMED.value,
                source_type='FILLING',
                source_id=filling_id,
                before_state=before_state,
                after_state=PalletFlowState.FILLED_IN_WAREHOUSE.value,
                before_warehouse_id=before_warehouse_id,
                before_site_id=before_site_id,
                before_line_id=before_line_id,
                after_warehouse_id=inventory.warehouse_id,
                after_site_id=inventory.site_id,
                after_line_id=inventory.current_line_id,
                before_remaining_packages=before_remaining_packages,
                after_remaining_packages=page_object.initial_packages,
                operator_id=user_id,
                occurred_at=current_time,
                idempotency_key=page_object.idempotency_key,
                request_hash=request_hash,
                test_batch_id=test_scope.batch_id,
            )
            await InventoryDao.add_event(query_db, inventory, event, test_scope)
            await query_db.commit()
            return cls._success(filling_id)
        except IntegrityError:
            await query_db.rollback()
            return await cls._recover_integrity_error(
                query_db,
                page_object,
                request_hash,
                current_user,
                test_scope,
            )
        except Exception:
            if not recovery_transaction_ended:
                await query_db.rollback()
            raise