Python additions Labs 2,3,4,5

Author: Eric Camplin

DownloadableCodeProjects/az-2007-m2-explain-document-python/library/application_core/entities/author.py

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+from dataclasses import dataclass
+
+@dataclass
+class Author:
+    id: int
+    name: str

DownloadableCodeProjects/az-2007-m2-explain-document-python/library/application_core/entities/book.py

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+from dataclasses import dataclass
+from typing import Optional
+from .author import Author
+
+@dataclass
+class Book:
+    id: int
+    title: str
+    author_id: int
+    genre: str
+    image_name: str
+    isbn: str
+    author: Optional[Author] = None

DownloadableCodeProjects/az-2007-m2-explain-document-python/library/application_core/entities/book_item.py

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+from dataclasses import dataclass
+from typing import Optional
+from datetime import datetime
+from .book import Book
+
+@dataclass
+class BookItem:
+    id: int
+    book_id: int
+    acquisition_date: datetime
+    condition: Optional[str] = None
+    book: Optional[Book] = None

DownloadableCodeProjects/az-2007-m2-explain-document-python/library/application_core/entities/loan.py

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+from dataclasses import dataclass
+from typing import Optional
+from datetime import datetime
+from .patron import Patron
+from .book_item import BookItem
+
+@dataclass
+class Loan:
+    id: int
+    book_item_id: int
+    patron_id: int
+    patron: Optional[Patron] = None
+    loan_date: datetime = None
+    due_date: datetime = None
+    return_date: Optional[datetime] = None
+    book_item: Optional[BookItem] = None

DownloadableCodeProjects/az-2007-m2-explain-document-python/library/application_core/entities/patron.py

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+from dataclasses import dataclass, field
+from typing import List, Optional
+from datetime import datetime
+# from .loan import Loan  # Use string annotation to avoid circular import
+
+@dataclass
+class Patron:
+    id: int
+    name: str
+    membership_end: datetime
+    membership_start: datetime
+    image_name: Optional[str] = None
+    loans: List['Loan'] = field(default_factory=list)

DownloadableCodeProjects/az-2007-m2-explain-document-python/library/application_core/enums/loan_extension_status.py

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+from enum import Enum
+
+class LoanExtensionStatus(Enum):
+    SUCCESS = 'Book loan extension was successful.'
+    LOAN_NOT_FOUND = 'Loan not found.'
+    LOAN_EXPIRED = 'Cannot extend book loan as it already has expired. Return the book instead.'
+    MEMBERSHIP_EXPIRED = "Cannot extend book loan due to expired patron's membership."
+    LOAN_RETURNED = 'Cannot extend book loan as the book is already returned.'
+    ERROR = 'Cannot extend book loan due to an error.'

DownloadableCodeProjects/az-2007-m2-explain-document-python/library/application_core/enums/loan_return_status.py

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+from enum import Enum
+
+class LoanReturnStatus(Enum):
+    SUCCESS = 'Book was successfully returned.'
+    LOAN_NOT_FOUND = 'Loan not found.'
+    ALREADY_RETURNED = 'Cannot return book as the book is already returned.'
+    ERROR = 'Cannot return book due to an error.'

DownloadableCodeProjects/az-2007-m2-explain-document-python/library/application_core/enums/membership_renewal_status.py

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+from enum import Enum
+
+class MembershipRenewalStatus(Enum):
+    SUCCESS = 'Membership renewal was successful.'
+    PATRON_NOT_FOUND = 'Patron not found.'
+    TOO_EARLY_TO_RENEW = 'It is too early to renew the membership.'
+    LOAN_NOT_RETURNED = 'Cannot renew membership due to an outstanding loan.'
+    ERROR = 'Cannot renew membership due to an error.'

DownloadableCodeProjects/az-2007-m2-explain-document-python/library/application_core/interfaces/iloan_repository.py

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+from abc import ABC, abstractmethod
+from typing import Optional
+from ..entities.loan import Loan
+
+class ILoanRepository(ABC):
+    @abstractmethod
+    def get_loan(self, loan_id: int) -> Optional[Loan]:
+        pass
+
+    @abstractmethod
+    def update_loan(self, loan: Loan) -> None:
+        pass

DownloadableCodeProjects/az-2007-m2-explain-document-python/library/application_core/interfaces/iloan_service.py

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+from abc import ABC, abstractmethod
+from ..enums.loan_return_status import LoanReturnStatus
+from ..enums.loan_extension_status import LoanExtensionStatus
+
+class ILoanService(ABC):
+    @abstractmethod
+    def return_loan(self, loan_id: int) -> LoanReturnStatus:
+        pass
+
+    @abstractmethod
+    def extend_loan(self, loan_id: int) -> LoanExtensionStatus:
+        pass