feat: add caching system

libpacstall/cache.py

@@ -0,0 +1,240 @@
+#     __    _ __    ____                  __        ____
+#    / /   (_) /_  / __ \____ ___________/ /_____ _/ / /
+#   / /   / / __ \/ /_/ / __ `/ ___/ ___/ __/ __ `/ / /
+#  / /___/ / /_/ / ____/ /_/ / /__(__  ) /_/ /_/ / / /
+# /_____/_/_.___/_/    \__,_/\___/____/\__/\__,_/_/_/
+#
+# Copyright (C) 2022-present
+#
+# This file is part of LibPacstall.
+#
+# LibPacstall is free software: you can redistribute it and/or modify it under the
+# terms of the GNU General Public License as published by the Free Software
+# Foundation, either version 3 of the License, or (at your option) any later
+# version.
+#
+# LibPacstall is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+# PARTICULAR PURPOSE. See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along with
+# LibPacstall. If not, see <https://www.gnu.org/licenses/>.
+
+"""Caching system for pacscripts."""
+
+from datetime import datetime
+from enum import Enum, auto
+from typing import Dict, List, Optional
+
+from sqlalchemy.types import JSON
+from sqlalchemy.types import Enum as SQLAlchemyEnum
+from sqlmodel import Column, Field, Relationship, SQLModel
+from sqlmodel.sql.expression import Select, SelectOfScalar
+
+# HACK: https://github.com/tiangolo/sqlmodel/issues/189#issuecomment-1065790432
+SelectOfScalar.inherit_cache = True  # type: ignore
+Select.inherit_cache = True  # type: ignore
+
+
+class InstallStatus(Enum):
+    """
+    Status of an installed package.
+
+    Attributes
+    ----------
+    NOT_INSTALLED
+        The dependency wasn't installed, indicating a source pacscript.
+    DIRECT
+        The dependency was directly installed by the user.
+    INDIRECT
+        The dependency was installed by another dependency.
+    """
+
+    NOT_INSTALLED = auto()
+    DIRECT = auto()
+    INDIRECT = auto()
+
+
+class APTDependencyPacscriptLink(SQLModel, table=True):
+    """
+    Link between an APT dependency and a pacscript.
+
+    Attributes
+    ----------
+    dependency_name
+        The name of the dependency.
+    pacscript_name
+        The name of the pacscript.
+    """
+
+    dependency_name: Optional[int] = Field(
+        default=None, foreign_key="aptdependency.name", primary_key=True
+    )
+    pacscript_name: Optional[str] = Field(
+        default=None, foreign_key="pacscript.name", primary_key=True
+    )
+
+
+class APTDependency(SQLModel, table=True):
+    """
+    SQLModel of an APT dependency for a pacscript.
+
+    Attributes
+    ----------
+    name
+        Name of the dependency.
+    dependents
+        List of pacscripts that depend on this dependency.
+    """
+
+    name: str = Field(primary_key=True)
+    dependents: List["Pacscript"] = Relationship(
+        back_populates="apt_dependencies", link_model=APTDependencyPacscriptLink
+    )
+
+
+class PacscriptDependencyLink(SQLModel, table=True):
+    """
+    Link between a pacscript dependency and a pacscript.
+
+    Attributes
+    ----------
+    pacscript_name
+        Name of the pacscript.
+    dependency_name
+        Name of the dependency.
+    """
+
+    pacscript_name: Optional[str] = Field(
+        default=None, foreign_key="pacscript.name", primary_key=True
+    )
+    dependency_name: Optional[str] = Field(
+        default=None, foreign_key="pacscriptdependency.name", primary_key=True
+    )
+
+
+class PacscriptDependency(SQLModel, table=True):
+    """
+    SQLModel of a pacscript dependency of a pacscript.
+
+    Attributes
+    ----------
+    name
+        Name of the dependency.
+    dependents
+        List of pacscripts that depend on this dependency.
+    """
+
+    name: str = Field(primary_key=True)
+    dependents: List["Pacscript"] = Relationship(
+        back_populates="pacscript_dependencies", link_model=PacscriptDependencyLink
+    )
+
+
+class Source(SQLModel, table=True):
+    """
+    SQLModel of a source.
+
+    Attributes
+    ----------
+    url
+        URL of the source.
+    last_updated
+        Last time the source was updated.
+    preference
+        Preference of the source.
+    pacscripts
+        List of pacscripts that are from this source.
+    """
+
+    url: str = Field(index=True, primary_key=True)
+    last_updated: datetime
+    preference: int
+    pacscripts: List["Pacscript"] = Relationship(back_populates="source")
+
+
+class Pacscript(SQLModel, table=True):
+    """
+    SQLModel to access and write to the Pacscript database.
+
+    There are two types of pacscripts stored in this table, installed
+    pacscripts, and source pacscripts. If the `Install_status` column is NULL
+    then the pacscript is a source pacscript. Otherwise it's an installed one.
+
+    Attributes
+    ----------
+    name
+        The name of the pacscript.
+    version
+        The version of the pacscript.
+    url
+        The URL of the pacscript.
+    homepage
+        The homepage of the pacscript.
+    description
+        The description of the pacscript.
+    source_url_id
+        The URL of the source of the pacscript. (Foreign key)
+    source
+        The source associated with the pacscript.
+    installed_size
+        The installed size of the pacscript's package in bytes.
+    download_size
+        The downloaded size of the pacscript's package in bytes.
+    date
+        The date the pacscript was last updated.
+    install_status
+        The installed status of the pacscript.
+    apt_dependencies
+        The list of apt dependencies of the pacscript.
+    apt_optional_dependencies
+        The list of apt optional dependencies of the pacscript.
+    pacscript_dependencies
+        The list of pacscript dependencies of the pacscript.
+    pacscript_optional_dependencies
+        The list of pacscript optional dependencies of the pacscript.
+    repology
+        The repology filters for the pacscript.
+    maintainer
+        The maintainer of the pacscript.
+    """
+
+    # Primary keys
+    name: str = Field(index=True, primary_key=True)
+    install_status: Optional[InstallStatus] = Field(
+        default=InstallStatus.NOT_INSTALLED,
+        sa_column=Column(SQLAlchemyEnum(InstallStatus), primary_key=True),
+    )
+
+    # Metadata defined in the pacscript
+    version: str
+    url: str
+    homepage: Optional[str] = None
+    description: str
+    repology: Optional[Dict[str, str]] = Field(default=None, sa_column=Column(JSON))
+    maintainer: Optional[str] = None
+
+    # Link to the pacscript source
+    source_url_id: Optional[int] = Field(default=None, foreign_key="source.url")
+    source: Source = Relationship(back_populates="pacscripts")
+
+    # Metadata generated about the pacscript
+    installed_size: Optional[int] = None
+    download_size: int
+    date: datetime
+
+    # Dependencies
+    apt_dependencies: Optional[List[APTDependency]] = Relationship(
+        back_populates="dependents",
+        link_model=APTDependencyPacscriptLink,
+    )
+    apt_optional_dependencies: Optional[Dict[str, str]] = Field(
+        default=None, sa_column=Column(JSON)
+    )
+    pacscript_dependencies: Optional[List[PacscriptDependency]] = Relationship(
+        back_populates="dependents",
+        link_model=PacscriptDependencyLink,
+    )
+    pacscript_optional_dependencies: Optional[Dict[str, str]] = Field(
+        default=None, sa_column=Column(JSON)
+    )