implement /packages/{name} as its own route

A few things added with this commit:

- aurweb.packages.util
    - A module providing package and pkgbase helpers.
- aurweb.template.register_filter
    - A decorator that can be used to register a filter:
      @register_filter("some_filter") def f(): pass

Additionally, template partials have been split off a bit
differently. Changes:

- /packages/{name} is defined in packages/show.html.
- partials/packages/package_actions.html is now
  partials/packages/actions.html.
- partials/packages/details.html has been added.
- partials/packages/comments.html has been added.
- partials/packages/comment.html has been added.
- models.dependency_type additions: name and id constants.
- models.relation_type additions: name and id constants.
- models.official_provider additions: base official url constant.

Signed-off-by: Kevin Morris <kevr@0cost.org>

aurweb/packages/util.py

@@ -0,0 +1,117 @@
+from http import HTTPStatus
+
+from fastapi import HTTPException
+from sqlalchemy import and_
+
+from aurweb import db
+from aurweb.models.official_provider import OFFICIAL_BASE, OfficialProvider
+from aurweb.models.package import Package
+from aurweb.models.package_base import PackageBase
+from aurweb.models.package_dependency import PackageDependency
+from aurweb.models.package_relation import PackageRelation
+from aurweb.models.relation_type import PROVIDES_ID, RelationType
+from aurweb.templates import register_filter
+
+
+def dep_depends_extra(dep: PackageDependency) -> str:
+    """ A function used to produce extra text for dependency display. """
+    return str()
+
+
+def dep_makedepends_extra(dep: PackageDependency) -> str:
+    """ A function used to produce extra text for dependency display. """
+    return "(make)"
+
+
+def dep_checkdepends_extra(dep: PackageDependency) -> str:
+    """ A function used to produce extra text for dependency display. """
+    return "(check)"
+
+
+def dep_optdepends_extra(dep: PackageDependency) -> str:
+    """ A function used to produce extra text for dependency display. """
+    return "(optional)"
+
+
+@register_filter("dep_extra")
+def dep_extra(dep: PackageDependency) -> str:
+    """ Some dependency types have extra text added to their
+    display. This function provides that output. However, it
+    **assumes** that the dep passed is bound to a valid one
+    of: depends, makedepends, checkdepends or optdepends. """
+    f = globals().get(f"dep_{dep.DependencyType.Name}_extra")
+    return f(dep)
+
+
+@register_filter("dep_extra_desc")
+def dep_extra_desc(dep: PackageDependency) -> str:
+    extra = dep_extra(dep)
+    return extra + f" – {dep.DepDesc}"
+
+
+@register_filter("pkgname_link")
+def pkgname_link(pkgname: str) -> str:
+    base = "/".join([OFFICIAL_BASE, "packages"])
+    pkg = db.query(Package).filter(Package.Name == pkgname)
+    official = db.query(OfficialProvider).filter(
+        OfficialProvider.Name == pkgname)
+    if not pkg.count() or official.count():
+        return f"{base}/?q={pkgname}"
+    return f"/packages/{pkgname}"
+
+
+@register_filter("package_link")
+def package_link(package: Package) -> str:
+    base = "/".join([OFFICIAL_BASE, "packages"])
+    official = db.query(OfficialProvider).filter(
+        OfficialProvider.Name == package.Name)
+    if official.count():
+        return f"{base}/?q={package.Name}"
+    return f"/packages/{package.Name}"
+
+
+@register_filter("provides_list")
+def provides_list(package: Package, depname: str) -> list:
+    providers = db.query(Package).join(
+        PackageRelation).join(RelationType).filter(
+        and_(
+            PackageRelation.RelName == depname,
+            RelationType.ID == PROVIDES_ID
+        )
+    )
+
+    string = str()
+    has_providers = providers.count() > 0
+
+    if has_providers:
+        string += "<em>("
+
+    string += ", ".join([
+        f'<a href="{package_link(pkg)}">{pkg.Name}</a>'
+        for pkg in providers
+    ])
+
+    if has_providers:
+        string += ")</em>"
+
+    return string
+
+
+def get_pkgbase(name: str) -> PackageBase:
+    """ Get a PackageBase instance by its name or raise a 404 if
+    it can't be foudn in the database.
+
+    :param name: PackageBase.Name
+    :raises HTTPException: With status code 404 if PackageBase doesn't exist
+    :return: PackageBase instance
+    """
+    pkgbase = db.query(PackageBase).filter(PackageBase.Name == name).first()
+    if not pkgbase:
+        raise HTTPException(status_code=int(HTTPStatus.NOT_FOUND))
+
+    provider = db.query(OfficialProvider).filter(
+        OfficialProvider.Name == name).first()
+    if provider:
+        raise HTTPException(status_code=int(HTTPStatus.NOT_FOUND))
+
+    return pkgbase