[proxy] make it possible to uninstall a package

This commit also brings some more refactoring under state_impl/.

4 files changed, 66 insertions, 19 deletions

diff --git a/src/hydrilla/proxy/state_impl/_operations/__init__.py b/src/hydrilla/proxy/state_impl/_operations/__init__.py
index ff34b0b..359e2f5 100644
--- a/src/hydrilla/proxy/state_impl/_operations/__init__.py
+++ b/src/hydrilla/proxy/state_impl/_operations/__init__.py
@@ -4,7 +4,7 @@
 #
 # Available under the terms of Creative Commons Zero v1.0 Universal.
 
-from .prune_packages import prune_packages
+from .prune_orphans import prune_orphans
 from .pull_missing_files import pull_missing_files
 from .load_packages import _load_packages_no_state_update
 from .recompute_dependencies import _recompute_dependencies_no_state_update
diff --git a/src/hydrilla/proxy/state_impl/_operations/load_packages.py b/src/hydrilla/proxy/state_impl/_operations/load_packages.py
index 107e8d6..f8fddfa 100644
--- a/src/hydrilla/proxy/state_impl/_operations/load_packages.py
+++ b/src/hydrilla/proxy/state_impl/_operations/load_packages.py
@@ -45,7 +45,7 @@ from .... import item_infos
 from ... import state
 from .recompute_dependencies import _recompute_dependencies_no_state_update, \
     FileResolver
-from .prune_packages import prune_packages
+from .prune_orphans import prune_orphans
 
 def make_repo_iteration(cursor: sqlite3.Cursor, repo_id: int) -> int:
     cursor.execute(
@@ -401,11 +401,16 @@ def _load_packages_no_state_update(
                 repo_id           = repo_id
             )
 
-    prune_packages(cursor)
+    if repo_id != 1:
+        # In case of local semirepo (repo_id = 1) all packages from previous
+        # iteration are already orphans and can be assumed to be in a pruned
+        # state no matter what.
+        prune_orphans(cursor)
 
     _recompute_dependencies_no_state_update(
-        cursor                 = cursor,
-        semirepo_file_resolver = MalcontentFileResolver(malcontent_path)
+        cursor                     = cursor,
+        unlocked_required_mappings = [],
+        semirepo_file_resolver     = MalcontentFileResolver(malcontent_path)
     )
 
     return repo_iteration_id
diff --git a/src/hydrilla/proxy/state_impl/_operations/prune_packages.py b/src/hydrilla/proxy/state_impl/_operations/prune_orphans.py
index 6f4b3e7..f4ebd52 100644
--- a/src/hydrilla/proxy/state_impl/_operations/prune_packages.py
+++ b/src/hydrilla/proxy/state_impl/_operations/prune_orphans.py
@@ -38,12 +38,12 @@ from pathlib import Path
 
 _remove_item_versions_sqls = [
     '''
-    CREATE TEMPORARY TABLE removed_versions(
+    CREATE TEMPORARY TABLE __removed_versions(
             item_version_id INTEGER PRIMARY KEY
     );
     ''', '''
     INSERT INTO
-            removed_versions
+            __removed_versions
     SELECT
             iv.item_version_id
     FROM
@@ -57,14 +57,14 @@ _remove_item_versions_sqls = [
     SET
             active_version_id = NULL
     WHERE
-            active_version_id IN removed_versions;
+            active_version_id IN __removed_versions;
     ''', '''
     DELETE FROM
             item_versions
     WHERE
-            item_version_id IN removed_versions;
+            item_version_id IN __removed_versions;
     ''', '''
-    DROP TABLE removed_versions;
+    DROP TABLE __removed_versions;
     '''
 ]
 
@@ -134,7 +134,7 @@ WHERE
         repo_id IN removed_repos;
 '''
 
-def prune_packages(cursor: sqlite3.Cursor) -> None:
+def prune_orphans(cursor: sqlite3.Cursor) -> None:
     assert cursor.connection.in_transaction
 
     for sql in _remove_item_versions_sqls:
diff --git a/src/hydrilla/proxy/state_impl/_operations/recompute_dependencies.py b/src/hydrilla/proxy/state_impl/_operations/recompute_dependencies.py
index d4c4d45..327a195 100644
--- a/src/hydrilla/proxy/state_impl/_operations/recompute_dependencies.py
+++ b/src/hydrilla/proxy/state_impl/_operations/recompute_dependencies.py
@@ -36,6 +36,7 @@ import typing as t
 
 from .... import item_infos
 from ... import simple_dependency_satisfying as sds
+from .. import base
 from .pull_missing_files import pull_missing_files, FileResolver, \
     DummyFileResolver
 
@@ -73,6 +74,41 @@ def _get_infos_of_type(cursor: sqlite3.Cursor, info_type: t.Type[AnyInfoVar],) \
 
     return result
 
+def _get_current_required_state(
+        cursor:                     sqlite3.Cursor,
+        unlocked_required_mappings: t.Sequence[int]
+) -> list[sds.MappingRequirement]:
+    # For mappings explicitly enabled by the user (+ all mappings they
+    # recursively depend on) let's make sure that their exact same versions will
+    # be enabled after the change. Make exception for mappings specified by the
+    # caller.
+    with base.temporary_ids_table(
+            cursor     = cursor,
+            ids        = unlocked_required_mappings,
+            table_name = '__unlocked_ids'
+    ):
+        cursor.execute(
+            '''
+            SELECT
+                    definition, repo, repo_iteration
+            FROM
+                    item_versions_extra
+            WHERE
+                    item_id NOT IN __unlocked_ids AND active = 'R';
+            ''',
+        )
+
+        rows = cursor.fetchall()
+
+    requirements: list[sds.MappingRequirement] = []
+
+    for definition, repo, iteration in rows:
+        info = item_infos.MappingInfo.load(definition, repo, iteration)
+        req = sds.MappingVersionRequirement(info.identifier, info)
+        requirements.append(req)
+
+    return requirements
+
 def _mark_version_installed(cursor: sqlite3.Cursor, version_id: int) -> None:
     cursor.execute(
         '''
@@ -87,8 +123,8 @@ def _mark_version_installed(cursor: sqlite3.Cursor, version_id: int) -> None:
     )
 
 def _recompute_dependencies_no_state_update_no_pull_files(
-        cursor:             sqlite3.Cursor,
-        extra_requirements: t.Iterable[sds.MappingRequirement]
+        cursor:                     sqlite3.Cursor,
+        unlocked_required_mappings: base.NoLockArg = [],
 ) -> None:
     cursor.execute('DELETE FROM payloads;')
 
@@ -98,7 +134,13 @@ def _recompute_dependencies_no_state_update_no_pull_files(
     resources_to_ids = dict((info, id) for id, info in ids_to_resources.items())
     mappings_to_ids  = dict((info, id) for id, info in ids_to_mappings.items())
 
-    requirements = [*extra_requirements]
+    if unlocked_required_mappings == 'all_mappings_unlocked':
+        requirements = []
+    else:
+        requirements = _get_current_required_state(
+            cursor                     = cursor,
+            unlocked_required_mappings = unlocked_required_mappings
+        )
 
     cursor.execute(
         '''
@@ -276,13 +318,13 @@ def _recompute_dependencies_no_state_update_no_pull_files(
 
 
 def _recompute_dependencies_no_state_update(
-        cursor:                 sqlite3.Cursor,
-        extra_requirements:     t.Iterable[sds.MappingRequirement] = (),
-        semirepo_file_resolver: FileResolver = DummyFileResolver()
+        cursor:                     sqlite3.Cursor,
+        unlocked_required_mappings: base.NoLockArg = [],
+        semirepo_file_resolver:     FileResolver   = DummyFileResolver()
 ) -> None:
     _recompute_dependencies_no_state_update_no_pull_files(
-        cursor,
-        extra_requirements
+        cursor                     = cursor,
+        unlocked_required_mappings = unlocked_required_mappings
     )
 
     pull_missing_files(cursor, semirepo_file_resolver)