[proxy] refactor state implementation

1 files changed, 137 insertions, 0 deletions

diff --git a/src/hydrilla/proxy/state_impl/payloads.py b/src/hydrilla/proxy/state_impl/payloads.py
new file mode 100644
index 0000000..2bee11f
--- /dev/null
+++ b/src/hydrilla/proxy/state_impl/payloads.py
@@ -0,0 +1,137 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+# Haketilo proxy data and configuration (PayloadRef subtype).
+#
+# This file is part of Hydrilla&Haketilo.
+#
+# Copyright (C) 2022 Wojtek Kosior
+#
+# This program 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.
+#
+# This program 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 this program.  If not, see <https://www.gnu.org/licenses/>.
+#
+#
+# I, Wojtek Kosior, thereby promise not to sue for violation of this
+# file's license. Although I request that you do not make use this code
+# in a proprietary program, I am not going to enforce this in court.
+
+"""
+This module provides an interface to interact with payloads inside Haketilo.
+"""
+
+# Enable using with Python 3.7.
+from __future__ import annotations
+
+import dataclasses as dc
+import typing as t
+
+from .. import state as st
+from . import base
+
+
+@dc.dataclass(frozen=True, unsafe_hash=True)
+class ConcretePayloadRef(st.PayloadRef):
+    state: base.HaketiloStateWithFields = dc.field(hash=False, compare=False)
+
+    def get_data(self) -> st.PayloadData:
+        try:
+            return self.state.payloads_data[self]
+        except KeyError:
+            raise st.MissingItemError()
+
+    def get_mapping(self) -> st.MappingVersionRef:
+        raise NotImplementedError()
+
+    def get_script_paths(self) \
+        -> t.Iterable[t.Sequence[str]]:
+        with self.state.cursor() as cursor:
+            cursor.execute(
+                '''
+                SELECT
+                        i.identifier, fu.name
+                FROM
+                                  payloads                    AS p
+                        LEFT JOIN resolved_depended_resources AS rdd
+                                USING (payload_id)
+                        LEFT JOIN item_versions               AS iv
+                                ON rdd.resource_item_id = iv.item_version_id
+                        LEFT JOIN items                       AS i
+                                USING (item_id)
+                        LEFT JOIN file_uses                   AS fu
+                                USING (item_version_id)
+                WHERE
+                        fu.type = 'W'    AND
+                        p.payload_id = ? AND
+                        (fu.idx IS NOT NULL OR rdd.idx IS NULL)
+                ORDER BY
+                        rdd.idx, fu.idx;
+                ''',
+                (self.id,)
+            )
+
+            paths: list[t.Sequence[str]] = []
+            for resource_identifier, file_name in cursor.fetchall():
+                if resource_identifier is None:
+                    # payload found but it had no script files
+                    return ()
+
+                paths.append((resource_identifier, *file_name.split('/')))
+
+        if paths == []:
+            # payload not found
+            raise st.MissingItemError()
+
+        return paths
+
+    def get_file_data(self, path: t.Sequence[str]) \
+        -> t.Optional[st.FileData]:
+        if len(path) == 0:
+            raise st.MissingItemError()
+
+        resource_identifier, *file_name_segments = path
+
+        file_name = '/'.join(file_name_segments)
+
+        with self.state.cursor() as cursor:
+            cursor.execute(
+                '''
+                SELECT
+                        f.data, fu.mime_type
+                FROM
+                             payloads                    AS p
+                        JOIN resolved_depended_resources AS rdd
+                                USING (payload_id)
+                        JOIN item_versions               AS iv
+                                ON rdd.resource_item_id = iv.item_version_id
+                        JOIN items                       AS i
+                                USING (item_id)
+                        JOIN file_uses                   AS fu
+                                USING (item_version_id)
+                        JOIN files                       AS f
+                                USING (file_id)
+                WHERE
+                        p.payload_id = ? AND
+                        i.identifier = ? AND
+                        fu.name = ?      AND
+                        fu.type = 'W';
+                ''',
+                (self.id, resource_identifier, file_name)
+            )
+
+            result = cursor.fetchall()
+
+        if result == []:
+            return None
+
+        (data, mime_type), = result
+
+        return st.FileData(type=mime_type, name=file_name, contents=data)