fase 2 afgerond

app/services/session_service.py

@@ -0,0 +1,169 @@
+import json
+import sqlite3
+from pathlib import Path
+
+from app.config import APP_DATA_DIR
+
+
+class SessionService:
+    def __init__(self) -> None:
+        self._db_path = Path(APP_DATA_DIR) / "session_state.sqlite3"
+        self._db_path.parent.mkdir(parents=True, exist_ok=True)
+        self._init_db()
+
+    def _connect(self) -> sqlite3.Connection:
+        conn = sqlite3.connect(self._db_path)
+        conn.row_factory = sqlite3.Row
+        return conn
+
+    def _init_db(self) -> None:
+        with self._connect() as conn:
+            conn.execute(
+                """
+                CREATE TABLE IF NOT EXISTS selected_episodes (
+                    selection_id INTEGER PRIMARY KEY AUTOINCREMENT,
+                    session_id TEXT NOT NULL,
+                    position INTEGER NOT NULL,
+                    payload_json TEXT NOT NULL
+                )
+                """
+            )
+            conn.execute(
+                """
+                CREATE UNIQUE INDEX IF NOT EXISTS idx_selected_episodes_session_position
+                ON selected_episodes(session_id, position)
+                """
+            )
+            conn.execute(
+                """
+                CREATE INDEX IF NOT EXISTS idx_selected_episodes_session
+                ON selected_episodes(session_id)
+                """
+            )
+
+    def list_selected_episodes(self, session_id: str) -> list[dict]:
+        with self._connect() as conn:
+            rows = conn.execute(
+                """
+                SELECT selection_id, position, payload_json
+                FROM selected_episodes
+                WHERE session_id = ?
+                ORDER BY position ASC
+                """,
+                (session_id,),
+            ).fetchall()
+
+        items = []
+        for row in rows:
+            payload = json.loads(row["payload_json"])
+            items.append(
+                {
+                    "selection_id": row["selection_id"],
+                    "position": row["position"],
+                    "episode": payload,
+                }
+            )
+        return items
+
+    def add_selected_episodes(self, session_id: str, items: list[dict]) -> list[dict]:
+        if not items:
+            return self.list_selected_episodes(session_id)
+
+        with self._connect() as conn:
+            current_max = conn.execute(
+                """
+                SELECT COALESCE(MAX(position), -1) AS max_position
+                FROM selected_episodes
+                WHERE session_id = ?
+                """,
+                (session_id,),
+            ).fetchone()
+            next_position = int(current_max["max_position"]) + 1
+
+            for item in items:
+                conn.execute(
+                    """
+                    INSERT INTO selected_episodes (session_id, position, payload_json)
+                    VALUES (?, ?, ?)
+                    """,
+                    (session_id, next_position, json.dumps(item, ensure_ascii=True)),
+                )
+                next_position += 1
+
+        return self.list_selected_episodes(session_id)
+
+    def clear_selected_episodes(self, session_id: str) -> None:
+        with self._connect() as conn:
+            conn.execute(
+                "DELETE FROM selected_episodes WHERE session_id = ?",
+                (session_id,),
+            )
+
+    def remove_selected_episode(self, session_id: str, selection_id: int) -> list[dict]:
+        with self._connect() as conn:
+            conn.execute(
+                """
+                DELETE FROM selected_episodes
+                WHERE session_id = ? AND selection_id = ?
+                """,
+                (session_id, selection_id),
+            )
+        return self._compact_positions(session_id)
+
+    def reorder_selected_episodes(
+        self,
+        session_id: str,
+        from_index: int,
+        to_index: int,
+    ) -> list[dict]:
+        current_items = self.list_selected_episodes(session_id)
+
+        if from_index < 0 or from_index >= len(current_items):
+            raise ValueError("from_index out of range")
+        if to_index < 0 or to_index >= len(current_items):
+            raise ValueError("to_index out of range")
+        if from_index == to_index:
+            return current_items
+
+        moved = current_items.pop(from_index)
+        current_items.insert(to_index, moved)
+
+        with self._connect() as conn:
+            # Two-phase update avoids transient UNIQUE conflicts on (session_id, position).
+            for position, item in enumerate(current_items):
+                conn.execute(
+                    """
+                    UPDATE selected_episodes
+                    SET position = ?
+                    WHERE session_id = ? AND selection_id = ?
+                    """,
+                    (-(position + 1), session_id, item["selection_id"]),
+                )
+
+            for position, item in enumerate(current_items):
+                conn.execute(
+                    """
+                    UPDATE selected_episodes
+                    SET position = ?
+                    WHERE session_id = ? AND selection_id = ?
+                    """,
+                    (position, session_id, item["selection_id"]),
+                )
+
+        return self.list_selected_episodes(session_id)
+
+    def _compact_positions(self, session_id: str) -> list[dict]:
+        items = self.list_selected_episodes(session_id)
+        with self._connect() as conn:
+            for position, item in enumerate(items):
+                if item["position"] == position:
+                    continue
+                conn.execute(
+                    """
+                    UPDATE selected_episodes
+                    SET position = ?
+                    WHERE session_id = ? AND selection_id = ?
+                    """,
+                    (position, session_id, item["selection_id"]),
+                )
+        return self.list_selected_episodes(session_id)