search service implementation

src/basic_memory/models/knowledge.py

@@ -25,6 +25,7 @@ class Entity(Base):
     __tablename__ = "entity"
     __table_args__ = (
         UniqueConstraint("entity_type", "name", name="uix_entity_type_name"),
+        UniqueConstraint("path_id", name="uix_entity_path_id"),  # Make path_id unique
         Index("ix_entity_type", "entity_type"),
         Index("ix_entity_doc_id", "doc_id"),
         Index("ix_entity_created_at", "created_at"),  # For timeline queries
@@ -35,8 +36,7 @@ class Entity(Base):
     id: Mapped[int] = mapped_column(Integer, primary_key=True)
     name: Mapped[str] = mapped_column(String)
     entity_type: Mapped[str] = mapped_column(String)
-    # Normalized path for URIs
-    # (entity_type, path_id) are unique
+    # Normalized path for URIs - must be unique
     path_id: Mapped[str] = mapped_column(String, index=True)
     # Actual filesystem relative path
     file_path: Mapped[str] = mapped_column(String, unique=True, index=True)
@@ -157,4 +157,4 @@ class Relation(Base):
     to_entity = relationship("Entity", foreign_keys=[to_id], back_populates="incoming_relations")
 
     def __repr__(self) -> str:
-        return f"Relation(id={self.id}, from_id={self.from_id}, to_id={self.to_id}, type='{self.relation_type}')"
+        return f"Relation(id={self.id}, from_id={self.from_id}, to_id={self.to_id}, type='{self.relation_type}')"

src/basic_memory/models/search.py

@@ -0,0 +1,15 @@
+"""Search models and tables."""
+
+from sqlalchemy import DDL
+
+# Define FTS5 virtual table creation
+CREATE_SEARCH_INDEX = DDL("""
+CREATE VIRTUAL TABLE IF NOT EXISTS search_index USING fts5(
+    content,           -- Searchable text content
+    path_id UNINDEXED, -- Link to entity/document (must be unique)
+    file_path UNINDEXED, -- Filesystem path
+    type UNINDEXED,    -- 'entity' or 'document'
+    metadata UNINDEXED, -- JSON with timestamps, types, etc.
+    tokenize='porter unicode61' -- Enable stemming + unicode
+);
+""")

src/basic_memory/repository/search_repository.py

@@ -0,0 +1,130 @@
+"""Repository for search operations."""
+
+import json
+from typing import List, Optional
+from datetime import datetime
+from sqlalchemy import text
+from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker
+
+from basic_memory import db
+from basic_memory.repository.repository import Repository
+from basic_memory.schemas.search import SearchQuery, SearchResult
+from basic_memory.models.search import CREATE_SEARCH_INDEX
+
+class SearchRepository():
+    """Repository for search index operations."""
+
+    def __init__(self, session_maker: async_sessionmaker[AsyncSession]):
+        self.session_maker = session_maker
+
+    async def init_search_index(self):
+        """Create or recreate the search index."""
+        async with db.scoped_session(self.session_maker) as session:
+            await session.execute(CREATE_SEARCH_INDEX)
+            await session.commit()
+
+    async def search(
+        self,
+        query: SearchQuery,
+        context: Optional[List[str]] = None
+    ) -> List[SearchResult]:
+        """Search across all indexed content."""
+        conditions = []
+        params = {}
+
+        # Handle text search
+        if query.text:
+            conditions.append(f"content MATCH '{query.text}'")
+
+        # Handle type filter
+        if query.types:
+            type_list = ", ".join(f"'{t}'" for t in query.types)
+            conditions.append(f"type IN ({type_list})")
+
+        # Handle entity type filter
+        if query.entity_types:
+            entity_type_list = ", ".join(f"'{t}'" for t in query.entity_types)
+            conditions.append(
+                f"json_extract(metadata, '$.entity_type') IN ({entity_type_list})"
+            )
+
+        # Handle date filter
+        if query.after_date:
+            params["after_date"] = query.after_date.isoformat()
+            conditions.append(
+                "json_extract(metadata, '$.created_at') > :after_date"
+            )
+
+        # Build WHERE clause
+        where_clause = " AND ".join(conditions) if conditions else "1=1"
+        
+        sql = f"""
+            SELECT 
+                path_id,
+                file_path,
+                type,
+                metadata,
+                bm25(search_index) as score
+            FROM search_index 
+            WHERE {where_clause}
+            ORDER BY score DESC
+        """
+
+        async with db.scoped_session(self.session_maker) as session:
+            result = await session.execute(text(sql), params)
+            rows = result.fetchall()
+
+            return [
+                SearchResult(
+                    path_id=row.path_id,
+                    file_path=row.file_path,
+                    type=row.type,
+                    score=row.score,
+                    metadata=json.loads(row.metadata)
+                )
+                for row in rows
+            ]
+
+    async def index_item(
+        self,
+        content: str,
+        path_id: str,
+        file_path: str,
+        type: str,
+        metadata: dict
+    ):
+        """Index or update a single item."""
+        async with db.scoped_session(self.session_maker) as session:
+            # Delete existing record if any
+            await session.execute(
+                text("DELETE FROM search_index WHERE path_id = :path_id"),
+                {"path_id": path_id}
+            )
+
+            # Insert new record
+            await session.execute(
+                text("""
+                    INSERT INTO search_index (
+                        content, path_id, file_path, type, metadata
+                    ) VALUES (
+                        :content, :path_id, :file_path, :type, :metadata
+                    )
+                """),
+                {
+                    "content": content,
+                    "path_id": path_id,
+                    "file_path": file_path,
+                    "type": type,
+                    "metadata": json.dumps(metadata)
+                }
+            )
+            await session.commit()
+
+    async def delete_by_path(self, path_id: str):
+        """Delete an item from the search index."""
+        async with db.scoped_session(self.session_maker) as session:
+            await session.execute(
+                text("DELETE FROM search_index WHERE path_id = :path_id"),
+                {"path_id": path_id}
+            )
+            await session.commit()

src/basic_memory/schemas/search.py

@@ -0,0 +1,16 @@
+from typing import Optional, List
+from datetime import datetime
+from pydantic import BaseModel
+
+class SearchQuery(BaseModel):
+    text: str
+    types: Optional[List[str]] = None
+    entity_types: Optional[List[str]] = None
+    after_date: Optional[datetime] = None
+
+class SearchResult(BaseModel):
+    path_id: str
+    file_path: str
+    type: str
+    score: float
+    metadata: dict

src/basic_memory/services/search_service.py

@@ -0,0 +1,69 @@
+"""Service for search operations."""
+
+from typing import List, Optional
+
+from basic_memory.repository.search_repository import SearchRepository
+from basic_memory.schemas.search import SearchQuery, SearchResult
+
+
+class SearchService:
+    """Service for search operations."""
+
+    def __init__(self, search_repository: SearchRepository):
+        self.repository = search_repository
+
+    async def init_search_index(self):
+        """Create FTS5 virtual table if it doesn't exist."""
+        await self.repository.init_search_index()
+
+    async def search(
+        self, query: SearchQuery, context: Optional[List[str]] = None
+    ) -> List[SearchResult]:
+        """Search across all indexed content."""
+        return await self.repository.search(query, context)
+
+    async def index_entity(self, entity, background_tasks=None):
+        """Index an entity and its components."""
+        # Build searchable content
+        content = "\n".join(
+            [
+                entity.name,
+                entity.description or "",
+                # Add observations
+                *[f"{obs.category}: {obs.content}" for obs in entity.observations],
+                # Add relations
+                *[
+                    f"{rel.relation_type} {rel.to_id}: {rel.context or ''}"
+                    for rel in entity.relations
+                ],
+            ]
+        )
+
+        metadata = {
+            "entity_type": entity.entity_type,
+            "created_at": entity.created_at.isoformat(),
+            "updated_at": entity.updated_at.isoformat(),
+        }
+
+        # Queue indexing if background_tasks provided
+        if background_tasks:
+            background_tasks.add_task(
+                self._do_index,
+                content=content,
+                path_id=entity.path_id,
+                file_path=entity.file_path,
+                type="entity",
+                metadata=metadata,
+            )
+        else:
+            await self._do_index(
+                content=content,
+                path_id=entity.path_id,
+                file_path=entity.file_path,
+                type="entity",
+                metadata=metadata,
+            )
+
+    async def _do_index(self, **kwargs):
+        """Actually perform the indexing."""
+        await self.repository.index_item(**kwargs)