feat(FN-011): complete Step 4 — repository connection model and connection manager

Fusion-Task-Id: FN-011
Fusion-Task-Lineage: 4a9aca6f-9d91-43aa-8d2a-d59657c1541a

apps/api/app/git/__init__.py

@@ -1,5 +1,6 @@
 """Git provider abstraction, credentials, SSH keys, and operations."""
 
+from app.git.connection import ConnectionManager, RepositoryConnectionData
 from app.git.credentials import AccessTokenCredential, CredentialStorage, GitCredential
 from app.git.provider import GitProvider
 from app.git.ssh_key import SshKeyLifecycle, SshKeyPair
@@ -7,12 +8,14 @@ from app.git.types import ConnectionStatus, CredentialKind, ProviderKind, SshKey
 
 __all__ = [
     "AccessTokenCredential",
+    "ConnectionManager",
     "ConnectionStatus",
     "CredentialKind",
     "CredentialStorage",
     "GitCredential",
     "GitProvider",
     "ProviderKind",
+    "RepositoryConnectionData",
     "SshKeyLifecycle",
     "SshKeyPair",
     "SshKeyStatus",

apps/api/app/git/connection.py

@@ -0,0 +1,93 @@
+"""Repository connection orchestration."""
+
+import uuid
+
+from pydantic import BaseModel
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.git.credentials import CredentialStorage, GitCredential
+from app.git.provider import GitProvider
+from app.git.types import ConnectionStatus, ProviderKind
+from app.models.repository_connection import RepositoryConnection
+
+
+class RepositoryConnectionData(BaseModel):
+    """Domain-level read model for a repository connection."""
+
+    id: uuid.UUID
+    project_id: uuid.UUID
+    repository_id: uuid.UUID | None
+    provider_kind: ProviderKind
+    credential_id: uuid.UUID | None
+    connection_status: ConnectionStatus
+    default_branch: str | None
+
+
+class ConnectionManager:
+    """Orchestrates creating, validating, and retrieving repository connections."""
+
+    def __init__(self, provider: GitProvider, storage: CredentialStorage) -> None:
+        self.provider = provider
+        self.storage = storage
+
+    async def connect(
+        self,
+        session: AsyncSession,
+        project_id: uuid.UUID,
+        git_url: str,
+        credential: GitCredential,
+    ) -> RepositoryConnectionData:
+        """Store *credential*, create a connection row, and validate with the provider."""
+        credential_id = self.storage.create(credential)
+
+        row = RepositoryConnection(
+            project_id=project_id,
+            provider_kind=str(self.provider.get_kind()),
+            credential_id=credential_id,
+            connection_status=str(ConnectionStatus.pending),
+        )
+        session.add(row)
+        await session.flush()
+
+        status = self.provider.validate_connection(git_url, str(credential_id))
+        if status == ConnectionStatus.connected:
+            row.connection_status = str(ConnectionStatus.connected)
+        else:
+            row.connection_status = str(ConnectionStatus.error)
+            await session.flush()
+            raise RuntimeError("Connection validation failed")
+
+        await session.refresh(row)
+        return _map_row(row)
+
+    async def disconnect(
+        self, session: AsyncSession, connection_id: uuid.UUID
+    ) -> None:
+        """Mark the connection as disconnected."""
+        row = await session.get(RepositoryConnection, connection_id)
+        if row is None:
+            return
+        row.connection_status = str(ConnectionStatus.disconnected)
+        await session.flush()
+
+    async def get_connection(
+        self, session: AsyncSession, connection_id: uuid.UUID
+    ) -> RepositoryConnectionData | None:
+        """Fetch a connection by ID and map it to the Pydantic read model."""
+        row = await session.get(RepositoryConnection, connection_id)
+        if row is None:
+            return None
+        return _map_row(row)
+
+
+def _map_row(row: RepositoryConnection) -> RepositoryConnectionData:
+    return RepositoryConnectionData(
+        id=row.id,
+        project_id=row.project_id,
+        repository_id=row.repository_id,
+        provider_kind=ProviderKind(row.provider_kind),
+        credential_id=row.credential_id,
+        connection_status=ConnectionStatus(row.connection_status),
+        default_branch=row.default_branch,
+    )