shared shell registry

src/ipython_shell/jupyter/app.py

@@ -1,7 +1,11 @@
 from collections.abc import AsyncIterator
+from datetime import UTC, datetime
+from time import monotonic
 from uuid import uuid4
 
-from ..utils import generate_good_names
+from ..models import AppInfo, ShellInfo
+from ..registry import ShellRegistry
+from ..utils import generate_call_id
 from .shell import JupyterShell
 from .transport import InputRequest, KernelMessage
 
@@ -10,36 +14,61 @@ class JupyterApp:
     """Coordinate named persistent shells backed by Jupyter kernels."""
 
     def __init__(self) -> None:
-        self.shells: dict[str, JupyterShell] = {}
-        self.last_shell: str | None = None
+        self.app_id = uuid4().hex
+        self.created_at = datetime.now(UTC).isoformat()
+        self._started_at = monotonic()
+        self._total_calls = 0
+        self._shell_registry = ShellRegistry(JupyterShell)
         self._calls: dict[str, JupyterShell] = {}
+        self._issued_call_ids: set[str] = set()
 
-    def _new_shell(self) -> tuple[str, JupyterShell]:
-        name = generate_good_names()
-        while name in self.shells:
-            name = generate_good_names()
-        shell = JupyterShell(name)
-        self.shells[name] = shell
-        self.last_shell = name
-        return name, shell
+    @property
+    def shells(self) -> dict[str, JupyterShell]:
+        """Expose the managed shells for compatibility with the sync app."""
+        return self._shell_registry.shells
+
+    @property
+    def last_shell(self) -> str | None:
+        """Return the name of the most recently selected shell."""
+        return self._shell_registry.last_shell
 
     def _select_shell(self, shell_name: str) -> tuple[str, JupyterShell]:
-        if shell_name == "new":
-            return self._new_shell()
-        if shell_name == "last":
-            if self.last_shell is None:
-                return self._new_shell()
-            return self.last_shell, self.shells[self.last_shell]
-        if shell_name not in self.shells:
-            self.shells[shell_name] = JupyterShell(shell_name)
-        self.last_shell = shell_name
-        return shell_name, self.shells[shell_name]
+        return self._shell_registry.select(shell_name)
 
-    def get_shell(self, shell_name: str) -> JupyterShell:
-        """Return a named Jupyter shell."""
-        if shell_name not in self.shells:
-            raise KeyError(f"Shell {shell_name} does not exist")
-        return self.shells[shell_name]
+    def list_shells(self) -> list[ShellInfo]:
+        """Return metadata for every known Jupyter shell."""
+        return self._shell_registry.list_shells()
+
+    def create_shell(self) -> ShellInfo:
+        """Create a fresh Jupyter shell and return its metadata."""
+        return self._shell_registry.create_shell()
+
+    def get_shell(self, shell_name: str) -> ShellInfo:
+        """Return frontend-safe metadata for one Jupyter shell."""
+        return self._shell_registry.get_shell(shell_name)
+
+    def get_last_shell(self) -> ShellInfo:
+        """Return metadata for the most recently selected Jupyter shell."""
+        return self._shell_registry.get_last_shell()
+
+    def info(self) -> AppInfo:
+        """Return runtime metadata without starting any kernels."""
+        return AppInfo(
+            app_id=self.app_id,
+            created_at=self.created_at,
+            uptime_seconds=monotonic() - self._started_at,
+            shell_count=len(self.shells),
+            last_shell=self.last_shell,
+            total_calls=self._total_calls,
+        )
+
+    def _new_call_id(self) -> str:
+        """Generate a readable call ID that is unique for this app."""
+        call_id = generate_call_id()
+        while call_id in self._issued_call_ids:
+            call_id = generate_call_id()
+        self._issued_call_ids.add(call_id)
+        return call_id
 
     async def run_code_stream(
         self,
@@ -48,7 +77,8 @@ class JupyterApp:
     ) -> AsyncIterator[KernelMessage | InputRequest]:
         """Execute code and yield its subprocess messages."""
         _, shell = self._select_shell(shell_name)
-        call_id = uuid4().hex
+        call_id = self._new_call_id()
+        self._total_calls += 1
         self._calls[call_id] = shell
         try:
             async for message in shell.run_cell_stream(code, call_id=call_id):

src/ipython_shell/jupyter/shell.py

@@ -1,6 +1,9 @@
 from collections.abc import AsyncIterator
 from dataclasses import replace
+from datetime import UTC, datetime
+from uuid import uuid4
 
+from ..models import ShellInfo, ShellStatus
 from .transport import InputRequest, JupyterTransport, KernelMessage
 
 
@@ -9,6 +12,11 @@ class JupyterShell:
 
     def __init__(self, name: str, transport: JupyterTransport | None = None) -> None:
         self.name = name
+        self.shell_id = uuid4().hex
+        self.created_at = datetime.now(UTC).isoformat()
+        self.last_used_at: str | None = None
+        self.status: ShellStatus = "ready"
+        self._last_execution_count = 0
         self.transport = transport or JupyterTransport()
         self._active_call_id: str | None = None
 
@@ -26,6 +34,7 @@ class JupyterShell:
         """Yield kernel messages while one cell executes."""
         await self.start()
         self._active_call_id = call_id
+        self.status = "running"
         try:
             kernel_call_id = await self.transport.execute(code)
             async for message in self.transport.messages_for(kernel_call_id):
@@ -33,10 +42,25 @@ class JupyterShell:
                     yield replace(message, call_id=call_id)
                 else:
                     # Keep the kernel's execution ID private to the transport.
-                    yield replace(message, parent_id=call_id)
+                    public_message = replace(message, parent_id=call_id)
+                    if public_message.msg_type == "execute_reply":
+                        self._last_execution_count = int(
+                            public_message.content.get(
+                                "execution_count", self._last_execution_count
+                            )
+                        )
+                        self.status = (
+                            "error"
+                            if public_message.content.get("status") == "error"
+                            else "ready"
+                        )
+                        self.last_used_at = datetime.now(UTC).isoformat()
+                    yield public_message
         finally:
             if self._active_call_id == call_id:
                 self._active_call_id = None
+            if self.status == "running" and self._active_call_id is None:
+                self.status = "ready"
 
     async def reply_to_input(self, call_id: str, value: str) -> None:
         """Send input to the cell currently waiting in this shell."""
@@ -47,3 +71,23 @@ class JupyterShell:
     async def shutdown(self) -> None:
         """Stop this shell's kernel process."""
         await self.transport.shutdown()
+
+    def describe(self) -> ShellInfo:
+        """Return metadata without starting an unused kernel."""
+        return ShellInfo(
+            shell_id=self.shell_id,
+            name=self.name,
+            status=self.status,
+            execution_count=self._last_execution_count,
+            created_at=self.created_at,
+            last_used_at=self.last_used_at,
+            capabilities=(
+                "stdout",
+                "stderr",
+                "display_data",
+                "execute_result",
+                "error",
+                "matplotlib-inline",
+                "input",
+            ),
+        )