# Per-User Session Isolation Implementation Guide

## Overview
This guide explains how to implement per-user session isolation in the ID Agents app so that each authenticated user has their own isolated workspace (chat histories, agents, patient data, etc.).

## Problem
Currently, all users share the same `gr.State()` objects, meaning:
- User A sees User B's chat messages
- User A's agents appear in User B's dropdown
- Everyone works in the same shared container

## Solution
Use Gradio's `gr.Request` object to identify users and store their data separately in a `UserSessionManager`.

## Files Created
1. **user_session_manager.py** - Core session storage with thread-safe operations
2. **session_helpers.py** - Helper functions for getting/setting user data

## Implementation Steps

### Step 1: Update Function Signatures

All functions that currently accept `gr.State` parameters need to accept `request: gr.Request` instead:

**Before:**
```python
def simple_chat_response(user_message, history):
    # Uses history parameter
    ...
```

**After:**
```python
def simple_chat_response(user_message, request: gr.Request):
    # Gets history from session manager
    history = get_user_simple_chat_history(request)
    ...
    # Saves history back to session manager
    set_user_simple_chat_history(request, updated_history)
```

### Step 2: Update Gradio Event Bindings

When binding functions to Gradio components, remove `gr.State` from inputs/outputs and add `request`:

**Before:**
```python
simple_input.submit(
    simple_chat_response,
    inputs=[simple_input, simple_chat_history],
    outputs=[simple_chatbot, simple_input]
)
```

**After:**
```python
simple_input.submit(
    simple_chat_response,
    inputs=[simple_input],  # request is added automatically by Gradio
    outputs=[simple_chatbot, simple_input]
)
```

### Step 3: Remove gr.State() Declarations

In `build_ui()`, remove these lines:
```python
simple_chat_history = gr.State([])
builder_chat_histories = gr.State({})
deployed_chat_histories = gr.State({})
```

These are now managed by the session manager per-user.

## Functions That Need Updates

### Critical Functions (High Priority)
1. ✅ `simple_chat_response` - Already updated
2. ✅ `chatpanel_handle` - Already updated  
3. `load_history` - Needs update
4. `reset_chat` - May need update if it affects per-user state
5. `save_deployed_agent` - If it stores to chat histories
6. `populate_from_preset` - If it affects builder state

### UI Event Bindings That Need Updates
All `.click()`, `.submit()`, `.change()` handlers that currently use:
- `simple_chat_history` 
- `builder_chat_histories`
- `deployed_chat_histories`
- Any other `gr.State()` objects

## Testing Checklist

After implementation, test with 2 different user accounts simultaneously:

- [ ] User1 and User2 have separate simple chat histories
- [ ] User1's agents don't appear in User2's dropdown
- [ ] User1 and User2 can build different agents without interference  
- [ ] Patient data is separate between users
- [ ] Reset/clear functions only affect the current user
- [ ] Logout/re-login maintains session (or clears if desired)

## Key Benefits

1. **True Multi-Tenancy**: Each user gets isolated workspace
2. **No Data Leakage**: User A cannot see User B's data
3. **Thread-Safe**: Concurrent users don't interfere with each other
4. **Scalable**: Can handle multiple simultaneous users
5. **Auditable**: Can log per-user actions for debugging

## Important Notes

- `gr.Request` only works when authentication is enabled
- Username comes from `request.username` (set by Gradio's auth system)
- Session data is stored in memory (lost on restart - could be persisted to database if needed)
- The session manager is thread-safe for concurrent access

## Migration Strategy

### Phase 1: Core Chat Functions (DONE)
- ✅ simple_chat_response
- ✅ chatpanel_handle  

### Phase 2: Agent Management
- load_history
- save_deployed_agent
- remove_selected_agent

### Phase 3: UI Bindings
- Update all .click() and .submit() bindings
- Remove gr.State declarations

### Phase 4: Testing & Verification
- Multi-user testing
- Session isolation verification
- Performance testing

## Quick Reference

```python
# Import at top of app.py (DONE)
from user_session_manager import session_manager, get_username_from_request, SessionKeys
from session_helpers import (
    get_user_simple_chat_history, set_user_simple_chat_history,
    get_user_builder_chat_histories, set_user_builder_chat_histories,
    get_user_deployed_chat_histories, set_user_deployed_chat_histories,
    get_current_username, log_user_access
)

# In any function:
def my_function(user_input, request: gr.Request):
    username = get_current_username(request)
    log_user_access(request, "my_function")
    
    # Get user-specific data
    data = session_manager.get_user_data(username, "my_key", default=[])
    
    # Process...
    
    # Save user-specific data
    session_manager.set_user_data(username, "my_key", new_data)
```

## Next Steps

To complete the implementation:

1. Search for all `gr.State(` declarations and remove them
2. Search for all functions that have `histories` or `history` parameters
3. Update each function to use session helpers
4. Update all Gradio event bindings
5. Test with multiple users
6. Deploy and verify

For assistance, see:
- user_session_manager.py - Core session storage
- session_helpers.py - Helper functions and examples