fix: improve memory provider error messages for missing packages (fixes #1630) (#1634)

* fix: improve memory provider error messages for missing packages (fixes #1630)

- Update mem0 import error messages to suggest pip install 'praisonaiagents[memory]'
- Modified Memory class to show ImportError for explicitly requested providers
- Preserve graceful fallback behavior for default provider
- Fixes misleading 'API Key not provided' error when mem0ai package is missing

Changes:
- memory/adapters/factories.py: Updated mem0 ImportError message
- knowledge/adapters/mem0_adapter.py: Updated mem0 ImportError message
- memory/memory.py: Show ImportError for explicit provider requests

Co-authored-by: praisonai-triage-agent[bot] <praisonai-triage-agent[bot]@users.noreply.github.com>

* fix: resolve critical issues in memory provider error handling

- Fix factory return value being discarded in memory.py
- Remove silent exception swallowing that broke backward compatibility
- Fix datetime import bug in MongoDB adapter (datetime.timezone.utc)
- Preserve original error propagation for misconfigured providers
- Ensure factory-created adapters are properly used when successful

Fixes issues identified by Greptile and CodeRabbit reviewers.

Co-authored-by: Mervin Praison <MervinPraison@users.noreply.github.com>

---------

Co-authored-by: praisonai-triage-agent[bot] <272766704+praisonai-triage-agent[bot]@users.noreply.github.com>
Co-authored-by: praisonai-triage-agent[bot] <praisonai-triage-agent[bot]@users.noreply.github.com>
Co-authored-by: Mervin Praison <MervinPraison@users.noreply.github.com>

Author: praisonai-triage-agent[bot]

src/praisonai-agents/praisonaiagents/knowledge/adapters/mem0_adapter.py

@@ -71,7 +71,8 @@ def _init_mem0(self):
             from mem0 import Memory
         except ImportError:
             raise ImportError(
-                "mem0 is not installed. Install with: pip install mem0ai"
+                "mem0ai is not installed. "
+                "Run: pip install 'praisonaiagents[memory]'"
             )
 
         if self._config:

src/praisonai-agents/praisonaiagents/memory/adapters/factories.py

@@ -40,7 +40,8 @@ def create_mem0_memory_adapter(**kwargs) -> MemoryProtocol:
         import mem0
     except ImportError:
         raise ImportError(
-            "mem0 is required for mem0 adapter. Install with: pip install mem0ai"
+            "mem0ai is not installed. "
+            "Run: pip install 'praisonaiagents[memory]'"
         )
 
     return Mem0MemoryAdapter(mem0_config=kwargs)
@@ -363,15 +364,15 @@ def _create_indexes(self):
 
     def store_short_term(self, text: str, metadata: Optional[Dict[str, Any]] = None, **kwargs) -> str:
         """Store in MongoDB short-term collection."""
-        from datetime import datetime
+        from datetime import datetime, timezone
         import time
 
         doc_id = str(time.time_ns())
         doc = {
             "_id": doc_id,
             "content": text,
             "metadata": metadata or {},
-            "created_at": datetime.now(datetime.timezone.utc),
+            "created_at": datetime.now(timezone.utc),
             "memory_type": "short_term"
         }
 
@@ -395,15 +396,15 @@ def search_short_term(self, query: str, limit: int = 5, **kwargs) -> List[Dict[s
 
     def store_long_term(self, text: str, metadata: Optional[Dict[str, Any]] = None, **kwargs) -> str:
         """Store in MongoDB long-term collection."""
-        from datetime import datetime
+        from datetime import datetime, timezone
         import time
 
         doc_id = str(time.time_ns())
         doc = {
             "_id": doc_id,
             "content": text,
             "metadata": metadata or {},
-            "created_at": datetime.now(datetime.timezone.utc),
+            "created_at": datetime.now(timezone.utc),
             "memory_type": "long_term"
         }
 

src/praisonai-agents/praisonaiagents/memory/memory.py

@@ -143,6 +143,9 @@ def _init_protocol_driven_memory(self):
         adapter_name = provider_mapping.get(provider, provider)
 
         # Try to get preferred adapter, fallback to available ones
+        adapter = None
+        provider_explicitly_requested = provider != "rag"  # "rag" is default, others are explicit
+        
         try:
             adapter_config = self._get_adapter_config_for_provider(adapter_name)
             adapter = get_memory_adapter(adapter_name, **adapter_config)
@@ -154,6 +157,37 @@ def _init_protocol_driven_memory(self):
             adapter = None
 
         if adapter is None:
+            # If the provider was explicitly requested, try to give a helpful error message
+            if provider_explicitly_requested:
+                try:
+                    # Try the factory function directly to get the specific ImportError message
+                    from .adapters.factories import (
+                        create_mem0_memory_adapter,
+                        create_chroma_memory_adapter,
+                        create_mongodb_memory_adapter,
+                    )
+                    factory_map = {
+                        "mem0": create_mem0_memory_adapter,
+                        "chroma": create_chroma_memory_adapter, 
+                        "mongodb": create_mongodb_memory_adapter,
+                    }
+                    if adapter_name in factory_map:
+                        # Call the factory to get ImportError with installation hint
+                        # or capture successful adapter creation
+                        adapter_config = self._get_adapter_config_for_provider(adapter_name)
+                        adapter = factory_map[adapter_name](**adapter_config)
+                except ImportError:
+                    # Re-raise ImportError with installation instructions
+                    raise
+                # All other exceptions (e.g., ValueError for missing API key) 
+                # propagate naturally, preserving backward compatibility
+            
+            # If factory succeeded, use that adapter
+            if adapter is not None:
+                self.memory_adapter = adapter
+                self.provider = adapter_name
+                return
+                
             # Fallback to first available adapter
             self._log_verbose(f"Provider '{adapter_name}' not available, trying fallbacks")
             # Try each fallback preference individually