Improve config validation with better error messages and automatic URL formatting

src/dolibarr_mcp/config.py

@@ -3,7 +3,7 @@
 import os
 from typing import Optional
 
-from pydantic import BaseModel, Field
+from pydantic import BaseModel, Field, validator
 from dotenv import load_dotenv
 
 # Load environment variables from .env file
@@ -28,20 +28,70 @@ class Config(BaseModel):
         default_factory=lambda: os.getenv("LOG_LEVEL", "INFO")
     )
     
-    def validate_config(self) -> None:
-        """Validate that required configuration is present."""
-        if not self.dolibarr_url:
+    @validator('dolibarr_url')
+    def validate_dolibarr_url(cls, v):
+        """Validate Dolibarr URL."""
+        if not v:
             raise ValueError("DOLIBARR_URL environment variable is required")
         
-        if not self.api_key:
-            raise ValueError("DOLIBARR_API_KEY environment variable is required")
-        
-        if not self.dolibarr_url.startswith(('http://', 'https://')):
+        if not v.startswith(('http://', 'https://')):
             raise ValueError("DOLIBARR_URL must start with http:// or https://")
+        
+        # Ensure it ends with the proper API path
+        if not v.endswith('/api/index.php'):
+            if v.endswith('/'):
+                v = v + 'api/index.php'
+            else:
+                v = v + '/api/index.php'
+                
+        return v
+    
+    @validator('api_key')
+    def validate_api_key(cls, v):
+        """Validate API key."""
+        if not v:
+            raise ValueError(
+                "DOLIBARR_API_KEY environment variable is required. "
+                "Please create an API key in Dolibarr at: Home → Setup → API/Web services"
+            )
+        
+        if len(v) < 10:
+            raise ValueError("DOLIBARR_API_KEY appears to be too short. Please check your API key.")
+            
+        return v
+    
+    @validator('log_level')
+    def validate_log_level(cls, v):
+        """Validate log level."""
+        valid_levels = {'DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL'}
+        if v.upper() not in valid_levels:
+            raise ValueError(f"LOG_LEVEL must be one of: {', '.join(valid_levels)}")
+        return v.upper()
     
     @classmethod
     def from_env(cls) -> "Config":
-        """Create configuration from environment variables."""
-        config = cls()
-        config.validate_config()
-        return config
+        """Create configuration from environment variables with validation."""
+        try:
+            return cls()
+        except Exception as e:
+            print(f"❌ Configuration Error: {e}")
+            print()
+            print("💡 Quick Setup Guide:")
+            print("1. Copy .env.example to .env")
+            print("2. Edit .env with your Dolibarr details:")
+            print("   DOLIBARR_URL=https://your-dolibarr-instance.com")
+            print("   DOLIBARR_API_KEY=your_api_key_here")
+            print()
+            print("🔧 Dolibarr API Key Setup:")
+            print("   1. Login to Dolibarr as admin")
+            print("   2. Go to: Home → Setup → Modules")
+            print("   3. Enable: 'Web Services API REST (developer)'")
+            print("   4. Go to: Home → Setup → API/Web services")
+            print("   5. Create a new API key")
+            print()
+            raise
+    
+    class Config:
+        """Pydantic config."""
+        env_file = '.env'
+        env_file_encoding = 'utf-8'