buster/api/prds/active/api_collections_sharing_delete.md

# API Collections Sharing - Delete Endpoint PRD

## Problem Statement
Users need the ability to remove sharing permissions for collections through a REST API endpoint.

## Technical Design

### Endpoint Specification
- **Method**: DELETE
- **Path**: /collections/:id/sharing
- **Description**: Removes sharing permissions for a collection
- **Authentication**: Required
- **Authorization**: User must have Owner or FullAccess permission for the collection

### Request Structure
```rust
#[derive(Debug, Deserialize)]
pub struct DeleteSharingRequest {
    pub emails: Vec<String>,
}
```

### Response Structure
```rust
// Success response is a simple message
// Error responses include appropriate status codes and error messages
```

### Implementation Details

#### New Files
1. `/src/routes/rest/routes/collections/sharing/delete_sharing.rs` - REST handler for deleting sharing permissions
2. `/libs/handlers/src/collections/sharing/delete_sharing_handler.rs` - Business logic for deleting sharing permissions

#### REST Handler Implementation
```rust
// delete_sharing.rs
pub async fn delete_collection_sharing_rest_handler(
    Extension(user): Extension<AuthenticatedUser>,
    Path(id): Path<Uuid>,
    Json(request): Json<DeleteSharingRequest>,
) -> Result<ApiResponse<String>, (StatusCode, String)> {
    tracing::info!("Processing DELETE request for collection sharing with ID: {}, user_id: {}", id, user.id);

    match delete_collection_sharing_handler(&id, &user.id, request.emails).await {
        Ok(_) => Ok(ApiResponse::Success("Sharing permissions removed successfully".to_string())),
        Err(e) => {
            tracing::error!("Error removing sharing permissions: {}", e);
            
            // Map specific errors to appropriate status codes
            if e.to_string().contains("not found") {
                return Err((StatusCode::NOT_FOUND, format!("Collection not found: {}", e)));
            } else if e.to_string().contains("permission") {
                return Err((StatusCode::FORBIDDEN, format!("Insufficient permissions: {}", e)));
            } else if e.to_string().contains("invalid email") {
                return Err((StatusCode::BAD_REQUEST, format!("Invalid email: {}", e)));
            }
            
            Err((StatusCode::INTERNAL_SERVER_ERROR, format!("Failed to remove sharing permissions: {}", e)))
        }
    }
}
```

#### Handler Implementation
```rust
// delete_sharing_handler.rs
pub async fn delete_collection_sharing_handler(
    collection_id: &Uuid,
    user_id: &Uuid,
    emails: Vec<String>,
) -> Result<()> {
    // 1. Validate the collection exists
    let collection = match get_collection_by_id(collection_id).await {
        Ok(Some(collection)) => collection,
        Ok(None) => return Err(anyhow!("Collection not found")),
        Err(e) => return Err(anyhow!("Error fetching collection: {}", e)),
    };

    // 2. Check if user has permission to remove sharing for the collection (Owner or FullAccess)
    let has_permission = has_permission(
        *collection_id,
        AssetType::Collection,
        *user_id,
        IdentityType::User,
        AssetPermissionRole::FullAccess, // Owner role implicitly has FullAccess permissions
    ).await?;

    if !has_permission {
        return Err(anyhow!("User does not have permission to remove sharing for this collection"));
    }

    // 3. Process each email and remove sharing permissions
    for email in emails {
        match remove_share_by_email(
            &email,
            *collection_id,
            AssetType::Collection,
        ).await {
            Ok(_) => {
                tracing::info!("Removed sharing permission for email: {} on collection: {}", email, collection_id);
            },
            Err(e) => {
                tracing::error!("Failed to remove sharing for email {}: {}", email, e);
                return Err(anyhow!("Failed to remove sharing for email {}: {}", email, e));
            }
        }
    }

    Ok(())
}
```

### Sharing Library Integration
This endpoint leverages the following functions from the sharing library:

1. `has_permission` from `@[api/libs/sharing/src]/check_asset_permission.rs`:
```rust
pub async fn has_permission(
    asset_id: Uuid,
    asset_type: AssetType,
    identity_id: Uuid,
    identity_type: IdentityType,
    required_role: AssetPermissionRole,
) -> Result<bool>
```
This function checks if a user has the required permission level for an asset. It's used to verify that the user has Owner or FullAccess permission to remove sharing for the collection.

2. `remove_share_by_email` from `@[api/libs/sharing/src]/remove_asset_permissions.rs`:
```rust
pub async fn remove_share_by_email(
    email: &str,
    asset_id: Uuid,
    asset_type: AssetType,
) -> Result<()>
```
This function removes sharing permissions for a user identified by email. It handles:
- Email validation
- User lookup by email
- Permission removal
- Error handling for invalid emails or non-existent users

### Error Handling
The handler will return appropriate error responses:
- 404 Not Found - If the collection doesn't exist
- 403 Forbidden - If the user doesn't have permission to remove sharing for the collection
- 400 Bad Request - For invalid email addresses
- 500 Internal Server Error - For database errors or other unexpected issues

### Input Validation
- Email addresses must be properly formatted (contains '@')
- The collection ID must be a valid UUID

### Testing Strategy

#### Unit Tests
- Test permission validation logic
- Test error handling for non-existent collections
- Test error handling for unauthorized users
- Test error handling for invalid emails
- Test successful sharing removal

#### Integration Tests
- Test DELETE /collections/:id/sharing with valid ID, authorized user, and valid emails
- Test DELETE /collections/:id/sharing with valid ID, unauthorized user
- Test DELETE /collections/:id/sharing with non-existent collection ID
- Test DELETE /collections/:id/sharing with invalid email formats
- Test DELETE /collections/:id/sharing with non-existent user emails

#### Test Cases
1. Should remove sharing permissions for valid emails
2. Should return 403 when user doesn't have Owner or FullAccess permission
3. Should return 404 when collection doesn't exist
4. Should return 400 when email is invalid
5. Should handle gracefully when trying to remove sharing for a user that doesn't have access

### Performance Considerations
- For bulk removal with many emails, consider implementing a background job for processing
- Monitor database performance for large batches of removal operations

### Security Considerations
- Ensure that only users with Owner or FullAccess permission can remove sharing
- Validate email addresses to prevent injection attacks
- Implement rate limiting to prevent abuse
- Prevent removal of the owner's own access

### Monitoring
- Log all requests with appropriate context
- Track performance metrics for the endpoint
- Monitor error rates and types
- Track sharing removal operations by user for audit purposes