import gradio as gr
from typing import Tuple, Optional, List
from openai import OpenAI
from utils.db_utils import DatabaseUtils
from utils.embedding_utils import parallel_generate_embeddings

def create_embeddings_tab(openai_client: OpenAI, db_utils: DatabaseUtils, databases: List[str]) -> Tuple[gr.Tab, dict]:
    """Create the embeddings generation tab UI
    
    Args:
        openai_client: OpenAI client instance
        db_utils: DatabaseUtils instance
        databases: List of available databases
        
    Returns:
        Tuple[gr.Tab, dict]: The tab component and its interface elements
    """
    def update_collections(db_name: str) -> gr.Dropdown:
        """Update collections dropdown when database changes"""
        collections = db_utils.get_collections(db_name)
        # If there's only one collection, select it by default
        value = collections[0] if len(collections) == 1 else None
        return gr.Dropdown(choices=collections, value=value)
        
    def update_fields(db_name: str, collection_name: str) -> gr.Dropdown:
        """Update fields dropdown when collection changes"""
        if db_name and collection_name:
            fields = db_utils.get_field_names(db_name, collection_name)
            return gr.Dropdown(choices=fields)
        return gr.Dropdown(choices=[])
    
    def generate_embeddings(
        db_name: str, 
        collection_name: str, 
        field_name: str, 
        embedding_field: str, 
        limit: int = 10, 
        progress=gr.Progress()
    ) -> Tuple[str, str]:
        """Generate embeddings for documents with progress tracking"""
        try:
            db = db_utils.client[db_name]
            collection = db[collection_name]
            
            # Count documents that need embeddings
            total_docs = collection.count_documents({field_name: {"$exists": True}})
            if total_docs == 0:
                return f"No documents found with field '{field_name}'", ""
                
            # Get total count of documents that need processing
            query = {
                field_name: {"$exists": True},
                embedding_field: {"$exists": False}  # Only get docs without embeddings
            }
            total_to_process = collection.count_documents(query)
            if total_to_process == 0:
                return "No documents found that need embeddings", ""
                
            # Apply limit if specified
            if limit > 0:
                total_to_process = min(total_to_process, limit)
                
            print(f"\nFound {total_to_process} documents that need embeddings...")
            
            # Progress tracking
            progress_text = ""
            def update_progress(prog: float, processed: int, total: int):
                nonlocal progress_text
                progress_text = f"Progress: {prog:.1f}% ({processed}/{total} documents)\n"
                print(progress_text)  # Terminal logging
                progress(prog/100, f"Processed {processed}/{total} documents")
                
            # Show initial progress
            update_progress(0, 0, total_to_process)
            
            # Create cursor for batch processing
            cursor = collection.find(query)
            if limit > 0:
                cursor = cursor.limit(limit)
                
            # Generate embeddings in parallel with cursor-based batching
            processed = parallel_generate_embeddings(
                collection=collection,
                cursor=cursor,
                field_name=field_name,
                embedding_field=embedding_field,
                openai_client=openai_client,
                total_docs=total_to_process,
                callback=update_progress
            )
                    
            # Return completion message and final progress
            instructions = f"""
Successfully generated embeddings for {processed} documents using parallel processing!

To create the vector search index in MongoDB Atlas:
1. Go to your Atlas cluster
2. Click on 'Search' tab
3. Create an index named 'vector_index' with this configuration:
{{
  "fields": [
    {{
      "type": "vector",
      "path": "{embedding_field}",
      "numDimensions": 1536,
      "similarity": "dotProduct"
    }}
  ]
}}

You can now use the search tab with:
- Field to search: {field_name}
- Embedding field: {embedding_field}
"""
            return instructions, progress_text
            
        except Exception as e:
            return f"Error: {str(e)}", ""
    
    # Create the tab UI
    with gr.Tab("Generate Embeddings") as tab:
        with gr.Row():
            db_input = gr.Dropdown(
                choices=databases,
                label="Select Database",
                info="Available databases in Atlas cluster"
            )
            collection_input = gr.Dropdown(
                choices=[],
                label="Select Collection",
                info="Collections in selected database"
            )
        with gr.Row():
            field_input = gr.Dropdown(
                choices=[],
                label="Select Field for Embeddings",
                info="Fields available in collection"
            )
            embedding_field_input = gr.Textbox(
                label="Embedding Field Name",
                value="embedding",
                info="Field name where embeddings will be stored"
            )
            limit_input = gr.Number(
                label="Document Limit",
                value=10,
                minimum=0,
                info="Number of documents to process (0 for all documents)"
            )
            
        generate_btn = gr.Button("Generate Embeddings")
        generate_output = gr.Textbox(label="Results", lines=10)
        progress_output = gr.Textbox(label="Progress", lines=3)
        
        # Set up event handlers
        db_input.change(
            fn=update_collections,
            inputs=[db_input],
            outputs=[collection_input]
        )
        
        collection_input.change(
            fn=update_fields,
            inputs=[db_input, collection_input],
            outputs=[field_input]
        )
        
        generate_btn.click(
            fn=generate_embeddings,
            inputs=[
                db_input, 
                collection_input, 
                field_input, 
                embedding_field_input, 
                limit_input
            ],
            outputs=[generate_output, progress_output]
        )
    
    # Return the tab and its interface elements
    interface = {
        'db_input': db_input,
        'collection_input': collection_input,
        'field_input': field_input,
        'embedding_field_input': embedding_field_input,
        'limit_input': limit_input,
        'generate_btn': generate_btn,
        'generate_output': generate_output,
        'progress_output': progress_output
    }
    
    return tab, interface