"""
OpenAI-compatible API endpoints
"""

from fastapi import APIRouter, HTTPException, Request
from fastapi.responses import StreamingResponse
import json
import asyncio
from typing import AsyncGenerator

from .models import (
    ChatCompletionRequest, ChatCompletionResponse, ChatCompletionChoice,
    CompletionRequest, CompletionResponse, CompletionChoice,
    ChatMessage, Usage
)
from ..services.ai_service import AIService
from ..core.config import ai_config

router = APIRouter()
ai_service = AIService()

@router.post("/chat/completions", response_model=ChatCompletionResponse)
async def create_chat_completion(request: ChatCompletionRequest):
    """
    Create a chat completion (OpenAI compatible)
    """
    try:
        # Check if this is a PPT-related request
        last_message = request.messages[-1].content if request.messages else ""
        
        if ai_service.is_ppt_request(last_message):
            # Handle PPT generation request
            response_content = await ai_service.handle_ppt_chat_request(request)
        else:
            # Handle general chat request
            response_content = await ai_service.handle_general_chat_request(request)
        
        # Calculate token usage (simplified)
        prompt_tokens = sum(len(msg.content.split()) for msg in request.messages)
        completion_tokens = len(response_content.split())
        
        choice = ChatCompletionChoice(
            index=0,
            message=ChatMessage(role="assistant", content=response_content),
            finish_reason="stop"
        )
        
        return ChatCompletionResponse(
            model=request.model,
            choices=[choice],
            usage=Usage(
                prompt_tokens=prompt_tokens,
                completion_tokens=completion_tokens,
                total_tokens=prompt_tokens + completion_tokens
            )
        )
        
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Error generating completion: {str(e)}")

@router.post("/completions", response_model=CompletionResponse)
async def create_completion(request: CompletionRequest):
    """
    Create a text completion (OpenAI compatible)
    """
    try:
        prompt = request.prompt if isinstance(request.prompt, str) else request.prompt[0]
        
        if ai_service.is_ppt_request(prompt):
            # Handle PPT generation request
            response_text = await ai_service.handle_ppt_completion_request(request)
        else:
            # Handle general completion request
            response_text = await ai_service.handle_general_completion_request(request)
        
        # Calculate token usage (simplified)
        prompt_tokens = len(prompt.split())
        completion_tokens = len(response_text.split())
        
        choice = CompletionChoice(
            text=response_text,
            index=0,
            finish_reason="stop"
        )
        
        return CompletionResponse(
            model=request.model,
            choices=[choice],
            usage=Usage(
                prompt_tokens=prompt_tokens,
                completion_tokens=completion_tokens,
                total_tokens=prompt_tokens + completion_tokens
            )
        )
        
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Error generating completion: {str(e)}")

@router.get("/models")
async def list_models():
    """
    List available models (OpenAI compatible)
    """
    return {
        "object": "list",
        "data": [
            {
                "id": "landppt-v1",
                "object": "model",
                "created": 1677610602,
                "owned_by": "landppt",
                "permission": [],
                "root": "landppt-v1",
                "parent": None
            },
            {
                "id": "landppt-ppt-generator",
                "object": "model", 
                "created": 1677610602,
                "owned_by": "landppt",
                "permission": [],
                "root": "landppt-ppt-generator",
                "parent": None
            }
        ]
    }

async def stream_chat_completion(request: ChatCompletionRequest) -> AsyncGenerator[str, None]:
    """
    Stream chat completion responses
    """
    try:
        # Simulate streaming response
        last_message = request.messages[-1].content if request.messages else ""
        
        if ai_service.is_ppt_request(last_message):
            response_content = await ai_service.handle_ppt_chat_request(request)
        else:
            response_content = await ai_service.handle_general_chat_request(request)
        
        # Split response into chunks for streaming
        words = response_content.split()
        for i, word in enumerate(words):
            chunk_data = {
                "id": f"chatcmpl-{i}",
                "object": "chat.completion.chunk",
                "created": 1677610602,
                "model": request.model,
                "choices": [{
                    "index": 0,
                    "delta": {"content": word + " "},
                    "finish_reason": None
                }]
            }
            yield f"data: {json.dumps(chunk_data)}\n\n"
            await asyncio.sleep(0.05)  # Simulate processing delay
        
        # Send final chunk
        final_chunk = {
            "id": f"chatcmpl-final",
            "object": "chat.completion.chunk", 
            "created": 1677610602,
            "model": request.model,
            "choices": [{
                "index": 0,
                "delta": {},
                "finish_reason": "stop"
            }]
        }
        yield f"data: {json.dumps(final_chunk)}\n\n"
        yield "data: [DONE]\n\n"
        
    except Exception as e:
        error_chunk = {
            "error": {
                "message": str(e),
                "type": "server_error"
            }
        }
        yield f"data: {json.dumps(error_chunk)}\n\n"