#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
G4F Chat API Server — FastAPI + g4f + Streaming SSE
"""

import g4f
import asyncio
import json
from fastapi import FastAPI, Request, HTTPException
from fastapi.responses import HTMLResponse, StreamingResponse, JSONResponse
from fastapi.middleware.cors import CORSMiddleware
from pathlib import Path
import uvicorn
import logging

# إعداد السجلات
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

app = FastAPI(title="G4F Chat API", version="2.1")

# ✅ تفعيل CORS
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# ─────────────────────────────────────────────
# ✅ دالة جلب المزودين والنماذج (آمنة)
# ─────────────────────────────────────────────
def get_providers_and_models():
    """جلب قائمة المزودين العاملين مع نماذجهم"""
    providers_data = {}
    
    try:
        # محاولة جلب المزودين من g4f
        provider_list = getattr(g4f.Provider, '__providers__', [])
        
        for provider in provider_list:
            try:
                name = getattr(provider, '__name__', None)
                if not name or not getattr(provider, 'working', False):
                    continue
                    
                # جلب النماذج المدعومة
                models = []
                if hasattr(provider, 'models') and provider.models:
                    models = list(provider.models) if isinstance(provider.models, (list, tuple)) else [provider.models]
                elif hasattr(provider, 'model') and provider.model:
                    models = [provider.model] if isinstance(provider.model, str) else list(provider.model)
                else:
                    models = ['default']
                
                providers_data[name] = {
                    'models': models,
                    'supports_stream': getattr(provider, 'supports_stream', True),
                    'needs_auth': getattr(provider, 'needs_auth', False),
                    'url': getattr(provider, 'url', ''),
                }
            except Exception as e:
                logger.warning(f"تخطي المزوّد: {e}")
                continue
                
    except Exception as e:
        logger.error(f"خطأ في جلب المزودين: {e}")
        # قائمة احتياطية في حال الفشل
        return {
            'g4f': {
                'models': ['gpt-4o', 'gpt-4o-mini', 'claude-3-5-sonnet', 'llama-3.1-70b'],
                'supports_stream': True,
                'needs_auth': False,
                'url': '',
            }
        }
    
    return providers_data


# ─────────────────────────────────────────────
# ✅ Endpoint: قائمة المزودين والنماذج
# ─────────────────────────────────────────────
@app.get("/api/providers")
async def list_providers():
    """إرجاع المزودين والنماذج المتاحة بصيغة JSON"""
    try:
        data = get_providers_and_models()
        return JSONResponse(content=data)
    except Exception as e:
        logger.error(f"Error in /api/providers: {e}")
        raise HTTPException(status_code=500, detail=str(e))


# ─────────────────────────────────────────────
# ✅ Endpoint: الدردشة العادية (Non-streaming)
# ─────────────────────────────────────────────
@app.post("/api/chat")
async def chat(request: Request):
    """معالجة طلب الدردشة العادي"""
    try:
        body = await request.json()
        messages = body.get("messages", [])
        model = body.get("model", "gpt-4o-mini")
        provider_name = body.get("provider", None)
        web_search = body.get("web_search", False)

        if not messages:
            raise HTTPException(status_code=400, detail="messages list is empty")

        # تحضير معاملات الاستدعاء
        kwargs = {
            "model": model,
            "messages": messages,
            "stream": False,
        }
        
        # إضافة المزوّد إذا حُدّد
        if provider_name and provider_name != "Auto":
            try:
                provider_cls = getattr(g4f.Provider, provider_name, None)
                if provider_cls:
                    kwargs["provider"] = provider_cls
            except AttributeError:
                pass
        
        # إضافة أداة البحث إذا فُعّلت
        if web_search and hasattr(g4f, 'tools') and hasattr(g4f.tools, 'search'):
            kwargs["tool_calls"] = [g4f.tools.search]

        # تنفيذ الطلب في thread منفصل لتجنب حجب الـ event loop
        loop = asyncio.get_running_loop()
        response = await loop.run_in_executor(
            None,
            lambda: g4f.ChatCompletion.create(**kwargs)
        )

        # معالجة الرد (قد يكون نصاً أو مولّداً)
        if hasattr(response, '__iter__') and not isinstance(response, (str, bytes)):
            response = "".join(str(chunk) for chunk in response if chunk)

        return JSONResponse({
            "response": str(response),
            "model": model,
            "provider": provider_name or "Auto"
        })

    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"Chat error: {e}", exc_info=True)
        raise HTTPException(status_code=500, detail=f"Server error: {str(e)[:200]}")


# ─────────────────────────────────────────────
# ✅ Endpoint: الدردشة المتدفقة (Streaming SSE)
# ─────────────────────────────────────────────
@app.post("/api/chat/stream")
async def chat_stream(request: Request):
    """معالجة طلب الدردشة مع البث المباشر (Server-Sent Events)"""
    try:
        body = await request.json()
        messages = body.get("messages", [])
        model = body.get("model", "gpt-4o-mini")
        provider_name = body.get("provider", None)
        web_search = body.get("web_search", False)

        if not messages:
            raise HTTPException(status_code=400, detail="messages list is empty")

        # تحضير معاملات الاستدعاء للبث
        kwargs = {
            "model": model,
            "messages": messages,
            "stream": True,
        }
        
        if provider_name and provider_name != "Auto":
            try:
                provider_cls = getattr(g4f.Provider, provider_name, None)
                if provider_cls:
                    kwargs["provider"] = provider_cls
            except AttributeError:
                pass
        
        if web_search and hasattr(g4f, 'tools') and hasattr(g4f.tools, 'search'):
            kwargs["tool_calls"] = [g4f.tools.search]

        async def event_generator():
            """مولّد أحداث SSE"""
            try:
                loop = asyncio.get_running_loop()
                
                # تنفيذ g4f في thread منفصل
                response = await loop.run_in_executor(
                    None,
                    lambda: g4f.ChatCompletion.create(**kwargs)
                )
                
                # معالجة الرد حسب نوعه
                if isinstance(response, str):
                    # رد نصي مباشر
                    yield f" {json.dumps({'chunk': response, 'type': 'text'})}\n\n"
                elif hasattr(response, '__iter__'):
                    # رد متدفق (generator)
                    for chunk in response:
                        if chunk:
                            chunk_str = str(chunk).strip()
                            if chunk_str:
                                yield f" {json.dumps({'chunk': chunk_str, 'type': 'chunk'})}\n\n"
                                await asyncio.sleep(0)  # Yield control to event loop
                else:
                    # معالجة غير متوقعة
                    yield f" {json.dumps({'chunk': str(response), 'type': 'text'})}\n\n"
                    
            except Exception as e:
                logger.error(f"Stream error: {e}", exc_info=True)
                yield f" {json.dumps({'error': str(e)[:300], 'type': 'error'})}\n\n"
            finally:
                # إشارة نهاية البث
                yield " [DONE]\n\n"

        return StreamingResponse(
            event_generator(),
            media_type="text/event-stream",
            headers={
                "Cache-Control": "no-cache, no-transform",
                "X-Accel-Buffering": "no",
                "Connection": "keep-alive",
            },
        )

    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"Stream endpoint error: {e}", exc_info=True)
        raise HTTPException(status_code=500, detail=f"Streaming error: {str(e)[:200]}")


# ─────────────────────────────────────────────
# ✅ تقديم الواجهة الأمامية
# ─────────────────────────────────────────────
@app.get("/", response_class=HTMLResponse)
async def root():
    """تقديم ملف index.html"""
    html_path = Path(__file__).parent / "index.html"
    
    if html_path.exists():
        content = html_path.read_text(encoding="utf-8")
        return HTMLResponse(content=content)
    
    return HTMLResponse(
        content="<h1 style='color:#fff;background:#111;padding:20px'>❌ index.html not found</h1>",
        status_code=404
    )


# ─────────────────────────────────────────────
# ✅ نقطة الدخول
# ─────────────────────────────────────────────
if __name__ == "__main__":
    import sys
    
    port = int(sys.argv[1]) if len(sys.argv) > 1 else 7860
    host = "0.0.0.0"
    
    print(f"\n🚀 G4F Chat Server starting...")
    print(f"📍 URL: http://{host if host != '0.0.0.0' else 'localhost'}:{port}")
    print(f"📦 g4f version: {getattr(g4f, '__version__', 'unknown')}")
    print(f"⚡ Press Ctrl+C to stop\n")
    
    uvicorn.run(
        app,
        host=host,
        port=port,
        log_level="info",
        access_log=True,
    )