"""
============================================================
Mentallico API v2 - Production-ready FastAPI
============================================================
Endpoints:

POST /api/v2/session/create        - يفتح جلسة جديدة
POST /api/v2/session/{id}/message  - يرسل رسالة (نصاً) ويحصل على الرد
POST /api/v2/session/{id}/audio    - يرسل ملف صوت + يرد عليه
POST /api/v2/session/{id}/reset    - يصفّي الجلسة
GET  /api/v2/session/{id}/state    - حالة الجلسة (debugging)
POST /api/v2/upload_documents      - يضيف PDF للـ knowledge base
GET  /api/v2/health                - فحص النظام

كل response بيتبع schema موحّد عشان frontend (Flutter / Web) يقدر يبني UI متّسق.
"""
import os
import shutil
import tempfile
from typing import List, Optional
from fastapi import FastAPI, HTTPException, UploadFile, File, Form
from fastapi.middleware.cors import CORSMiddleware
from pydantic import BaseModel, Field
import uvicorn

from orchestrator import get_brain

# ============= Schemas =============
class MessageInput(BaseModel):
    text: str = Field(..., description="User message text")


class MessageResponse(BaseModel):
    type: str = Field(..., description="chat | probing | diagnosis | error")
    response: str
    diagnosis: Optional[str] = None
    confidence: float = 0.0
    urgency: str = "normal"
    session_id: str
    audio_info: Optional[dict] = None
    internal: Optional[dict] = None


class SessionResponse(BaseModel):
    session_id: str


class HealthResponse(BaseModel):
    status: str
    components: dict


class UploadResult(BaseModel):
    filename: str
    status: str
    message: str


class UploadResponse(BaseModel):
    details: List[UploadResult]


# ============= App =============
app = FastAPI(
    title="Mentallico AI v2",
    description="Integrated mental-health diagnosis & support system "
                "(RAG + Multi-Model Classifier + STT)",
    version="2.0.0"
)

# CORS - frontend Flutter ممكن يحتاجه
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],  # في production غيّرها لـ domain الـ frontend
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)


# ============= Endpoints =============

@app.get("/api/v2/health", response_model=HealthResponse)
async def health():
    """فحص حالة المكونات"""
    try:
        brain = get_brain()
        components = {
            "classifier_primary": brain.diagnoser.primary_model is not None,
            "classifier_secondary": brain.diagnoser.secondary_model is not None,
            "classifier_emotion": brain.diagnoser.emotion_pipe is not None,
            "rag": brain.rag is not None and brain.rag.vector_db is not None,
            "stt": brain.transcriber is not None,
        }
        all_ok = all(components.values())
        # نسمح بفقدان بعض المكونات بس ميكونش fail بالكامل
        critical = components["rag"] or any([
            components["classifier_primary"],
            components["classifier_secondary"],
            components["classifier_emotion"]
        ])
        return HealthResponse(
            status="ok" if critical else "degraded",
            components=components
        )
    except Exception as e:
        return HealthResponse(
            status="error",
            components={"error": str(e)}
        )


@app.post("/api/v2/session/create", response_model=SessionResponse)
async def create_session():
    """ينشئ جلسة جديدة - بترجع session_id يستخدمه الـ frontend في الرسائل التالية"""
    brain = get_brain()
    sid = brain.create_session()
    return SessionResponse(session_id=sid)


@app.post("/api/v2/session/{session_id}/message", response_model=MessageResponse)
async def send_message(session_id: str, payload: MessageInput):
    """رسالة نصية"""
    if not payload.text or not payload.text.strip():
        raise HTTPException(status_code=400, detail="Empty message")
    brain = get_brain()
    result = brain.process_message(session_id, payload.text.strip())
    return MessageResponse(**result)


@app.post("/api/v2/session/{session_id}/audio", response_model=MessageResponse)
async def send_audio(
    session_id: str,
    audio: UploadFile = File(...),
    language: Optional[str] = Form(None)
):
    """رسالة صوتية - بتعدي STT الأول ثم باقي الـ pipeline"""
    if not audio.filename:
        raise HTTPException(status_code=400, detail="No audio file provided")

    # حفظ مؤقت
    suffix = os.path.splitext(audio.filename)[1] or ".wav"
    with tempfile.NamedTemporaryFile(delete=False, suffix=suffix) as tmp:
        shutil.copyfileobj(audio.file, tmp)
        tmp_path = tmp.name

    try:
        brain = get_brain()
        # نعدي بالـ audio path - الـ orchestrator هيعمل STT ثم باقي الـ flow
        result = brain.process_message(session_id, user_text="", user_audio_path=tmp_path)
        return MessageResponse(**result)
    finally:
        if os.path.exists(tmp_path):
            os.remove(tmp_path)


@app.post("/api/v2/session/{session_id}/reset")
async def reset_session(session_id: str):
    """يمسح الجلسة"""
    brain = get_brain()
    brain.reset_session(session_id)
    return {"status": "ok", "message": f"Session {session_id} reset"}


@app.get("/api/v2/session/{session_id}/state")
async def session_state(session_id: str):
    """حالة الجلسة - مفيد للـ debugging"""
    brain = get_brain()
    state = brain.conv_mgr.get_session(session_id)
    return {
        "session_id": state.session_id,
        "messages_count": len(state.messages),
        "user_messages_count": len([m for m in state.messages if m.role == 'user']),
        "diagnosis_confirmed": state.diagnosis_confirmed,
        "final_diagnosis": state.final_diagnosis,
        "final_confidence": state.final_confidence,
        "messages": [
            {"role": m.role, "content": m.content,
             "prediction": m.prediction['label'] if m.prediction else None}
            for m in state.messages
        ]
    }


@app.post("/api/v2/upload_documents", response_model=UploadResponse)
async def upload_documents(file: UploadFile = File(...)):
    """رفع ملف PDF واحد للـ knowledge base"""
    brain = get_brain()
    
    if not file.filename.lower().endswith(".pdf"):
        return UploadResponse(details=[UploadResult(
            filename=file.filename,
            status="error",
            message="Only PDF files are allowed"
        )])

    # حفظ مؤقت
    with tempfile.NamedTemporaryFile(delete=False, suffix=".pdf") as tmp:
        shutil.copyfileobj(file.file, tmp)
        tmp_path = tmp.name

    try:
        result = brain.add_pdf(tmp_path)
        return UploadResponse(details=[UploadResult(
            filename=file.filename,
            status=result['status'],
            message=result['message']
        )])
    finally:
        if os.path.exists(tmp_path):
            os.remove(tmp_path)


# ============= Backwards-compat (الـ endpoint القديم) =============
@app.post("/api/v1/diagnose")
async def diagnose_legacy(payload: MessageInput):
    """
    Backwards-compatible endpoint - بيعمل single-shot diagnosis
    (يفتح session مؤقت، يبعت رسالة، يرجع الرد، يقفل الـ session).
    موجود عشان الـ frontend القديم يكمل شغل من غير ما نعدّل عليه دلوقتي.
    """
    brain = get_brain()
    sid = brain.create_session()
    try:
        result = brain.process_message(sid, payload.text)
        return {"answer": result['response']}
    finally:
        brain.reset_session(sid)


# ============= Run =============
if __name__ == "__main__":
    uvicorn.run("app:app", host="0.0.0.0", port=7860, reload=False)