"""Các utility functions cho evaluation."""

import os
import sys
import re
import csv
from pathlib import Path
from datetime import datetime
from dotenv import find_dotenv, load_dotenv
from concurrent.futures import ThreadPoolExecutor, as_completed

REPO_ROOT = Path(__file__).resolve().parents[1]
if str(REPO_ROOT) not in sys.path:
    sys.path.insert(0, str(REPO_ROOT))
load_dotenv(find_dotenv(usecwd=True))

from openai import OpenAI
from core.rag.embedding_model import EmbeddingConfig, QwenEmbeddings
from core.rag.vector_store import ChromaConfig, ChromaVectorDB
from core.rag.retrival import Retriever
from core.rag.generator import RAGGenerator


def strip_thinking(text: str) -> str:
    """Loại bỏ các block <think>...</think> từ output của LLM."""
    return re.sub(r'<think>.*?</think>\s*', '', text, flags=re.DOTALL).strip()


def load_csv_data(csv_path: str, sample_size: int = 0) -> tuple[list, list]:
    """Đọc dữ liệu câu hỏi và ground truth từ file CSV."""
    questions, ground_truths = [], []
    with open(csv_path, 'r', encoding='utf-8') as f:
        for row in csv.DictReader(f):
            if row.get('question') and row.get('ground_truth'):
                questions.append(row['question'])
                ground_truths.append(row['ground_truth'])
    
    # Giới hạn số lượng sample 
    if sample_size > 0:
        questions = questions[:sample_size]
        ground_truths = ground_truths[:sample_size]
    
    return questions, ground_truths


def init_rag() -> tuple[RAGGenerator, QwenEmbeddings, OpenAI]:
    """Khởi tạo các components RAG cho evaluation."""
    embeddings = QwenEmbeddings(EmbeddingConfig())
    db = ChromaVectorDB(embedder=embeddings, config=ChromaConfig())
    retriever = Retriever(vector_db=db)
    rag = RAGGenerator(retriever=retriever)
    
    # Khởi tạo LLM client
    api_key = os.getenv("SILICONFLOW_API_KEY", "").strip()
    if not api_key:
        raise ValueError("Chưa đặt SILICONFLOW_API_KEY")
    
    llm_client = OpenAI(api_key=api_key, base_url="https://api.siliconflow.com/v1", timeout=60.0)
    return rag, embeddings, llm_client


def generate_answers(
    rag: RAGGenerator,
    questions: list,
    llm_client: OpenAI,
    llm_model: str = "nex-agi/DeepSeek-V3.1-Nex-N1",
    retrieval_mode: str = "hybrid_rerank",
    max_workers: int = 8,
) -> tuple[list, list]:
    """Generate câu trả lời cho danh sách câu hỏi với parallel processing."""
    
    def process(idx_q):
        """Xử lý một câu hỏi: retrieve + generate."""
        idx, q = idx_q
        try:
            # Retrieve và chuẩn bị context
            prepared = rag.retrieve_and_prepare(q, mode=retrieval_mode)
            if not prepared["results"]:
                return idx, "Không tìm thấy thông tin.", []
            
            # Gọi LLM để generate answer
            resp = llm_client.chat.completions.create(
                model=llm_model,
                messages=[{"role": "user", "content": prepared["prompt"]}],
                temperature=0.0,
                max_tokens=4096,
            )
            answer = strip_thinking(resp.choices[0].message.content or "")
            return idx, answer, prepared["contexts"]
        except Exception as e:
            print(f"  Q{idx+1} Lỗi: {e}")
            return idx, "Không thể trả lời.", []
    
    n = len(questions)
    answers, contexts = [""] * n, [[] for _ in range(n)]
    
    print(f"  Đang generate {n} câu trả lời...")
    
    # Xử lý song song với ThreadPoolExecutor
    with ThreadPoolExecutor(max_workers=max_workers) as executor:
        futures = {executor.submit(process, (i, q)): i for i, q in enumerate(questions)}
        for i, future in enumerate(as_completed(futures), 1):
            idx, ans, ctx = future.result(timeout=120)
            answers[idx], contexts[idx] = ans, ctx
            print(f"  [{i}/{n}] Xong")
    
    return answers, contexts