import os
from dotenv import load_dotenv
from langgraph.graph import START, StateGraph, MessagesState, END
from langgraph.prebuilt import tools_condition, ToolNode
from langchain_google_genai import ChatGoogleGenerativeAI
from langchain_groq import ChatGroq
from langchain_huggingface import ChatHuggingFace, HuggingFaceEndpoint
from langchain_community.tools.tavily_search import TavilySearchResults
from langchain_community.document_loaders import WikipediaLoader, ArxivLoader
from langchain_core.messages import SystemMessage, HumanMessage, AIMessage
from langchain_core.tools import tool
from langchain_groq import ChatGroq
from supabase import create_client
from langchain_huggingface import HuggingFaceEmbeddings
from langchain_community.vectorstores import SupabaseVectorStore
from langchain_openai import ChatOpenAI
from langchain_core.documents import Document
import json
import pdfplumber
import pandas as pd
from transformers import BlipProcessor, BlipForConditionalGeneration
from PIL import Image
import torch
import matplotlib.pyplot as plt
import cmath
# from code_interpreter import CodeInterpreter
import uuid
import tempfile
import requests
from urllib.parse import urlparse
from typing import Optional
import io
import contextlib
import base64
import subprocess
import sqlite3
import traceback

load_dotenv()

# ------------------- TOOL DEFINITIONS -------------------
@tool
def multiply(a: int, b: int) -> int:
    """Multiply two numbers."""
    return a * b

@tool
def add(a: int, b: int) -> int:
    """Add two numbers."""
    return a + b

@tool
def subtract(a: int, b: int) -> int:
    """Subtract b from a."""
    return a - b

@tool
def divide(a: int, b: int) -> float:
    """Divide a by b. Raise error if b is zero."""
    if b == 0:
        raise ValueError("Cannot divide by zero.")
    return a / b

@tool
def modulus(a: int, b: int) -> int:
    """Get remainder of a divided by b."""
    return a % b

@tool
def square_root(a: float) -> float | complex:
    """
    Get the square root of a number.
    Args:
        a (float): the number to get the square root of
    """
    if a >= 0:
        return a**0.5
    return cmath.sqrt(a)

@tool
def power(a: float, b: float) -> float:
    """
    Get the power of two numbers.
    Args:
        a (float): the first number
        b (float): the second number
    """
    return a**b


@tool
def wiki_search(query: str) -> str:
    """Search Wikipedia for a query (max 2 results)."""
    docs = WikipediaLoader(query=query, load_max_docs=2).load()
    return "\n\n".join([doc.page_content for doc in docs])

@tool
def web_search(query: str) -> str:
    """Search the web using Tavily (max 3 results)."""
    results = TavilySearchResults(max_results=3).invoke(query)
    texts = [doc.get("content", "") or doc.get("text", "") for doc in results if isinstance(doc, dict)]
    return "\n\n".join(texts)

@tool
def arvix_search(query: str) -> str:
    """Search Arxiv for academic papers (max 3 results, truncated to 1000 characters each)."""
    docs = ArxivLoader(query=query, load_max_docs=3).load()
    return "\n\n".join([doc.page_content[:1000] for doc in docs])

@tool
def read_excel_file(path: str) -> str:
    """Read an Excel file and return the first few rows of each sheet as text."""
    import pandas as pd
    try:
        xls = pd.ExcelFile(path)
        content = ""
        for sheet in xls.sheet_names:
            df = xls.parse(sheet)
            content += f"Sheet: {sheet}\n"
            content += df.head(5).to_string(index=False) + "\n\n"
        return content.strip()
    except Exception as e:
        return f"Error reading Excel file: {str(e)}"
    
@tool
def extract_text_from_pdf(path: str) -> str:
    """Extract text from a PDF file given its local path."""
    try:
        text = ""
        with pdfplumber.open(path) as pdf:
            for page in pdf.pages[:5]:  # 限前5页，避免过大
                page_text = page.extract_text()
                if page_text:
                    text += page_text + "\n\n"
        return text.strip() if text else "No text extracted from PDF."
    except Exception as e:
        return f"Error reading PDF: {str(e)}"

# 初始化模型（首次加载可能稍慢）
processor = BlipProcessor.from_pretrained("Salesforce/blip-image-captioning-base")
model = BlipForConditionalGeneration.from_pretrained("Salesforce/blip-image-captioning-base")

@tool
def blip_image_caption(image_path: str) -> str:
    """Generate a description for an image using BLIP."""
    try:
        image = Image.open(image_path).convert("RGB")
        inputs = processor(image, return_tensors="pt")
        with torch.no_grad():
            out = model.generate(**inputs)
        caption = processor.decode(out[0], skip_special_tokens=True)
        return caption
    except Exception as e:
        return f"Failed to process image with BLIP: {str(e)}"
    
# @tool
# def execute_code_multilang(code: str, language: str = "python") -> str:
#     """Execute code in multiple languages (Python, Bash, SQL, C, Java) and return results.
#     Args:
#         code (str): The source code to execute.
#         language (str): The language of the code. Supported: "python", "bash", "sql", "c", "java".
#     Returns:
#         A string summarizing the execution results (stdout, stderr, errors, plots, dataframes if any).
#     """
#     supported_languages = ["python", "bash", "sql", "c", "java"]
#     language = language.lower()
#     interpreter_instance = CodeInterpreter()

#     if language not in supported_languages:
#         return f"❌ Unsupported language: {language}. Supported languages are: {', '.join(supported_languages)}"

#     result = interpreter_instance.execute_code(code, language=language)

#     response = []

#     if result["status"] == "success":
#         response.append(f"✅ Code executed successfully in **{language.upper()}**")

#         if result.get("stdout"):
#             response.append(
#                 "\n**Standard Output:**\n```\n" + result["stdout"].strip() + "\n```"
#             )

#         if result.get("stderr"):
#             response.append(
#                 "\n**Standard Error (if any):**\n```\n"
#                 + result["stderr"].strip()
#                 + "\n```"
#             )

#         if result.get("result") is not None:
#             response.append(
#                 "\n**Execution Result:**\n```\n"
#                 + str(result["result"]).strip()
#                 + "\n```"
#             )

#         if result.get("dataframes"):
#             for df_info in result["dataframes"]:
#                 response.append(
#                     f"\n**DataFrame `{df_info['name']}` (Shape: {df_info['shape']})**"
#                 )
#                 df_preview = pd.DataFrame(df_info["head"])
#                 response.append("First 5 rows:\n```\n" + str(df_preview) + "\n```")

#         if result.get("plots"):
#             response.append(
#                 f"\n**Generated {len(result['plots'])} plot(s)** (Image data returned separately)"
#             )

#     else:
#         response.append(f"❌ Code execution failed in **{language.upper()}**")
#         if result.get("stderr"):
#             response.append(
#                 "\n**Error Log:**\n```\n" + result["stderr"].strip() + "\n```"
#             )

#     return "\n".join(response)

@tool
def save_and_read_file(content: str, filename: Optional[str] = None) -> str:
    """
    Save content to a file and return the path.
    Args:
        content (str): the content to save to the file
        filename (str, optional): the name of the file. If not provided, a random name file will be created.
    """
    temp_dir = tempfile.gettempdir()
    if filename is None:
        temp_file = tempfile.NamedTemporaryFile(delete=False, dir=temp_dir)
        filepath = temp_file.name
    else:
        filepath = os.path.join(temp_dir, filename)

    with open(filepath, "w") as f:
        f.write(content)

    return f"File saved to {filepath}. You can read this file to process its contents."


@tool
def download_file_from_url(url: str, filename: Optional[str] = None) -> str:
    """
    Download a file from a URL and save it to a temporary location.
    Args:
        url (str): the URL of the file to download.
        filename (str, optional): the name of the file. If not provided, a random name file will be created.
    """
    try:
        # Parse URL to get filename if not provided
        if not filename:
            path = urlparse(url).path
            filename = os.path.basename(path)
            if not filename:
                filename = f"downloaded_{uuid.uuid4().hex[:8]}"

        # Create temporary file
        temp_dir = tempfile.gettempdir()
        filepath = os.path.join(temp_dir, filename)

        # Download the file
        response = requests.get(url, stream=True)
        response.raise_for_status()

        # Save the file
        with open(filepath, "wb") as f:
            for chunk in response.iter_content(chunk_size=8192):
                f.write(chunk)

        return f"File downloaded to {filepath}. You can read this file to process its contents."
    except Exception as e:
        return f"Error downloading file: {str(e)}"
    
@tool
def analyze_csv_file(file_path: str, query: str) -> str:
    """
    Analyze a CSV file using pandas and answer a question about it.
    Args:
        file_path (str): the path to the CSV file.
        query (str): Question about the data
    """
    try:
        # Read the CSV file
        df = pd.read_csv(file_path)

        # Run various analyses based on the query
        result = f"CSV file loaded with {len(df)} rows and {len(df.columns)} columns.\n"
        result += f"Columns: {', '.join(df.columns)}\n\n"

        # Add summary statistics
        result += "Summary statistics:\n"
        result += str(df.describe())

        return result

    except Exception as e:
        return f"Error analyzing CSV file: {str(e)}"


def execute_code_multilang(code: str, language: str = "python") -> str:
    """
    Execute code in Python, Bash, SQL, C, or Java and return formatted results.

    Args:
        code (str): Source code.
        language (str): Language of the code. One of: 'python', 'bash', 'sql', 'c', 'java'.

    Returns:
        str: Human-readable execution result.
    """
    language = language.lower()
    exec_id = str(uuid.uuid4())
    result = {
        "stdout": "",
        "stderr": "",
        "status": "error",
        "plots": [],
        "dataframes": [],
    }

    try:
        if language == "python":
            plt.switch_backend("Agg")
            stdout_buffer = io.StringIO()
            stderr_buffer = io.StringIO()
            globals_dict = {"pd": pd, "plt": plt, "Image": Image}

            with contextlib.redirect_stdout(stdout_buffer), contextlib.redirect_stderr(stderr_buffer):
                exec(code, globals_dict)

            # Save plots
            if plt.get_fignums():
                for i, fig_num in enumerate(plt.get_fignums()):
                    fig = plt.figure(fig_num)
                    img_path = os.path.join(tempfile.gettempdir(), f"{exec_id}_plot_{i}.png")
                    fig.savefig(img_path)
                    with open(img_path, "rb") as f:
                        img_data = base64.b64encode(f.read()).decode()
                        result["plots"].append(img_data)

            # Check for dataframes
            for var_name, var_val in globals_dict.items():
                if isinstance(var_val, pd.DataFrame):
                    result["dataframes"].append((var_name, var_val.head().to_string()))

            result["stdout"] = stdout_buffer.getvalue()
            result["stderr"] = stderr_buffer.getvalue()
            result["status"] = "success"

        elif language == "bash":
            completed = subprocess.run(code, shell=True, capture_output=True, text=True, timeout=30)
            result["stdout"] = completed.stdout
            result["stderr"] = completed.stderr
            result["status"] = "success" if completed.returncode == 0 else "error"

        elif language == "sql":
            conn = sqlite3.connect(":memory:")
            cur = conn.cursor()
            cur.execute(code)
            if code.strip().lower().startswith("select"):
                cols = [desc[0] for desc in cur.description]
                rows = cur.fetchall()
                df = pd.DataFrame(rows, columns=cols)
                result["dataframes"].append(("query_result", df.head().to_string()))
            conn.commit()
            conn.close()
            result["status"] = "success"
            result["stdout"] = "SQL executed successfully."

        elif language == "c":
            with tempfile.TemporaryDirectory() as tmp:
                src = os.path.join(tmp, "main.c")
                bin_path = os.path.join(tmp, "main")
                with open(src, "w") as f:
                    f.write(code)
                comp = subprocess.run(["gcc", src, "-o", bin_path], capture_output=True, text=True)
                if comp.returncode != 0:
                    result["stderr"] = comp.stderr
                else:
                    run = subprocess.run([bin_path], capture_output=True, text=True, timeout=30)
                    result["stdout"] = run.stdout
                    result["stderr"] = run.stderr
                    result["status"] = "success" if run.returncode == 0 else "error"

        elif language == "java":
            with tempfile.TemporaryDirectory() as tmp:
                src = os.path.join(tmp, "Main.java")
                with open(src, "w") as f:
                    f.write(code)
                comp = subprocess.run(["javac", src], capture_output=True, text=True)
                if comp.returncode != 0:
                    result["stderr"] = comp.stderr
                else:
                    run = subprocess.run(["java", "-cp", tmp, "Main"], capture_output=True, text=True, timeout=30)
                    result["stdout"] = run.stdout
                    result["stderr"] = run.stderr
                    result["status"] = "success" if run.returncode == 0 else "error"

        else:
            return f"❌ Unsupported language: {language}."

    except Exception as e:
        result["stderr"] = traceback.format_exc()

    # Format response
    summary = []
    if result["status"] == "success":
        summary.append(f"✅ Code executed successfully in **{language.upper()}**")
        if result["stdout"]:
            summary.append(f"\n**Output:**\n```\n{result['stdout'].strip()}\n```")
        if result["stderr"]:
            summary.append(f"\n**Warnings/Errors:**\n```\n{result['stderr'].strip()}\n```")
        for name, df in result["dataframes"]:
            summary.append(f"\n**DataFrame `{name}` Preview:**\n```\n{df}\n```")
        if result["plots"]:
            summary.append(f"\n📊 {len(result['plots'])} plot(s) generated (base64-encoded).")
    else:
        summary.append(f"❌ Execution failed for **{language.upper()}**")
        if result["stderr"]:
            summary.append(f"\n**Error:**\n```\n{result['stderr'].strip()}\n```")

    return "\n".join(summary)


tools = [multiply, add, subtract, divide, modulus, 
         wiki_search, web_search, arvix_search, read_excel_file, extract_text_from_pdf,
         blip_image_caption, save_and_read_file, download_file_from_url, analyze_csv_file,
         execute_code_multilang]

# ------------------- SYSTEM PROMPT -------------------
system_prompt_path = "system_prompt.txt"
if os.path.exists(system_prompt_path):
    with open(system_prompt_path, "r", encoding="utf-8") as f:
        system_prompt = f.read()
else:
    system_prompt = (
        "You are an intelligent AI agent who can solve math, science, factual, and research-based problems. "
        "You can use tools like Wikipedia, Web search, or Arxiv when needed. Always give precise and helpful answers."
    )
sys_msg = SystemMessage(content=system_prompt)

# ------------------- GRAPH CONSTRUCTION -------------------
def build_graph(provider: str = "groq"):
    if provider == "google":
        llm = ChatGoogleGenerativeAI(model="gemini-2.0-flash", temperature=0)
    elif provider == "groq":
        groq_key = os.getenv("GROQ_API_KEY")
        if not groq_key:
            raise ValueError("GROQ_API_KEY is not set.")
        llm = ChatGroq(model="qwen-qwq-32b", temperature=0, api_key=groq_key)
    elif provider == "huggingface":
        llm = ChatHuggingFace(
            llm=HuggingFaceEndpoint(
                url="https://api-inference.huggingface.co/models/Meta-DeepLearning/llama-2-7b-chat-hf",
                temperature=0
            )
        )
    elif provider == "openai":
        openai_key = os.getenv("OPENAI_API_KEY")
        if not openai_key:
            raise ValueError("OPENAI_API_KEY is not set.")
        llm = ChatOpenAI(model="gpt-3.5-turbo", temperature=0, api_key=openai_key)
    else:
        raise ValueError("Invalid provider")

    llm_with_tools = llm.bind_tools(tools)

    def assistant(state: MessagesState):
        return {"messages": [sys_msg] + [llm_with_tools.invoke(state["messages"])]}

    SUPABASE_URL = os.getenv("SUPABASE_URL")
    SUPABASE_KEY = os.getenv("SUPABASE_SERVICE_KEY")
    supabase = create_client(SUPABASE_URL, SUPABASE_KEY)

    embedding_model = HuggingFaceEmbeddings(model_name="sentence-transformers/all-mpnet-base-v2")
    vectorstore = SupabaseVectorStore(
        client=supabase,
        embedding=embedding_model,
        table_name="QA_db"
    )
    retriever = vectorstore.as_retriever(search_kwargs={"k": 1})


    # ✅ 替换 similarity_search_by_vector_with_relevance_scores 方法，直接调用 supabase.rpc
    original_fn = vectorstore.similarity_search_by_vector_with_relevance_scores

    # ✅ 覆盖 vectorstore 的方法
    def patched_fn(embedding, k=4, filter=None, **kwargs):
        response = supabase.rpc(
            "match_documents",
            {
                "query_embedding": embedding,
                "match_count": k
            }
        ).execute()

        documents = []
        for r in response.data:
            metadata = r["metadata"]
            if isinstance(metadata, str):
                try:
                    metadata = json.loads(metadata)
                except Exception:
                    metadata = {}
            doc = Document(
                page_content=r["content"],
                metadata=metadata
            )
            documents.append((doc, r["similarity"]))
        return documents

    # ✅ 覆盖 vectorstore 的方法
    vectorstore.similarity_search_by_vector_with_relevance_scores = patched_fn

    def qa_retriever_node(state: MessagesState):
        user_question = state["messages"][-1].content
        docs = retriever.invoke(user_question)
        if docs:
            return {
                "messages": state["messages"] + [AIMessage(content=docs[0].page_content)],
                "__condition__": "complete"
            }
        return {"messages": state["messages"], "__condition__": "default"}

    builder = StateGraph(MessagesState)
    builder.add_node("retriever", qa_retriever_node)
    builder.add_node("assistant", assistant)
    builder.add_node("tools", ToolNode(tools))

    builder.add_edge(START, "retriever")
    builder.add_conditional_edges("retriever", {
        "default": lambda x: "assistant",
        "complete": lambda x: END,
    })
    builder.add_conditional_edges("assistant", tools_condition)
    builder.add_edge("tools", "assistant")

    return builder.compile()

# ------------------- LOCAL TEST -------------------
if __name__ == "__main__":
    question = "When was a picture of St. Thomas Aquinas first added to the Wikipedia page on the Principle of double effect?"
    graph = build_graph(provider="openai")
    messages = graph.invoke({"messages": [HumanMessage(content=question)]})
    print("=== AI Agent Response ===")
    for m in messages["messages"]:
        m.pretty_print()