import re, os, threading, queue, requests
from typing import List, Optional, Union
from pydantic import BaseModel, Field
from pydantic_settings import BaseSettings

from api_types import ChatMessage


def parse_think_response(full_response: str):
    think_start = full_response.find("<think")
    if think_start == -1:
        return None, full_response.strip()

    think_end = full_response.find("</think>")
    if think_end == -1:  # 未闭合的情况
        reasoning = full_response[think_start:].strip()
        content = ""
    else:
        reasoning = full_response[think_start : think_end + 9].strip()  # +9包含完整标签
        content = full_response[think_end + 9 :].strip()

    # 清理标签保留内容
    reasoning_content = reasoning.replace("<think", "").replace("</think>", "").strip()
    return reasoning_content, content


def cleanMessages(messages: List[ChatMessage], removeThinkingContent: bool = False):
    promptStrList = []

    for message in messages:
        content = message.content.strip()
        content = re.sub(r"\n+", "\n", content)
        promptStrList.append(
            f"{message.role.strip().lower().capitalize()}: {content if message.role.strip().lower().capitalize()!='Assistant' or not removeThinkingContent else remove_nested_think_tags_stack(content)}"
        )

    return "\n\n".join(promptStrList)


def remove_nested_think_tags_stack(text):
    stack = []
    result = ""
    i = 0
    while i < len(text):
        if text[i : i + 7] == "<think>":
            stack.append("<think>")
            i += 7
        elif text[i : i + 8] == "</think>":
            if stack and stack[-1] == "<think>":
                stack.pop()
                i += 8
            else:
                result += text[i : i + 8]
                i += 8
        elif not stack:
            result += text[i]
            i += 1
        else:
            i += 1
    return result


def format_bytes(size):
    power = 2**10
    n = 0
    power_labels = {0: "", 1: "K", 2: "M", 3: "G", 4: "T"}
    while size > power:
        size /= power
        n += 1
    return f"{size:.4f}{power_labels[n]+'B'}"


LOGGER_QUEUE = queue.Queue(5)


def logger():
    print("enable")
    while True:
        item = LOGGER_QUEUE.get()
        try:
            LOG_PORT = os.environ.get("LOG_PORT")
            if LOG_PORT:
                requests.post(
                    LOG_PORT,
                    headers={"Content-Type": "application/json"},
                    json=item,
                )
        except Exception:
            pass


if os.environ.get("LOG_PORT"):
    threading.Thread(target=logger).start()


def log(item):
    LOGGER_QUEUE.put_nowait(item)


def web_search(query: str, top_k: int = 3) -> str:
    """Perform a simple web search via DuckDuckGo HTML and return top_k results as a combined string.

    This is a lightweight fallback search that does not call external model services —
    it queries a public search endpoint, parses titles/snippets/urls and returns them as
    formatted text to be included into the model's prompt context.
    """
    if not query or query.strip() == "":
        return ""
    try:
        from bs4 import BeautifulSoup
    except Exception:
        return ""
    try:
        headers = {"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64)"}
        q = query.strip()
        resp = requests.get("https://duckduckgo.com/html/", params={"q": q}, headers=headers, timeout=10)
        soup = BeautifulSoup(resp.text, "html.parser")
        # DuckDuckGo's html structure: results are in `div.result` containers.
        results = []
        for r in soup.find_all("div", class_="result", limit=top_k):
            a = r.find("a", class_="result__a") or r.find("a", href=True)
            title = a.get_text(strip=True) if a else ""
            href = a.get("href") if a else ""
            snippet = ""
            s = r.find("a", class_="result__snippet") or r.find("div", class_="result__snippet")
            if s:
                snippet = s.get_text(strip=True)
            results.append(f"{title} - {snippet} - {href}")
        return "\n".join(results)
    except Exception:
        return ""


def calc(expr: str) -> str:
    """Safely evaluate a simple arithmetic expression and return the result as string.

    This uses ast parsing to disallow attributes and only permit arithmetic operators.
    """
    try:
        import ast, operator as op

        # supported operators
        allowed_ops = {
            ast.Add: op.add,
            ast.Sub: op.sub,
            ast.Mult: op.mul,
            ast.Div: op.truediv,
            ast.Pow: op.pow,
            ast.BitXor: op.xor,
            ast.USub: op.neg,
            ast.Mod: op.mod,
            ast.FloorDiv: op.floordiv,
        }

        def _eval(node):
            if isinstance(node, ast.Num):  # <number>
                return node.n
            elif isinstance(node, ast.BinOp):
                left = _eval(node.left)
                right = _eval(node.right)
                op_type = type(node.op)
                if op_type in allowed_ops:
                    return allowed_ops[op_type](left, right)
                else:
                    raise ValueError("Unsupported operator")
            elif isinstance(node, ast.UnaryOp):
                operand = _eval(node.operand)
                op_type = type(node.op)
                if op_type in allowed_ops:
                    return allowed_ops[op_type](operand)
                raise ValueError("Unsupported unary op")
            else:
                raise ValueError("Unsupported expression type")

        node = ast.parse(expr, mode='eval')
        result = _eval(node.body)
        return str(result)
    except Exception as e:
        return f"ERROR: {e}"


def detect_tools_and_reasoning(text_or_messages) -> dict:
    """Detects whether web_search, calc, or reasoning are likely needed based on heuristics.

    Accepts either a single string prompt or a list of ChatMessage. Returns a dict with booleans and detected tools list.
    """
    if isinstance(text_or_messages, list):
        try:
            text = "\n\n".join([m.get('content', '') if isinstance(m, dict) else (getattr(m, 'content', '') or '') for m in text_or_messages if m])
        except Exception:
            text = ""
    else:
        text = str(text_or_messages or "")

    t = text.lower()
    # Simple heuristics
    need_calc = False
    need_web_search = False
    need_reasoning = False
    need_universal = False
    detected_tools = []

    # Heuristic for calc: presence of operators AND numbers OR keywords 'calculate/compute' plus numeric tokens
    if (re.search(r"\d+\s*[-+*/%]\s*\d+", t) or (re.search(r"\b(calculate|compute|solve|evaluate|sum|add|subtract|multiply|divide)\b", t) and re.search(r"\d", t))):
        need_calc = True
        # Try to extract a most-likely arithmetic expression from the text
        # Accept digits, parentheses and operators
        m = re.search(r"([\d\(\)\s+\-*/%^.]+)", text)
        expr = m.group(0).strip() if m else None
        # only keep if it includes an operator
        if expr and not re.search(r"[-+*/%]", expr):
            expr = None
        detected_tools.append({"name": "calc", "args": {"expression": expr, "confidence": 0.95 if expr else 0.5}})

    # Heuristic for web search: 'who is', 'what is', 'current', 'latest', 'news', or question words with facts
    # Heuristic for web search: question words + facts or 'current/latest' signals; avoid math queries
    if (
        re.search(r"\b(who is|who's|what is|what's|when is|where is|current|latest|news|is the president|president of|population of|capital of|how many|GDP of)\b", t)
        and not re.search(r"\d+\s*[-+*/%]\s*\d+", t)
    ):
        need_web_search = True
        detected_tools.append({"name": "web_search", "args": {"query": text, "confidence": 0.9}})

    # Heuristic for reasoning: words like 'explain', 'why', 'reason', 'prove', 'derive', 'compare'
    if re.search(r"\b(explain|why|because|reason|prove|derive|compare|analysis|analysis:|evaluate|argue|consequence|trade-offs)\b", t):
        need_reasoning = True

    # Heuristic for universal tool: requests to "use tool", "execute tool", or generic function-call language
    if re.search(r"\b(use (a )?tool|execute (a )?tool|call (a )?tool|function call|run tool|do this via a tool|invoke tool|call tool)\b", t):
        need_universal = True

    # compute confidence summary
    # For now, we use a simple heuristic: reasoning >0.8 if key words present; web_search 0.9; calc 0.95 if numeric
    confs = {
        "calc_confidence": 0.95 if need_calc else 0.0,
        "web_search_confidence": 0.9 if need_web_search else 0.0,
        "reasoning_confidence": 0.85 if need_reasoning else 0.0,
        "universal_confidence": 0.65 if need_universal else 0.0,
    }
    return {
        "need_calc": need_calc,
        "need_web_search": need_web_search,
        "need_reasoning": need_reasoning,
        "need_universal": need_universal,
        "detected_tools": detected_tools,
        "confidence": confs,
    }


def ensure_upload_dir():
    from config import CONFIG
    try:
        os.makedirs(CONFIG.UPLOAD_DIR, exist_ok=True)
    except Exception:
        pass


from typing import Optional


def save_bytes_to_upload(filename: Optional[str], data: bytes) -> dict:
    from config import CONFIG
    import hashlib, time, uuid

    ensure_upload_dir()
    _id = str(uuid.uuid4())
    safe_name = f"{_id}_{os.path.basename(str(filename or 'uploaded_file'))}"
    path = os.path.join(CONFIG.UPLOAD_DIR, safe_name)
    try:
        with open(path, 'wb') as f:
            f.write(data)
        size = os.path.getsize(path)
        import mimetypes
        mime_type = mimetypes.guess_type(path)[0]
        return {
            'file_id': _id,
            'filename': filename,
            'path': path,
            'mime_type': mime_type,
            'size': size,
            'uploaded_at': int(time.time()),
        }
    except Exception as e:
        return {'error': str(e)}


def file_read_from_path(path: str, max_bytes: int = 100000) -> str:
    try:
        if not path or not os.path.exists(path):
            return ""
        with open(path, 'rb') as f:
            b = f.read(max_bytes)
            try:
                return b.decode('utf-8', errors='replace')
            except Exception:
                return str(b)
    except Exception:
        return ""


def universal_tool(args: dict, allow_web_search: bool = True, allow_tools: bool = True, allow_file_tool: bool = True) -> dict:
    """Universal tool: if 'action' is provided, call the corresponding tool; otherwise autodetect using heuristics.

    Supported actions: 'calc', 'web_search'. If the action is not provided, attempt to detect the appropriate tool.
    Returns a string result for prompt injection.
    """
    if not isinstance(args, dict):
        return {"error": "ERROR: invalid args for universal tool"}

    action = args.get("action")
    query = args.get("query")
    # explicit action
    if action == "calc":
        if not allow_tools:
            return {"action": "calc", "result": None, "metadata": {"error": "disabled_by_policy", "confidence": 0.0}}
        expr = args.get("expression") or query
        if not expr:
            return {"action": "calc", "result": None, "metadata": {"error": "no expression provided", "confidence": 0.0}}
        res = calc(str(expr))
        return {"action": "calc", "result": str(res), "metadata": {"expression": expr, "confidence": 0.98}}
    if action == "web_search":
        if not allow_web_search:
            return {"action": "web_search", "result": "", "metadata": {"error": "disabled_by_policy", "confidence": 0.0}}
        q = args.get("query") or query
        if not q:
            return {"action": "web_search", "result": "", "metadata": {"confidence": 0.0}}
        res = web_search(str(q), int(args.get("top_k") or 3))
        return {"action": "web_search", "result": str(res), "metadata": {"query": q, "top_k": int(args.get("top_k") or 3), "confidence": 0.9}}
    if action == 'file_read':
        if not allow_file_tool:
            return {"action": "file_read", "result": None, "metadata": {"error": "disabled_by_policy", "confidence": 0.0}}
        fpath = args.get('path') or args.get('file_path')
        if not fpath and args.get('file_id'):
            from config import CONFIG
            fid = args.get('file_id')
            if fid:
                candidate = os.path.join(CONFIG.UPLOAD_DIR, os.path.basename(str(fid)))
            else:
                candidate = None
            if candidate and os.path.exists(candidate):
                fpath = candidate
        if not fpath:
            return {"action": "file_read", "result": None, "metadata": {"error": "no_path_or_id", "confidence": 0.0}}
        content = file_read_from_path(fpath, int(args.get('max_bytes') or 100000))
        return {"action": "file_read", "result": str(content), "metadata": {"path": fpath, "confidence": 0.9}}
    # auto-detect based on query content
    if query:
        # if expression - use calc
        if re.search(r"\d+\s*[-+*/%]\s*\d+", str(query)):
            if not allow_tools:
                return {"action": "calc", "result": None, "metadata": {"error": "disabled_by_policy", "confidence": 0.0}}
            res = calc(str(query))
            return {"action": "calc", "result": str(res), "metadata": {"expression": str(query), "confidence": 0.95}}
        # else, web_search
        if not allow_web_search:
            return {"action": "web_search", "result": "", "metadata": {"error": "disabled_by_policy", "confidence": 0.0}}
        res = web_search(str(query), int(args.get("top_k") or 3))
        return {"action": "web_search", "result": str(res), "metadata": {"query": str(query), "top_k": int(args.get("top_k") or 3), "confidence": 0.9}}

    return {"error": "ERROR: could not determine action for universal tool"}