from __future__ import annotations

import ast
import json
import re
from typing import Any

from models import ChatRequest


def clamp01(x: Any, default: float = 0.5) -> float:
    try:
        v = float(x)
        return max(0.0, min(1.0, v))
    except Exception:
        return default


def normalize_spaces(text: str) -> str:
    return re.sub(r"\s+", " ", text).strip()


def clean_math_text(text: str) -> str:
    t = text
    t = t.replace("×", "*").replace("÷", "/").replace("–", "-").replace("—", "-")
    t = t.replace("−", "-").replace("^", "**")
    return t


def extract_text_from_any_payload(payload: Any) -> str:
    if payload is None:
        return ""

    if isinstance(payload, str):
        s = payload.strip()

        if (s.startswith("{") and s.endswith("}")) or (s.startswith("[") and s.endswith("]")):
            try:
                decoded = json.loads(s)
                return extract_text_from_any_payload(decoded)
            except Exception:
                pass

        try:
            decoded = ast.literal_eval(s)
            if isinstance(decoded, (dict, list)):
                return extract_text_from_any_payload(decoded)
        except Exception:
            pass

        return s

    if isinstance(payload, dict):
        for key in [
            "message", "prompt", "query", "text", "user_message",
            "input", "data", "payload", "body", "content"
        ]:
            if key in payload:
                extracted = extract_text_from_any_payload(payload[key])
                if extracted:
                    return extracted

        strings = []
        for v in payload.values():
            if isinstance(v, (str, dict, list)):
                maybe = extract_text_from_any_payload(v)
                if maybe:
                    strings.append(maybe)
        return "\n".join(strings).strip()

    if isinstance(payload, list):
        parts = [extract_text_from_any_payload(x) for x in payload]
        return "\n".join([p for p in parts if p]).strip()

    return str(payload).strip()


def get_user_text(req: ChatRequest, raw_body: Any = None) -> str:
    for field in ["message", "prompt", "query", "text", "user_message"]:
        value = getattr(req, field, None)
        if isinstance(value, str) and value.strip():
            return value.strip()

    return extract_text_from_any_payload(raw_body).strip()