import re
import hashlib
from typing import Iterable, List, Tuple, Any


TOOL_NAME_PATTERN = re.compile(r"^[a-zA-Z0-9_-]{1,64}$")


class ToolValidationError(Exception):
    pass


def sanitize_tool_name(name: str, max_len: int = 64) -> str:
    safe = re.sub(r"[^a-zA-Z0-9_-]", "_", name or "tool")
    if len(safe) > max_len:
        suffix = hashlib.sha1(safe.encode()).hexdigest()[:8]
        safe = safe[: max_len - 9] + "_" + suffix
    return safe or "tool"


def _find_illegal_chars(name: str) -> List[str]:
    return sorted(list(set(re.findall(r"[^a-zA-Z0-9_-]", name))))


def _get_name(obj: Any) -> str:
    return getattr(obj, "name", None) or getattr(obj, "tool_name", None) or getattr(obj, "__name__", "tool")


def validate_tool_names(
    tools: Iterable[Any], *, strict: bool = True, max_len: int = 64
) -> Tuple[bool, List[str]]:
    """
    Validate that tool names conform to OpenAI-compatible constraints:
    - Allowed chars: a-z, A-Z, 0-9, underscore, hyphen
    - Max length: 64

    Returns (ok, messages). If strict=True and invalid tools exist,
    raises ToolValidationError with a detailed report.
    """
    messages: List[str] = []
    errors: List[str] = []
    for idx, t in enumerate(tools):
        name = _get_name(t)
        if TOOL_NAME_PATTERN.match(name or ""):
            continue
        parts: List[str] = [f"第{idx}个工具名称不合法: '{name}'"]
        if not name:
            parts.append("原因: 为空")
        else:
            illegal = _find_illegal_chars(name)
            if illegal:
                parts.append(f"包含非法字符: {''.join(illegal)} (仅允许[a-zA-Z0-9_-])")
            if len(name) > max_len:
                parts.append(f"长度超限: {len(name)} > {max_len}")
        suggestion = sanitize_tool_name(name or "tool", max_len=max_len)
        parts.append(f"建议名称: '{suggestion}'")
        errors.append("; ".join(parts))

    if errors:
        report = "\n".join(errors)
        messages.append(report)
        if strict:
            raise ToolValidationError(report)
        return False, messages

    return True, messages