"""Safety helpers for child-friendly voice co-creation sessions."""

from __future__ import annotations

from dataclasses import dataclass

UNSAFE_KEYWORD_GROUPS: dict[str, tuple[str, ...]] = {
    "violence": (
        "打死",
        "杀掉",
        "砍伤",
        "流很多血",
        "炸弹",
        "爆炸",
        "开枪",
        "刀子",
        "互相打",
    ),
    "horror": (
        "鬼屋",
        "鬼怪",
        "僵尸",
        "诅咒",
        "恶魔",
        "吃人",
        "恐怖",
        "吓死人",
    ),
    "danger": (
        "毒药",
        "绑架",
        "自杀",
        "跳楼",
        "伤害自己",
        "把人关起来",
    ),
    "adult": (
        "色情",
        "裸",
        "亲热",
        "不穿衣服",
    ),
}


@dataclass(frozen=True)
class VoiceSafetyResult:
    """Result of one voice safety evaluation."""

    is_safe: bool
    flags: list[str]
    replacement_text: str | None = None
    message: str | None = None


def _collect_safety_flags(text: str) -> list[str]:
    normalized = text.replace(" ", "").strip()
    flags: list[str] = []
    if not normalized:
        return flags

    for flag, keywords in UNSAFE_KEYWORD_GROUPS.items():
        if any(keyword in normalized for keyword in keywords):
            flags.append(flag)
    return flags


def _redirect_prefix(flags: list[str]) -> str:
    if "adult" in flags:
        return "这个方向不适合小朋友的睡前故事。"
    if "danger" in flags or "violence" in flags:
        return "这个方向有点太危险了。"
    if "horror" in flags:
        return "这个方向有点太吓人了。"
    return "这个方向现在不太适合继续讲下去。"


def build_child_safe_redirect(flags: list[str]) -> str:
    """Build a child-friendly redirect prompt after an unsafe request."""

    return (
        f"{_redirect_prefix(flags)}"
        "我们把它改成温柔、安全、适合小朋友的冒险吧。"
        "你可以试试说：让小伙伴一起想办法、让事情变得更明亮，或者让新朋友来帮忙。"
    )


def build_safe_story_fallback(*, premise: str | None = None) -> str:
    """Build a safe replacement narrative segment for unsafe assistant output."""

    subject = (premise or "小伙伴们").strip()
    if len(subject) > 12:
        subject = subject[:12]

    return (
        f"{subject}决定把眼前的难题变成一次温柔又勇敢的冒险。"
        "大家先停下来想一想，再一起找到一个善良、安全、让人安心的解决办法，"
        "故事也朝着明亮的方向继续展开。"
    )


def check_user_transcript_safety(transcript_text: str) -> VoiceSafetyResult:
    """Screen user transcript text before it enters the story flow."""

    flags = _collect_safety_flags(transcript_text)
    if not flags:
        return VoiceSafetyResult(is_safe=True, flags=[])

    message = build_child_safe_redirect(flags)
    return VoiceSafetyResult(
        is_safe=False,
        flags=flags,
        replacement_text=message,
        message=message,
    )


def check_assistant_output_safety(
    assistant_text: str,
    *,
    premise: str | None = None,
) -> VoiceSafetyResult:
    """Screen assistant output and replace it with a child-safe segment when needed."""

    flags = _collect_safety_flags(assistant_text)
    if not flags:
        return VoiceSafetyResult(is_safe=True, flags=[])

    replacement_text = build_safe_story_fallback(premise=premise)
    return VoiceSafetyResult(
        is_safe=False,
        flags=flags,
        replacement_text=replacement_text,
        message="系统已把不适合孩子的内容改写为更温和安全的版本。",
    )