"""
Reader-Pull Checker (追读力检查器)

检查钩子强度、期待管理、追读力：
- 章节开头的钩子
- 章节结尾的悬念
- 追读力债务
"""

from dataclasses import dataclass, field
from typing import List, Dict, Any, Optional


@dataclass
class ReaderPullIssue:
    """追读力问题"""
    chapter: int
    issue_type: str  # weak_hook / no_ending_hook / debt_high
    description: str
    severity: str


@dataclass
class ReaderPullReport:
    """追读力检查报告"""
    chapter: int
    hook_strength: float  # 0-1
    ending_hook: bool
    debt_level: float
    issues: List[ReaderPullIssue] = field(default_factory=list)
    passed: bool = True
    summary: str = ""


class ReaderPullChecker:
    """
    追读力检查器

    检查：
    1. 章节开头的钩子强度
    2. 章节结尾的悬念
    3. 追读力债务水平
    """

    # 强钩子关键词
    STRONG_HOOK_KEYWORDS = [
        "危机", "危险", "困境", "生死", "抉择", "真相",
        "震惊", "意外", "转折", "揭秘", "冲突", "大战"
    ]

    # 结尾悬念关键词
    ENDING_HOOK_KEYWORDS = [
        "然而", "但是", "就在这时", "突然", "意外",
        "未完待续", "敬请期待", "欲知后事", "悬念",
        "却不知道", "更大的"
    ]

    # 悬念关键词
    SUSPENSE_KEYWORDS = [
        "悬念", "伏笔", "暗示", "预示", "危机", "威胁"
    ]

    def __init__(self):
        self.chapter_debts: List[float] = []

    def check_chapter(
        self,
        chapter_num: int,
        chapter_text: str,
        previous_debt: float = 0.0
    ) -> ReaderPullReport:
        """检查单章追读力"""
        # 分析开头钩子
        opening = chapter_text[:500] if len(chapter_text) > 500 else chapter_text
        hook_strength = self._analyze_hook_strength(opening)

        # 分析结尾悬念
        ending = chapter_text[-500:] if len(chapter_text) > 500 else chapter_text
        ending_hook = self._has_ending_hook(ending)

        # 计算本章追读力债务
        debt_level = self._calculate_debt_level(chapter_text, hook_strength, ending_hook)

        report = ReaderPullReport(
            chapter=chapter_num,
            hook_strength=hook_strength,
            ending_hook=ending_hook,
            debt_level=debt_level
        )

        # 检测问题
        if hook_strength < 0.3:
            report.issues.append(ReaderPullIssue(
                chapter=chapter_num,
                issue_type="weak_hook",
                description="章节开头钩子较弱，可能无法吸引读者",
                severity="medium"
            ))

        if not ending_hook:
            report.issues.append(ReaderPullIssue(
                chapter=chapter_num,
                issue_type="no_ending_hook",
                description="章节结尾缺少悬念，读者缺乏继续阅读的动力",
                severity="high"
            ))

        # 检查追读力债务
        total_debt = previous_debt + debt_level
        if total_debt > 80:
            report.issues.append(ReaderPullIssue(
                chapter=chapter_num,
                issue_type="debt_high",
                description=f"追读力债务过高（{total_debt:.0f}），建议释放",
                severity="critical"
            ))

        self.chapter_debts.append(debt_level)
        report.passed = len([i for i in report.issues if i.severity == "critical"]) == 0

        if report.passed:
            report.summary = f"钩子强度 {hook_strength:.0%}，追读力债务 {total_debt:.0f}"
        else:
            report.summary = f"发现问题: {', '.join(i.issue_type for i in report.issues)}"

        return report

    def _analyze_hook_strength(self, opening: str) -> float:
        """分析钩子强度"""
        if not opening:
            return 0.0

        strength = 0.3  # 基础分

        # 检查强钩子关键词
        strong_count = sum(1 for kw in self.STRONG_HOOK_KEYWORDS if kw in opening)
        strength += min(0.4, strong_count * 0.1)

        # 检查疑问句
        question_count = opening.count('?') + opening.count('？')
        strength += min(0.2, question_count * 0.1)

        # 检查省略号（制造悬念）
        ellipsis_count = opening.count('...')
        strength += min(0.1, ellipsis_count * 0.05)

        return min(1.0, strength)

    def _has_ending_hook(self, ending: str) -> bool:
        """检查结尾是否有悬念"""
        if not ending:
            return False

        # 检查结尾悬念关键词
        for kw in self.ENDING_HOOK_KEYWORDS:
            if kw in ending:
                return True

        # 检查是否以冲突/悬念结尾
        suspense_ending = ["？", "！", "……"]
        if any(ending.strip().endswith(s) for s in suspense_ending):
            return True

        return False

    def _calculate_debt_level(
        self,
        text: str,
        hook_strength: float,
        ending_hook: bool
    ) -> float:
        """计算追读力债务"""
        debt = 0.0

        # 无开头钩子
        if hook_strength < 0.3:
            debt += 20

        # 无结尾悬念
        if not ending_hook:
            debt += 30

        # 积累的悬念/伏笔
        unresolved_count = 0
        for kw in self.SUSPENSE_KEYWORDS:
            unresolved_count += text.count(kw)

        debt += min(30, unresolved_count * 5)

        # 钩子强度可以抵消部分债务
        debt -= hook_strength * 20

        return max(0, min(100, debt))

    def get_arc_reader_pull(self, start_chapter: int, end_chapter: int) -> Dict[str, Any]:
        """分析情节弧的追读力"""
        if not self.chapter_debts:
            return {"status": "no_data"}

        relevant = self.chapter_debts[start_chapter - 1:end_chapter]

        return {
            "chapters": f"{start_chapter}-{end_chapter}",
            "avg_hook_strength": sum(h.hook_strength for h in self.chapter_debts[start_chapter-1:end_chapter]) / len(relevant) if relevant else 0,
            "avg_debt": sum(relevant) / len(relevant) if relevant else 0,
            "debt_trend": relevant[-1] - relevant[0] if len(relevant) > 1 else 0
        }