"""
Source.json 质量评估模块

基于字段完整性和文本量对调研结果进行评分，识别低质量内容并支持二次筛选。

评分维度：
1. 字段完整性（40分）：有效字段占比
2. 文本质量（40分）：body_text 长度和信息密度
3. 互动数据（20分）：点赞数、时间戳等
"""

import json
import re
from pathlib import Path
from typing import Dict, List, Tuple
from datetime import datetime, timedelta

_HTML_TAG_RE = re.compile(r"<[^>]+>")


def _strip_html(text) -> str:
    """Remove inline HTML tags (e.g. <em class="highlight">) from search-result text."""
    if not text:
        return ""
    return _HTML_TAG_RE.sub("", str(text))


class SourceQualityEvaluator:
    """Source 数据质量评估器"""

    # 字段权重配置
    FIELD_WEIGHTS = {
        "title": 5,
        "body_text": 15,
        "like_count": 5,
        "publish_timestamp": 5,
        "images": 3,
        "videos": 3,
        "link": 2,
        "content_type": 2,
    }

    # 文本质量阈值
    TEXT_LENGTH_THRESHOLDS = {
        "excellent": 200,   # 优秀：200字以上
        "good": 100,        # 良好：100-200字
        "fair": 50,         # 一般：50-100字
        "poor": 20,         # 较差：20-50字
        # < 20字：极差
    }

    def __init__(self, time_window_days: int = 180):
        """
        Args:
            time_window_days: 时效性窗口（天），默认180天（半年）
        """
        self.time_window_days = time_window_days
        self.cutoff_timestamp = (
            datetime.now() - timedelta(days=time_window_days)
        ).timestamp()

    def evaluate_post(self, post: dict) -> Dict[str, any]:
        """
        评估单个 post 的质量

        Returns:
            {
                "field_score": float,      # 字段完整性得分 (0-40)
                "text_score": float,       # 文本质量得分 (0-40)
                "engagement_score": float, # 互动数据得分 (0-20)
                "total_score": float,      # 总分 (0-100)
                "grade": str,              # 等级 A/B/C/D/F
                "issues": List[str],       # 问题列表
                "valid_fields": int,       # 有效字段数
                "total_fields": int,       # 总字段数
            }
        """
        # Video posts (content_type=="video" 或 videos 字段非空) 通常没有 body_text，
        # 仅靠 caption + 互动数据评分，避免被 body 长度一律打低分。
        is_video = (
            post.get("content_type") == "video"
            or bool(post.get("videos"))
        )

        result = {
            "mode": "video" if is_video else "text",
            "field_score": 0.0,
            "text_score": 0.0,       # video 模式下含义为 title-only (0-15)
            "engagement_score": 0.0, # video 模式下扩展为 (0-45)
            "total_score": 0.0,
            "grade": "F",
            "issues": [],
            "valid_fields": 0,
            "total_fields": len(self.FIELD_WEIGHTS),
        }

        # 1. 字段完整性评分 (0-40 分)
        field_score, valid_count = self._evaluate_fields(post)
        result["field_score"] = field_score
        result["valid_fields"] = valid_count

        # 2 & 3. 文本/互动评分（视频模式跳过 body 长度，重分权重到 title + 互动）
        if is_video:
            title_score, eng_score, issues = self._evaluate_video_signals(post)
            result["text_score"] = title_score
            result["engagement_score"] = eng_score
            result["issues"].extend(issues)
        else:
            text_score, text_issues = self._evaluate_text(post)
            engagement_score, engagement_issues = self._evaluate_engagement(post)
            result["text_score"] = text_score
            result["engagement_score"] = engagement_score
            result["issues"].extend(text_issues + engagement_issues)

        # 计算总分和等级
        result["total_score"] = round(
            result["field_score"] + result["text_score"] + result["engagement_score"], 2
        )
        result["grade"] = self._calculate_grade(result["total_score"])

        return result

    # ── video-mode 阈值（mirror body length tiers, but on seconds） ──
    DURATION_THRESHOLDS = {
        "very_short": 30,    # <30s     -> 5/30
        "short":      60,    # 30-60s   -> 12/30
        "fair":       120,   # 60-120s  -> 20/30
        "good":       300,   # 2-5 min  -> 26/30
        "long":       1800,  # 5-30 min -> 30/30 (best)
        # >=1800s (>30 min) -> 22/30 (信息密度下降)
    }

    def _evaluate_video_signals(self, post: dict) -> Tuple[float, float, List[str]]:
        """For video posts: replaces body-length scoring with video-duration scoring.

        Composition: title (0-10) + duration (0-30) + engagement (0-20) = 0-60,
        mirroring the article-post weights but with duration as the content signal.

        Reads `duration_sec` from the post (populated by search() via
        transcription.probe_durations_for_posts before scoring). If absent
        (probe failed / no video URL), duration_score is 0 with an issue noted.
        """
        issues: List[str] = []

        # ── title 0-10 ──
        title = _strip_html(post.get("title", "")).strip()
        tlen = len(title)
        if tlen == 0:
            title_score = 0
            issues.append("标题为空")
        elif tlen < 10:
            title_score = 3
            issues.append(f"标题过短 ({tlen}字)")
        elif tlen < 20:
            title_score = 6
        else:
            title_score = 10

        # ── duration 0-30 (replaces body_text length) ──
        duration = post.get("duration_sec")
        if not isinstance(duration, (int, float)) or duration <= 0:
            dur_score = 0
            issues.append("无视频时长")
        elif duration < self.DURATION_THRESHOLDS["very_short"]:
            dur_score = 5
            issues.append(f"视频极短 ({duration:.0f}s)")
        elif duration < self.DURATION_THRESHOLDS["short"]:
            dur_score = 12
            issues.append(f"视频较短 ({duration:.0f}s)")
        elif duration < self.DURATION_THRESHOLDS["fair"]:
            dur_score = 20
        elif duration < self.DURATION_THRESHOLDS["good"]:
            dur_score = 26
        elif duration < self.DURATION_THRESHOLDS["long"]:
            dur_score = 30
        else:
            dur_score = 22
            issues.append(f"视频较长 ({duration:.0f}s，>30 分钟密度可能下降)")

        # ── engagement 0-20 (与文章帖相同) ──
        like_count = post.get("like_count", 0)
        if not isinstance(like_count, (int, float)):
            like_count = 0
        if like_count == 0:
            like_score = 0
            issues.append("无点赞数据")
        elif like_count < 10:
            like_score = 3
        elif like_count < 100:
            like_score = 6
        elif like_count < 1000:
            like_score = 8
        else:
            like_score = 10

        timestamp = post.get("publish_timestamp", 0)
        if not isinstance(timestamp, (int, float)):
            timestamp = 0
        if timestamp == 0:
            ts_score = 0
            issues.append("无发布时间")
        elif timestamp < self.cutoff_timestamp:
            ts_score = 2
            issues.append(f"内容过时（超过{self.time_window_days}天）")
        else:
            ts_score = 10

        # text_score 字段在 video mode 下含义 = title + duration (0-40)
        return float(title_score + dur_score), float(like_score + ts_score), issues

    def _evaluate_fields(self, post: dict) -> Tuple[float, int]:
        """评估字段完整性"""
        total_weight = sum(self.FIELD_WEIGHTS.values())
        earned_weight = 0.0
        valid_count = 0

        for field, weight in self.FIELD_WEIGHTS.items():
            value = post.get(field)
            is_valid = False

            if field == "title":
                is_valid = bool(value and len(str(value).strip()) > 0)
            elif field == "body_text":
                is_valid = bool(value and len(str(value).strip()) > 0)
            elif field == "like_count":
                is_valid = isinstance(value, (int, float)) and value > 0
            elif field == "publish_timestamp":
                is_valid = isinstance(value, (int, float)) and value > 0
            elif field in ("images", "videos"):
                is_valid = isinstance(value, list) and len(value) > 0
            elif field == "link":
                is_valid = bool(value and len(str(value).strip()) > 0)
            elif field == "content_type":
                is_valid = bool(value and len(str(value).strip()) > 0)

            if is_valid:
                earned_weight += weight
                valid_count += 1

        # 转换为 0-40 分
        field_score = (earned_weight / total_weight) * 40
        return round(field_score, 2), valid_count

    def _evaluate_text(self, post: dict) -> Tuple[float, List[str]]:
        """评估文本质量"""
        issues = []
        body_text = post.get("body_text", "")
        title = post.get("title", "")

        # 清理 HTML 标签（如 <em class="keyword">）
        import re
        body_text_clean = re.sub(r'<[^>]+>', '', body_text)
        title_clean = re.sub(r'<[^>]+>', '', title)

        body_len = len(body_text_clean.strip())
        title_len = len(title_clean.strip())

        # 标题评分 (0-10分)
        if title_len == 0:
            title_score = 0
            issues.append("标题为空")
        elif title_len < 10:
            title_score = 3
            issues.append(f"标题过短 ({title_len}字)")
        elif title_len < 20:
            title_score = 6
        else:
            title_score = 10

        # 正文评分 (0-30分)
        if body_len == 0:
            body_score = 0
            issues.append("正文为空")
        elif body_len < self.TEXT_LENGTH_THRESHOLDS["poor"]:
            body_score = 5
            issues.append(f"正文极短 ({body_len}字)")
        elif body_len < self.TEXT_LENGTH_THRESHOLDS["fair"]:
            body_score = 12
            issues.append(f"正文较短 ({body_len}字)")
        elif body_len < self.TEXT_LENGTH_THRESHOLDS["good"]:
            body_score = 20
        elif body_len < self.TEXT_LENGTH_THRESHOLDS["excellent"]:
            body_score = 26
        else:
            body_score = 30

        text_score = title_score + body_score
        return round(text_score, 2), issues

    def _evaluate_engagement(self, post: dict) -> Tuple[float, List[str]]:
        """评估互动数据"""
        issues = []
        score = 0.0

        # 点赞数评分 (0-10分)
        like_count = post.get("like_count", 0)
        if not isinstance(like_count, (int, float)):
            like_count = 0

        if like_count == 0:
            issues.append("无点赞数据")
        elif like_count < 10:
            score += 3
        elif like_count < 100:
            score += 6
        elif like_count < 1000:
            score += 8
        else:
            score += 10

        # 时间戳评分 (0-10分)
        timestamp = post.get("publish_timestamp", 0)
        if not isinstance(timestamp, (int, float)):
            timestamp = 0

        if timestamp == 0:
            issues.append("无发布时间")
        elif timestamp < self.cutoff_timestamp:
            issues.append(f"内容过时（超过{self.time_window_days}天）")
            score += 2
        else:
            score += 10

        return round(score, 2), issues

    def _calculate_grade(self, score: float) -> str:
        """计算等级"""
        if score >= 80:
            return "A"
        elif score >= 60:
            return "B"
        elif score >= 40:
            return "C"
        elif score >= 20:
            return "D"
        else:
            return "F"

    def evaluate_source_file(self, source_file: Path) -> Dict[str, any]:
        """
        评估整个 source.json 文件

        Returns:
            {
                "total_sources": int,
                "grade_distribution": Dict[str, int],  # A/B/C/D/F 的数量分布
                "avg_score": float,
                "low_quality_count": int,  # C/D/F 的数量
                "low_quality_indices": List[int],  # 低质量条目的索引
                "details": List[Dict],  # 每条的详细评分
            }
        """
        with open(source_file, "r", encoding="utf-8") as f:
            data = json.load(f)

        sources = data.get("sources", [])
        total = len(sources)

        grade_dist = {"A": 0, "B": 0, "C": 0, "D": 0, "F": 0}
        scores = []
        low_quality_indices = []
        details = []

        for idx, source in enumerate(sources):
            post = source.get("post", {})
            eval_result = self.evaluate_post(post)
            eval_result["index"] = idx
            eval_result["case_id"] = source.get("case_id", "")
            eval_result["platform"] = source.get("platform", "")

            grade_dist[eval_result["grade"]] += 1
            scores.append(eval_result["total_score"])
            details.append(eval_result)

            # C/D/F 视为低质量
            if eval_result["grade"] in ("C", "D", "F"):
                low_quality_indices.append(idx)

        avg_score = round(sum(scores) / total, 2) if total > 0 else 0.0

        return {
            "total_sources": total,
            "grade_distribution": grade_dist,
            "avg_score": avg_score,
            "low_quality_count": len(low_quality_indices),
            "low_quality_indices": low_quality_indices,
            "details": details,
        }

    def filter_low_quality(
        self, source_file: Path, output_file: Path, min_score: float = 40.0
    ) -> Dict[str, any]:
        """
        过滤低质量内容，生成新的 source.json

        Args:
            source_file: 原始 source.json 路径
            output_file: 输出文件路径
            min_score: 最低分数阈值（默认40分，即C级以上）

        Returns:
            {
                "original_count": int,
                "filtered_count": int,
                "removed_count": int,
                "removed_cases": List[str],  # 被移除的 case_id
            }
        """
        with open(source_file, "r", encoding="utf-8") as f:
            data = json.load(f)

        sources = data.get("sources", [])
        original_count = len(sources)

        filtered_sources = []
        removed_sources = []
        removed_cases = []

        for source in sources:
            post = source.get("post", {})
            eval_result = self.evaluate_post(post)

            if eval_result["total_score"] >= min_score:
                filtered_sources.append(source)
            else:
                source["filter_reason"] = f"完备性评分不足 (得分: {eval_result['total_score']} < {min_score})"
                removed_sources.append(source)
                removed_cases.append(source.get("case_id", "unknown"))

        # 将被过滤的数据保存到 filtered_cases.json
        if removed_sources:
            filtered_cases_file = output_file.parent / "filtered_cases.json"
            filtered_data = {"total": len(removed_sources), "sources": removed_sources}
            with open(filtered_cases_file, "w", encoding="utf-8") as f:
                json.dump(filtered_data, f, ensure_ascii=False, indent=2)

        # 更新数据
        data["sources"] = filtered_sources
        data["total"] = len(filtered_sources)
        data["quality_filter"] = {
            "min_score": min_score,
            "original_count": original_count,
            "filtered_count": len(filtered_sources),
            "removed_count": len(removed_cases),
            "filter_timestamp": datetime.now().isoformat(),
        }

        # 写入新文件
        with open(output_file, "w", encoding="utf-8") as f:
            json.dump(data, f, ensure_ascii=False, indent=2)

        return {
            "original_count": original_count,
            "filtered_count": len(filtered_sources),
            "removed_count": len(removed_cases),
            "removed_cases": removed_cases,
        }


def generate_quality_report(source_file: Path, output_report: Path = None):
    """生成质量评估报告"""
    evaluator = SourceQualityEvaluator()
    result = evaluator.evaluate_source_file(source_file)

    # 生成报告文本
    report_lines = [
        "=" * 60,
        f"Source 质量评估报告",
        f"文件：{source_file}",
        f"评估时间：{datetime.now().strftime('%Y-%m-%d %H:%M:%S')}",
        "=" * 60,
        "",
        f"📊 总体统计",
        f"   总条目数：{result['total_sources']}",
        f"   平均得分：{result['avg_score']}/100",
        f"   低质量数：{result['low_quality_count']} ({result['low_quality_count']/result['total_sources']*100:.1f}%)",
        "",
        f"📈 等级分布",
    ]

    for grade in ["A", "B", "C", "D", "F"]:
        count = result["grade_distribution"][grade]
        pct = count / result["total_sources"] * 100 if result["total_sources"] > 0 else 0
        bar = "█" * int(pct / 2)
        report_lines.append(f"   {grade}: {count:3d} ({pct:5.1f}%) {bar}")

    report_lines.extend([
        "",
        f"⚠️  低质量条目详情 (C/D/F 级)",
        "",
    ])

    # 只显示低质量条目
    low_quality_details = [d for d in result["details"] if d["grade"] in ("C", "D", "F")]
    low_quality_details.sort(key=lambda x: x["total_score"])

    for detail in low_quality_details[:20]:  # 最多显示20条
        report_lines.extend([
            f"[{detail['index']:3d}] {detail['case_id']} | 得分: {detail['total_score']}/100 ({detail['grade']})",
            f"      字段: {detail['field_score']}/40 ({detail['valid_fields']}/{detail['total_fields']}个有效)",
            f"      文本: {detail['text_score']}/40",
            f"      互动: {detail['engagement_score']}/20",
        ])
        if detail["issues"]:
            report_lines.append(f"      问题: {', '.join(detail['issues'])}")
        report_lines.append("")

    if len(low_quality_details) > 20:
        report_lines.append(f"   ... 还有 {len(low_quality_details) - 20} 条低质量条目未显示")

    report_text = "\n".join(report_lines)

    # 输出到控制台
    print(report_text)

    # 保存到文件
    if output_report:
        with open(output_report, "w", encoding="utf-8") as f:
            f.write(report_text)
        print(f"\n报告已保存到：{output_report}")

    return result


if __name__ == "__main__":
    import argparse

    parser = argparse.ArgumentParser(description="评估 source.json 的质量")
    parser.add_argument("source_file", type=Path, help="source.json 文件路径")
    parser.add_argument("--report", type=Path, help="输出报告文件路径")
    parser.add_argument("--filter", type=Path, help="过滤后输出文件路径")
    parser.add_argument("--min-score", type=float, default=40.0, help="最低分数阈值（默认40）")
    args = parser.parse_args()

    if not args.source_file.exists():
        print(f"错误：文件不存在 {args.source_file}")
        exit(1)

    # 生成评估报告
    result = generate_quality_report(args.source_file, args.report)

    # 如果指定了过滤输出
    if args.filter:
        evaluator = SourceQualityEvaluator()
        filter_result = evaluator.filter_low_quality(
            args.source_file, args.filter, args.min_score
        )
        print(f"\n🔍 质量过滤完成")
        print(f"   原始条目：{filter_result['original_count']}")
        print(f"   保留条目：{filter_result['filtered_count']}")
        print(f"   移除条目：{filter_result['removed_count']}")
        print(f"   输出文件：{args.filter}")