"""
附件类章节识别：标题匹配、expand_outline 跳过、以及正文模式（完整正文 vs 仅单图单表）。
"""
from __future__ import annotations

import json
import logging
import os
import re
from typing import Any, Dict, List, Optional

import config

logger = logging.getLogger(__name__)

DEFAULT_ATTACHMENT_RULES: Dict[str, Any] = {
    'schema_version': 1,
    'title_regex': [
        r'附件\s*[一二三四五六七八九十0-9A-Za-z、：:.]',
        r'附\s*图',
        r'附\s*表',
        r'附\s*件\s*\(',
        r'^\s*[\d一二三四五六七八九十\.．、]+\s*附件',
    ],
    'table_hint_keywords': [
        '附表', '一览表', '清单表', '统计表', '明细表',
    ],
    'figure_hint_keywords': [
        '附图', '示意图', '平面图', '流程图', '布置图', '组织图', '横道',
    ],
    'default_kind_when_ambiguous': 'table',
    # stack_charts_only：默认，意图栈只输出 [FIGURE]/[TABLE] 无正文；full：长文；single_chart_only：栈顶仅一块
    'attachment_leaf_body_mode': 'stack_charts_only',
}


def attachment_rules_path() -> str:
    return os.path.join(config.DATA_DIR, 'attachment_section_rules.json')


def load_attachment_rules(path: Optional[str] = None) -> Dict[str, Any]:
    p = path or attachment_rules_path()
    data = dict(DEFAULT_ATTACHMENT_RULES)
    if not os.path.isfile(p):
        return data
    try:
        with open(p, encoding='utf-8') as f:
            raw = json.load(f)
        if isinstance(raw, dict):
            for k, v in raw.items():
                if k.startswith('_'):
                    continue
                data[k] = v
    except Exception as e:
        logger.warning('加载 attachment_section_rules.json 失败，使用内置默认: %s', e)
    return data


def attachment_leaf_body_mode(rules: Optional[Dict[str, Any]] = None) -> str:
    """
    附件叶节点正文策略：
    stack_charts_only（默认）、full（完整技术正文）、single_chart_only（栈顶仅一块图或表）。
    """
    r = rules or get_attachment_rules_cached()
    mode = (r.get('attachment_leaf_body_mode') or 'stack_charts_only').strip().lower()
    if mode in ('single_chart_only', 'stack_charts_only', 'full'):
        return mode
    return 'stack_charts_only'


def use_attachment_stack_charts_body(rules: Optional[Dict[str, Any]] = None) -> bool:
    """附件走「意图栈仅图/表、无长文」路径（含 single_chart_only 的单栈顶版本）。"""
    m = attachment_leaf_body_mode(rules)
    return m in ('stack_charts_only', 'single_chart_only')


def use_attachment_single_chart_only_body(rules: Optional[Dict[str, Any]] = None) -> bool:
    return attachment_leaf_body_mode(rules) == 'single_chart_only'


def use_attachment_full_body(rules: Optional[Dict[str, Any]] = None) -> bool:
    return attachment_leaf_body_mode(rules) == 'full'


def is_attachment_only_section(section_title: str, rules: Optional[Dict[str, Any]] = None) -> bool:
    """标题是否属于附件类（附图/附表/附件N 等），用于 expand_outline 跳过与正文分支。"""
    t = (section_title or '').strip()
    if not t:
        return False
    r = rules or load_attachment_rules()
    patterns: List[str] = list(r.get('title_regex') or [])
    for pat in patterns:
        try:
            if re.search(pat, t):
                return True
        except re.error:
            logger.warning('无效 attachment title_regex，已跳过: %s', pat[:80])
    return False


def pick_single_figure_or_table(
    section_title: str,
    enable_figure: bool,
    enable_table: bool,
    rules: Optional[Dict[str, Any]] = None,
) -> Optional[str]:
    """
    返回 'figure' | 'table' | None。
    两开关均关返回 None；仅开一个则取对应类型。
    """
    if not enable_figure and not enable_table:
        return None
    if enable_figure and not enable_table:
        return 'figure'
    if enable_table and not enable_figure:
        return 'table'

    r = rules or load_attachment_rules()
    t = (section_title or '')
    tbl_kw = list(r.get('table_hint_keywords') or [])
    fig_kw = list(r.get('figure_hint_keywords') or [])
    # 单独「表」字易误判，仅当同时存在附表类或与其它词组合时再偏表
    for kw in tbl_kw:
        if kw and kw in t:
            return 'table'
    for kw in fig_kw:
        if kw and kw in t:
            return 'figure'
    # 泛「表」在附件语境下常见
    if '表' in t and '图' not in t:
        return 'table'
    if '图' in t and '表' not in t:
        return 'figure'

    default = (r.get('default_kind_when_ambiguous') or 'table').strip().lower()
    if default == 'figure':
        return 'figure'
    return 'table'


_cached_rules: Optional[Dict[str, Any]] = None


def get_attachment_rules_cached() -> Dict[str, Any]:
    global _cached_rules
    if _cached_rules is None:
        _cached_rules = load_attachment_rules()
    return _cached_rules


def should_skip_expand_subchapters(title: str) -> bool:
    """
    AI 自动填充小章节（expand_outline）时：附件类一级主章不调用子章节生成。
    判定与 is_attachment_only_section 一致。
    """
    return is_attachment_only_section(title, get_attachment_rules_cached())


# 从标题中提取「附件几」等标签，用于日志
_ATTACHMENT_LABEL_RE = re.compile(
    r'附件\s*[:：]?\s*([一二三四五六七八九十百0-9A-Za-z]+)',
)
_ATTACHMENT_FIG_TBL_RE = re.compile(r'附\s*[图表]\s*([一二三四五六七八九十百0-9]*)')


def parse_attachment_label(title: str) -> Optional[str]:
    t = (title or '').strip()
    if not t:
        return None
    m = _ATTACHMENT_LABEL_RE.search(t)
    if m:
        return m.group(1).strip() or None
    m2 = _ATTACHMENT_FIG_TBL_RE.search(t)
    if m2:
        rest = (m2.group(1) or '').strip()
        if rest:
            return rest
        matched = m2.group(0)
        if '图' in matched:
            return '附图'
        return '附表'
    if re.search(r'附\s*图', t):
        return '附图'
    if re.search(r'附\s*表', t):
        return '附表'
    return None