"""
工具函数模块：语言检测、HTML清洗、内容提取、时间解析、AI API调用、文本换行
"""

import re
import requests
from datetime import datetime, timedelta, timezone
from email.utils import parsedate_to_datetime


def is_chinese(text):
    """判断文本是否为中文（汉字占比 > 20%）"""
    if not text:
        return True
    chinese_chars = sum(1 for c in text if '\u4e00' <= c <= '\u9fff')
    return chinese_chars > len(text) * 0.2


def clean_html(html_text):
    """清理HTML标签，合并空白字符"""
    if not html_text:
        return ""
    text = re.sub(r'<[^>]+>', ' ', html_text)
    text = re.sub(r'\s+', ' ', text)
    return text.strip()


def extract_content(entry):
    """从RSS条目提取完整正文内容"""
    content = entry.get('summary', '') or entry.get('description', '')
    if not content:
        content_list = entry.get('content', [{}])
        if content_list and isinstance(content_list, list):
            content = content_list[0].get('value', '')
    return clean_html(content)


def parse_pub_time(entry):
    """解析发布时间，统一转换为北京时间（UTC+8）"""
    beijing_tz = timezone(timedelta(hours=8))

    time_fields = ['published_parsed', 'updated_parsed', 'created_parsed']
    for field in time_fields:
        if entry.get(field):
            try:
                utc_time = datetime(*entry[field][:6], tzinfo=timezone.utc)
                return utc_time.astimezone(beijing_tz).replace(tzinfo=None)
            except Exception:
                continue

    for field in ['published', 'updated', 'created']:
        if entry.get(field):
            try:
                dt = parsedate_to_datetime(entry[field])
                if dt.tzinfo is not None:
                    return dt.astimezone(beijing_tz).replace(tzinfo=None)
                return dt
            except Exception:
                continue

    return datetime.now()


def call_ai(messages, api_key, base_url, model, temperature=0.3, max_tokens=800, purpose=None):
    """调用 OpenAI 兼容的 Chat Completion API"""
    if not api_key:
        raise ValueError('OPENAI_API_KEY 未配置')

    headers = {
        'Content-Type': 'application/json',
        'Authorization': f'Bearer {api_key}'
    }

    data = {
        'model': model,
        'messages': messages,
        'temperature': temperature,
        'max_tokens': max_tokens,
    }

    try:
        response = requests.post(
            f'{base_url}/chat/completions',
            headers=headers,
            json=data,
            timeout=120
        )
        response.raise_for_status()
        result = response.json()['choices'][0]['message']['content']
        _record_api_success(model, purpose, max_tokens)
        return result
    except Exception:
        _record_api_failure(model, purpose, max_tokens)
        raise


def wrap_text(text, font, max_width, draw):
    """将长文本按像素宽度自动换行，返回行列表"""
    lines = []
    current_line = ""

    for char in text:
        test_line = current_line + char
        bbox = draw.textbbox((0, 0), test_line, font=font)
        line_width = bbox[2] - bbox[0]

        if line_width <= max_width:
            current_line = test_line
        else:
            if current_line:
                lines.append(current_line)
            current_line = char

    if current_line:
        lines.append(current_line)

    return lines


def _record_api_success(model, purpose, max_tokens):
    try:
        from .monitor import get_monitor
        get_monitor().record_api_call(model or "unknown", purpose or "unknown", max_tokens, True)
    except Exception:
        pass


def _record_api_failure(model, purpose, max_tokens):
    try:
        from .monitor import get_monitor
        get_monitor().record_api_call(model or "unknown", purpose or "unknown", max_tokens, False)
    except Exception:
        pass