"""
通义千问文生图（DashScope 多模态生成 API）。
默认模型：qwen-image-2.0-pro（与阿里云 Model Studio 文档一致）。
文档：https://www.alibabacloud.com/help/en/model-studio/qwen-image-api
"""
from __future__ import annotations

import json
import logging
import re
from typing import Any, Optional

import requests

import config

logger = logging.getLogger(__name__)

# 北京地域同步接口（与 QWEN_BASE_URL 常用配置同账号）
DEFAULT_MULTIMODAL_BASE = 'https://dashscope.aliyuncs.com/api/v1'
MULTIMODAL_GENERATION_PATH = '/services/aigc/multimodal-generation/generation'

_NEG_DEFAULT = (
    '低分辨率, 模糊, 畸形手指, 过度饱和, 蜡像感, 杂乱构图, 扭曲文字, '
    '公司商标, 企业LOGO, 投标人名称, 水印, 证件照'
)

_PLACEHOLDER_KEY_RE = re.compile(r'^sk-your|^sk-xxxx', re.I)


def _effective_multimodal_base() -> str:
    raw = (getattr(config, 'QWEN_MULTIMODAL_BASE', '') or '').strip().rstrip('/')
    if raw:
        return raw
    return DEFAULT_MULTIMODAL_BASE


def _generation_url() -> str:
    return f'{_effective_multimodal_base()}{MULTIMODAL_GENERATION_PATH}'


def _qwen_api_key() -> str:
    key = (getattr(config, 'QWEN_API_KEY', '') or '').strip()
    if not key or _PLACEHOLDER_KEY_RE.match(key):
        return ''
    return key


def _extract_image_url(payload: dict[str, Any]) -> Optional[str]:
    try:
        out = payload.get('output') or {}
        choices = out.get('choices') or []
        if not choices:
            return None
        msg = (choices[0] or {}).get('message') or {}
        content = msg.get('content')
        if isinstance(content, list):
            for part in content:
                if isinstance(part, dict):
                    url = part.get('image')
                    if isinstance(url, str) and url.startswith('http'):
                        return url
        if isinstance(content, dict):
            url = content.get('image')
            if isinstance(url, str) and url.startswith('http'):
                return url
    except Exception:
        return None
    return None


def _truncate_prompt(text: str, max_chars: int = 780) -> str:
    t = (text or '').strip().replace('\r\n', '\n').replace('\r', '\n')
    if len(t) <= max_chars:
        return t
    return t[: max_chars - 3] + '...'


def build_attachment_figure_prompt(title: str, body: str) -> str:
    """投标附件用图：专业工程示意风格，避免标识与暗标敏感信息。"""
    core = _truncate_prompt(f'{title}\n{body}', 720)
    head = (
        '建筑施工投标技术标附件插图：清晰线稿或浅色块示意，横版；可含简短中文标注。'
        '禁止公司名、商标、LOGO、投标人信息。'
    )
    sched_keys = ('进度', '网络图', '横道', '开工', '完工', '工期', '里程碑')
    site_keys = ('总平面', '平面布置', '布置图')
    t = f'{title}\n{body}'
    extra = ''
    if any(k in t for k in sched_keys):
        extra += (
            '【进度图】仅表现文字中已给出的开工完工逻辑、清单节点与工期关系；'
            '不得添加正文中未出现的日历日、工序名称或里程碑；无具体日期时不写具体年月日数字。'
        )
    if any(k in t for k in site_keys):
        extra += (
            '【总平面图】临时设施分区与面积须与文字中的临时用地表一致；'
            '施工机械仅绘制文字明确列出的机型，禁止无关挖掘机、塔吊等；无机械列表时只画分区块不写机械剪影。'
        )
    extra = _truncate_prompt(extra, 200) if extra else ''
    parts = [head]
    if extra:
        parts.append(extra)
    parts.append('内容要点：\n' + core)
    return '\n'.join(parts)


def generate_qwen_image_png(
    prompt: str,
    *,
    size: Optional[str] = None,
    timeout: Optional[int] = None,
) -> tuple[Optional[bytes], Optional[str]]:
    """
    调用 qwen-image-2.0-pro 同步文生图，返回 PNG 字节。
    失败时 (None, error_message)。
    """
    api_key = _qwen_api_key()
    if not api_key:
        return None, '未配置有效的通义千问 API Key（文生图与文本模型共用 DashScope Key）'

    model = getattr(config, 'QWEN_IMAGE_MODEL', 'qwen-image-2.0-pro') or 'qwen-image-2.0-pro'
    sz = (size or getattr(config, 'QWEN_IMAGE_SIZE', '1536*1024') or '1536*1024').strip()
    prompt_clean = _truncate_prompt(prompt, 800)
    url = _generation_url()

    body = {
        'model': model,
        'input': {
            'messages': [
                {
                    'role': 'user',
                    'content': [{'text': prompt_clean}],
                }
            ]
        },
        'parameters': {
            'negative_prompt': getattr(config, 'QWEN_IMAGE_NEGATIVE_PROMPT', _NEG_DEFAULT),
            'prompt_extend': bool(getattr(config, 'QWEN_IMAGE_PROMPT_EXTEND', True)),
            'watermark': bool(getattr(config, 'QWEN_IMAGE_WATERMARK', False)),
            'size': sz,
        },
    }

    to = timeout if timeout is not None else max(120, int(getattr(config, 'REQUEST_TIMEOUT', 180) or 180))
    try:
        resp = requests.post(
            url,
            headers={
                'Authorization': f'Bearer {api_key}',
                'Content-Type': 'application/json',
            },
            data=json.dumps(body, ensure_ascii=False).encode('utf-8'),
            timeout=to,
        )
    except requests.RequestException as e:
        logger.warning('qwen-image 请求异常: %s', e)
        return None, str(e)

    try:
        data = resp.json()
    except Exception:
        return None, f'文生图接口返回非 JSON，HTTP {resp.status_code}'

    if resp.status_code != 200:
        msg = data.get('message') or data.get('code') or resp.text[:500]
        logger.warning('qwen-image HTTP %s: %s', resp.status_code, msg)
        return None, f'文生图失败 HTTP {resp.status_code}: {msg}'

    code = data.get('code')
    if code and str(code).upper() not in ('OK', 'SUCCESS', '200', ''):
        msg = data.get('message') or str(code)
        logger.warning('qwen-image 业务错误: %s', msg)
        return None, f'文生图接口错误: {msg}'

    img_url = _extract_image_url(data)
    if not img_url:
        logger.warning('qwen-image 响应无图片 URL: %s', str(data)[:800])
        return None, '文生图响应中未找到图片 URL'

    try:
        ir = requests.get(img_url, timeout=min(to, 120))
        ir.raise_for_status()
        return ir.content, None
    except requests.RequestException as e:
        logger.warning('下载生成图片失败: %s', e)
        return None, f'下载图片失败: {e}'


def generate_attachment_figure_png(title: str, content: str) -> tuple[Optional[bytes], Optional[str]]:
    """附件 [FIGURE] 专用：拼装提示词并生成 PNG。"""
    prompt = build_attachment_figure_prompt(title or '附图', content or '')
    return generate_qwen_image_png(prompt)