"""Volcano Engine ARK video generation API client."""

import requests
from django.conf import settings


# API error code → user-friendly Chinese message
ERROR_MESSAGES = {
    'InputImageSensitiveContentDetected.PrivacyInformation': '参考图片中检测到真实人脸，系统不允许处理包含真人面部的图片',
    'InputImageSensitiveContentDetected': '参考图片包含敏感内容，请更换图片后重试',
    'InputVideoSensitiveContentDetected': '参考视频包含敏感内容，请更换视频后重试',
    'InvalidParameter': '请求参数无效，请检查输入',
    'RateLimitExceeded': 'API 调用频率超限，请稍后重试',
    'InsufficientBalance': '账户余额不足，请联系管理员充值',
}


class AirDramaAPIError(Exception):
    """Raised when video generation API returns an error response."""
    def __init__(self, code, message, status_code=400):
        self.code = code
        self.api_message = message
        self.status_code = status_code
        # Use friendly message if available, otherwise use API message
        self.user_message = ERROR_MESSAGES.get(code, message)
        super().__init__(self.user_message)


MODEL_MAP = {
    'seedance_2.0': 'doubao-seedance-2-0-260128',
    'seedance_2.0_fast': 'doubao-seedance-2-0-fast-260128',
}


def _headers():
    return {
        'Content-Type': 'application/json',
        'Authorization': f'Bearer {settings.ARK_API_KEY}',
    }


def create_task(prompt, model, content_items, aspect_ratio, duration, generate_audio=True):
    """Create a video generation task.

    Args:
        prompt: Text prompt for video generation.
        model: Model key ('airdrama' or 'airdrama_fast').
        content_items: List of media content dicts (image_url, video_url, audio_url).
        aspect_ratio: Video aspect ratio ('16:9', '9:16', etc.).
        duration: Video duration in seconds.
        generate_audio: Whether to generate audio with the video.

    Returns:
        dict: API response with task id and status.
    """
    url = f'{settings.ARK_BASE_URL}/contents/generations/tasks'

    content = []
    if prompt:
        content.append({'type': 'text', 'text': prompt})
    content.extend(content_items)

    payload = {
        'model': MODEL_MAP.get(model, model),
        'content': content,
        'generate_audio': generate_audio,
        'ratio': aspect_ratio,
        'duration': duration,
        'watermark': False,
    }

    resp = requests.post(url, json=payload, headers=_headers(), timeout=60)
    if resp.status_code != 200:
        # Extract human-readable error from API response
        try:
            err = resp.json().get('error', {})
            code = err.get('code', '')
            message = err.get('message', resp.text)
        except Exception:
            code, message = '', resp.text
        raise AirDramaAPIError(code, message, resp.status_code)
    return resp.json()


def query_task(task_id):
    """Query a video generation task by its ARK task ID.

    Returns:
        dict: Task status, content (video URL on success), usage info.
    """
    url = f'{settings.ARK_BASE_URL}/contents/generations/tasks/{task_id}'
    resp = requests.get(url, headers=_headers(), timeout=30)
    resp.raise_for_status()
    return resp.json()


def extract_video_url(task_response):
    """Extract the video URL from a completed task response."""
    content = task_response.get('content')
    if not content:
        return None

    # content could be a list of items or a dict
    if isinstance(content, list):
        for item in content:
            if item.get('type') == 'video_url':
                return item.get('video_url', {}).get('url')
    elif isinstance(content, dict):
        if 'video_url' in content:
            url = content['video_url']
            return url.get('url') if isinstance(url, dict) else url

    return None


def map_status(ark_status):
    """Map ARK task status to our DB status."""
    mapping = {
        'running': 'processing',
        'submitted': 'queued',
        'queued': 'queued',
        'succeeded': 'completed',
        'failed': 'failed',
    }
    return mapping.get(ark_status, 'processing')