"""
Tencent Cloud TIIA helpers.

We use Tencent Cloud "Image and Video AI" (TIIA) CreateImage API to upload an image
referenced by URL into a gallery group.

This module only provides a single upload function (not a scheduled task).

SDK reference: https://github.com/TencentCloud/tencentcloud-sdk-python
"""

import json
import time
import uuid
from urllib.parse import urlparse

from django.conf import settings

from api_v1.utils.media import build_public_media_url

def _truncate(s: str, max_len: int) -> str:
    s = s or ''
    if len(s) <= max_len:
        return s
    return s[:max_len]


class SimpleRateLimiter:
    """
    Very small in-process rate limiter (token-bucket-ish) to keep API calls under QPS.

    This is used by the scheduled task to respect TencentCloud API limits (e.g. 10 req/s).
    """

    def __init__(self, *, qps: float):
        if qps <= 0:
            raise ValueError('qps 必须 > 0')
        self._min_interval = 1.0 / float(qps)
        self._last_ts = 0.0

    def wait(self) -> None:
        now = time.monotonic()
        elapsed = now - self._last_ts
        if self._last_ts > 0 and elapsed < self._min_interval:
            time.sleep(self._min_interval - elapsed)
        self._last_ts = time.monotonic()

def _strip_data_url_base64_prefix(s: str) -> str:
    """
    Accept both raw base64 and data URL format like:
      data:image/png;base64,AAAA...
    Return the base64 payload part.
    """
    s = (s or '').strip()
    if not s:
        return s
    lower = s[:64].lower()
    if lower.startswith('data:') and 'base64,' in lower:
        return s.split('base64,', 1)[1].strip()
    return s


def search_image_url_in_tencent_tiia(
    *,
    image_url: str | None = None,
    image_base64: str | None = None,
    limit: int | None = 10,
    offset: int | None = 0,
    match_threshold: int | None = None,
    rate_limiter: SimpleRateLimiter | None = None,
) -> dict:
    """
    Search an image by URL in Tencent Cloud TIIA gallery using SearchImage.

    This is the counterpart of CreateImage (upload) and is typically used for "similar image search".

    Required settings:
    - TENCENTCLOUD_SECRET_ID
    - TENCENTCLOUD_SECRET_KEY
    - TENCENTCLOUD_TIIA_GROUP_ID

    Optional settings:
    - TENCENTCLOUD_TOKEN                      (STS token, if applicable)
    - TENCENTCLOUD_TIIA_REGION                (default: ap-guangzhou)
    - TENCENTCLOUD_TIIA_ENDPOINT              (default: tiia.tencentcloudapi.com)

    Args:
        image_url: Absolute URL to search. (preferred when both provided)
        image_base64: Base64-encoded image content.
        limit/offset/match_threshold: Optional SearchImage request parameters.
        rate_limiter: Optional in-process limiter to keep requests under QPS.

    Returns:
        Parsed JSON response dict from TencentCloud SDK.
    """
    image_url = (image_url or '').strip()
    image_base64 = _strip_data_url_base64_prefix(image_base64 or '')

    if not image_url and not image_base64:
        raise ValueError('imageUrl 和 imageBase64 必须至少提供一个')

    if image_url:
        parsed = urlparse(image_url)
        if not (parsed.scheme and parsed.netloc):
            raise ValueError('imageUrl 必须为绝对 URL（包含 scheme 与 host）')

    group_id = (getattr(settings, 'TENCENTCLOUD_TIIA_GROUP_ID', '') or '').strip()
    if not group_id:
        raise ValueError('缺少 settings: TENCENTCLOUD_TIIA_GROUP_ID')

    secret_id = (getattr(settings, 'TENCENTCLOUD_SECRET_ID', '') or '').strip()
    secret_key = (getattr(settings, 'TENCENTCLOUD_SECRET_KEY', '') or '').strip()
    token = (getattr(settings, 'TENCENTCLOUD_TOKEN', '') or '').strip() or None
    if not secret_id or not secret_key:
        raise ValueError('缺少 settings: TENCENTCLOUD_SECRET_ID / TENCENTCLOUD_SECRET_KEY')

    region = (getattr(settings, 'TENCENTCLOUD_TIIA_REGION', None) or 'ap-guangzhou').strip()
    endpoint = (getattr(settings, 'TENCENTCLOUD_TIIA_ENDPOINT', None) or 'tiia.tencentcloudapi.com').strip()

    try:
        from tencentcloud.common import credential
        from tencentcloud.common.profile.client_profile import ClientProfile
        from tencentcloud.common.profile.http_profile import HttpProfile
        from tencentcloud.tiia.v20190529 import tiia_client, models
    except Exception as e:  # pragma: no cover
        raise RuntimeError(
            "TencentCloud SDK 未安装或不可用，请先安装依赖：tencentcloud-sdk-python"
        ) from e

    if rate_limiter is not None:
        rate_limiter.wait()

    cred = credential.Credential(secret_id, secret_key, token)
    http_profile = HttpProfile(endpoint=endpoint, reqTimeout=30)
    client_profile = ClientProfile(httpProfile=http_profile)
    client = tiia_client.TiiaClient(cred, region, client_profile)

    req = models.SearchImageRequest()
    req.GroupId = str(group_id)
    # TencentCloud: ImageUrl + ImageBase64 can be both provided, but ImageUrl wins.
    if image_url:
        req.ImageUrl = str(image_url)
    else:
        req.ImageBase64 = str(image_base64)

    if limit is not None:
        req.Limit = int(limit)
    if offset is not None:
        req.Offset = int(offset)
    if match_threshold is not None:
        req.MatchThreshold = int(match_threshold)

    resp = client.SearchImage(req)
    return json.loads(resp.to_json_string())


def upload_image_url_to_tencent_tiia(*, image_url: str, entity_id: str) -> dict:
    """
    Upload an image by URL to Tencent Cloud TIIA gallery using CreateImage.

    Only `image_url` and `entity_id` are required; other fields are derived from Django settings.

    Required settings:
    - TENCENTCLOUD_SECRET_ID
    - TENCENTCLOUD_SECRET_KEY
    - TENCENTCLOUD_TIIA_GROUP_ID

    Optional settings:
    - TENCENTCLOUD_TOKEN                      (STS token, if applicable)
    - TENCENTCLOUD_TIIA_REGION                (default: ap-guangzhou)
    - TENCENTCLOUD_TIIA_ENDPOINT              (default: tiia.tencentcloudapi.com)
    - TENCENTCLOUD_TIIA_PIC_NAME_PREFIX       (default: plate_order)

    Returns:
        Parsed JSON response dict from TencentCloud SDK.
    """
    image_url = (image_url or '').strip()
    if not image_url:
        raise ValueError('image_url 不能为空')

    entity_id = (entity_id or '').strip()
    if not entity_id:
        raise ValueError('entity_id 不能为空')

    parsed = urlparse(image_url)
    if not (parsed.scheme and parsed.netloc):
        raise ValueError('image_url 必须为绝对 URL（包含 scheme 与 host）')

    group_id = (getattr(settings, 'TENCENTCLOUD_TIIA_GROUP_ID', '') or '').strip()
    if not group_id:
        raise ValueError('缺少 settings: TENCENTCLOUD_TIIA_GROUP_ID')

    secret_id = (getattr(settings, 'TENCENTCLOUD_SECRET_ID', '') or '').strip()
    secret_key = (getattr(settings, 'TENCENTCLOUD_SECRET_KEY', '') or '').strip()
    token = (getattr(settings, 'TENCENTCLOUD_TOKEN', '') or '').strip() or None
    if not secret_id or not secret_key:
        raise ValueError('缺少 settings: TENCENTCLOUD_SECRET_ID / TENCENTCLOUD_SECRET_KEY')

    region = (getattr(settings, 'TENCENTCLOUD_TIIA_REGION', None) or 'ap-guangzhou').strip()
    endpoint = (getattr(settings, 'TENCENTCLOUD_TIIA_ENDPOINT', None) or 'tiia.tencentcloudapi.com').strip()

    pic_prefix = (getattr(settings, 'TENCENTCLOUD_TIIA_PIC_NAME_PREFIX', None) or 'plate_order').strip() or 'plate_order'

    # CreateImage requires PicName; we auto-generate it.
    uid = uuid.uuid4().hex
    # NOTE: 云端对字段长度通常有限制，这里做一个保守截断，避免超长导致 400。
    entity_id = _truncate(entity_id, 128)
    basename = (parsed.path.rsplit('/', 1)[-1] or '').strip()
    pic_name = f'{pic_prefix}_{basename}' if basename else f'{pic_prefix}_{uid}'
    pic_name = _truncate(pic_name, 128)

    try:
        from tencentcloud.common import credential
        from tencentcloud.common.profile.client_profile import ClientProfile
        from tencentcloud.common.profile.http_profile import HttpProfile
        from tencentcloud.tiia.v20190529 import tiia_client, models
    except Exception as e:  # pragma: no cover
        raise RuntimeError(
            "TencentCloud SDK 未安装或不可用，请先安装依赖：tencentcloud-sdk-python"
        ) from e

    cred = credential.Credential(secret_id, secret_key, token)
    http_profile = HttpProfile(endpoint=endpoint, reqTimeout=30)
    client_profile = ClientProfile(httpProfile=http_profile)
    client = tiia_client.TiiaClient(cred, region, client_profile)

    req = models.CreateImageRequest()
    req.GroupId = str(group_id)
    req.EntityId = str(entity_id)
    req.PicName = str(pic_name)
    req.ImageUrl = str(image_url)

    resp = client.CreateImage(req)
    return json.loads(resp.to_json_string())

def _extract_urls_from_plate_image(plate_image) -> list[str]:
    """
    从 PlateOrder.plate_image(JSON) 中提取所有可能的图片 URL/Path。

    plate_image 在本项目中通常为 list[dict]，dict 里常见字段：
    - url: 绝对 URL 或相对路径
    - path: 相对路径（uploads/...）
    也兼容：
    - imageUrl/ImageURL: 外部系统字段名
    - 直接 string（url/path）
    """
    if not plate_image:
        return []

    if isinstance(plate_image, dict):
        items = [plate_image]
    elif isinstance(plate_image, list):
        items = plate_image
    elif isinstance(plate_image, str):
        items = [plate_image]
    else:
        return []

    urls: list[str] = []
    for it in items:
        raw = None
        if isinstance(it, str):
            raw = it
        elif isinstance(it, dict):
            raw = (
                it.get('url')
                or it.get('imageUrl')
                or it.get('ImageUrl')
                or it.get('imageURL')
                or it.get('ImageURL')
                or it.get('path')
            )
        if not raw:
            continue
        normalized = build_public_media_url(str(raw), request=None)
        if normalized:
            urls.append(normalized)

    # 去重（保序）
    seen = set()
    deduped: list[str] = []
    for u in urls:
        if u in seen:
            continue
        seen.add(u)
        deduped.append(u)
    return deduped


def upload_plate_order_images_to_tencent_tiia(*, plate_order_id: int, rate_limiter: SimpleRateLimiter | None = None) -> list[dict]:
    """
    包装函数：给定 plate_order_id，读取 PlateOrder.plate_image(JSONField) 中所有图片并上传到腾讯云图库。

    - entity_id 使用 plate_order_id（字符串化）
    - 逐张上传；单张失败不会中断整体，会返回 errors 供人工排查

    Returns:
        list[dict] 每张图片一条结果：
        - image_url: str
        - ok: bool
        - response: dict | None
        - error: str | None
    """
    if plate_order_id is None:
        raise ValueError('plate_order_id 不能为空')
    try:
        plate_order_id_int = int(plate_order_id)
    except (TypeError, ValueError):
        raise ValueError('plate_order_id 必须为整数')

    from printing.models import PlateOrder

    try:
        po = PlateOrder.objects.get(id=plate_order_id_int)
    except PlateOrder.DoesNotExist:
        raise ValueError(f'PlateOrder {plate_order_id_int} 不存在')

    urls = _extract_urls_from_plate_image(getattr(po, 'plate_image', None))
    if not urls:
        return []

    entity_id = str(plate_order_id_int)
    results: list[dict] = []
    for url in urls:
        url_str = (url or '').strip()
        if not url_str:
            continue
        parsed = urlparse(url_str)
        if not (parsed.scheme and parsed.netloc):
            results.append({
                'image_url': url_str,
                'ok': False,
                'response': None,
                'error': '图片 URL 不是绝对地址（请确保存储了绝对 url，或正确配置 QINIU_BUCKET_DOMAIN）',
            })
            continue
        try:
            if rate_limiter is not None:
                rate_limiter.wait()
            resp = upload_image_url_to_tencent_tiia(image_url=url_str, entity_id=entity_id)
            results.append({'image_url': url_str, 'ok': True, 'response': resp, 'error': None})
        except Exception as e:
            results.append({'image_url': url_str, 'ok': False, 'response': None, 'error': str(e)})
    return results


__all__ = [
    'SimpleRateLimiter',
    'upload_image_url_to_tencent_tiia',
    'search_image_url_in_tencent_tiia',
    'upload_plate_order_images_to_tencent_tiia',
]