"""
模板应用工具：把 CardTemplate 的预设（theme + background + design）应用到 Project。
- 复制 LibraryAsset 中的素材到 projects/<pid>/<asset_type>/<asset_key>_xxx.png
- 在 Project 的 design 中写 background_color / border_color / suit_colors 等
"""
import os
import shutil
from time import time
from django.conf import settings
from apps.projects.models import Project, Asset, LibraryAsset


def _copy_lib_to_project(project, lib, asset_type, asset_key):
    """把 LibraryAsset 的文件复制到 projects/<pid>/<asset_type>/ 下，并在 Project.assets 建记录"""
    project_media_dir = f'projects/{project.id}/{asset_type}'
    full_dir = os.path.join(settings.MEDIA_ROOT, project_media_dir)
    os.makedirs(full_dir, exist_ok=True)

    src = os.path.join(settings.MEDIA_ROOT, lib.file_path)
    if not os.path.exists(src):
        return None

    ts = int(time() * 1000)
    fn = f'{asset_key}_{ts}_{lib.file_name}'
    dst_rel = f'{project_media_dir}/{fn}'
    shutil.copy2(src, os.path.join(settings.MEDIA_ROOT, dst_rel))

    # 读图尺寸
    width = height = None
    try:
        from PIL import Image
        with Image.open(os.path.join(settings.MEDIA_ROOT, dst_rel)) as im:
            width, height = im.size
    except Exception:
        pass

    # 删除同 (asset_type, asset_key) 的旧记录
    Asset.objects.filter(project=project, asset_type=asset_type, asset_key=asset_key).delete()
    return Asset.objects.create(
        project=project,
        asset_type=asset_type,
        asset_key=asset_key,
        file_path=dst_rel,
        file_name=fn,
        width=width,
        height=height,
    )


def apply_template_to_project(project, template):
    """根据 CardTemplate 的预设填充项目：写 design + 复制 JQK/Joker 素材

    默认行为：
    - 整副牌 background_color / border_color 等设计项按模板的 design_override 写入
    - 模板绑定的 theme_id 对应的所有 LibraryAsset 复制成 JQK/Joker 资产
    - 应用到所有 4 个花色 + 大小王
    """
    # 1. 应用 design 覆盖
    base_design = dict(project.design or {})
    override = template.design_override or {}
    base_design.update(override)
    # 同步花色颜色
    if 'suit_symbols' not in base_design:
        base_design['suit_symbols'] = {}
    base_design['suit_symbols']['spade'] = {'type': 'text', 'value': '♠', 'color': template.color_spade, 'asset_id': None}
    base_design['suit_symbols']['heart'] = {'type': 'text', 'value': '♥', 'color': template.color_heart, 'asset_id': None}
    base_design['suit_symbols']['club']  = {'type': 'text', 'value': '♣', 'color': template.color_club,  'asset_id': None}
    base_design['suit_symbols']['diamond'] = {'type': 'text', 'value': '♦', 'color': template.color_diamond, 'asset_id': None}
    # 背景色
    base_design['background_color'] = template.color_background
    project.design = base_design

    # 2. 初始化背面设计（如果尚未设置）
    if not project.back_design:
        from apps.projects.models import default_back_design
        project.back_design = default_back_design()

    project.save()

    # 2. 复制主题素材（如果绑定了 theme_id）
    theme_id = template.theme_id
    if not theme_id:
        return {'applied': 0, 'theme_id': None}

    libs = LibraryAsset.objects.filter(theme_id=theme_id)
    if not libs.exists():
        return {'applied': 0, 'theme_id': theme_id, 'warning': f'no library assets for theme {theme_id}'}

    applied = []
    for lib in libs:
        # asset_type: J/Q/K -> face_card；joker -> joker
        if lib.role == 'joker':
            asset_type = 'joker'
            # 默认应用到 joker-big
            asset_key = 'joker-big'
            # 同主题如果有 small 的角色素材就分别处理
            if lib.asset_id == 'small':
                asset_key = 'joker-small'
        else:
            asset_type = 'face_card'
            # 4 个花色都复制
            for suit in ('spade', 'heart', 'club', 'diamond'):
                asset_key = f'{suit}-{lib.role}'
                a = _copy_lib_to_project(project, lib, asset_type, asset_key)
                if a:
                    applied.append(a.id)
            continue
        a = _copy_lib_to_project(project, lib, asset_type, asset_key)
        if a:
            applied.append(a.id)

    return {
        'applied': len(applied),
        'theme_id': theme_id,
        'asset_ids': applied,
    }