"""转场特效预设库.

视频片段之间的转场效果，基于 FFmpeg xfade 滤镜实现。
所有转场预设包含时长范围和默认参数。
"""

from __future__ import annotations

from dataclasses import dataclass, field
from typing import List, Optional


@dataclass(frozen=True)
class TransitionPreset:
    """转场特效预设"""

    id: str
    name: str
    category: str  # 分类：basic / fade / slide / zoom / warp / special
    description: str = ""
    tags: List[str] = field(default_factory=list)
    # FFmpeg xfade transition 名称
    transition: str = "fade"
    # 默认时长（秒）
    default_duration: float = 0.5
    # 支持的时长范围
    min_duration: float = 0.1
    max_duration: float = 3.0
    # 是否需要额外参数
    has_custom_params: bool = False


# ── 预设库清单 ────────────────────────────────────────────────────────────────

TRANSITION_PRESET_LIBRARY: List[TransitionPreset] = [
    # ── 基础 basic ────────────────────────────────────────────────────
    TransitionPreset(
        id="transition_none",
        name="无转场",
        category="basic",
        description="硬切，无过渡效果",
        tags=["硬切", "无"],
        transition="none",
        default_duration=0.0,
        min_duration=0.0,
        max_duration=0.0,
    ),
    TransitionPreset(
        id="transition_random",
        name="随机",
        category="basic",
        description="随机选择一个转场效果",
        tags=["随机", "惊喜"],
        transition="random",
        default_duration=0.5,
    ),
    # ── 淡入淡出 fade ────────────────────────────────────────────────
    TransitionPreset(
        id="transition_fade",
        name="淡入淡出",
        category="fade",
        description="经典交叉淡入淡出",
        tags=["经典", "柔和"],
        transition="fade",
        default_duration=0.5,
        min_duration=0.2,
        max_duration=2.0,
    ),
    TransitionPreset(
        id="transition_fadeblack",
        name="黑场过渡",
        category="fade",
        description="经过黑色画面过渡",
        tags=["黑场", "电影感"],
        transition="fadeblack",
        default_duration=0.6,
        min_duration=0.2,
        max_duration=2.0,
    ),
    TransitionPreset(
        id="transition_fadewhite",
        name="白场过渡",
        category="fade",
        description="经过白色画面过渡",
        tags=["白场", "梦幻"],
        transition="fadewhite",
        default_duration=0.6,
        min_duration=0.2,
        max_duration=2.0,
    ),
    TransitionPreset(
        id="transition_fadegrays",
        name="灰度过渡",
        category="fade",
        description="经过灰度画面过渡",
        tags=["灰度", "文艺"],
        transition="fadegrays",
        default_duration=0.6,
        min_duration=0.2,
        max_duration=2.0,
    ),
    # ── 滑动 slide ──────────────────────────────────────────────────
    TransitionPreset(
        id="transition_slideleft",
        name="左滑",
        category="slide",
        description="画面向左滑动",
        tags=["滑动", "左"],
        transition="slideleft",
        default_duration=0.5,
        min_duration=0.2,
        max_duration=1.5,
    ),
    TransitionPreset(
        id="transition_slideright",
        name="右滑",
        category="slide",
        description="画面向右滑动",
        tags=["滑动", "右"],
        transition="slideright",
        default_duration=0.5,
        min_duration=0.2,
        max_duration=1.5,
    ),
    TransitionPreset(
        id="transition_slideup",
        name="上滑",
        category="slide",
        description="画面向上滑动",
        tags=["滑动", "上"],
        transition="slideup",
        default_duration=0.5,
        min_duration=0.2,
        max_duration=1.5,
    ),
    TransitionPreset(
        id="transition_slidedown",
        name="下滑",
        category="slide",
        description="画面向下滑动",
        tags=["滑动", "下"],
        transition="slidedown",
        default_duration=0.5,
        min_duration=0.2,
        max_duration=1.5,
    ),
    # ── 缩放 zoom ───────────────────────────────────────────────────
    TransitionPreset(
        id="transition_zoomin",
        name="放大进入",
        category="zoom",
        description="下一段画面从中心放大出现",
        tags=["放大", "冲击"],
        transition="zoomin",
        default_duration=0.5,
        min_duration=0.2,
        max_duration=1.5,
    ),
    TransitionPreset(
        id="transition_zoomout",
        name="缩小退出",
        category="zoom",
        description="当前画面缩小退出",
        tags=["缩小", "拉远"],
        transition="zoomout",
        default_duration=0.5,
        min_duration=0.2,
        max_duration=1.5,
    ),
    # ── 擦除 warp ───────────────────────────────────────────────────
    TransitionPreset(
        id="transition_dissolve",
        name="溶解",
        category="warp",
        description="像素溶解效果",
        tags=["溶解", "像素"],
        transition="dissolve",
        default_duration=0.8,
        min_duration=0.3,
        max_duration=2.0,
    ),
    TransitionPreset(
        id="transition_wipeleft",
        name="左擦除",
        category="warp",
        description="从右向左擦除",
        tags=["擦除", "左"],
        transition="wipeleft",
        default_duration=0.5,
        min_duration=0.2,
        max_duration=1.5,
    ),
    TransitionPreset(
        id="transition_wiperight",
        name="右擦除",
        category="warp",
        description="从左向右擦除",
        tags=["擦除", "右"],
        transition="wiperight",
        default_duration=0.5,
        min_duration=0.2,
        max_duration=1.5,
    ),
    TransitionPreset(
        id="transition_wipeup",
        name="上擦除",
        category="warp",
        description="从下向上擦除",
        tags=["擦除", "上"],
        transition="wipeup",
        default_duration=0.5,
        min_duration=0.2,
        max_duration=1.5,
    ),
    TransitionPreset(
        id="transition_wipedown",
        name="下擦除",
        category="warp",
        description="从上向下擦除",
        tags=["擦除", "下"],
        transition="wipedown",
        default_duration=0.5,
        min_duration=0.2,
        max_duration=1.5,
    ),
    TransitionPreset(
        id="transition_circlecrop",
        name="圆形展开",
        category="warp",
        description="圆形从中心展开",
        tags=["圆形", "展开"],
        transition="circlecrop",
        default_duration=0.6,
        min_duration=0.2,
        max_duration=1.5,
    ),
    # ── 特效 special ───────────────────────────────────────────────
    TransitionPreset(
        id="transition_hblur",
        name="水平模糊",
        category="special",
        description="水平方向模糊过渡",
        tags=["模糊", "水平"],
        transition="hblur",
        default_duration=0.5,
        min_duration=0.2,
        max_duration=1.5,
    ),
    TransitionPreset(
        id="transition_wipeblur",
        name="模糊擦除",
        category="special",
        description="带模糊效果的擦除",
        tags=["模糊", "擦除"],
        transition="wipeblur",
        default_duration=0.6,
        min_duration=0.2,
        max_duration=1.5,
    ),
]


# ── 工具函数 ──────────────────────────────────────────────────────────────────


def get_transition_preset(preset_id: str) -> Optional[TransitionPreset]:
    """根据 ID 获取转场预设"""
    for p in TRANSITION_PRESET_LIBRARY:
        if p.id == preset_id:
            return p
    return None


def list_transition_presets(
    *,
    category: Optional[str] = None,
    keyword: Optional[str] = None,
) -> List[TransitionPreset]:
    """筛选转场预设列表

    Args:
        category: 按分类筛选
        keyword: 关键词搜索

    Returns:
        筛选后的预设列表
    """
    results = TRANSITION_PRESET_LIBRARY

    if category:
        results = [p for p in results if p.category == category]

    if keyword:
        kw = keyword.lower()
        results = [
            p
            for p in results
            if kw in p.name.lower() or kw in p.description.lower() or any(kw in t.lower() for t in p.tags)
        ]

    return results


def get_default_transition() -> TransitionPreset:
    """获取默认转场（无转场/硬切）"""
    return get_transition_preset("transition_none")  # type: ignore