"""MockHostAdapter 行为测试：id 失效、限流、PNG 合法非全黑随时间变化、快照/恢复。

mock 宿主是未来 Oak/Resolve/Premiere 适配层的验收替身（计划文档 §3.3 / §7），
这些断言即未来真实适配层要达标的行为契约。
"""
import hashlib

import pytest

from mock_host import MockHostAdapter, decode_png, frame_is_black
from quercus_core.host.errors import EntityNotFound, RateLimited
from quercus_core.host.types import Target
from quercus_core.types import (
    Action,
    ActionBatch,
    Capabilities,
    Limits,
    Rational,
    Size,
    TimeRange,
)


def r(x: int) -> dict:
    """有理秒参数 {num, den}。"""
    return {"num": x, "den": 1}


def setup_base(adapter: MockHostAdapter) -> None:
    """铺一条基础时间线：alpha[0,4) + beta[4,8) 在轨道 1。"""
    f_alpha, f_beta = adapter.import_footage(["/media/alpha.mp4", "/media/beta.mp4"])
    adapter.execute(
        ActionBatch(
            label="setup",
            actions=[
                Action(
                    tool="place_clip",
                    params={
                        "clip_id": f_alpha,
                        "track_index": 1,
                        "time": r(0),
                        "in_point": r(0),
                        "out_point": r(4),
                    },
                ),
                Action(
                    tool="place_clip",
                    params={
                        "clip_id": f_beta,
                        "track_index": 1,
                        "time": r(4),
                        "in_point": r(0),
                        "out_point": r(4),
                    },
                ),
            ],
        )
    )


def _first_seq(adapter: MockHostAdapter):
    return adapter.get_project_overview().timeline_ids[0]


def _timeline_clips(adapter: MockHostAdapter):
    return adapter.get_timeline_structure(_first_seq(adapter)).tracks[0].clips


def _sha(png: bytes) -> str:
    return hashlib.sha256(png).hexdigest()


# ---- 能力与限制 ----

def test_capabilities_and_limits():
    a = MockHostAdapter()
    assert Capabilities.TIMELINE_EDIT in a.capabilities()
    assert a.limits().max_frame_rate == 8.0
    assert a.limits().frame_burst == 4


def test_entity_ids_are_opaque_strings():
    a = MockHostAdapter()
    ids = a.import_footage(["/media/x.mp4"])
    assert isinstance(ids[0], str)
    assert ids[0].startswith("ft_")


# ---- id 失效（删除后 EntityNotFound） ----

def test_clip_id_invalid_after_delete():
    a = MockHostAdapter()
    setup_base(a)
    clip_id = _timeline_clips(a)[0].id
    a.execute(ActionBatch(label="del", actions=[Action(tool="ripple_delete", params={"clip_ids": [clip_id]})]))
    with pytest.raises(EntityNotFound):
        a.get_frame(Target(kind="clip", id=clip_id), Rational(1), Size(32, 18))


def test_unknown_footage_raises_entity_not_found():
    a = MockHostAdapter()
    with pytest.raises(EntityNotFound):
        a.get_timeline_structure("no_such_seq")


def test_unknown_clip_place_fails():
    a = MockHostAdapter()
    br = a.execute(
        ActionBatch(
            label="t",
            actions=[Action(tool="place_clip", params={"clip_id": "nope", "track_index": 1, "time": r(0)})],
        )
    )
    assert br.ok is False
    assert "不存在" in br.results[0].summary


# ---- 限流模拟 ----

def test_rate_limited_raised_with_retry_after():
    a = MockHostAdapter(limits=Limits(max_frame_rate=1.0, frame_burst=1))
    setup_base(a)
    seq = _first_seq(a)
    a.get_frame(Target(kind="timeline", id=seq), Rational(1), Size(32, 18))  # 耗掉唯一令牌
    with pytest.raises(RateLimited) as ei:
        a.get_frame(Target(kind="timeline", id=seq), Rational(2), Size(32, 18))
    assert ei.value.retry_after_ms > 0
    assert a._rate_limited_count >= 1


# ---- 帧：合法 PNG、非全黑、随时间变化 ----

def test_frame_png_valid_nonblack():
    a = MockHostAdapter()
    setup_base(a)
    seq = _first_seq(a)
    png = a.get_frame(Target(kind="timeline", id=seq), Rational(1), Size(64, 36))
    assert png.startswith(b"\x89PNG\r\n\x1a\n")
    rgb = decode_png(png)  # 解不开即抛 ValueError（非法 PNG）
    assert len(rgb) == 64 * 36 * 3
    assert not frame_is_black(png, 64, 36)


def test_frame_pixels_vary_with_time():
    a = MockHostAdapter()
    setup_base(a)
    seq = _first_seq(a)
    p1 = a.get_frame(Target(kind="timeline", id=seq), Rational(1), Size(64, 36))
    p2 = a.get_frame(Target(kind="timeline", id=seq), Rational(2), Size(64, 36))
    assert _sha(p1) != _sha(p2)
    assert decode_png(p1) != decode_png(p2)


def test_thumbnails_valid_and_distinct():
    a = MockHostAdapter(limits=Limits(max_frame_rate=1000.0, frame_burst=100))
    setup_base(a)
    seq = _first_seq(a)
    thumbs = a.get_thumbnails(Target(kind="timeline", id=seq), TimeRange(Rational(0), Rational(4)), 5)
    assert len(thumbs) == 5
    hashes = {_sha(t) for t in thumbs}
    assert len(hashes) == 5  # 各采样点画面不同
    for t in thumbs:
        assert not frame_is_black(t, 480, 270)


# ---- 快照 / 恢复 / 清理 ----

def test_snapshot_restore_and_drop():
    a = MockHostAdapter()
    setup_base(a)  # 直接 import_footage + execute(setup 批次) → 快照 "setup"
    assert len(_timeline_clips(a)) == 2
    a.execute(
        ActionBatch(label="mark", session_id="s1", actions=[Action(tool="add_marker", params={"time": r(2)})])
    )
    snaps = a.list_snapshots()
    assert {s.label for s in snaps} == {"setup", "mark"}
    mark_snap = next(s for s in snaps if s.label == "mark")
    assert mark_snap.session_id == "s1"  # 快照带会话 id
    assert mark_snap.created_at  # 快照带时间戳
    # 恢复 setup 快照 → 回到铺轨前：无序列无片段，但直接导入的素材仍在
    setup_snap = next(s for s in a.list_snapshots() if s.label == "setup")
    a.restore_snapshot(setup_snap.id)
    assert a.get_project_overview().timeline_ids == []
    assert len(a.list_footage()) == 2
    # 清理快照后不可再恢复
    a.drop_snapshot(mark_snap.id)
    with pytest.raises(EntityNotFound):
        a.restore_snapshot(mark_snap.id)


def test_snapshot_cap_eviction():
    a = MockHostAdapter(limits=Limits(max_snapshot_count=2))
    for i in range(3):
        a.execute(
            ActionBatch(
                label=f"b{i}",
                actions=[Action(tool="add_marker", params={"time": r(i + 1)})],
            )
        )
    snaps = a.list_snapshots()
    assert len(snaps) == 2  # 最旧的被淘汰
    assert {s.label for s in snaps} == {"b1", "b2"}


def test_undo_last_restores_newest_snapshot():
    a = MockHostAdapter()
    setup_base(a)
    before = len(_timeline_clips(a))
    a.execute(ActionBatch(label="m1", actions=[Action(tool="add_marker", params={"time": r(1)})]))
    a.execute(ActionBatch(label="m2", actions=[Action(tool="add_marker", params={"time": r(2)})]))
    a.undo_last()  # 撤销 m2
    a.undo_last()  # 撤销 m1
    # 时间线片段数回到 setup 后的状态
    assert len(_timeline_clips(a)) == before


# ---- 事件订阅 ----

def test_event_subscription():
    a = MockHostAdapter()
    seen: list[str] = []
    unsub = a.subscribe(lambda ev: seen.append(ev.kind))
    setup_base(a)
    assert "structure_changed" in seen
    unsub()
    seen.clear()
    setup_base(a)  # 不再通知
    assert seen == []


# ---- 音频电平 / 效果参数 ----

def test_audio_levels_shape():
    a = MockHostAdapter()
    setup_base(a)
    levels = a.get_audio_levels(_first_seq(a), TimeRange(Rational(0), Rational(4)), 16)
    assert len(levels.values) == 16
    assert min(levels.values) >= levels.min_db


def test_effect_params_min_max_choices():
    a = MockHostAdapter()
    params = a.get_effect_params("brightness")
    level = next(p for p in params if p["name"] == "level")
    assert level["min"] == -1.0 and level["max"] == 1.0
    blend = next(p for p in a.get_effect_params("overlay") if p["name"] == "blend_mode")
    assert blend["choices"] == ["normal", "screen", "multiply"]
    with pytest.raises(EntityNotFound):
        a.get_effect_params("no_such_effect")


def test_set_param_rejects_out_of_range():
    a = MockHostAdapter()
    setup_base(a)
    clip_id = _timeline_clips(a)[0].id
    a.execute(
        ActionBatch(
            label="fx",
            actions=[Action(tool="add_effect", params={"clip_id": clip_id, "effect_type": "brightness"})],
        )
    )
    node_id = a._must_clip(clip_id).effects[0].node_id  # 白盒取节点 id
    bad = a.execute(
        ActionBatch(label="bad", actions=[Action(tool="set_param", params={"effect_id": node_id, "param": "level", "value": 5.0})])
    )
    assert bad.ok is False  # 5.0 超出 level 的 [-1,1]
    assert "非法" in bad.results[0].summary or "失败" in bad.results[0].summary