test(viral-video): 补单测覆盖动态积分定价全部分支（diff覆盖率46%→78%）

- points_rules: resolve_video_dimensions/_match_model_prefix/_infer_resolution_key
  /calculate_viral_video_credits 覆盖别名/has_video_input/actual_tokens/兜底/防御分支（+28 tests，覆盖94%）
- points_service: deduct/settle/refund_viral_video 覆盖none/refund/deduct/余额不足/异常分支（+11 tests，覆盖71%）
- viral_video routes: confirm-copy 预扣/402/already_paid/estimate-credits端点（+8 tests，覆盖53%，全部缺失行已覆盖）

tests/unit/test_points_rules.py

@@ -117,3 +117,269 @@ class TestCalculatePointsCost:
     def test_retired_scenes_return_zero(self, scene):
         assert calculate_points_cost(scene, is_member=False) == 0
         assert calculate_points_cost(scene, is_member=True, duration_minutes=10) == 0
+
+
+# ============ 爆款视频动态定价 (#2151) ============
+
+
+class TestResolveVideoDimensions:
+    """resolve_video_dimensions(): 分辨率别名、比例、默认兜底。"""
+
+    def test_1080p_16_9(self):
+        """1080p + 16:9 → w=1920, h=1080。"""
+        from packages.domain.points_rules import resolve_video_dimensions
+
+        w, h = resolve_video_dimensions("1080p", "16:9")
+        assert (w, h) == (1920, 1080)
+
+    def test_480p_16_9(self):
+        """480p + 16:9 → h=480, w 按 16//9 计算。"""
+        from packages.domain.points_rules import resolve_video_dimensions
+
+        w, h = resolve_video_dimensions("480p", "16:9")
+        assert h == 480
+        assert w == 480 * 16 // 9
+
+    def test_720p_1_1(self):
+        """1:1 正方形 → w == h。"""
+        from packages.domain.points_rules import resolve_video_dimensions
+
+        w, h = resolve_video_dimensions("720p", "1:1")
+        assert (w, h) == (720, 720)
+
+    def test_1080p_1_1(self):
+        from packages.domain.points_rules import resolve_video_dimensions
+
+        w, h = resolve_video_dimensions("1080p", "1:1")
+        assert (w, h) == (1080, 1080)
+
+    def test_resolution_aliases(self):
+        """中文/英文别名应正确映射到对应高度。"""
+        from packages.domain.points_rules import resolve_video_dimensions
+
+        cases = [
+            ("普清", 480), ("sd", 480), ("low", 480), ("default", 480),
+            ("高清", 720), ("medium", 720), ("hd", 720),
+            ("超清", 1080), ("fhd", 1080), ("ultra", 1080),
+            ("全能", 1080), ("high", 1080),
+        ]
+        for alias, expected_h in cases:
+            _, h = resolve_video_dimensions(alias, "1:1")
+            assert h == expected_h, f"{alias} -> h={h}, expected {expected_h}"
+
+    def test_unknown_resolution_falls_back_to_720p(self):
+        """未知分辨率字符串兜底到 720p。"""
+        from packages.domain.points_rules import resolve_video_dimensions
+
+        w, h = resolve_video_dimensions("2160p", "1:1")
+        assert h == 720
+        assert w == 720
+
+    def test_empty_resolution_defaults_to_720p_9_16(self):
+        """空 resolution + 空 ratio → 默认 720p + 9:16。"""
+        from packages.domain.points_rules import resolve_video_dimensions
+
+        w, h = resolve_video_dimensions("", "")
+        assert h == 720
+        assert w == 720 * 9 // 16
+
+    def test_none_resolution_default_ratio(self):
+        """None resolution + None ratio → 720p + 9:16 默认。"""
+        from packages.domain.points_rules import resolve_video_dimensions
+
+        w, h = resolve_video_dimensions(None, None)
+        assert h == 720
+        assert w == 720 * 9 // 16
+
+    def test_whitespace_resolution_case_insensitive(self):
+        """前后空格 + 大写应被规范化处理。"""
+        from packages.domain.points_rules import resolve_video_dimensions
+
+        w, h = resolve_video_dimensions("  1080P  ", " 16:9 ")
+        assert (w, h) == (1920, 1080)
+
+
+class TestMatchModelPrefix:
+    """_match_model_prefix() 前缀匹配 + 兜底。"""
+
+    def test_seedance_2_5_exact(self):
+        from packages.domain.points_rules import _match_model_prefix
+
+        assert _match_model_prefix("seedance-2.5") == "seedance-2.5"
+
+    def test_seedance_2_5_with_variant(self):
+        """带后缀版本号（如 seedance-2.5-pro）仍匹配 seedance-2.5。"""
+        from packages.domain.points_rules import _match_model_prefix
+
+        assert _match_model_prefix("seedance-2.5-pro") == "seedance-2.5"
+
+    def test_seedance_2_0_exact(self):
+        from packages.domain.points_rules import _match_model_prefix
+
+        assert _match_model_prefix("seedance-2.0") == "seedance-2.0"
+
+    def test_seedance_2_0_with_variant(self):
+        from packages.domain.points_rules import _match_model_prefix
+
+        assert _match_model_prefix("seedance-2.0-lite") == "seedance-2.0"
+
+    def test_unknown_model_falls_back_to_2_5(self):
+        """未知模型前缀兜底 seedance-2.5。"""
+        from packages.domain.points_rules import _match_model_prefix
+
+        assert _match_model_prefix("kling-v1") == "seedance-2.5"
+        assert _match_model_prefix("") == "seedance-2.5"
+        assert _match_model_prefix(None) == "seedance-2.5"
+
+    def test_case_insensitive(self):
+        from packages.domain.points_rules import _match_model_prefix
+
+        assert _match_model_prefix("SEEDANCE-2.0") == "seedance-2.0"
+
+
+class TestInferResolutionKey:
+    """_infer_resolution_key(): 1000+/650-999/<650 三个分支。"""
+
+    def test_height_ge_1000_is_1080p(self):
+        from packages.domain.points_rules import _infer_resolution_key
+
+        assert _infer_resolution_key(1000) == "1080p"
+        assert _infer_resolution_key(1080) == "1080p"
+        assert _infer_resolution_key(2160) == "1080p"
+
+    def test_height_650_to_999_is_720p(self):
+        from packages.domain.points_rules import _infer_resolution_key
+
+        assert _infer_resolution_key(650) == "720p"
+        assert _infer_resolution_key(720) == "720p"
+        assert _infer_resolution_key(999) == "720p"
+
+    def test_height_lt_650_is_480p(self):
+        from packages.domain.points_rules import _infer_resolution_key
+
+        assert _infer_resolution_key(480) == "480p"
+        assert _infer_resolution_key(649) == "480p"
+        assert _infer_resolution_key(0) == "480p"
+
+
+class TestCalculateViralVideoCredits:
+    """calculate_viral_video_credits()：爆款视频动态定价核心函数。"""
+
+    def test_default_args_returns_float(self):
+        """默认参数返回 float。"""
+        from packages.domain.points_rules import calculate_viral_video_credits
+
+        credits = calculate_viral_video_credits(15, 1280, 720)
+        assert isinstance(credits, float)
+
+    def test_return_is_rounded_to_two_decimals(self):
+        """round(..., 2) 后值本身就是两位小数（再 round 不变化）。"""
+        from packages.domain.points_rules import calculate_viral_video_credits
+
+        for dur, w, h in [(15, 1280, 720), (5, 854, 480), (30, 1920, 1080), (10, 720, 720)]:
+            credits = calculate_viral_video_credits(dur, w, h)
+            assert round(credits, 2) == credits
+
+    def test_has_video_input_uses_lower_price(self):
+        """has_video_input=True 时使用参考视频价格（有视频输入便宜）。"""
+        from packages.domain.points_rules import calculate_viral_video_credits
+
+        no_input = calculate_viral_video_credits(15, 1280, 720, model="seedance-2.5", has_video_input=False)
+        with_input = calculate_viral_video_credits(15, 1280, 720, model="seedance-2.5", has_video_input=True)
+        assert with_input < no_input
+
+    def test_unknown_model_falls_back_to_seedance_2_5(self):
+        """未知 model 前缀兜底到 seedance-2.5 价格，与默认等价。"""
+        from packages.domain.points_rules import calculate_viral_video_credits
+
+        unknown = calculate_viral_video_credits(15, 1280, 720, model="unknown-model")
+        default = calculate_viral_video_credits(15, 1280, 720, model="seedance-2.5")
+        assert unknown == default
+
+    def test_actual_tokens_overrides_calculation(self):
+        """传入 actual_tokens>0 时用它替代公式计算的 tokens。"""
+        from packages.domain.points_rules import (
+            VIRAL_VIDEO_FIXED_COST,
+            VIRAL_VIDEO_MODEL_PRICES,
+            VIRAL_VIDEO_PROFIT_MULTIPLIER,
+            calculate_viral_video_credits,
+        )
+
+        price = VIRAL_VIDEO_MODEL_PRICES[("seedance-2.5", "720p", False)]
+        actual_tokens = 2_000_000
+        expected = round((actual_tokens / 1_000_000 * price + VIRAL_VIDEO_FIXED_COST) * VIRAL_VIDEO_PROFIT_MULTIPLIER, 2)
+        credits = calculate_viral_video_credits(15, 1280, 720, actual_tokens=actual_tokens)
+        assert credits == expected
+
+    def test_zero_duration_width_height_defensive_max1(self):
+        """duration/width/height 为 0/None 时 max(1,...) 防御，结果>0。"""
+        from packages.domain.points_rules import calculate_viral_video_credits
+
+        c_zero = calculate_viral_video_credits(0, 0, 0)
+        assert c_zero > 0
+        c_none = calculate_viral_video_credits(None, None, None)
+        assert c_none > 0
+        c_one = calculate_viral_video_credits(1, 1, 1)
+        assert c_none == c_one
+
+    def test_non_default_fps_affects_tokens(self):
+        """fps 非默认值(30) 应比默认(24) 积分高。"""
+        from packages.domain.points_rules import calculate_viral_video_credits
+
+        c24 = calculate_viral_video_credits(15, 1280, 720, fps=24)
+        c30 = calculate_viral_video_credits(15, 1280, 720, fps=30)
+        assert c30 > c24
+
+    def test_seedance_2_0_priced_lower_than_2_5_at_1080p(self):
+        """seedance-2.0 在 1080p 无视频输入时定价低于 seedance-2.5。"""
+        from packages.domain.points_rules import calculate_viral_video_credits
+
+        c20 = calculate_viral_video_credits(15, 1920, 1080, model="seedance-2.0", has_video_input=False)
+        c25 = calculate_viral_video_credits(15, 1920, 1080, model="seedance-2.5", has_video_input=False)
+        assert c20 < c25
+
+    def test_formula_includes_fixed_cost_and_multiplier(self):
+        """手算公式结果应与函数返回一致（固定成本 + 利润系数）。"""
+        from packages.domain.points_rules import (
+            VIRAL_VIDEO_FIXED_COST,
+            VIRAL_VIDEO_FPS,
+            VIRAL_VIDEO_MODEL_PRICES,
+            VIRAL_VIDEO_PROFIT_MULTIPLIER,
+            calculate_viral_video_credits,
+        )
+
+        dur, w, h = 10, 1280, 720
+        price = VIRAL_VIDEO_MODEL_PRICES[("seedance-2.5", "720p", False)]
+        tokens = dur * w * h * VIRAL_VIDEO_FPS / 1024.0
+        expected = round((tokens / 1_000_000 * price + VIRAL_VIDEO_FIXED_COST) * VIRAL_VIDEO_PROFIT_MULTIPLIER, 2)
+        assert calculate_viral_video_credits(dur, w, h) == expected
+
+    def test_seedance_2_0_with_video_input_falls_back_to_seedance_2_5_price(self):
+        """seedance-2.0 + has_video_input=True 组合不在价格表，走 line 111 fallback 到 seedance-2.5 的 720p False 价格。"""
+        from packages.domain.points_rules import (
+            VIRAL_VIDEO_FIXED_COST,
+            VIRAL_VIDEO_FPS,
+            VIRAL_VIDEO_MODEL_PRICES,
+            VIRAL_VIDEO_PROFIT_MULTIPLIER,
+            calculate_viral_video_credits,
+        )
+
+        dur, w, h = 10, 1280, 720
+        # 兜底价格 = seedance-2.5/720p/False = 70.0
+        price = VIRAL_VIDEO_MODEL_PRICES[("seedance-2.5", "720p", False)]
+        assert price == 70.0
+        tokens = dur * w * h * VIRAL_VIDEO_FPS / 1024.0
+        expected = round((tokens / 1_000_000 * price + VIRAL_VIDEO_FIXED_COST) * VIRAL_VIDEO_PROFIT_MULTIPLIER, 2)
+        credits = calculate_viral_video_credits(dur, w, h, model="seedance-2.0", has_video_input=True)
+        assert credits == expected
+
+
+    def test_fps_zero_or_none_falls_back_to_default(self):
+        """fps=0/None 时 int(fps or 24) 兜底到默认 24，结果与 fps=24 一致。"""
+        from packages.domain.points_rules import calculate_viral_video_credits
+
+        c_default = calculate_viral_video_credits(10, 1280, 720, fps=24)
+        c_zero = calculate_viral_video_credits(10, 1280, 720, fps=0)
+        c_none = calculate_viral_video_credits(10, 1280, 720, fps=None)
+        assert c_zero == c_default
+        assert c_none == c_default

tests/unit/test_points_service.py

@@ -179,3 +179,180 @@ class TestCreateOrder:
     def test_unknown_order_type_raises(self, service, db_session, user_id):
         with pytest.raises(ValueError, match="Unknown order type"):
             service.create_order(user_id, "insurance", "basic", db_session)
+
+
+# ============ 爆款视频（viral_video）动态定价方法 ============
+
+
+class TestDeductViralVideo:
+    """deduct_viral_video(): 预扣积分，委托给 deduct_points。"""
+
+    def test_delegates_to_deduct_points_with_correct_args(self, service, db_session, user_id):
+        """deduct_viral_video 应以 source='viral_video', ref_id=job_id 调用 deduct_points。"""
+        from unittest.mock import MagicMock, patch
+
+        expected = {"success": True, "balance": 50.0, "transaction_id": "t1"}
+        with patch.object(service, "deduct_points", return_value=expected) as mock_dp:
+            result = service.deduct_viral_video(user_id, 10.5, "job-abc", db_session)
+
+        assert result == expected
+        mock_dp.assert_called_once()
+        kwargs = mock_dp.call_args.kwargs
+        assert kwargs["user_id"] == user_id
+        assert kwargs["amount"] == 10.5
+        assert kwargs["source"] == "viral_video"
+        assert kwargs["db"] is db_session
+        assert kwargs["description"] == "爆款视频生成"
+        assert kwargs["ref_id"] == "job-abc"
+
+    def test_none_credits_coerced_to_zero(self, service, db_session, user_id):
+        """credits=None 时应被 float(credits or 0) 转为 0，不抛异常。"""
+        from unittest.mock import patch
+
+        with patch.object(service, "deduct_points", return_value={"success": True, "balance": 0, "transaction_id": "t"}) as mock_dp:
+            service.deduct_viral_video(user_id, None, "job-nil", db_session)
+        assert mock_dp.call_args.kwargs["amount"] == 0.0
+
+
+class TestSettleViralVideo:
+    """settle_viral_video(): 多退少补结算。"""
+
+    def test_no_action_when_diff_below_epsilon(self, service, db_session, user_id):
+        """|diff|<0.01 时返回 action=none，不调 refund/deduct。"""
+        from unittest.mock import patch
+
+        with (
+            patch.object(service, "refund_points") as mock_refund,
+            patch.object(service, "deduct_points") as mock_deduct,
+        ):
+            result = service.settle_viral_video(user_id, estimated=10.00, actual=10.001, txn_id="t1", db=db_session)
+
+        assert result["success"] is True
+        assert result["action"] == "none"
+        assert result["diff"] == 0.0
+        mock_refund.assert_not_called()
+        mock_deduct.assert_not_called()
+
+    def test_refund_when_actual_less_than_estimated(self, service, db_session, user_id):
+        """actual<estimated 时走 refund_points，返回 action=refund。"""
+        from unittest.mock import patch
+
+        refund_res = {"success": True, "balance": 60.0, "transaction_id": "tr-1"}
+        with patch.object(service, "refund_points", return_value=refund_res) as mock_refund:
+            result = service.settle_viral_video(user_id, estimated=20.0, actual=15.0, txn_id="t2", db=db_session)
+
+        assert result["success"] is True
+        assert result["action"] == "refund"
+        assert result["amount"] == 5.0
+        assert result["diff"] == -5.0
+        mock_refund.assert_called_once()
+        rk = mock_refund.call_args.kwargs
+        assert rk["user_id"] == user_id
+        assert rk["amount"] == 5.0
+        assert rk["source"] == "viral_video"
+        assert rk["ref_id"] == "t2"
+        assert rk["description"] == "爆款视频结算退费"
+
+    def test_refund_exception_returns_failure(self, service, db_session, user_id):
+        """refund_points 抛异常时，应捕获并返回 success=False。"""
+        from unittest.mock import patch
+
+        with patch.object(service, "refund_points", side_effect=RuntimeError("db down")):
+            result = service.settle_viral_video(user_id, estimated=20.0, actual=10.0, txn_id="t3", db=db_session)
+
+        assert result["success"] is False
+        assert result["action"] == "refund"
+
+    def test_deduct_when_actual_greater_than_estimated_success(self, service, db_session, user_id):
+        """actual>estimated 且补扣成功 → action=deduct, success=True。"""
+        from unittest.mock import patch
+
+        deduct_res = {"success": True, "balance": 40.0, "transaction_id": "td-1"}
+        with patch.object(service, "deduct_points", return_value=deduct_res) as mock_deduct:
+            result = service.settle_viral_video(user_id, estimated=15.0, actual=20.0, txn_id="t4", db=db_session)
+
+        assert result["success"] is True
+        assert result["action"] == "deduct"
+        assert result["amount"] == 5.0
+        assert result["diff"] == 5.0
+        mock_deduct.assert_called_once()
+        dk = mock_deduct.call_args.kwargs
+        assert dk["amount"] == 5.0
+        assert dk["source"] == "viral_video"
+        assert dk["ref_id"] == "t4"
+
+    def test_deduct_insufficient_balance_returns_success_false_not_raise(self, service, db_session, user_id):
+        """actual>estimated 补扣时余额不足（success=False）应记录 warning 但不抛异常。"""
+        import logging
+        from unittest.mock import patch
+
+        deduct_res = {"success": False, "balance": 2.0, "transaction_id": None}
+        with (
+            patch.object(service, "deduct_points", return_value=deduct_res),
+            patch("packages.domain.points_service.logger") as mock_logger,
+        ):
+            result = service.settle_viral_video(user_id, estimated=15.0, actual=20.0, txn_id="t5", db=db_session)
+
+        # 即使补扣失败，函数也返回 action=deduct 但 success=False（不阻塞任务完成）
+        assert result["success"] is False
+        assert result["action"] == "deduct"
+        assert result["amount"] == 5.0
+        # 应打印 warning
+        mock_logger.warning.assert_called_once()
+
+    def test_deduct_exception_returns_failure(self, service, db_session, user_id):
+        """deduct_points 抛异常时应捕获并返回 success=False。"""
+        from unittest.mock import patch
+
+        with patch.object(service, "deduct_points", side_effect=RuntimeError("db boom")):
+            result = service.settle_viral_video(user_id, estimated=10.0, actual=20.0, txn_id="t6", db=db_session)
+
+        assert result["success"] is False
+        assert result["action"] == "deduct"
+        assert result["diff"] == 10.0
+
+
+class TestRefundViralVideo:
+    """refund_viral_video(): 爆款视频失败全额退款。"""
+
+    def test_zero_amount_returns_none_action(self, service, db_session, user_id):
+        """amount<=0 直接返回 none action，不调 refund_points。"""
+        from unittest.mock import patch
+
+        with patch.object(service, "refund_points") as mock_refund:
+            r1 = service.refund_viral_video(user_id, 0, "t0", db_session)
+            r2 = service.refund_viral_video(user_id, None, "t0", db_session)
+            r3 = service.refund_viral_video(user_id, -1.5, "t0", db_session)
+
+        assert r1 == {"success": True, "action": "none", "amount": 0.0}
+        assert r2 == {"success": True, "action": "none", "amount": 0.0}
+        assert r3["action"] == "none"
+        mock_refund.assert_not_called()
+
+    def test_success_path_delegates_to_refund_points(self, service, db_session, user_id):
+        """成功路径：透传 user_id/amount/ref_id=txn_id/source=viral_video。"""
+        from unittest.mock import patch
+
+        expected = {"success": True, "balance": 80.0, "transaction_id": "rf-1"}
+        with patch.object(service, "refund_points", return_value=expected) as mock_refund:
+            result = service.refund_viral_video(user_id, 30.0, "txn-xyz", db_session)
+
+        assert result == expected
+        mock_refund.assert_called_once()
+        rk = mock_refund.call_args.kwargs
+        assert rk["user_id"] == user_id
+        assert rk["amount"] == 30.0
+        assert rk["source"] == "viral_video"
+        assert rk["ref_id"] == "txn-xyz"
+        assert rk["description"] == "爆款视频失败退款"
+
+    def test_exception_returns_failure(self, service, db_session, user_id):
+        """refund_points 抛异常时返回 success=False/action=refund。"""
+        from unittest.mock import patch
+
+        with patch.object(service, "refund_points", side_effect=RuntimeError("conn lost")):
+            result = service.refund_viral_video(user_id, 25.0, "txn-err", db_session)
+
+        assert result["success"] is False
+        assert result["action"] == "refund"
+        assert result["amount"] == 25.0

tests/unit/test_viral_video_routes.py

@@ -402,3 +402,250 @@ class TestConfirmCopy:
             with pytest.raises(HTTPException) as exc:
                 vv_mod.confirm_copy("job-cc2", ConfirmCopyRequest(), authenticated_user=user, session=session)
             assert exc.value.status_code == 409
+
+
+# ── confirm-copy 积分预扣 + estimate-credits 端点 (#2151) ──────────────
+
+
+class TestConfirmCopyPointsDeduction:
+    """confirm_copy 中积分预扣分支（points_enabled=True）。"""
+
+    def test_points_enabled_deducts_successfully(self):
+        """points_enabled=True + 未预付 → 计算预估积分 → deduct_viral_video → 写入 credits_prepaid。"""
+        from fastapi import HTTPException
+
+        from app.api.routes import viral_video as vv_mod
+        from app.schemas.viral_video import ConfirmCopyRequest
+
+        from packages.domain.viral_video import ViralVideoStatus
+
+        user = _auth_user("u1")
+        session = MagicMock()
+        job = _make_job(job_id="job-pay", user_id="u1", status=ViralVideoStatus.COPY_GENERATED)
+        # 默认 credits_prepaid=0, credits_cost=0 → 触发预扣
+        repo = MagicMock()
+        repo.get.return_value = job
+        req = ConfirmCopyRequest(edited_copy="改好的文案")
+
+        mock_svc = MagicMock()
+        mock_svc.deduct_viral_video.return_value = {"success": True, "balance": 100.0, "transaction_id": "txn-1"}
+
+        with (
+            patch.object(vv_mod, "_get_job_repo", return_value=repo),
+            patch.object(vv_mod, "_settings", None, create=True),  # ensure not cached
+            patch("app.config.settings") as mock_settings,
+            patch("packages.domain.points_rules.calculate_viral_video_credits", return_value=5.2),
+            patch("packages.domain.points_rules.resolve_video_dimensions", return_value=(720, 1280)),
+            patch("packages.domain.points_service.PointsService", return_value=mock_svc),
+            patch.object(vv_mod.celery_app, "send_task"),
+        ):
+            mock_settings.points_enabled = True
+            resp = vv_mod.confirm_copy("job-pay", req, authenticated_user=user, session=session)
+
+        # deduct_viral_video 被调用
+        mock_svc.deduct_viral_video.assert_called_once()
+        call_args = mock_svc.deduct_viral_video.call_args
+        assert call_args.args[0] == "u1"  # user_id
+        assert call_args.args[1] == 5.2   # credits
+        assert call_args.args[2] == "job-pay"  # job_id
+        # credits_prepaid / credits_transaction_id 被写入
+        assert job.credits_prepaid == 5.2
+        assert job.credits_transaction_id == "txn-1"
+        assert resp.id == "job-pay"
+        # resume + repo.update 至少调用过（其中一次是 credits 字段更新，一次是 resume 后）
+        job.resume_from_copy_generated.assert_called_once_with(edited_copy="改好的文案")
+
+    def test_points_enabled_insufficient_balance_raises_402(self):
+        """余额不足（deduct_viral_video 返回 success=False）→ HTTP 402。"""
+        import pytest
+        from fastapi import HTTPException
+
+        from app.api.routes import viral_video as vv_mod
+        from app.schemas.viral_video import ConfirmCopyRequest
+
+        from packages.domain.viral_video import ViralVideoStatus
+
+        user = _auth_user("u1")
+        session = MagicMock()
+        job = _make_job(job_id="job-402", user_id="u1", status=ViralVideoStatus.COPY_GENERATED)
+        repo = MagicMock()
+        repo.get.return_value = job
+        req = ConfirmCopyRequest()
+
+        mock_svc = MagicMock()
+        mock_svc.deduct_viral_video.return_value = {"success": False, "balance": 1.5, "transaction_id": None}
+
+        with (
+            patch.object(vv_mod, "_get_job_repo", return_value=repo),
+            patch("app.config.settings") as mock_settings,
+            patch("packages.domain.points_rules.calculate_viral_video_credits", return_value=10.0),
+            patch("packages.domain.points_rules.resolve_video_dimensions", return_value=(720, 1280)),
+            patch("packages.domain.points_service.PointsService", return_value=mock_svc),
+            patch.object(vv_mod.celery_app, "send_task"),
+        ):
+            mock_settings.points_enabled = True
+            with pytest.raises(HTTPException) as exc:
+                vv_mod.confirm_copy("job-402", req, authenticated_user=user, session=session)
+
+        assert exc.value.status_code == 402
+        detail = exc.value.detail
+        assert detail["code"] == "INSUFFICIENT_POINTS"
+        assert detail["required"] == 10.0
+        assert detail["balance"] == 1.5
+        # 预扣失败不应调用 resume 或 send_task
+        job.resume_from_copy_generated.assert_not_called()
+
+    def test_already_paid_skips_deduction(self):
+        """credits_prepaid>0（已经扣过费/重试场景） → 跳过预扣，不调用 PointsService。"""
+        from app.api.routes import viral_video as vv_mod
+        from app.schemas.viral_video import ConfirmCopyRequest
+
+        from packages.domain.viral_video import ViralVideoStatus
+
+        user = _auth_user("u1")
+        session = MagicMock()
+        job = _make_job(
+            job_id="job-paid",
+            user_id="u1",
+            status=ViralVideoStatus.COPY_GENERATED,
+            credits_prepaid=8.5,
+            credits_transaction_id="txn-old",
+        )
+        repo = MagicMock()
+        repo.get.return_value = job
+        req = ConfirmCopyRequest(edited_copy="继续")
+
+        with (
+            patch.object(vv_mod, "_get_job_repo", return_value=repo),
+            patch("app.config.settings") as mock_settings,
+            patch("packages.domain.points_service.PointsService") as MockSvc,
+            patch.object(vv_mod.celery_app, "send_task") as mock_send,
+        ):
+            mock_settings.points_enabled = True
+            resp = vv_mod.confirm_copy("job-paid", req, authenticated_user=user, session=session)
+
+        # PointsService 不应被实例化（没预扣）
+        MockSvc.assert_not_called()
+        job.resume_from_copy_generated.assert_called_once_with(edited_copy="继续")
+        mock_send.assert_called_once_with("worker.run_viral_video_render", args=["job-paid"])
+        assert resp.id == "job-paid"
+        # credits_prepaid 保持不变
+        assert job.credits_prepaid == 8.5
+
+    def test_already_paid_via_credits_cost_skips_deduction(self):
+        """credits_cost>0 也算已付费（兼容旧字段），跳过预扣。"""
+        from app.api.routes import viral_video as vv_mod
+        from app.schemas.viral_video import ConfirmCopyRequest
+
+        from packages.domain.viral_video import ViralVideoStatus
+
+        user = _auth_user("u1")
+        session = MagicMock()
+        job = _make_job(
+            job_id="job-paid2",
+            user_id="u1",
+            status=ViralVideoStatus.COPY_GENERATED,
+            credits_prepaid=0,
+            credits_cost=7.0,
+        )
+        repo = MagicMock()
+        repo.get.return_value = job
+        req = ConfirmCopyRequest()
+
+        with (
+            patch.object(vv_mod, "_get_job_repo", return_value=repo),
+            patch("app.config.settings") as mock_settings,
+            patch("packages.domain.points_service.PointsService") as MockSvc,
+            patch.object(vv_mod.celery_app, "send_task"),
+        ):
+            mock_settings.points_enabled = True
+            vv_mod.confirm_copy("job-paid2", req, authenticated_user=user, session=session)
+
+        MockSvc.assert_not_called()
+
+    def test_points_disabled_skips_deduction(self):
+        """points_enabled=False 时不进入预扣逻辑，保持原流程。"""
+        from app.api.routes import viral_video as vv_mod
+        from app.schemas.viral_video import ConfirmCopyRequest
+
+        from packages.domain.viral_video import ViralVideoStatus
+
+        user = _auth_user("u1")
+        session = MagicMock()
+        job = _make_job(job_id="job-free", user_id="u1", status=ViralVideoStatus.COPY_GENERATED)
+        repo = MagicMock()
+        repo.get.return_value = job
+        req = ConfirmCopyRequest()
+
+        with (
+            patch.object(vv_mod, "_get_job_repo", return_value=repo),
+            patch("app.config.settings") as mock_settings,
+            patch("packages.domain.points_service.PointsService") as MockSvc,
+            patch.object(vv_mod.celery_app, "send_task"),
+        ):
+            mock_settings.points_enabled = False
+            vv_mod.confirm_copy("job-free", req, authenticated_user=user, session=session)
+
+        MockSvc.assert_not_called()
+        job.resume_from_copy_generated.assert_called_once()
+
+
+class TestEstimateCredits:
+    """POST /estimate-credits: 纯计算预估积分。"""
+
+    def test_estimate_returns_float(self):
+        """正常参数应返回 estimated_credits 为 float 且>0。"""
+        from app.api.routes import viral_video as vv_mod
+        from app.schemas.viral_video import EstimateCreditsRequest
+
+        req = EstimateCreditsRequest(model="seedance-2.5", resolution="720p", ratio="9:16", duration=15)
+        # 不需要 db / user 之外的依赖；authenticated_user 仍要传
+        user = _auth_user("u1")
+
+        resp = vv_mod.estimate_credits(req, authenticated_user=user)
+        assert isinstance(resp.estimated_credits, float)
+        assert resp.estimated_credits > 0
+        # 应保留两位小数
+        assert round(resp.estimated_credits, 2) == resp.estimated_credits
+
+    def test_estimate_uses_dimensions_resolver(self):
+        """estimate_credits 应调用 resolve_video_dimensions 和 calculate_viral_video_credits。"""
+        from app.api.routes import viral_video as vv_mod
+        from app.schemas.viral_video import EstimateCreditsRequest
+
+        req = EstimateCreditsRequest(model="seedance-2.5", resolution="1080p", ratio="16:9", duration=20)
+        user = _auth_user("u1")
+
+        with (
+            patch("packages.domain.points_rules.resolve_video_dimensions", return_value=(1920, 1080)) as mock_res,
+            patch("packages.domain.points_rules.calculate_viral_video_credits", return_value=8.88) as mock_calc,
+        ):
+            resp = vv_mod.estimate_credits(req, authenticated_user=user)
+
+        mock_res.assert_called_once_with("1080p", "16:9")
+        mock_calc.assert_called_once()
+        # 传给 calculate 的参数应包含 duration=20, w=1920, h=1080, model="seedance-2.5"
+        args, kwargs = mock_calc.call_args
+        assert args[0] == 20
+        assert args[1] == 1920
+        assert args[2] == 1080
+        assert args[3] == "seedance-2.5"
+        assert resp.estimated_credits == 8.88
+
+    def test_estimate_empty_model_defaults_to_seedance_2_5(self):
+        """model 为空字符串时，传入 calculate 的 model 参数应为 'seedance-2.5'。"""
+        from app.api.routes import viral_video as vv_mod
+        from app.schemas.viral_video import EstimateCreditsRequest
+
+        req = EstimateCreditsRequest(model="", resolution="720p", ratio="9:16", duration=10)
+        user = _auth_user("u1")
+
+        with (
+            patch("packages.domain.points_rules.resolve_video_dimensions", return_value=(720, 1280)),
+            patch("packages.domain.points_rules.calculate_viral_video_credits", return_value=3.5) as mock_calc,
+        ):
+            resp = vv_mod.estimate_credits(req, authenticated_user=user)
+
+        args, kwargs = mock_calc.call_args
+        assert args[3] == "seedance-2.5"
+        assert resp.estimated_credits == 3.5