"""``ChartService`` 的单元测试（任务 8）。

覆盖需求：
- 4.1 / 4.2：预测带由 ``compute`` 产出的**真实** CI 网格直接渲染，**不含任何硬编码
  比例系数**——断言渲染层消费的上下界与传入数据逐点一致（不缩放、不推导）。
- 4.4：一级动力学非对称带——上下半宽不相等的形态被原样保留。
- 11.5：多 CQA 叠加图，并按木桶原理标注短板 CQA（shelf_life 最短者）。
- 14.3：统一红 / 黄 / 绿 QbD 风险色板，识别中英文与高 / 中 / 低三档。
- 14.1 关联：加载内嵌中文字体；缺失 / 禁用时降级英文标签，不报错。
- design Property 7：matplotlib / numpy 缺失时优雅降级（ok=False + warning），不崩溃。

测试自包含：不触网；图像仅校验是否成功生成内联 PNG 与其结构属性，
不对像素做脆弱断言。导入路径由 tests/conftest.py 设置（底座以顶层包 ``services`` 导入）。
"""

from __future__ import annotations

import math

import pytest

from services.chart_service import (  # noqa: E402
    ChartService,
    CIBand,
    ObservedTrace,
    ChartResult,
    QBD_RISK_COLORS,
)

np = pytest.importorskip("numpy")
pytest.importorskip("matplotlib")


# ---------------------------------------------------------------------------
# 测试夹具：构造真实 CI 网格（零级喇叭形 / 一级非对称）
# ---------------------------------------------------------------------------

def _zero_order_band(label="含量", spec_limit=95.0, spec_type="lower", shelf_life=None):
    """零级（线性）模型的对称喇叭形 CI 网格：半宽随 |t - t̄| 增大。"""
    times = np.linspace(0.0, 24.0, 25)
    t_bar = times.mean()
    point = 100.0 - 0.3 * times  # 含量随时间线性下降
    # 对称喇叭形半宽：随偏离均值增大（模拟 SE_pred 的展宽，但由"上游"给出）。
    half = 0.5 + 0.05 * np.abs(times - t_bar)
    lower = point - half
    upper = point + half
    return CIBand(
        times=times, point=point, lower=lower, upper=upper,
        label=label, spec_type=spec_type, spec_limit=spec_limit,
        shelf_life=shelf_life, observed_t=[0, 6, 12], observed_y=[100.1, 98.0, 96.5],
    )


def _first_order_band(label="杂质", spec_limit=1.0, spec_type="upper", shelf_life=None):
    """一级模型在实数空间的非对称 CI 网格：上半宽 != 下半宽。"""
    times = np.linspace(0.0, 24.0, 25)
    # 在对数空间对称，经 exp 映射回实数 → 非对称包络。
    ln_point = math.log(0.2) + 0.06 * times
    ln_half = 0.1 + 0.02 * times
    point = np.exp(ln_point)
    lower = np.exp(ln_point - ln_half)
    upper = np.exp(ln_point + ln_half)
    return CIBand(
        times=times, point=point, lower=lower, upper=upper,
        label=label, spec_type=spec_type, spec_limit=spec_limit,
        shelf_life=shelf_life,
    )


# ---------------------------------------------------------------------------
# QbD 风险色板（需求 14.3）
# ---------------------------------------------------------------------------

def test_risk_palette_is_red_yellow_green():
    palette = ChartService.risk_palette()
    assert palette["high"] == "#dc3545"    # 红
    assert palette["medium"] == "#ffc107"  # 黄
    assert palette["low"] == "#28a745"     # 绿
    # 返回副本，外部修改不影响内部常量。
    palette["high"] = "#000000"
    assert QBD_RISK_COLORS["high"] == "#dc3545"


@pytest.mark.parametrize(
    "level,expected",
    [
        ("high", "high"), ("High", "high"), ("高危", "high"), ("不合格", "high"),
        ("non_compliant", "high"), ("red", "high"),
        ("medium", "medium"), ("临界", "medium"), ("marginal", "medium"),
        ("warning", "medium"), ("yellow", "medium"),
        ("low", "low"), ("合格", "low"), ("compliant", "low"), ("pass", "low"),
        ("green", "low"),
    ],
)
def test_normalize_risk_level_recognizes_zh_en_aliases(level, expected):
    assert ChartService.normalize_risk_level(level) == expected


def test_normalize_risk_level_substring_and_default():
    # 子串匹配（如「高风险等级」）。
    assert ChartService.normalize_risk_level("高风险等级") == "high"
    # 无法识别 → 默认中危（保守）。
    assert ChartService.normalize_risk_level("unknown-xyz") == "medium"
    assert ChartService.normalize_risk_level(None) == "medium"


def test_risk_color_maps_to_palette():
    assert ChartService.risk_color("高危") == QBD_RISK_COLORS["high"]
    assert ChartService.risk_color("临界") == QBD_RISK_COLORS["medium"]
    assert ChartService.risk_color("合格") == QBD_RISK_COLORS["low"]


# ---------------------------------------------------------------------------
# 真实 CI 带：零硬编码系数（需求 4.1 / 4.2）
# ---------------------------------------------------------------------------

def test_validate_band_returns_arrays_unchanged():
    """validate_band 原样返回上下界，不做任何缩放 / 推导（需求 4.2 硬保证）。"""
    band = _zero_order_band()
    times, point, lower, upper = ChartService.validate_band(band)
    np.testing.assert_array_almost_equal(times, np.asarray(band.times, dtype=float))
    np.testing.assert_array_almost_equal(point, np.asarray(band.point, dtype=float))
    # 关键：上下界与传入数据逐点一致 —— 渲染层不重算带宽。
    np.testing.assert_array_almost_equal(lower, np.asarray(band.lower, dtype=float))
    np.testing.assert_array_almost_equal(upper, np.asarray(band.upper, dtype=float))


def test_validate_band_rejects_mismatched_lengths():
    band = CIBand(times=[0, 1, 2], point=[1, 2], lower=[0, 1], upper=[2, 3])
    with pytest.raises(ValueError, match="长度不一致"):
        ChartService.validate_band(band)


def test_validate_band_rejects_empty():
    band = CIBand(times=[], point=[], lower=[], upper=[])
    with pytest.raises(ValueError, match="为空"):
        ChartService.validate_band(band)


def test_validate_band_rejects_lower_above_upper():
    band = CIBand(times=[0, 1], point=[1, 1], lower=[2, 2], upper=[1, 1])
    with pytest.raises(ValueError, match="lower > upper"):
        ChartService.validate_band(band)


def test_band_halfwidths_match_input_exactly_no_scaling():
    """半宽 == 传入 (upper-point) 与 (point-lower)，证明无 se_scale 之类硬编码系数。"""
    band = _zero_order_band()
    up_half, low_half = ChartService.band_halfwidths(band)
    expected_up = np.asarray(band.upper, dtype=float) - np.asarray(band.point, dtype=float)
    expected_low = np.asarray(band.point, dtype=float) - np.asarray(band.lower, dtype=float)
    np.testing.assert_array_almost_equal(up_half, expected_up)
    np.testing.assert_array_almost_equal(low_half, expected_low)


def test_zero_order_band_widens_with_extrapolation():
    """零级带半宽随 |t - t̄| 单调不减（喇叭形，需求 4.3 关联）。"""
    band = _zero_order_band()
    up_half, _ = ChartService.band_halfwidths(band)
    times = np.asarray(band.times, dtype=float)
    dist = np.abs(times - times.mean())
    order = np.argsort(dist)
    sorted_half = up_half[order]
    # 按到均值距离排序后，半宽应单调不减。
    assert np.all(np.diff(sorted_half) >= -1e-9)


# ---------------------------------------------------------------------------
# 一级动力学非对称带（需求 4.4）
# ---------------------------------------------------------------------------

def test_first_order_band_is_asymmetric():
    """一级动力学：对 t>0，upper-point != point-lower（非对称，需求 4.4）。"""
    band = _first_order_band()
    up_half, low_half = ChartService.band_halfwidths(band)
    # 至少在外推段存在显著非对称（上半宽大于下半宽）。
    assert np.any(np.abs(up_half - low_half) > 1e-6)
    # exp 映射特性：上半宽整体 >= 下半宽。
    assert np.mean(up_half[1:]) > np.mean(low_half[1:])


# ---------------------------------------------------------------------------
# 渲染：单 CQA 预测带
# ---------------------------------------------------------------------------

def test_prediction_band_renders_png():
    svc = ChartService()
    result = svc.prediction_band(_zero_order_band(shelf_life=18.0))
    assert isinstance(result, ChartResult)
    assert result.ok is True
    assert result.image_base64.startswith("data:image/png;base64,")
    assert len(result.image_base64) > 100
    assert bool(result) is True


def test_prediction_band_renders_first_order():
    svc = ChartService()
    result = svc.prediction_band(_first_order_band(shelf_life=12.0))
    assert result.ok is True
    assert result.image_base64.startswith("data:image/png;base64,")


def test_prediction_band_rejects_bad_data():
    svc = ChartService()
    bad = CIBand(times=[0, 1], point=[1, 1], lower=[5, 5], upper=[1, 1])
    result = svc.prediction_band(bad)
    assert result.ok is False
    assert "不合法" in result.error


# ---------------------------------------------------------------------------
# 多 CQA 叠加 / 分图 + 短板标注（需求 11.5）
# ---------------------------------------------------------------------------

def test_resolve_limiting_picks_shortest_shelf_life():
    """缺省短板判定取 shelf_life 最短者（木桶原理）。"""
    assay = _zero_order_band(label="含量", shelf_life=24.0)
    impurity = _first_order_band(label="杂质", shelf_life=15.0)
    limiting = ChartService._resolve_limiting([assay, impurity], None)
    assert limiting == "杂质"


def test_resolve_limiting_respects_explicit():
    assay = _zero_order_band(label="含量", shelf_life=24.0)
    impurity = _first_order_band(label="杂质", shelf_life=15.0)
    limiting = ChartService._resolve_limiting([assay, impurity], "含量")
    assert limiting == "含量"


def test_multi_cqa_panels_renders_and_marks_limiting():
    svc = ChartService()
    assay = _zero_order_band(label="含量", shelf_life=24.0)
    impurity = _first_order_band(label="杂质", shelf_life=15.0)
    result = svc.multi_cqa_overlay([assay, impurity], mode="panels")
    assert result.ok is True
    assert result.image_base64.startswith("data:image/png;base64,")


def test_multi_cqa_overlay_mode_renders():
    svc = ChartService()
    assay = _zero_order_band(label="含量", shelf_life=24.0)
    impurity = _first_order_band(label="杂质", shelf_life=15.0)
    result = svc.multi_cqa_overlay(
        [assay, impurity], limiting_cqa="杂质", mode="overlay"
    )
    assert result.ok is True
    assert result.image_base64.startswith("data:image/png;base64,")


def test_multi_cqa_empty_returns_error():
    svc = ChartService()
    result = svc.multi_cqa_overlay([])
    assert result.ok is False
    assert "未提供" in result.error


def test_multi_cqa_rejects_bad_band():
    svc = ChartService()
    bad = CIBand(times=[0, 1], point=[1, 1], lower=[5, 5], upper=[1, 1])
    result = svc.multi_cqa_overlay([bad])
    assert result.ok is False
    assert "不合法" in result.error


# ---------------------------------------------------------------------------
# 中文字体加载与英文降级（需求 14.1 关联）
# ---------------------------------------------------------------------------

def test_chinese_font_available_by_default():
    """内嵌字体存在时，默认以中文标签渲染。"""
    svc = ChartService()
    # 仓库内置 fonts/NotoSansSC-Regular.otf，应被发现。
    assert svc.chinese_available is True
    assert svc.lang == "zh"
    assert svc.label("time_axis") == "时间 (月)"


def test_english_fallback_when_chinese_disabled():
    """显式关闭中文（或字体缺失）时降级英文标签，不报错。"""
    svc = ChartService(enable_chinese=False)
    assert svc.chinese_available is False
    assert svc.lang == "en"
    assert svc.label("time_axis") == "Time (months)"
    # 仍能正常渲染（英文标签）；用 ASCII CQA 名避免缺字形告警。
    result = svc.prediction_band(_zero_order_band(label="Assay"))
    assert result.ok is True
    assert result.used_chinese_font is False


def test_missing_font_path_degrades_to_english(tmp_path):
    """字体路径不存在 → 降级英文标签，渲染照常成功。"""
    missing = tmp_path / "no-such-font.otf"
    svc = ChartService(font_path=str(missing))
    assert svc.chinese_available is False
    assert svc.lang == "en"
    result = svc.prediction_band(_first_order_band(label="Impurity"))
    assert result.ok is True
    assert result.used_chinese_font is False


def test_label_unknown_key_returns_key():
    svc = ChartService()
    assert svc.label("___nonexistent___") == "___nonexistent___"


# ---------------------------------------------------------------------------
# 重依赖缺失优雅降级（design Property 7）
# ---------------------------------------------------------------------------

def test_graceful_degradation_when_backend_missing(monkeypatch):
    """模拟 matplotlib / numpy 不可用：返回 ok=False + warning，绝不抛异常。"""
    svc = ChartService()
    monkeypatch.setattr(svc, "_ensure_backend", lambda: None)

    pred = svc.prediction_band(_zero_order_band())
    assert pred.ok is False
    assert "matplotlib" in pred.warning

    multi = svc.multi_cqa_overlay([_zero_order_band()])
    assert multi.ok is False
    assert "matplotlib" in multi.warning


if __name__ == "__main__":  # pragma: no cover
    import sys
    sys.exit(pytest.main([__file__, "-v"]))


# ---------------------------------------------------------------------------
# 实测数据趋势图（数据梳理可视化）
# ---------------------------------------------------------------------------

def test_observed_trends_renders_png():
    """多条实测序列渲染为内联 PNG，且不依赖任何外推数据。"""
    svc = ChartService()
    traces = [
        ObservedTrace(times=[0, 3, 6, 9, 12], values=[0.1, 0.13, 0.16, 0.19, 0.22],
                      label="B1@25C_60RH"),
        ObservedTrace(times=[0, 3, 6], values=[0.1, 0.5, 1.0], label="B1@40C_75RH"),
    ]
    res = svc.observed_trends(traces, spec_limit=0.5)
    assert isinstance(res, ChartResult)
    assert res.ok
    assert res.image_base64.startswith("data:image/png;base64,")


def test_observed_trends_no_spec_line_when_absent():
    """未提供规格限时仍能正常渲染（不画规格参考线，不报错）。"""
    svc = ChartService()
    res = svc.observed_trends(
        [ObservedTrace(times=[0, 6, 12], values=[0.2, 0.3, 0.4], label="B1")],
        spec_limit=None,
    )
    assert res.ok
    assert res.image_base64.startswith("data:image/png;base64,")


def test_observed_trends_empty_returns_not_ok():
    """无有效序列时优雅返回 ok=False，不抛异常。"""
    svc = ChartService()
    res = svc.observed_trends([])
    assert not res.ok
    assert res.error


# ---------------------------------------------------------------------------
# 目标预测时间点高亮标记（用户反馈：直观感受预测点位置）
# ---------------------------------------------------------------------------

def test_prediction_band_with_target_timepoints_renders():
    """带目标预测时间点的预测带应成功渲染（标记不报错）。"""
    band = _zero_order_band()
    band.target_timepoints = [12.0, 24.0]
    res = ChartService().prediction_band(band)
    assert res.ok
    assert res.image_base64.startswith("data:image/png;base64,")


def test_prediction_band_target_timepoints_out_of_range_safe():
    """目标时间点超出网格范围时跳过标记、仍正常渲染（不报错）。"""
    band = _zero_order_band()
    band.target_timepoints = [999.0]  # 超出 0–24 网格
    res = ChartService().prediction_band(band)
    assert res.ok


def test_prediction_band_no_target_timepoints_backward_compatible():
    """未提供目标时间点时与旧行为一致，正常渲染。"""
    band = _zero_order_band()
    assert band.target_timepoints is None
    res = ChartService().prediction_band(band)
    assert res.ok


# ---------------------------------------------------------------------------
# 自适应可视化新增图型（adaptive-report-visualization 任务 9）
# ---------------------------------------------------------------------------

def _is_png_datauri(s: str) -> bool:
    return isinstance(s, str) and s.startswith("data:image/png;base64,")


def test_grouped_bar_renders_png():
    svc = ChartService()
    res = svc.grouped_bar(["20μg", "40μg", "60μg"], [5.3, 6.1, 4.8],
                          title="水分", value_label="%",
                          reference_lines=[{"value": 12.0, "label": "≤12.0", "kind": "upper"}])
    assert res.ok and _is_png_datauri(res.image_base64)


def test_grouped_dot_variant():
    svc = ChartService()
    res = svc.grouped_bar(["A", "B"], [1.0, 2.0], dot=True)
    assert res.ok and _is_png_datauri(res.image_base64)


def test_distribution_dot_with_av_line():
    svc = ChartService()
    res = svc.distribution_dot([99.19, 100.0, 97.68, 96.0, 98.81], title="含量均匀度",
                               value_label="%", mean=98.336,
                               reference_lines=[{"value": 15.0, "label": "AV≤15", "kind": "av"}])
    assert res.ok and _is_png_datauri(res.image_base64)


def test_distribution_box_variant():
    svc = ChartService()
    res = svc.distribution_dot([99.1, 100.0, 97.6, 98.8, 96.0], box=True)
    assert res.ok and _is_png_datauri(res.image_base64)


def test_status_matrix_renders_with_marks():
    svc = ChartService()
    rows = [{"label": "水分 20μg", "status": "pass"},
            {"label": "总杂 40μg", "status": "fail"},
            {"label": "含量% 60μg", "status": "na"}]
    res = svc.status_matrix(rows, title="限度符合性")
    assert res.ok and _is_png_datauri(res.image_base64)


def test_new_charts_english_fallback_when_no_font():
    # 显式关闭中文字体：仍应成功出图（英文/符号降级）。
    svc = ChartService(enable_chinese=False)
    assert svc.lang == "en"
    assert svc.grouped_bar(["A", "B"], [1, 2]).ok
    assert svc.distribution_dot([1, 2, 3]).ok
    assert svc.status_matrix([{"label": "x", "status": "pass"}]).ok