import { describe, expect, it } from "vitest";
import {
  computeFreightDensity,
  densityPcfToFreightClass,
  formatFreightClassDensityTip,
  formatNmfcDensityClassChartZh,
  freightClassDensityMismatchMessage,
  NMFC_DENSITY_CLASS_BANDS,
  NMFC_NON_DENSITY_FREIGHT_CLASSES,
} from "@/lib/flock/freight-class-density";

describe("freight-class-density（NMFTA 2025 十三档，对齐 Flock）", () => {
  it("官网样例：6×48×40×48、2000lb → 320 ft³ / 6.25 PCF → Class 125", () => {
    const d = computeFreightDensity({
      lengthIn: 48,
      widthIn: 40,
      heightIn: 48,
      quantity: 6,
      totalWeightLb: 2000,
    });
    expect(d).not.toBeNull();
    expect(d!.cubicFeet).toBeCloseTo(320, 2);
    expect(d!.densityPcf).toBeCloseTo(6.25, 2);
    expect(d!.suggestedClass).toBe("125");
    expect(d!.rangeLabelZh).toBe("6 – <8");
    expect(formatFreightClassDensityTip(d)).toContain("基于密度的货运等级：125");
  });

  it("官网样例：2×48×40×48、5000lb → ~46.88 PCF → Class 55", () => {
    const d = computeFreightDensity({
      lengthIn: 48,
      widthIn: 40,
      heightIn: 48,
      quantity: 2,
      totalWeightLb: 5000,
    });
    expect(d!.suggestedClass).toBe("55");
    expect(d!.densityPcf).toBeCloseTo(46.875, 2);
  });

  it("十三档边界全部对齐 NMFTA「X but less than Y」", () => {
    const cases: Array<[number, string]> = [
      [0.5, "400"],
      [0.999, "400"],
      [1, "300"],
      [1.999, "300"],
      [2, "250"],
      [3.999, "250"],
      [4, "175"],
      [5.999, "175"],
      [6, "125"],
      [7.999, "125"],
      [8, "100"],
      [9.999, "100"],
      [10, "92.5"],
      [11.999, "92.5"],
      [12, "85"],
      [14.999, "85"],
      [15, "70"],
      [22.499, "70"],
      [22.5, "65"],
      [29.999, "65"],
      [30, "60"],
      [34.999, "60"],
      [35, "55"],
      [49.999, "55"],
      [50, "50"],
      [100, "50"],
    ];
    for (const [pcf, expected] of cases) {
      expect(densityPcfToFreightClass(pcf), `pcf=${pcf}`).toBe(expected);
    }
  });

  it("密度推算绝不会落到商品条件档 77.5/110/150/200/500", () => {
    const densClasses = new Set(
      NMFC_DENSITY_CLASS_BANDS.map((b) => b.freightClass),
    );
    for (const c of NMFC_NON_DENSITY_FREIGHT_CLASSES) {
      expect(densClasses.has(c)).toBe(false);
    }
    // 扫一圈常见 PCF，结果必须在十三档内
    for (let p = 0.1; p <= 60; p += 0.37) {
      const c = densityPcfToFreightClass(p);
      expect(c).not.toBeNull();
      expect(densClasses.has(c!)).toBe(true);
      expect(
        (NMFC_NON_DENSITY_FREIGHT_CLASSES as readonly string[]).includes(c!),
      ).toBe(false);
    }
  });

  it("体积↑或重量↓ → 等级数字↑（用户感知：参数越「稀」等级越高）", () => {
    const base = {
      lengthIn: 48,
      widthIn: 40,
      heightIn: 48,
      quantity: 1,
      totalWeightLb: 1000,
    };
    const dense = computeFreightDensity(base)!; // ~18.75 → 70
    const bulkier = computeFreightDensity({ ...base, heightIn: 96 })!; // 体积翻倍
    const lighter = computeFreightDensity({ ...base, totalWeightLb: 200 })!;
    expect(Number(bulkier.suggestedClass)).toBeGreaterThan(
      Number(dense.suggestedClass),
    );
    expect(Number(lighter.suggestedClass)).toBeGreaterThan(
      Number(dense.suggestedClass),
    );
  });

  it("分档表文案含全部十三档与非密度档说明", () => {
    const chart = formatNmfcDensityClassChartZh();
    for (const b of NMFC_DENSITY_CLASS_BANDS) {
      expect(chart).toContain(`等级 ${b.freightClass}`);
    }
    expect(chart).toContain("77.5");
    expect(formatFreightClassDensityTip(null)).toContain("总体积");
  });

  it("手选与推算不一致才提示", () => {
    const d = computeFreightDensity({
      lengthIn: 48,
      widthIn: 40,
      heightIn: 48,
      quantity: 6,
      totalWeightLb: 2000,
    });
    expect(freightClassDensityMismatchMessage("100", d)).toMatch(
      /请选择货运等级 125/,
    );
    expect(freightClassDensityMismatchMessage("125", d)).toBeNull();
    expect(freightClassDensityMismatchMessage("density", d)).toBeNull();
  });
});