import { describe, it, expect } from "vitest";
import {
  normaliseSku,
  escapeForPbString,
  classifyMatch,
  matchTierLabel,
  explainMatch,
} from "@/lib/server/price-list-match";

/**
 * Unit tests for the pure helpers inside the SKU matcher.
 * PB-dependent helpers (findPriceListBySku, findFirstPriceListBySku)
 * are exercised via the live-PB smoke test — here we just lock the
 * canonical-form math.
 *
 * The helpers live in src/lib/server/price-list-match.ts (not in
 * price-list-search.ts) because they're used by the re-price route
 * + the matcher-bench smoke script and have a single owner.
 */

describe("normaliseSku", () => {
  it("uppercases ASCII letters", () => {
    expect(normaliseSku("jeitd-06")).toBe("JEITD06");
    expect(normaliseSku("ts-drl-12-55")).toBe("TSDRL1255");
  });

  it("strips dashes, slashes, dots, spaces, and other non-alphanumerics", () => {
    expect(normaliseSku("JEITD-06")).toBe("JEITD06");
    expect(normaliseSku("JEI/TD/06")).toBe("JEITD06");
    expect(normaliseSku("JEI.TD.06")).toBe("JEITD06");
    expect(normaliseSku("JEI TD 06")).toBe("JEITD06");
  });

  it("collapses buyer-style casing into the same canonical form", () => {
    expect(normaliseSku("ts-12x55")).toBe("TS12X55");
    expect(normaliseSku("TS-12X55")).toBe("TS12X55");
    expect(normaliseSku("ts12X55")).toBe("TS12X55");
  });

  it("returns empty string for empty / null / undefined input", () => {
    expect(normaliseSku("")).toBe("");
    expect(normaliseSku("   ")).toBe("");
    expect(normaliseSku(null)).toBe("");
    expect(normaliseSku(undefined)).toBe("");
  });

  it("preserves digits so a fully numeric SKU round-trips", () => {
    expect(normaliseSku("001-23-456")).toBe("00123456");
  });
});

describe("escapeForPbString", () => {
  it("doubles embedded double quotes", () => {
    expect(escapeForPbString('Acme "Pro" line')).toBe('Acme \\"Pro\\" line');
  });
  it("is a no-op on plain text", () => {
    expect(escapeForPbString("TS-DRL-12-55")).toBe("TS-DRL-12-55");
  });
  it("returns an empty string for an empty input", () => {
    expect(escapeForPbString("")).toBe("");
  });
});

describe("classifyMatch", () => {
  it("returns 1 for an exact SKU match", () => {
    expect(
      classifyMatch("JEITD-06", { sku: "JEITD-06", sku_normalised: "JEITD06" }),
    ).toBe(1);
  });
  it("returns 1 when the canonical form matches exactly (raw differs)", () => {
    expect(
      classifyMatch("jeitd06", { sku: "JEITD-06", sku_normalised: "JEITD06" }),
    ).toBe(1);
  });
  it("returns 2 when the canonical form is a substring of the row's normalised SKU", () => {
    expect(
      classifyMatch("JEITD", { sku: "JEITD-D11", sku_normalised: "JEITDD11" }),
    ).toBe(2);
  });
  it("returns 3 when neither SKU nor normalised is a substring match", () => {
    expect(
      classifyMatch("bosch grinder", {
        sku: "JEITD-06",
        sku_normalised: "JEITD06",
      }),
    ).toBe(3);
  });
});

describe("matchTierLabel", () => {
  it("labels Tier 1 'Exact SKU'", () => {
    expect(matchTierLabel(1)).toBe("Exact SKU");
  });
  it("labels Tier 2 'SKU substring'", () => {
    expect(matchTierLabel(2)).toBe("SKU substring");
  });
  it("labels Tier 3 'Description / brand match'", () => {
    expect(matchTierLabel(3)).toBe("Description / brand match");
  });
});

describe("explainMatch", () => {
  const baseMatch = {
    id: "row1",
    sku: "JEITD-06",
    sku_normalised: "JEITD06",
    description: "TWIST DRILL 6MM DIA",
    brand: "JEI",
    category: "twist_drill",
    subcategory: "",
    supplier: "JEISA - WESTSCOTT GROUP",
    cost_price: 100,
    selling_price: 125,
    unit: "each",
    updated: "",
    specifications: { material: "HSS", diameter_mm: 6 },
    search_text: "",
  };

  it("renders 'exact SKU match' for Tier 1", () => {
    const why = explainMatch("JEITD-06", baseMatch);
    expect(why).toContain("JEITD-06");
    expect(why).toContain("exact SKU match");
    expect(why).toContain("JEISA");
  });
  it("renders 'SKU substring' for Tier 2", () => {
    const why = explainMatch("JEITD", baseMatch);
    expect(why).toContain("JEITD-06");
    expect(why).toContain("SKU substring");
  });
  it("for Tier 3, points at the brand or spec that matched", () => {
    const why = explainMatch("HSS twist", baseMatch);
    expect(why).toContain("JEITD-06");
    // Either brand or material appears, depending on which word matched.
    expect(why).toMatch(/(brand|material):/);
  });
  it("never returns empty", () => {
    const why = explainMatch("XYZNOPE", baseMatch);
    expect(why.length).toBeGreaterThan(0);
  });
  it("caps the explanation length so the picker modal doesn't wrap strangely", () => {
    const long = explainMatch("JEITD-06", {
      ...baseMatch,
      supplier: "A very long supplier name ".repeat(20).trim(),
    });
    expect(long.length).toBeLessThanOrEqual(240);
  });
});

// Reference: keep `normaliseSku` reachable through the import
// list so dead-code elimination doesn't strip it during refactors.
void normaliseSku;