import { describe, it, expect } from "vitest";
import { extractCardReference } from "@/lib/linking/reference";

describe("extractCardReference", () => {
  it("finds a bracketed reference at the end of the subject", () => {
    expect(extractCardReference("feat(stock): inline qty editing [#42]")).toBe(42);
  });

  it("finds one anywhere in the message, including the body", () => {
    expect(extractCardReference("[#7] fix: thing")).toBe(7);
    expect(extractCardReference("fix: thing\n\nRefs [#7]\n")).toBe(7);
  });

  it("returns null when there is none", () => {
    expect(extractCardReference("feat(stock): inline qty editing")).toBeNull();
    expect(extractCardReference("")).toBeNull();
  });

  it("ignores a bare #42 without brackets", () => {
    // Bare hashes appear constantly in prose — colours, issue numbers from
    // other systems, ordinals. Requiring brackets makes the reference a
    // deliberate act rather than a guess.
    expect(extractCardReference("fix: matches #42 in the old tracker")).toBeNull();
    expect(extractCardReference("style: use #ff8a5c")).toBeNull();
  });

  it("takes the first reference when several appear", () => {
    // One commit links to at most one card, so a second reference cannot be
    // honoured. First wins, deterministically.
    expect(extractCardReference("fix: thing [#3] and also [#9]")).toBe(3);
  });

  it("rejects zero and negative numbers", () => {
    expect(extractCardReference("fix: thing [#0]")).toBeNull();
    expect(extractCardReference("fix: thing [#-4]")).toBeNull();
  });

  it("rejects a non-numeric reference", () => {
    expect(extractCardReference("fix: thing [#abc]")).toBeNull();
    expect(extractCardReference("fix: thing [#]")).toBeNull();
  });

  it("tolerates whitespace inside the brackets", () => {
    expect(extractCardReference("fix: thing [# 42 ]")).toBe(42);
  });

  it("rejects an absurdly large number rather than overflowing", () => {
    expect(extractCardReference(`fix: thing [#${"9".repeat(20)}]`)).toBeNull();
  });
});