import { describe, expect, test } from "vitest";
import { composeFrontmatter, docFrontmatterToPairs, parseNote, serializeFrontmatter } from "./frontmatter";

describe("parseNote", () => {
  test("splits frontmatter and body, strips BOM", () => {
    const { frontmatter, body } = parseNote("---\ntitle: Hi\n---\nHello\n");
    expect(frontmatter).toEqual({ title: "Hi" });
    expect(body).toBe("Hello\n");
  });
  test("no frontmatter returns empty object and full body", () => {
    expect(parseNote("Just text")).toEqual({ frontmatter: {}, body: "Just text" });
  });
});

describe("docFrontmatterToPairs", () => {
  test("converts a record to ordered string pairs", () => {
    const pairs = docFrontmatterToPairs({
      title: "Hello",
      date: new Date("2026-02-06T00:00:00Z"),
      draft: true,
    });
    expect(pairs).toEqual([
      { key: "title", value: "Hello" },
      { key: "date", value: "2026-02-06" },
      { key: "draft", value: "true" },
    ]);
  });
  test("empty record yields an empty array", () => {
    expect(docFrontmatterToPairs({})).toEqual([]);
  });
});

describe("composeFrontmatter", () => {
  const doc = [
    { key: "title", value: "Hello" },
    { key: "date", value: "2026-02-06" },
  ];
  const editable = [
    { key: "layout", value: "post" },
    { key: "kind", value: "essay" },
  ];

  test("merge on: document fields first, then editable rows", () => {
    expect(composeFrontmatter(doc, editable, true)).toEqual([
      { key: "title", value: "Hello" },
      { key: "date", value: "2026-02-06" },
      { key: "layout", value: "post" },
      { key: "kind", value: "essay" },
    ]);
  });
  test("merge off: only the editable rows", () => {
    expect(composeFrontmatter(doc, editable, false)).toEqual(editable);
  });
  test("an editable row overrides a document field with the same key (doc field dropped)", () => {
    const ed = [
      { key: "title", value: "Override" },
      { key: "layout", value: "post" },
    ];
    expect(composeFrontmatter(doc, ed, true)).toEqual([
      { key: "date", value: "2026-02-06" },
      { key: "title", value: "Override" },
      { key: "layout", value: "post" },
    ]);
  });
  test("blank-key editable rows are skipped", () => {
    const ed = [
      { key: "", value: "" },
      { key: "layout", value: "post" },
      { key: "  ", value: "x" },
    ];
    expect(composeFrontmatter([], ed, true)).toEqual([{ key: "layout", value: "post" }]);
  });
  test("duplicate editable keys: last value wins at first position", () => {
    const ed = [
      { key: "tag", value: "a" },
      { key: "tag", value: "b" },
    ];
    expect(composeFrontmatter([], ed, false)).toEqual([{ key: "tag", value: "b" }]);
  });
});

describe("serializeFrontmatter", () => {
  test("bare-safe values unquoted, others JSON-quoted", () => {
    const out = serializeFrontmatter([
      { key: "layout", value: "post" },
      { key: "date", value: "2026-06-11" },
      { key: "title", value: "On making a game" },
      { key: "description", value: "And how it's different" },
    ]);
    expect(out).toBe(
      `---\nlayout: post\ndate: 2026-06-11\ntitle: On making a game\ndescription: "And how it's different"\n---\n`
    );
  });
  test("empty value becomes quoted empty string", () => {
    expect(serializeFrontmatter([{ key: "tags", value: "" }])).toBe(`---\ntags: ""\n---\n`);
  });
  test("YAML-special boolean strings are quoted", () => {
    expect(serializeFrontmatter([{ key: "draft", value: "true" }])).toBe(`---\ndraft: "true"\n---\n`);
    expect(serializeFrontmatter([{ key: "published", value: "false" }])).toBe(`---\npublished: "false"\n---\n`);
  });
  test("numeric-looking strings are quoted", () => {
    expect(serializeFrontmatter([{ key: "n", value: "42" }])).toBe(`---\nn: "42"\n---\n`);
  });
  test("ISO date strings remain bare (not quoted as numeric)", () => {
    expect(serializeFrontmatter([{ key: "date", value: "2026-06-11" }])).toBe(`---\ndate: 2026-06-11\n---\n`);
  });
});