import { describe, expect, test } from "bun:test";
import { draftIncoming, draftSettled, draftStartSave, newDraft, type Draft, formatDateRange, formatPartialDate, formatRating, friendlyError, parsePartialDate, rollupLabel, shortDate } from "../src/format.ts";

describe("formatRating", () => {
  test("5 stars with halves", () => {
    expect(formatRating(90, "5half")).toBe("★★★★½");
    expect(formatRating(100, "5half")).toBe("★★★★★");
    expect(formatRating(80, "5half")).toBe("★★★★☆");
    expect(formatRating(0, "5half")).toBe("☆☆☆☆☆");
  });
  test("null is empty on every scale", () => {
    expect(formatRating(null, "5half")).toBe("");
    expect(formatRating(null, "10")).toBe("");
    expect(formatRating(undefined, "100")).toBe("");
  });
  test("whole stars, 10 and 100 point scales", () => {
    expect(formatRating(90, "5")).toBe("★★★★★");
    expect(formatRating(70, "5")).toBe("★★★★☆");
    expect(formatRating(90, "10")).toBe("9/10");
    expect(formatRating(85, "10")).toBe("8.5/10");
    expect(formatRating(73, "100")).toBe("73/100");
  });
});

describe("formatPartialDate", () => {
  test("renders by precision", () => {
    expect(formatPartialDate({ value: "2025-03", precision: "month" })).toBe("Mar 2025");
    expect(formatPartialDate({ value: "2019", precision: "year" })).toBe("2019");
    expect(formatPartialDate({ value: "2026-09-14", precision: "day" })).toBe("14 Sep 2026");
    expect(formatPartialDate({ value: "2026-09-04T23:30:00-05:00", precision: "day" })).toBe("4 Sep 2026");
    expect(formatPartialDate({ value: "", precision: "unknown" })).toBe("");
    expect(formatPartialDate(null)).toBe("");
  });
});

describe("formatDateRange", () => {
  test("flags dates that are not exact", () => {
    expect(formatDateRange(null, { value: "2025-03", precision: "month" })).toBe("Mar 2025 (no exact date)");
    expect(formatDateRange({ value: "2026-09-02", precision: "day" }, { value: "2026-09-14", precision: "day" })).toBe(
      "2 Sep – 14 Sep 2026",
    );
    expect(formatDateRange({ value: "2025-12-30", precision: "day" }, { value: "2026-01-02", precision: "day" })).toBe(
      "30 Dec 2025 – 2 Jan 2026",
    );
    expect(formatDateRange({ value: "2026-09-02", precision: "day" }, null)).toBe("Started 2 Sep 2026");
    expect(formatDateRange(null, null)).toBe("No dates");
  });
});

describe("parsePartialDate", () => {
  test("accepts year, month and day, rejects the rest", () => {
    expect(parsePartialDate("2019")).toEqual({ value: "2019", precision: "year" });
    expect(parsePartialDate(" 2025-03 ")).toEqual({ value: "2025-03", precision: "month" });
    expect(parsePartialDate("2024-02-29")).toEqual({ value: "2024-02-29", precision: "day" });
    expect(parsePartialDate("2023-02-29")).toBeNull();
    expect(parsePartialDate("03/04/2019")).toBeNull();
    expect(parsePartialDate("")).toBeNull();
  });
});

describe("rollupLabel", () => {
  test("children roll up as 'season 3 of 5'", () => {
    expect(rollupLabel("show", { total: 5, completed: 3 })).toBe("season 3 of 5");
    expect(rollupLabel("show", { total: 5, completed: 0 })).toBe("5 seasons");
    expect(rollupLabel("podcast", { total: 200, completed: 200 })).toBe("all 200 episodes");
    expect(rollupLabel("book", null)).toBeNull();
  });
});

describe("friendlyError", () => {
  const v = (message: string, status = 400) => ({ status, code: "validation", message });
  test("maps validation reasons to plain copy", () => {
    expect(friendlyError(v("customFields.Website: not_url"))).toBe("Website needs a full web address, starting with https://.");
    expect(friendlyError(v("finishedAt: not_date"))).toBe("Finished needs a date like 2025, 2025-03 or 2025-03-14.");
    expect(friendlyError(v("rating: out_of_range"))).toBe("Pick a rating between 0 and 5 stars.");
    expect(friendlyError(v("rating: out_of_range"), { ratingScale: "10" })).toBe("Pick a rating between 0 and 10.");
    expect(friendlyError(v("customFields.Mood: out_of_range"), { ratingScale: "5" })).toBe("Pick a rating for Mood between 0 and 5 stars.");
    expect(friendlyError(v("title: required"))).toBe("Title can't be empty.");
    expect(friendlyError(v("review: too_long"))).toBe("Review is too long. Shorten it and try again.");
    expect(friendlyError(v("password: Too small: expected string to have >=8 characters"))).toBe("Passwords need at least 8 characters.");
    expect(friendlyError(v("title: Too big: expected string to have <=1000 characters"))).toBe("Title is too long. Shorten it and try again.");
    expect(friendlyError(v("mime: unsupported file type"))).toBe("That file type isn't supported. Use an image, a PDF or a text file.");
    expect(friendlyError(v("customFields.Mood: unknown_option"))).toBe("Mood has an option that no longer exists. Pick one from the list.");
    expect(friendlyError(v("displayName: weird_reason"))).toBe("Display name wasn't accepted. Check it and try again.");
  });
  test("413 means the file is too large", () => {
    expect(friendlyError({ status: 413, code: "validation", message: "Request body is too large (max 50 MB)." })).toBe("That file is too large. The limit is 25 MB.");
    expect(friendlyError(v("file: larger than 25 MB"))).toBe("That file is too large. The limit is 25 MB.");
  });
  test("other API errors keep the server's message; unknown errors get a generic line", () => {
    expect(friendlyError({ status: 401, code: "unauthenticated", message: "Wrong username or password." })).toBe("Wrong username or password.");
    expect(friendlyError(new Error("boom"))).toBe("Something went wrong. Try again.");
  });
});

test("shortDate", () => {
  expect(shortDate("2026-10-12T10:00:00")).toBe("12 Oct");
});

describe("review draft sync", () => {
  const draft = (text: string, synced: string): Draft => ({ ...newDraft(synced), text });
  const pick = (d: Draft) => [d.text, d.synced, d.pending];

  test("a rollback after a failed save keeps the local text", () => {
    const save = { was: "First thoughts.", stored: "Second thoughts." };
    let d = draftStartSave(draft("Second thoughts.", save.was), save);
    d = draftIncoming(d, save.stored); // optimistic update
    d = draftIncoming(d, save.was); // rollback
    d = draftSettled(d, save, false);
    expect(pick(d)).toEqual(["Second thoughts.", "First thoughts.", 0]);
  });

  // Two overlapping saves: "a" (was "old"), then "b" (was "a"). Incoming values mirror what the cache does.
  const A = { was: "old", stored: "a" };
  const B = { was: "a", stored: "b" };
  const twoSaves = () => draftIncoming(draftIncoming(draftStartSave({ ...draftStartSave(draft("a", "old"), A), text: "b" }, B), "a"), "b");

  test("two overlapping saves both settle and the flag clears (success, success)", () => {
    let d = twoSaves();
    expect(d.pending).toBe(2);
    d = draftSettled(draftSettled(d, A, true), B, true);
    expect(pick(d)).toEqual(["b", "b", 0]);
    expect(d.echoes).toEqual([]);
  });

  test("two overlapping saves: fail then success ends synced; success then fail keeps text unsaved", () => {
    let d = draftIncoming(twoSaves(), "old"); // A's rollback
    d = draftSettled(draftSettled(d, A, false), B, true);
    expect(pick(d)).toEqual(["b", "b", 0]);
    let e = draftIncoming(twoSaves(), "a"); // B's rollback
    e = draftSettled(draftSettled(e, A, true), B, false);
    expect(pick(e)).toEqual(["b", "a", 0]);
  });

  test("an incoming value that arrives while saving is applied once saving ends", () => {
    const save = { was: "x", stored: "y" };
    let d = draftStartSave(draft("y", "x"), save);
    d = draftIncoming(d, "Restored.");
    expect(d.text).toBe("y");
    d = draftSettled(d, save, true);
    expect(pick(d)).toEqual(["Restored.", "Restored.", 0]);
  });

  test("a change from elsewhere replaces untouched text but not edited text", () => {
    expect(draftIncoming(draft("Second.", "Second."), "First.").text).toBe("First.");
    expect(draftIncoming(draft("Typed.", "Second."), "Other.").text).toBe("Typed.");
  });
});