import { describe, expect, test } from "bun:test";
import {
  formatFileSize,
  formatSecondsShort,
  formatDuration,
  formatNumber,
  formatTokens,
  formatRelativeTime,
  formatRelativeTimeAgo,
  formatLogMetadata,
} from "../format";

describe("formatFileSize", () => {
  test("formats bytes", () => {
    expect(formatFileSize(500)).toBe("500 bytes");
  });

  test("formats kilobytes", () => {
    expect(formatFileSize(1536)).toBe("1.5KB");
  });

  test("formats megabytes", () => {
    expect(formatFileSize(1.5 * 1024 * 1024)).toBe("1.5MB");
  });

  test("formats gigabytes", () => {
    expect(formatFileSize(2 * 1024 * 1024 * 1024)).toBe("2GB");
  });

  test("removes trailing .0", () => {
    expect(formatFileSize(1024)).toBe("1KB");
  });
});

describe("formatSecondsShort", () => {
  test("formats milliseconds to seconds", () => {
    expect(formatSecondsShort(1234)).toBe("1.2s");
  });

  test("formats zero", () => {
    expect(formatSecondsShort(0)).toBe("0.0s");
  });

  test("formats sub-second", () => {
    expect(formatSecondsShort(500)).toBe("0.5s");
  });
});

describe("formatDuration", () => {
  test("formats 0 as 0s", () => {
    expect(formatDuration(0)).toBe("0s");
  });

  test("formats seconds", () => {
    expect(formatDuration(5000)).toBe("5s");
  });

  test("formats minutes and seconds", () => {
    expect(formatDuration(125000)).toBe("2m 5s");
  });

  test("formats hours", () => {
    expect(formatDuration(3661000)).toBe("1h 1m 1s");
  });

  test("formats days", () => {
    expect(formatDuration(90000000)).toBe("1d 1h 0m");
  });

  test("hideTrailingZeros removes zero components", () => {
    expect(formatDuration(3600000, { hideTrailingZeros: true })).toBe("1h");
    expect(formatDuration(60000, { hideTrailingZeros: true })).toBe("1m");
  });

  test("mostSignificantOnly returns largest unit", () => {
    expect(formatDuration(90000000, { mostSignificantOnly: true })).toBe("1d");
    expect(formatDuration(3661000, { mostSignificantOnly: true })).toBe("1h");
  });
});

describe("formatNumber", () => {
  test("formats small numbers as-is", () => {
    expect(formatNumber(900)).toBe("900");
  });

  test("formats thousands with k suffix", () => {
    expect(formatNumber(1321)).toBe("1.3k");
  });

  test("formats millions", () => {
    expect(formatNumber(1500000)).toBe("1.5m");
  });

  test("formats 0 as-is", () => {
    expect(formatNumber(0)).toBe("0");
  });

  test("formats billions", () => {
    expect(formatNumber(1500000000)).toBe("1.5b");
  });
});

describe("formatTokens", () => {
  test("removes .0 from formatted number", () => {
    expect(formatTokens(1000)).toBe("1k");
  });

  test("formats small numbers", () => {
    expect(formatTokens(500)).toBe("500");
  });

  test("formats 1000 without .0", () => {
    expect(formatTokens(1000)).toBe("1k");
  });

  test("formats 1500 as 1.5k", () => {
    expect(formatTokens(1500)).toBe("1.5k");
  });
});

describe("formatRelativeTime", () => {
  const now = new Date("2026-01-15T12:00:00Z");

  test("formats seconds ago", () => {
    const date = new Date("2026-01-15T11:59:30Z");
    expect(formatRelativeTime(date, { now })).toBe("30s ago");
  });

  test("formats minutes ago", () => {
    const date = new Date("2026-01-15T11:55:00Z");
    expect(formatRelativeTime(date, { now })).toBe("5m ago");
  });

  test("formats future time", () => {
    const date = new Date("2026-01-15T13:00:00Z");
    expect(formatRelativeTime(date, { now })).toBe("in 1h");
  });

  test("handles zero difference", () => {
    expect(formatRelativeTime(now, { now })).toBe("0s ago");
  });

  test("formats hours ago", () => {
    const date = new Date("2026-01-15T09:00:00Z");
    expect(formatRelativeTime(date, { now })).toBe("3h ago");
  });

  test("formats days ago", () => {
    const date = new Date("2026-01-13T12:00:00Z");
    expect(formatRelativeTime(date, { now })).toBe("2d ago");
  });

  test("formats weeks ago", () => {
    const date = new Date("2026-01-01T12:00:00Z");
    expect(formatRelativeTime(date, { now })).toBe("2w ago");
  });
});

describe("formatRelativeTimeAgo", () => {
  const now = new Date("2026-01-15T12:00:00Z");

  test("formats past date with 'ago' suffix", () => {
    const date = new Date("2026-01-15T11:59:30Z");
    const result = formatRelativeTimeAgo(date, { now });
    expect(result).toBe("30s ago");
  });

  test("formats future date without 'ago' suffix", () => {
    const date = new Date("2026-01-15T13:00:00Z");
    const result = formatRelativeTimeAgo(date, { now });
    expect(result).toBe("in 1h");
  });

  test("formats minutes ago", () => {
    const date = new Date("2026-01-15T11:55:00Z");
    const result = formatRelativeTimeAgo(date, { now });
    expect(result).toBe("5m ago");
  });

  test("formats hours ago", () => {
    const date = new Date("2026-01-15T09:00:00Z");
    const result = formatRelativeTimeAgo(date, { now });
    expect(result).toBe("3h ago");
  });

  test("formats days ago", () => {
    const date = new Date("2026-01-13T12:00:00Z");
    const result = formatRelativeTimeAgo(date, { now });
    expect(result).toBe("2d ago");
  });

  test("handles date equal to now as past", () => {
    // date === now, treated as past (not future)
    const result = formatRelativeTimeAgo(now, { now });
    expect(result).toBe("0s ago");
  });

  test("uses numeric always for past dates", () => {
    // Should always use numeric format for past dates
    const date = new Date("2026-01-15T11:59:00Z");
    const result = formatRelativeTimeAgo(date, { now });
    expect(result).toContain("ago");
  });

  test("future date does not contain 'ago'", () => {
    const date = new Date("2026-01-15T14:00:00Z");
    const result = formatRelativeTimeAgo(date, { now });
    expect(result).not.toContain("ago");
  });
});

describe("formatLogMetadata", () => {
  // Use a date very recently in the past so it always shows "Xs ago" or similar
  const modified = new Date(Date.now() - 5 * 60 * 1000); // 5 minutes ago

  test("includes relative time and message count", () => {
    const result = formatLogMetadata({
      modified,
      messageCount: 10,
    });
    expect(result).toContain("ago");
    expect(result).toContain("10 messages");
  });

  test("uses fileSize instead of messageCount when provided", () => {
    const result = formatLogMetadata({
      modified,
      messageCount: 5,
      fileSize: 1536,
    });
    expect(result).toContain("1.5KB");
    expect(result).not.toContain("messages");
  });

  test("includes gitBranch when provided", () => {
    const result = formatLogMetadata({
      modified,
      messageCount: 3,
      gitBranch: "main",
    });
    expect(result).toContain("main");
  });

  test("omits gitBranch when not provided", () => {
    const result = formatLogMetadata({
      modified,
      messageCount: 3,
    });
    // Should not have a dangling separator from missing branch
    expect(result).not.toMatch(/^ · | · $/);
  });

  test("includes tag when provided", () => {
    const result = formatLogMetadata({
      modified,
      messageCount: 3,
      tag: "my-tag",
    });
    expect(result).toContain("#my-tag");
  });

  test("includes agentSetting when provided", () => {
    const result = formatLogMetadata({
      modified,
      messageCount: 3,
      agentSetting: "custom-agent",
    });
    expect(result).toContain("@custom-agent");
  });

  test("includes prNumber when provided", () => {
    const result = formatLogMetadata({
      modified,
      messageCount: 3,
      prNumber: 42,
    });
    expect(result).toContain("#42");
  });

  test("includes prRepository with prNumber when both provided", () => {
    const result = formatLogMetadata({
      modified,
      messageCount: 3,
      prNumber: 99,
      prRepository: "owner/repo",
    });
    expect(result).toContain("owner/repo#99");
  });

  test("parts are joined with ' · ' separator", () => {
    const result = formatLogMetadata({
      modified,
      messageCount: 5,
      gitBranch: "feat/x",
    });
    expect(result).toContain(" · ");
  });
});