import { describe, expect, it } from 'vitest';

import { formatBytes, formatEta, formatSpeed, PopupStore, progressPercent } from '../../src/popup/store.js';
import type { TaskSummary } from '../../src/shared/protocol/index.js';

function summary(over: Partial<TaskSummary> = {}): TaskSummary {
  return {
    taskId: 't1',
    filename: 'file.zip',
    saveDir: '/home/u/Downloads',
    url: 'https://example.com/file.zip',
    downloadedBytes: 0,
    state: 'downloading',
    speedBps: 0,
    resumable: true,
    segments: 1,
    createdAt: '2026-01-01T00:00:00Z',
    ...over,
  };
}

describe('PopupStore', () => {
  it('starts empty', () => {
    const s = new PopupStore();
    expect(s.rows()).toEqual([]);
    expect(s.size).toBe(0);
  });

  it('seeds from download.list', () => {
    const s = new PopupStore();
    s.setInitial([summary({ taskId: 'a' }), summary({ taskId: 'b', filename: 'b.zip' })]);
    expect(s.size).toBe(2);
  });

  it('adds a row on event.task.added', () => {
    const s = new PopupStore();
    s.onAdded({ taskId: 't1', summary: summary() });
    expect(s.rows()).toHaveLength(1);
    expect(s.rows()[0]!.filename).toBe('file.zip');
  });

  it('applies event.task.progress as a patch, not a rebuild', () => {
    const s = new PopupStore();
    s.setInitial([summary({ taskId: 't1', sizeBytes: 1000 })]);
    s.onProgress({ at: '2026-01-01T00:00:00Z', tasks: [{ taskId: 't1', downloadedBytes: 500, speedBps: 2048, etaSeconds: 4 }] });
    const row = s.rows()[0]!;
    expect(row.downloadedBytes).toBe(500);
    expect(row.speedBps).toBe(2048);
    expect(row.etaSeconds).toBe(4);
    expect(row.filename).toBe('file.zip'); // untouched by the patch
  });

  it('ignores a progress tick for an unknown task rather than inserting a partial row', () => {
    const s = new PopupStore();
    s.onProgress({ at: '2026-01-01T00:00:00Z', tasks: [{ taskId: 'ghost', downloadedBytes: 1, speedBps: 1 }] });
    expect(s.size).toBe(0);
  });

  it('replaces the row on event.task.state when a summary is attached', () => {
    const s = new PopupStore();
    s.setInitial([summary({ taskId: 't1', state: 'downloading' })]);
    s.onState({ taskId: 't1', state: 'paused', summary: summary({ taskId: 't1', state: 'paused' }) });
    expect(s.rows()[0]!.state).toBe('paused');
  });

  it('updates just the state when event.task.state has no summary', () => {
    const s = new PopupStore();
    s.setInitial([summary({ taskId: 't1', state: 'downloading' })]);
    s.onState({ taskId: 't1', state: 'failed' });
    expect(s.rows()[0]!.state).toBe('failed');
  });

  it('drops the row on event.task.removed', () => {
    const s = new PopupStore();
    s.setInitial([summary({ taskId: 't1' })]);
    s.onRemoved({ taskId: 't1', deletedFile: false });
    expect(s.size).toBe(0);
  });

  it('sorts active tasks before paused/finished ones, then by filename', () => {
    const s = new PopupStore();
    s.setInitial([
      summary({ taskId: 'z', filename: 'z-paused.zip', state: 'paused' }),
      summary({ taskId: 'b', filename: 'b-active.zip', state: 'downloading' }),
      summary({ taskId: 'a', filename: 'a-active.zip', state: 'downloading' }),
    ]);
    expect(s.rows().map((r) => r.taskId)).toEqual(['a', 'b', 'z']);
  });
});

describe('format helpers', () => {
  it('formats bytes', () => {
    expect(formatBytes(500)).toBe('500 B');
    expect(formatBytes(2048)).toBe('2.0 KB');
    expect(formatBytes(5 * 1024 * 1024)).toBe('5.0 MB');
  });

  it('formats speed, blank when idle', () => {
    expect(formatSpeed(0)).toBe('');
    expect(formatSpeed(1024)).toBe('1.0 KB/s');
  });

  it('formats eta, blank when unknown', () => {
    expect(formatEta(null)).toBe('');
    expect(formatEta(-1)).toBe('');
    expect(formatEta(45)).toBe('45s');
    expect(formatEta(125)).toBe('2m 5s');
  });

  it('computes a progress percent, null when size is unknown', () => {
    expect(progressPercent({ taskId: 't', filename: 'f', state: 'downloading', downloadedBytes: 50, sizeBytes: 100, speedBps: 0, etaSeconds: null })).toBe(50);
    expect(progressPercent({ taskId: 't', filename: 'f', state: 'downloading', downloadedBytes: 50, sizeBytes: null, speedBps: 0, etaSeconds: null })).toBeNull();
  });
});