// running-view.test.mjs — pure function tests for the Running tab
//
// Tests:
//   filterRunningTasks(tasks)       — returns only tasks where state === RUNNING
//   formatElapsed(startISO)         — returns elapsed string like "2m 30s", "1h 5m"
//   fetchRecentExecutions(basePath, fetchFn) — calls /api/executions?since=24h
//   formatDuration(startISO, endISO) — returns duration string for history table
//
// Run with: node --test web/test/running-view.test.mjs

import { describe, it } from 'node:test';
import assert from 'node:assert/strict';

// ── Inline implementations ─────────────────────────────────────────────────────

function extractLogLines(lines, max = 500) {
  if (lines.length <= max) return lines;
  return lines.slice(lines.length - max);
}

function filterRunningTasks(tasks) {
  return tasks.filter(t => t.state === 'RUNNING');
}

function formatElapsed(startISO) {
  if (startISO == null) return '';
  const elapsed = Math.floor((Date.now() - new Date(startISO).getTime()) / 1000);
  if (elapsed < 0) return '0s';
  const h = Math.floor(elapsed / 3600);
  const m = Math.floor((elapsed % 3600) / 60);
  const s = elapsed % 60;
  if (h > 0) return `${h}h ${m}m`;
  if (m > 0) return `${m}m ${s}s`;
  return `${s}s`;
}

async function fetchRecentExecutions(basePath, fetchFn) {
  const res = await fetchFn(`${basePath}/api/executions?since=24h`);
  if (!res.ok) throw new Error(`HTTP ${res.status}`);
  return res.json();
}

// formatDuration: returns human-readable duration between two ISO timestamps.
// If endISO is null/undefined, uses now (for in-progress tasks).
// If startISO is null/undefined, returns '--'.
function formatDuration(startISO, endISO) {
  if (startISO == null) return '--';
  const start = new Date(startISO).getTime();
  const end = endISO != null ? new Date(endISO).getTime() : Date.now();
  const elapsed = Math.max(0, Math.floor((end - start) / 1000));
  const h = Math.floor(elapsed / 3600);
  const m = Math.floor((elapsed % 3600) / 60);
  const s = elapsed % 60;
  if (h > 0) return `${h}h ${m}m`;
  if (m > 0) return `${m}m ${s}s`;
  return `${s}s`;
}

// ── Tests: filterRunningTasks ─────────────────────────────────────────────────

describe('filterRunningTasks', () => {
  it('returns only RUNNING tasks from mixed list', () => {
    const tasks = [
      { id: '1', state: 'RUNNING' },
      { id: '2', state: 'COMPLETED' },
      { id: '3', state: 'RUNNING' },
      { id: '4', state: 'QUEUED' },
    ];
    const result = filterRunningTasks(tasks);
    assert.equal(result.length, 2);
    assert.ok(result.every(t => t.state === 'RUNNING'));
  });

  it('returns empty array when no tasks are RUNNING', () => {
    const tasks = [
      { id: '1', state: 'COMPLETED' },
      { id: '2', state: 'QUEUED' },
    ];
    assert.deepEqual(filterRunningTasks(tasks), []);
  });

  it('handles empty task list', () => {
    assert.deepEqual(filterRunningTasks([]), []);
  });

  it('does not include QUEUED tasks', () => {
    const tasks = [{ id: '1', state: 'QUEUED' }];
    assert.deepEqual(filterRunningTasks(tasks), []);
  });

  it('does not include READY tasks', () => {
    const tasks = [{ id: '1', state: 'READY' }];
    assert.deepEqual(filterRunningTasks(tasks), []);
  });
});

// ── Tests: formatElapsed ──────────────────────────────────────────────────────

describe('formatElapsed', () => {
  it('returns empty string for null', () => {
    assert.equal(formatElapsed(null), '');
  });

  it('returns empty string for undefined', () => {
    assert.equal(formatElapsed(undefined), '');
  });

  it('returns Xs format for elapsed under a minute', () => {
    const start = new Date(Date.now() - 45 * 1000).toISOString();
    assert.equal(formatElapsed(start), '45s');
  });

  it('returns Xm Ys format for 2 minutes 30 seconds ago', () => {
    const start = new Date(Date.now() - (2 * 60 + 30) * 1000).toISOString();
    assert.equal(formatElapsed(start), '2m 30s');
  });

  it('returns Xh Ym format for over an hour', () => {
    const start = new Date(Date.now() - (1 * 3600 + 5 * 60) * 1000).toISOString();
    assert.equal(formatElapsed(start), '1h 5m');
  });

  it('returns 0s for future timestamp', () => {
    const start = new Date(Date.now() + 60 * 1000).toISOString();
    assert.equal(formatElapsed(start), '0s');
  });
});

// ── Tests: fetchRecentExecutions ──────────────────────────────────────────────

describe('fetchRecentExecutions', () => {
  it('calls /api/executions?since=24h with basePath prefix', async () => {
    let calledUrl;
    const mockFetch = async (url) => {
      calledUrl = url;
      return { ok: true, json: async () => [] };
    };
    await fetchRecentExecutions('/claudomator', mockFetch);
    assert.equal(calledUrl, '/claudomator/api/executions?since=24h');
  });

  it('calls with empty basePath', async () => {
    let calledUrl;
    const mockFetch = async (url) => {
      calledUrl = url;
      return { ok: true, json: async () => [] };
    };
    await fetchRecentExecutions('', mockFetch);
    assert.equal(calledUrl, '/api/executions?since=24h');
  });

  it('returns parsed JSON response', async () => {
    const data = [{ id: 'exec-1', task_id: 't-1', status: 'COMPLETED' }];
    const mockFetch = async () => ({ ok: true, json: async () => data });
    const result = await fetchRecentExecutions('', mockFetch);
    assert.deepEqual(result, data);
  });

  it('throws on non-OK HTTP status', async () => {
    const mockFetch = async () => ({ ok: false, status: 500 });
    await assert.rejects(
      () => fetchRecentExecutions('', mockFetch),
      /HTTP 500/,
    );
  });
});

// ── Tests: formatDuration ─────────────────────────────────────────────────────

describe('formatDuration', () => {
  it('returns -- for null startISO', () => {
    assert.equal(formatDuration(null, null), '--');
  });

  it('returns -- for undefined startISO', () => {
    assert.equal(formatDuration(undefined, null), '--');
  });

  it('returns Xs for duration under a minute', () => {
    const start = new Date(Date.now() - 45 * 1000).toISOString();
    const end = new Date().toISOString();
    assert.equal(formatDuration(start, end), '45s');
  });

  it('returns Xm Ys for duration between 1 and 60 minutes', () => {
    const start = new Date(Date.now() - (3 * 60 + 15) * 1000).toISOString();
    const end = new Date().toISOString();
    assert.equal(formatDuration(start, end), '3m 15s');
  });

  it('returns Xh Ym for duration over an hour', () => {
    const start = new Date(Date.now() - (2 * 3600 + 30 * 60) * 1000).toISOString();
    const end = new Date().toISOString();
    assert.equal(formatDuration(start, end), '2h 30m');
  });

  it('uses current time when endISO is null', () => {
    // Start was 10s ago, no end → should return ~10s
    const start = new Date(Date.now() - 10 * 1000).toISOString();
    const result = formatDuration(start, null);
    assert.match(result, /^\d+s$/);
  });
});

// ── sortExecutionsDesc: inline implementation ─────────────────────────────────

function sortExecutionsDesc(executions) {
  return [...executions].sort((a, b) =>
    new Date(b.started_at).getTime() - new Date(a.started_at).getTime(),
  );
}

// ── Tests: sortExecutionsDesc ─────────────────────────────────────────────────

describe('sortExecutionsDesc', () => {
  it('sorts executions newest first', () => {
    const execs = [
      { id: 'a', started_at: '2024-01-01T00:00:00Z' },
      { id: 'b', started_at: '2024-01-03T00:00:00Z' },
      { id: 'c', started_at: '2024-01-02T00:00:00Z' },
    ];
    const result = sortExecutionsDesc(execs);
    assert.equal(result[0].id, 'b');
    assert.equal(result[1].id, 'c');
    assert.equal(result[2].id, 'a');
  });

  it('returns empty array for empty input', () => {
    assert.deepEqual(sortExecutionsDesc([]), []);
  });

  it('does not mutate the original array', () => {
    const execs = [
      { id: 'a', started_at: '2024-01-01T00:00:00Z' },
      { id: 'b', started_at: '2024-01-03T00:00:00Z' },
    ];
    const copy = [execs[0], execs[1]];
    sortExecutionsDesc(execs);
    assert.deepEqual(execs, copy);
  });

  it('returns single-element array unchanged', () => {
    const execs = [{ id: 'a', started_at: '2024-01-01T00:00:00Z' }];
    assert.equal(sortExecutionsDesc(execs)[0].id, 'a');
  });
});

// ── Tests: filterRunningTasks (explicit empty input check) ─────────────────────

describe('filterRunningTasks (empty input)', () => {
  it('returns [] for empty input', () => {
    assert.deepEqual(filterRunningTasks([]), []);
  });
});

// ── Tests: extractLogLines ────────────────────────────────────────────────────

describe('extractLogLines', () => {
  it('returns lines unchanged when count is below max', () => {
    const lines = ['a', 'b', 'c'];
    assert.deepEqual(extractLogLines(lines, 500), lines);
  });

  it('returns lines unchanged when count equals max', () => {
    const lines = Array.from({ length: 500 }, (_, i) => `line${i}`);
    assert.equal(extractLogLines(lines, 500).length, 500);
    assert.equal(extractLogLines(lines, 500)[0], 'line0');
  });

  it('truncates to last max lines when count exceeds max', () => {
    const lines = Array.from({ length: 600 }, (_, i) => `line${i}`);
    const result = extractLogLines(lines, 500);
    assert.equal(result.length, 500);
    assert.equal(result[0], 'line100');
    assert.equal(result[499], 'line599');
  });

  it('uses default max of 500', () => {
    const lines = Array.from({ length: 501 }, (_, i) => `line${i}`);
    const result = extractLogLines(lines);
    assert.equal(result.length, 500);
    assert.equal(result[0], 'line1');
  });

  it('returns empty array for empty input', () => {
    assert.deepEqual(extractLogLines([]), []);
  });

  it('does not mutate the original array', () => {
    const lines = Array.from({ length: 600 }, (_, i) => `line${i}`);
    const copy = [...lines];
    extractLogLines(lines, 500);
    assert.deepEqual(lines, copy);
  });
});