import { describe, it, expect } from 'vitest';
import {
  capChips, doneStats, backlogSeries, throughputSeries, areaPath,
  type KpiTask,
} from '../src/server/board/viewmodel.js';

const day = 24 * 3600 * 1000;
const iso = (msAgo: number) => new Date(Date.now() - msAgo).toISOString();

describe('capChips', () => {
  it('shows all chips when at most max', () => {
    const chips = [{ name: 'claude', minutes: 5 }, { name: 'codex', minutes: 2 }];
    expect(capChips(chips, 3)).toEqual({ visible: chips, hidden: 0 });
  });
  it('caps at max and reports the hidden count', () => {
    const chips = ['a', 'b', 'c', 'd', 'e'].map((name) => ({ name, minutes: 1 }));
    const r = capChips(chips, 3);
    expect(r.visible.map((c) => c.name)).toEqual(['a', 'b', 'c']);
    expect(r.hidden).toBe(2);
  });
});

describe('doneStats', () => {
  it('computes share and weekly count, excluding cancelled from total', () => {
    const tasks: KpiTask[] = [
      { id: '1', status: 'done', updatedAt: iso(2 * day) },
      { id: '2', status: 'done', updatedAt: iso(10 * day) },
      { id: '3', status: 'open' },
      { id: '4', status: 'cancelled' },
    ];
    const r = doneStats(tasks);
    expect(r.done).toBe(2);
    expect(r.total).toBe(3); // cancelled excluded
    expect(r.pct).toBe(67);
    expect(r.doneThisWeek).toBe(1);
  });
  it('handles empty input', () => {
    expect(doneStats([])).toEqual({ done: 0, total: 0, pct: 0, doneThisWeek: 0 });
  });
});

describe('backlogSeries', () => {
  it('returns one value per day, oldest first, ending today', () => {
    const tasks: KpiTask[] = [
      { id: '1', status: 'open', createdAt: iso(3 * day) },
      { id: '2', status: 'done', createdAt: iso(13 * day), updatedAt: iso(1 * day) },
    ];
    const s = backlogSeries(tasks, 14);
    expect(s).toHaveLength(14);
    expect(s[13]).toBe(1); // today: only the open task is backlog
    expect(s[0]).toBe(1); // 13 days ago: only task 2 existed and was not done yet
  });
});

describe('throughputSeries', () => {
  it('counts done tasks per day', () => {
    const tasks: KpiTask[] = [
      { id: '1', status: 'done', updatedAt: iso(0) },
      { id: '2', status: 'done', updatedAt: iso(0) },
      { id: '3', status: 'done', updatedAt: iso(5 * day) },
      { id: '4', status: 'open', updatedAt: iso(0) },
    ];
    const s = throughputSeries(tasks, 14);
    expect(s).toHaveLength(14);
    expect(s[13]).toBe(2); // today
    expect(s[8]).toBe(1); // 5 days ago
    expect(s.reduce((a, b) => a + b, 0)).toBe(3);
  });
});

describe('areaPath', () => {
  it('builds line and area paths scaled to width/height', () => {
    const { line, area } = areaPath([0, 5, 10], 100, 50);
    expect(line).toBe('M0,50 L50,25 L100,0');
    expect(area).toBe('M0,50 L50,25 L100,0 L100,50 L0,50 Z');
  });
  it('flattens when all values are equal (no division by zero)', () => {
    const { line } = areaPath([3, 3, 3], 90, 30);
    expect(line).toBe('M0,15 L45,15 L90,15');
  });
});