import { describe, expect, it } from 'bun:test';
import { calculatePlanningInternal, type PlanningRequest } from './leave-planner.core';
import { createOptimizationPresetRules } from './rule-service';

const presets = createOptimizationPresetRules();
const preset = (id: string) => presets.find((rule) => rule.id === id)!;

describe('choosing among obligation solutions', () => {
	it('plans from the solution ranked best before the preferences', () => {
		// The obligation day can take either balance. Before the preferences, the
		// at-risk RTT ranks first because it leaves no at-risk leave unplaced. Funding
		// it with the CP instead would let the RTT gain three days around Easter
		// later; ADR 0010 accepts that loss to run the preferences only once.
		const request: PlanningRequest & { calculationDate: string } = {
			calculationDate: '2026-04-03',
			horizon: { start: '2026-04-03', end: '2026-05-24' },
			balances: [
				{ id: 'cp', type: 'cp', quantity: 1, expiryDate: '2026-06-30' },
				{ id: 'rtt', type: 'rtt', quantity: 1, expiryDate: '2026-05-23' },
			],
			rules: [
				preset('default-unplaced-at-risk'),
				preset('default-supporting-placements'),
				preset('default-non-working-day-gain'),
				{
					id: 'thursday',
					type: 'time_window',
					force: 'obligation',
					startDate: '2026-04-09',
					endDate: '2026-04-09',
					placeDays: 1,
					placeType: 'any',
				},
			],
		};

		const outcome = calculatePlanningInternal(request);

		expect(outcome.kind).toBe('Plan');
		if (outcome.kind !== 'Plan') return;
		expect(outcome.placements).toEqual([
			{
				date: '2026-04-09',
				balanceId: 'rtt',
				type: 'rtt',
				ruleIds: ['thursday'],
				supporting: false,
			},
		]);
		expect(outcome.metrics.unplacedAtRisk).toBe(0);
	});

	it('plans from the next solution when the best-ranked one earns its leave too late', () => {
		const request: PlanningRequest & { calculationDate: string } = {
			calculationDate: '2026-07-09',
			horizon: { start: '2026-07-09', end: '2026-07-25' },
			balances: [
				{
					id: 'cp',
					type: 'cp',
					quantity: 3,
					availableFrom: '2026-07-13',
					expiryDate: '2026-08-10',
				},
			],
			rules: [
				{
					id: 'tuesday',
					type: 'if_then',
					force: 'preference',
					dayOfWeek: 2,
					placeDays: 1,
					placeType: 'any',
					placement: 'auto',
					rewardDays: 2,
					rewardType: 'rtt',
				},
				{
					id: 'late-july',
					type: 'time_window',
					force: 'obligation',
					startDate: '2026-07-23',
					endDate: '2026-08-02',
					placeDays: 2,
					placeType: 'any',
				},
			],
		};

		const outcome = calculatePlanningInternal(request);

		expect(outcome.kind).toBe('Plan');
		if (outcome.kind !== 'Plan') return;
		expect(
			outcome.placements.map(({ date, balanceId, ruleIds }) => [date, balanceId, ruleIds]),
		).toEqual([
			['2026-07-13', 'cp', ['tuesday']],
			['2026-07-23', 'cp', ['late-july']],
			['2026-07-24', 'cp', ['late-july']],
		]);
	});
});