import { describe, it, expect } from 'vitest';
import { buildLayout, NODE_W, NODE_H, COL_GAP, ROW_GAP } from './buildLayout';
import canonicalFixture from '../__fixtures__/stammbaum.json';
import type { components } from '$lib/generated/api';

type PersonNodeDTO = components['schemas']['PersonNodeDTO'];
type RelationshipDTO = components['schemas']['RelationshipDTO'];

const PARENT = '00000000-0000-0000-0000-000000000001';
const CHILD = '00000000-0000-0000-0000-000000000002';
const SPOUSE_A = '00000000-0000-0000-0000-000000000003';
const SPOUSE_B = '00000000-0000-0000-0000-000000000004';
const NEGATIVE_A = '00000000-0000-0000-0000-000000000005';
const NEGATIVE_B = '00000000-0000-0000-0000-000000000006';
const NEGATIVE_C = '00000000-0000-0000-0000-000000000007';

function node(id: string, displayName: string, generation: number | null = null): PersonNodeDTO {
	return generation == null
		? { id, displayName, familyMember: true }
		: { id, displayName, familyMember: true, generation };
}

function parentEdge(parentId: string, childId: string, id = parentId + childId): RelationshipDTO {
	return {
		id,
		personId: parentId,
		relatedPersonId: childId,
		personDisplayName: '',
		relatedPersonDisplayName: '',
		relationType: 'PARENT_OF'
	};
}

function spouseEdge(a: string, b: string, id = a + b): RelationshipDTO {
	return {
		id,
		personId: a,
		relatedPersonId: b,
		personDisplayName: '',
		relatedPersonDisplayName: '',
		relationType: 'SPOUSE_OF'
	};
}

function yOf(layout: ReturnType<typeof buildLayout>, id: string): number {
	const p = layout.positions.get(id);
	if (!p) throw new Error(`No position for ${id}`);
	return p.y;
}

describe('buildLayout — generation seeding (#689)', () => {
	it('Herbert Cram regression: two parented G=3 spouses share the same row', () => {
		// Both Herbert (G 3) and Clara (G 3) are parented children of their respective
		// G 2 ancestors. They are spouses. Before #689 the iterative longest-path put
		// Herbert one row deeper than Clara via the spouse-pulldown of his loose parent.
		// With imported generation as a strict seed both render at the same y.
		const layout = buildLayout(
			[node(SPOUSE_A, 'Herbert', 3), node(SPOUSE_B, 'Clara', 3)],
			[spouseEdge(SPOUSE_A, SPOUSE_B)]
		);

		expect(yOf(layout, SPOUSE_A)).toBe(yOf(layout, SPOUSE_B));
	});

	it('strict-seed override: imported generation pins rank even when parent edges imply deeper', () => {
		// PARENT has no explicit generation → falls back to 0. CHILD is parented under
		// PARENT but has imported generation = 3. The seeded rank wins; the heuristic
		// must not push CHILD to rank 1.
		const layout = buildLayout(
			[node(PARENT, 'Parent'), node(CHILD, 'Child', 3)],
			[parentEdge(PARENT, CHILD)]
		);

		expect(yOf(layout, CHILD)).toBe(3 * (NODE_H + ROW_GAP));
	});

	it('fallback inherits seeded parent rank: G 2 parent → null-gen child lands at rank 3', () => {
		// CHILD has no imported generation. PARENT has generation = 2. The fallback
		// reads PARENT's rank from the unified rank map (2) and computes 2 + 1 = 3.
		const layout = buildLayout(
			[node(PARENT, 'Parent', 2), node(CHILD, 'Child')],
			[parentEdge(PARENT, CHILD)]
		);

		expect(yOf(layout, CHILD)).toBe(3 * (NODE_H + ROW_GAP));
	});

	it('normalise is a no-op when all ranks are non-negative', () => {
		// Seeded ranks [3, 4, 5] → y must reflect [3, 4, 5] without any shift.
		const G3 = '00000000-0000-0000-0000-000000000031';
		const G4 = '00000000-0000-0000-0000-000000000032';
		const G5 = '00000000-0000-0000-0000-000000000033';
		const layout = buildLayout(
			[node(G3, 'three', 3), node(G4, 'four', 4), node(G5, 'five', 5)],
			[]
		);

		expect(yOf(layout, G3)).toBe(3 * (NODE_H + ROW_GAP));
		expect(yOf(layout, G4)).toBe(4 * (NODE_H + ROW_GAP));
		expect(yOf(layout, G5)).toBe(5 * (NODE_H + ROW_GAP));
	});

	it('normalise shifts negative seeds so min rank becomes 0', () => {
		// Seeded ranks [-1, 0, 1] → after shift they render at [0, 1, 2] y-rows.
		const layout = buildLayout(
			[node(NEGATIVE_A, 'minus-one', -1), node(NEGATIVE_B, 'zero', 0), node(NEGATIVE_C, 'one', 1)],
			[]
		);

		expect(yOf(layout, NEGATIVE_A)).toBe(0);
		expect(yOf(layout, NEGATIVE_B)).toBe(1 * (NODE_H + ROW_GAP));
		expect(yOf(layout, NEGATIVE_C)).toBe(2 * (NODE_H + ROW_GAP));
	});
});

describe('buildLayout — multi-spouse + intra-family marriage (#361)', () => {
	const FOCAL = '00000000-0000-0000-0000-000000000010';
	const SPOUSE_X = '00000000-0000-0000-0000-000000000011';
	const SPOUSE_Y = '00000000-0000-0000-0000-000000000012';
	const UNKNOWN = '00000000-0000-0000-0000-000000000099';

	it('preserves_both_marriages_when_person_has_two_SPOUSE_OF_edges', () => {
		// Before #361 the spouse map was Map<string, string>; the second
		// .set() clobbered the first, so a person with N spouses (Albert de
		// Gruyter, 4) silently lost N-1 of them. Asserting that every spouse
		// has a layout position is the minimal presence check.
		const layout = buildLayout(
			[node(FOCAL, 'Focal', 3), node(SPOUSE_X, 'Alice'), node(SPOUSE_Y, 'Bob')],
			[spouseEdge(FOCAL, SPOUSE_X, 'fx'), spouseEdge(FOCAL, SPOUSE_Y, 'fy')]
		);

		expect(layout.positions.get(FOCAL)).toBeDefined();
		expect(layout.positions.get(SPOUSE_X)).toBeDefined();
		expect(layout.positions.get(SPOUSE_Y)).toBeDefined();
	});

	it('ignores_SPOUSE_OF_edge_with_unknown_relatedPersonId', () => {
		// Robustness gap flagged by NullX during persona review: an edge
		// pointing to a UUID not in the node list must not crash buildLayout
		// and must not introduce a phantom node into the positions map.
		const buildIt = () =>
			buildLayout([node(FOCAL, 'Focal', 3)], [spouseEdge(FOCAL, UNKNOWN, 'fu')]);
		expect(buildIt).not.toThrow();

		const layout = buildIt();
		expect(layout.positions.get(FOCAL)).toBeDefined();
		expect(layout.positions.get(UNKNOWN)).toBeUndefined();
	});

	it('canonical_fixture_assigns_a_position_to_every_node_with_multiple_spouses', () => {
		// Real-data structural assertion against the canonical Stammbaum
		// snapshot. Today the only multi-spouse case is Albert de Gruyter
		// (4 marriages); the assertion stays valid as the graph grows.
		const fixtureNodes = canonicalFixture.nodes as unknown as PersonNodeDTO[];
		const fixtureEdges = canonicalFixture.edges as unknown as RelationshipDTO[];
		const layout = buildLayout(fixtureNodes, fixtureEdges);

		const partners = new Map<string, Set<string>>();
		for (const e of fixtureEdges) {
			if (e.relationType !== 'SPOUSE_OF') continue;
			addPartner(partners, e.personId, e.relatedPersonId);
			addPartner(partners, e.relatedPersonId, e.personId);
		}
		const multi = [...partners.entries()].filter(([, set]) => set.size >= 2);
		expect(multi.length).toBeGreaterThan(0);

		for (const [id, set] of multi) {
			expect(layout.positions.get(id)).toBeDefined();
			for (const partnerId of set) {
				expect(layout.positions.get(partnerId)).toBeDefined();
			}
		}
	});
});

function addPartner(map: Map<string, Set<string>>, key: string, value: string) {
	const s = map.get(key);
	if (s) s.add(value);
	else map.set(key, new Set([value]));
}

describe('buildLayout — multi-spouse ordering (#361)', () => {
	const PARENT = '00000000-0000-0000-0000-0000000000c0';
	const FOCAL = '00000000-0000-0000-0000-0000000000c1';
	const SPOUSE_1925 = '00000000-0000-0000-0000-0000000000c2';
	const SPOUSE_NULL = '00000000-0000-0000-0000-0000000000c3';
	const SPOUSE_1910 = '00000000-0000-0000-0000-0000000000c4';

	function spouseEdgeWithYear(
		a: string,
		b: string,
		fromYear: number | undefined,
		id = a + b
	): RelationshipDTO {
		return { ...spouseEdge(a, b, id), fromYear };
	}

	it('multi_spouses_ordered_by_fromYear_then_displayName', () => {
		// Synthetic year-branch exercise. Focal X is parented (under PARENT)
		// at G=1, with three loose spouses at years 1925, null, 1910. After
		// the sort, the order to the right of X is: 1910, 1925, null —
		// earliest first, NULLS LAST, displayName tiebreaker.
		const layout = buildLayout(
			[
				node(PARENT, 'P', 0),
				node(FOCAL, 'Focal', 1),
				// Names chosen so alphabetical order does NOT match the
				// year-sort order — otherwise the test couldn't tell the
				// two sort keys apart.
				node(SPOUSE_1925, 'Alpha'),
				node(SPOUSE_NULL, 'Beta'),
				node(SPOUSE_1910, 'Gamma')
			],
			[
				parentEdge(PARENT, FOCAL),
				spouseEdgeWithYear(FOCAL, SPOUSE_1925, 1925, 'ya'),
				spouseEdgeWithYear(FOCAL, SPOUSE_NULL, undefined, 'yn'),
				spouseEdgeWithYear(FOCAL, SPOUSE_1910, 1910, 'yg')
			]
		);

		const pos = (id: string) => layout.positions.get(id)!;
		const xFocal = pos(FOCAL).x;
		const x1910 = pos(SPOUSE_1910).x;
		const x1925 = pos(SPOUSE_1925).x;
		const xNull = pos(SPOUSE_NULL).x;

		// All spouses sit to the right of focal …
		expect(x1910).toBeGreaterThan(xFocal);
		expect(x1925).toBeGreaterThan(xFocal);
		expect(xNull).toBeGreaterThan(xFocal);
		// … in year-sort order.
		expect(x1910).toBeLessThan(x1925);
		expect(x1925).toBeLessThan(xNull);
	});

	it('intra_family_marriage_places_both_spouses_adjacent_across_sibling_blocks', () => {
		// AC2 (#361). Two parented persons at the same imported generation,
		// each in a separate sibling block under their own parent, marry each
		// other. Before the fix the block-packer left them split, drawing a
		// long spouse line across an intervening sibling. After the fix the
		// two blocks merge with the spouses sitting on the join boundary.
		const A1 = '00000000-0000-0000-0000-0000000000d1';
		const B1 = '00000000-0000-0000-0000-0000000000d2';
		const A2 = '00000000-0000-0000-0000-0000000000d3';
		const A3 = '00000000-0000-0000-0000-0000000000d4';
		const B2 = '00000000-0000-0000-0000-0000000000d5';

		const layout = buildLayout(
			[
				node(A1, 'A1', 0),
				node(B1, 'B1', 0),
				node(A2, 'A2', 1),
				node(A3, 'A3', 1),
				node(B2, 'B2', 1)
			],
			[
				parentEdge(A1, A2, 'p1'),
				parentEdge(A1, A3, 'p2'),
				parentEdge(B1, B2, 'p3'),
				spouseEdge(A2, B2, 'sp')
			]
		);

		const posA2 = layout.positions.get(A2)!;
		const posB2 = layout.positions.get(B2)!;
		expect(posA2.y).toBe(posB2.y);
		expect(Math.abs(posA2.x - posB2.x)).toBe(NODE_W + COL_GAP);

		// Tighter contract (Sara's cycle-2 follow-up): no third node may sit
		// at an x strictly between the two spouses on the same y. The integer-
		// slot adjacency check above (==NODE_W+COL_GAP) is correct today but
		// would silently pass if a future layout change introduced fractional
		// offsets and placed a node at a non-slot x between the spouses.
		const minX = Math.min(posA2.x, posB2.x);
		const maxX = Math.max(posA2.x, posB2.x);
		for (const [id, p] of layout.positions) {
			if (id === A2 || id === B2) continue;
			if (p.y !== posA2.y) continue;
			expect(p.x <= minX || p.x >= maxX).toBe(true);
		}
	});

	it('canonical_fixture_multi_spouse_falls_through_to_displayName_when_no_fromYear', () => {
		// Real-data assertion: 0 of 28 SPOUSE_OF rows in the canonical fixture
		// have fromYear populated, so the sort collapses to alphabetical by
		// displayName for the only multi-spouse person (Albert de Gruyter).
		const fixtureNodes = canonicalFixture.nodes as unknown as PersonNodeDTO[];
		const fixtureEdges = canonicalFixture.edges as unknown as RelationshipDTO[];

		// Precondition: this test asserts the *fallback* branch of the
		// multi-spouse sort (fromYear ASC NULLS LAST, displayName ASC), which
		// only collapses to alphabetical-by-displayName when every SPOUSE_OF
		// row is null on fromYear. The day any canonical row gets a year
		// backfilled, this test would silently start asserting year-order;
		// fail fast instead so the maintainer either updates the test or
		// splits into a year-branch / name-branch pair.
		const spouseEdgesWithYear = fixtureEdges.filter(
			(e) => e.relationType === 'SPOUSE_OF' && e.fromYear != null
		);
		expect(
			spouseEdgesWithYear,
			'Precondition violated: a canonical SPOUSE_OF row now carries fromYear. Update this test (or split into year-branch / name-branch).'
		).toHaveLength(0);

		const layout = buildLayout(fixtureNodes, fixtureEdges);

		const partners = new Map<string, Set<string>>();
		for (const e of fixtureEdges) {
			if (e.relationType !== 'SPOUSE_OF') continue;
			addPartner(partners, e.personId, e.relatedPersonId);
			addPartner(partners, e.relatedPersonId, e.personId);
		}
		const [multiPersonId, multiPartnerSet] =
			[...partners.entries()].find(([, set]) => set.size >= 3) ?? [];
		expect(multiPersonId).toBeDefined();
		if (!multiPersonId || !multiPartnerSet) return;

		const focalX = layout.positions.get(multiPersonId)!.x;
		const partnerNames = new Map(
			fixtureNodes.filter((n) => multiPartnerSet.has(n.id)).map((n) => [n.id, n.displayName])
		);
		// Spouses ordered alphabetically by displayName, all to the right of focal.
		const sorted = [...multiPartnerSet].sort((a, b) =>
			(partnerNames.get(a) ?? '').localeCompare(partnerNames.get(b) ?? '')
		);
		let prevX = focalX;
		for (const id of sorted) {
			const x = layout.positions.get(id)!.x;
			expect(x).toBeGreaterThan(prevX);
			prevX = x;
		}
	});
});