import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
import { newFixture, type Fixture } from '../helpers/fixture.js';
import { parseMetricsQuery } from '../../src/lib/metrics.js';

let fixture: Fixture;
beforeEach(async () => {
    vi.resetModules();
    fixture = await newFixture([]);
});
afterEach(async () => {
    vi.restoreAllMocks();
    await fixture.cleanup();
});

describe('historical metrics', () => {
    it('weights occupancy by time and excludes failed checks and collection gaps', async () => {
        const { recordMetrics, readMetrics } =
            await import('../../src/lib/server/fleet/metrics.js');
        const sample = { server: 'one', game: 't5', map: 'Moon', players: 2, capacity: 4 };
        const at = Date.UTC(2026, 0, 2, 12);
        recordMetrics([sample], at);
        recordMetrics([{ ...sample, players: 0 }], at + 30_000);
        recordMetrics([{ ...sample, players: null }], at + 60_000);
        const result = readMetrics(1, at + 3600_000);
        expect(result.summary.active * 3600).toBeCloseTo(30);
        expect(result.summary.idle * 3600).toBeCloseTo(30);
        expect(result.summary.unknown * 3600).toBeCloseTo(90);
        expect(result.summary.playerHours * 3600).toBeCloseTo(60);
        expect(result.points.reduce((sum, p) => sum + p.observed, 0)).toBeCloseTo(
            result.summary.observed
        );
    });

    it('counts no-empty map time from players even without capacity or with unknown lobbies', async () => {
        const { recordMetrics, readMetrics } =
            await import('../../src/lib/server/fleet/metrics.js');
        const at = Date.UTC(2026, 0, 2, 12);
        const sample = { server: 'one', game: 't5', map: 'Moon', players: 4, capacity: 4 };
        recordMetrics([sample, { ...sample, server: 'two' }], at);
        recordMetrics(
            [
                { ...sample, players: 1 },
                { ...sample, server: 'two', players: 2 }
            ],
            at + 30_000
        );
        recordMetrics(
            [
                { ...sample, capacity: null },
                { ...sample, server: 'two', capacity: null }
            ],
            at + 60_000
        );
        recordMetrics([sample, { ...sample, server: 'two', players: null }], at + 90_000);
        const result = readMetrics(1, at + 120_000);
        expect(result.maps[0].noEmpty * 3600).toBeCloseTo(120);
        expect(result.maps[0].availabilityObserved * 3600).toBeCloseTo(120);
        expect(result.maps[0].availabilityUnknown).toBe(0);
    });

    it('treats an empty spare as available and all-unknown map observations as unknown', async () => {
        const { recordMetrics, readMetrics } =
            await import('../../src/lib/server/fleet/metrics.js');
        const at = Date.UTC(2026, 0, 2, 12);
        const sample = { server: 'one', game: 't5', map: 'Moon', players: 1, capacity: null };
        recordMetrics([sample, { ...sample, server: 'two', players: 0 }], at);
        recordMetrics(
            [
                { ...sample, players: null },
                { ...sample, server: 'two', players: 0 }
            ],
            at + 30_000
        );
        recordMetrics(
            [
                { ...sample, players: null },
                { ...sample, server: 'two', players: null }
            ],
            at + 60_000
        );
        const result = readMetrics(1, at + 90_000);
        expect(result.maps[0].noEmpty).toBe(0);
        expect(result.maps[0].availabilityObserved * 3600).toBeCloseTo(60);
        expect(result.maps[0].availabilityUnknown * 3600).toBeCloseTo(30);
        expect(result.pooledAvailability.value).toBe(0);
        expect(result.pooledAvailability.unknownMapHours * 3600).toBeCloseTo(30);
    });

    it('clips the reporting window and splits observations across UTC chart boundaries', async () => {
        const { recordMetrics, readMetrics } =
            await import('../../src/lib/server/fleet/metrics.js');
        const midnight = Date.UTC(2026, 0, 2);
        const sample = { server: 'one', game: 't5', map: 'Moon', players: 1, capacity: 4 };
        recordMetrics([sample], midnight - 15_000);
        let result = readMetrics(1, midnight + 15_000);
        expect(result.points.filter((p) => p.active > 0).map((p) => p.active * 3600)).toEqual([
            15, 15
        ]);
        result = readMetrics(1, midnight + 86400_000);
        expect(result.summary.active * 3600).toBeCloseTo(75);
        expect(result.points.reduce((sum, p) => sum + p.active, 0)).toBeCloseTo(
            result.summary.active
        );
    });

    it('retains history without a live server and prunes observations older than 31 days', async () => {
        const { recordMetrics, readMetrics } =
            await import('../../src/lib/server/fleet/metrics.js');
        const { db } = await import('../../src/lib/server/db/index.js');
        const at = Date.UTC(2026, 0, 2);
        const sample = { server: 'removed', game: 't6', map: 'Town', players: 1, capacity: null };
        recordMetrics([sample], at);
        expect(readMetrics(1, at + 30_000).servers[0].server).toBe('removed');
        recordMetrics([sample], at + 32 * 86400_000);
        expect(db().prepare('SELECT COUNT(*) AS n FROM metric_samples').get()).toEqual({ n: 1 });
    });

    it('distinguishes retained history, an empty range, and current collection targets', async () => {
        const { recordMetrics, readMetrics } =
            await import('../../src/lib/server/fleet/metrics.js');
        const { db } = await import('../../src/lib/server/db/index.js');
        const at = Date.UTC(2026, 0, 2);
        expect(readMetrics(1, at)).toMatchObject({
            firstRetainedSampleAt: null,
            latestSampleAt: null,
            registeredServerCount: 0,
            servers: [],
            maps: []
        });
        db().prepare('INSERT INTO servers (name, destroyed_at) VALUES (?, ?)').run('current', null);
        db()
            .prepare('INSERT INTO servers (name, destroyed_at) VALUES (?, ?)')
            .run('removed', new Date(at).toISOString());
        const sample = { server: 'removed', game: 't6', map: 'Town', players: 1, capacity: null };
        recordMetrics([sample], at);
        const emptyRange = readMetrics(1, at + 2 * 86400_000);
        expect(emptyRange).toMatchObject({
            firstRetainedSampleAt: at,
            latestSampleAt: at,
            registeredServerCount: 1,
            servers: [],
            maps: [],
            summary: { observed: 0, unknown: 0 }
        });
        expect(
            emptyRange.points.every((point) => point.observed === 0 && point.unknown === 0)
        ).toBe(true);
    });

    it('keeps unknown status separate from no samples and preserves zero elapsed observations', async () => {
        const { recordMetrics, readMetrics } =
            await import('../../src/lib/server/fleet/metrics.js');
        const at = Date.UTC(2026, 0, 2, 12);
        recordMetrics(
            [{ server: 'one', game: 't5', map: 'Moon', players: null, capacity: null }],
            at
        );
        const initial = readMetrics(1, at);
        expect(initial.latestSampleAt).toBe(at);
        expect(initial.servers).toHaveLength(1);
        expect(initial.summary).toEqual({
            observed: 0,
            active: 0,
            idle: 0,
            unknown: 0,
            playerHours: 0
        });
        const later = readMetrics(1, at + 120_000);
        expect(later.summary.observed).toBe(0);
        expect(later.summary.unknown * 3600).toBeCloseTo(90);
        expect(later.maps[0].availabilityObserved).toBe(0);
        expect(later.maps[0].availabilityUnknown * 3600).toBeCloseTo(90);
        expect(later.pooledAvailability.value).toBeNull();
        expect(initial.running).toEqual({ average: null, peak: 0, capturedHours: 0 });
    });

    it('returns clipped interval boundaries and marks only partial UTC buckets', async () => {
        const { readMetrics } = await import('../../src/lib/server/fleet/metrics.js');
        const now = Date.UTC(2026, 0, 8, 12, 30);
        for (const days of [1, 7, 30] as const) {
            const result = readMetrics(days, now);
            expect(result.points[0].startAt).toBe(result.since);
            expect(result.points.at(-1)?.endAt).toBe(now);
            expect(result.points[0].partial).toBe(true);
            expect(result.points.at(-1)?.partial).toBe(true);
            expect(result.points.slice(1, -1).every((point) => !point.partial)).toBe(true);
            expect(result.points.reduce((ms, point) => ms + point.endAt - point.startAt, 0)).toBe(
                days * 86400_000
            );
        }
        expect(
            readMetrics(1, Date.UTC(2026, 0, 8, 12)).points.every((point) => !point.partial)
        ).toBe(true);
    });

    it('uses complete collection boundaries across fleet changes and keeps map availability in wall time', async () => {
        const { recordMetrics, readMetrics } =
            await import('../../src/lib/server/fleet/metrics.js');
        const at = Date.UTC(2026, 0, 2, 23, 59, 40);
        const one = { server: 'one', game: 't6', map: 'Town', players: 4, capacity: 4 };
        const two = { ...one, server: 'two' };
        recordMetrics([one, two], at);
        // Removing a lobby ends its previous observation at the next complete collection.
        recordMetrics([{ ...one, map: 'Farm', players: 0 }], at + 30_000);
        // A collection outage is excluded; an identically named map in another game remains separate.
        recordMetrics([{ ...one, game: 't5', players: 2, capacity: null }], at + 150_000);
        const result = readMetrics(1, at + 180_000);
        expect(result.summary.active * 3600).toBeCloseTo(90);
        expect(result.summary.idle * 3600).toBeCloseTo(90);
        expect(result.summary.playerHours * 3600).toBeCloseTo(300);
        expect(
            result.servers.find((server) => server.server === 'two')!.observed * 3600
        ).toBeCloseTo(30);
        const town = result.maps.find((map) => map.game === 't6' && map.map === 'Town')!;
        expect(town.observed * 3600).toBeCloseTo(60);
        expect(town.availabilityObserved * 3600).toBeCloseTo(30);
        expect(town.noEmpty * 3600).toBeCloseTo(30);
        expect(
            result.maps.find((map) => map.game === 't5')!.availabilityObserved * 3600
        ).toBeCloseTo(30);
        for (const field of ['observed', 'active', 'idle', 'unknown', 'playerHours'] as const) {
            expect(result.points.reduce((sum, point) => sum + point[field], 0)).toBeCloseTo(
                result.summary[field]
            );
            expect(result.servers.reduce((sum, server) => sum + server[field], 0)).toBeCloseTo(
                result.summary[field]
            );
            expect(result.maps.reduce((sum, map) => sum + map[field], 0)).toBeCloseTo(
                result.summary[field]
            );
        }
    });

    it('does not include future samples in collection metadata or aggregates', async () => {
        const { recordMetrics, readMetrics } =
            await import('../../src/lib/server/fleet/metrics.js');
        const at = Date.UTC(2026, 0, 2, 12);
        const sample = { server: 'one', game: 't5', map: 'Moon', players: 1, capacity: 4 };
        recordMetrics([sample], at);
        recordMetrics([{ ...sample, players: 4 }], at + 60_000);
        const result = readMetrics(1, at + 30_000);
        expect(result.latestSampleAt).toBe(at);
        expect(result.summary.playerHours * 3600).toBeCloseTo(30);
    });

    it('shares the range parser and response contract between SSR and the uncached refresh endpoint', async () => {
        const { recordMetrics } = await import('../../src/lib/server/fleet/metrics.js');
        const { GET } = await import('../../src/routes/api/metrics/+server.js');
        const { load } = await import('../../src/routes/metrics/+page.server.js');
        const at = Date.UTC(2026, 0, 2, 12);
        recordMetrics([{ server: 'one', game: 't5', map: 'Moon', players: 2, capacity: 4 }], at);
        vi.spyOn(Date, 'now').mockReturnValue(at + 30_000);
        for (const range of ['1', '7', '30', 'invalid', '365', '-1', '']) {
            const url = new URL(`http://localhost/metrics?days=${range}`);
            const response = await GET({ url });
            const payload = await response.json();
            expect(response.headers.get('cache-control')).toBe('no-store');
            expect(payload).toEqual(await load({ url } as Parameters<typeof load>[0]));
            expect(payload.days).toBe(['1', '7', '30'].includes(range) ? Number(range) : 7);
        }
        expect(
            (await (await GET({ url: new URL('http://localhost/api/metrics') })).json()).days
        ).toBe(7);
        for (const search of [
            'days=1&game=t5&map=Moon&timeZone=Asia%2FKathmandu',
            'days=7&map=Moon',
            'game=t6&timeZone=Invalid'
        ]) {
            const url = new URL(`http://localhost/metrics?${search}`);
            const payload = await (await GET({ url })).json();
            const { days, ...scope } = parseMetricsQuery(url.searchParams);
            expect(payload).toEqual(await load({ url } as Parameters<typeof load>[0]));
            expect(payload).toMatchObject({ days, scope });
        }
    });

    it('normalizes malformed scopes consistently and requires a game for a map selection', () => {
        expect(
            parseMetricsQuery(new URLSearchParams('days=365&map=Moon&timeZone=Invalid/Zone'))
        ).toEqual({ days: 7, game: null, map: null, timeZone: 'America/New_York' });
        expect(
            parseMetricsQuery(new URLSearchParams({ game: 't5; DROP TABLE', map: 'Moon' }))
        ).toMatchObject({ game: null, map: null });
        expect(
            parseMetricsQuery(
                new URLSearchParams({
                    game: ' t5 ',
                    map: 'Moon',
                    timeZone: 'Asia/Kathmandu',
                    days: '30'
                })
            )
        ).toEqual({ days: 30, game: 't5', map: 'Moon', timeZone: 'Asia/Kathmandu' });
        for (const map of ['', ' ', 'a'.repeat(201), 'Moon\nTown']) {
            expect(parseMetricsQuery(new URLSearchParams({ game: 't5', map })).map).toBeNull();
        }
        expect(
            parseMetricsQuery(new URLSearchParams({ game: 't5', map: 'Not recorded yet' })).map
        ).toBe('Not recorded yet');
    });

    it('filters every derived value by exact game and map while preserving unfiltered collection boundaries', async () => {
        const { recordMetrics, readMetrics } =
            await import('../../src/lib/server/fleet/metrics.js');
        const now = Date.UTC(2026, 0, 3, 12);
        const since = now - 86400_000;
        const moon = { server: 'one', game: 't5', map: 'Moon', players: 4, capacity: 4 };
        const other = { ...moon, server: 'other', game: 't6', players: 2 };
        recordMetrics([moon, other], since - 30_000);
        recordMetrics([other], since);
        recordMetrics(
            [moon, other, { ...moon, server: 'town', map: 'Town', players: 0 }],
            now - 60_000
        );
        recordMetrics([other], now - 45_000);
        recordMetrics([{ ...moon, players: 0 }, other], now - 30_000);
        const query = parseMetricsQuery(
            new URLSearchParams({ days: '1', game: 't5', map: 'Moon', timeZone: 'UTC' })
        );
        const result = readMetrics(query, now);
        expect(result.scope).toEqual({ game: 't5', map: 'Moon', timeZone: 'UTC' });
        expect(result.summary.active * 3600).toBeCloseTo(15);
        expect(result.summary.idle * 3600).toBeCloseTo(30);
        expect(result.summary.playerHours * 3600).toBeCloseTo(60);
        expect(result.previous.summary.active * 3600).toBeCloseTo(30);
        expect(result.previous.summary.playerHours * 3600).toBeCloseTo(120);
        expect(result.servers.map((server) => server.server)).toEqual(['one']);
        expect(result.maps.map((map) => [map.game, map.map])).toEqual([['t5', 'Moon']]);
        expect(result.scopeOptions).toEqual({
            games: ['t5', 't6'],
            maps: [
                { game: 't5', map: 'Moon' },
                { game: 't5', map: 'Town' },
                { game: 't6', map: 'Moon' }
            ]
        });
        expect(result.scopeFirstSampleAt).toBe(since - 30_000);
        expect(result.scopeLatestSampleAt).toBe(now - 30_000);
        expect(result.pooledAvailability.value).toBeCloseTo(100 / 3);
        expect(result.running.average).toBe(1);
        expect(result.running.peak).toBe(1);
        expect(result.running.capturedHours * 3600).toBeCloseTo(45);
        expect(result.previous.running.average).toBe(1);
        expect(result.previous.running.capturedHours * 3600).toBeCloseTo(30);
        for (const field of ['observed', 'active', 'idle', 'unknown', 'playerHours'] as const) {
            expect(result.points.reduce((sum, point) => sum + point[field], 0)).toBeCloseTo(
                result.summary[field]
            );
            expect(result.heatmap.cells.reduce((sum, cell) => sum + cell[field], 0)).toBeCloseTo(
                result.summary[field]
            );
        }
        const gameOnly = readMetrics({ ...query, map: null }, now);
        expect(gameOnly.maps.map((map) => map.map).sort()).toEqual(['Moon', 'Town']);
        expect(gameOnly.running.average).toBeCloseTo(4 / 3);
        expect(gameOnly.running.peak).toBe(2);
        expect(gameOnly.running.capturedHours * 3600).toBeCloseTo(45);
        const missing = readMetrics({ ...query, map: 'Unrecorded' }, now);
        expect(missing).toMatchObject({
            scopeFirstSampleAt: null,
            scopeLatestSampleAt: null,
            summary: { observed: 0, unknown: 0 },
            maps: [],
            servers: [],
            pooledAvailability: { value: null },
            running: { average: null, peak: 0, capturedHours: 0 },
            previous: { firstSampleAt: null, lastSampleAt: null, partialHistory: true }
        });
        expect(missing.scopeOptions).toEqual(result.scopeOptions);
    });

    it('separates scoped evidence timestamps from global collection timestamps', async () => {
        const { recordMetrics, readMetrics } =
            await import('../../src/lib/server/fleet/metrics.js');
        const at = Date.UTC(2026, 0, 3, 12);
        const sample = { server: 'one', game: 't5', map: 'Moon', players: 1, capacity: 4 };
        recordMetrics([{ ...sample, game: 't6' }], at - 60_000);
        recordMetrics([sample], at - 30_000);
        recordMetrics([{ ...sample, game: 't6' }], at);
        const result = readMetrics(
            parseMetricsQuery(new URLSearchParams({ game: 't5' })),
            at + 30_000
        );
        expect(result.firstRetainedSampleAt).toBe(at - 60_000);
        expect(result.latestSampleAt).toBe(at);
        expect(result.scopeFirstSampleAt).toBe(at - 30_000);
        expect(result.scopeLatestSampleAt).toBe(at - 30_000);
    });

    it('averages concurrent tracked lobbies over captured wall time, including unknowns and excluding gaps', async () => {
        const { recordMetrics, readMetrics } =
            await import('../../src/lib/server/fleet/metrics.js');
        const now = Date.UTC(2026, 0, 3, 12);
        const since = now - 86400_000;
        const one = { server: 'one', game: 't5', map: 'Moon', players: 1, capacity: null };
        const two = { ...one, server: 'two', players: 0 };
        const three = { ...one, server: 'three', players: null };
        const four = { ...one, server: 'four', players: null };
        recordMetrics([one, two, three, four], since - 120_000);
        recordMetrics([one, two, three], now - 180_000);
        recordMetrics([three], now - 150_000);
        recordMetrics([one, two], now - 30_000);
        const result = readMetrics(1, now);
        expect(result.running.average).toBeCloseTo(1.6);
        expect(result.running.peak).toBe(3);
        expect(result.running.capturedHours * 3600).toBeCloseTo(150);
        expect(result.previous.running.average).toBe(4);
        expect(result.previous.running.peak).toBe(4);
        expect(result.previous.running.capturedHours * 3600).toBeCloseTo(90);
        expect(result.points.reduce((sum, point) => sum + point.capturedHours, 0)).toBeCloseTo(
            result.running.capturedHours
        );
        const point = result.points.find((point) => point.capturedHours > 0)!;
        expect((point.observed + point.unknown) / point.capturedHours).toBeCloseTo(1.6);
        expect(result.summary.observed + result.summary.unknown).toBeCloseTo(
            result.running.average! * result.running.capturedHours
        );
    });

    it('matches current policy context through map aliases and prefers the durable owner', async () => {
        const { recordMetrics, readMetrics } =
            await import('../../src/lib/server/fleet/metrics.js');
        const { db } = await import('../../src/lib/server/db/index.js');
        const at = Date.UTC(2026, 0, 3, 12);
        const insert = db().prepare(
            `INSERT INTO autoscaling_policies
                (id,game,map_slug,settings,mode,paused_reason,owns_map,updated_at)
                VALUES (?,?,?,?,?,?,?,?)`
        );
        insert.run(
            't5-all',
            't5',
            '*',
            JSON.stringify({ minimum: 1, maximum: 4, spares: 2 }),
            'create-destroy',
            null,
            1,
            'now'
        );
        insert.run(
            'moon',
            't5',
            'moon',
            JSON.stringify({ minimum: 1, maximum: 2, spares: 1 }),
            'off',
            'Operator paused.',
            0,
            'now'
        );
        insert.run(
            'town',
            't6',
            'town',
            JSON.stringify({ minimum: 2, maximum: 3, spares: 1 }),
            'create-destroy',
            null,
            1,
            'now'
        );
        const sample = { server: 'one', game: 't5', map: 'Moon', players: 1, capacity: null };
        recordMetrics(
            [
                sample,
                { ...sample, server: 'two', map: 'Kino Der Toten' },
                { ...sample, server: 'three', game: 't6', map: 'Town Survival' },
                { ...sample, server: 'four', game: 't6', map: 'zm_transit' },
                { ...sample, server: 'five', game: 't6', map: 'Moon' },
                { ...sample, server: 'six', map: 'zombie_cosmodrome' },
                { ...sample, server: 'seven', map: 'unknown-map' }
            ],
            at
        );
        const result = readMetrics(1, at + 30_000);
        expect(result.maps.find((map) => map.game === 't5' && map.map === 'Moon')!.policy).toEqual({
            id: 't5-all',
            mode: 'create-destroy',
            minimum: 1,
            maximum: 4,
            spares: 2,
            pausedReason: null
        });
        expect(result.maps.find((map) => map.map === 'Kino Der Toten')!.policy?.id).toBe('t5-all');
        expect(result.maps.find((map) => map.map === 'zombie_cosmodrome')!.policy?.id).toBe(
            't5-all'
        );
        expect(result.maps.find((map) => map.map === 'Town Survival')!.policy?.id).toBe('town');
        expect(result.maps.find((map) => map.map === 'zm_transit')!.policy).toBeNull();
        expect(
            result.maps.find((map) => map.game === 't6' && map.map === 'Moon')!.policy
        ).toBeNull();
        expect(result.maps.find((map) => map.map === 'unknown-map')!.policy).toBeNull();
        db().prepare('UPDATE autoscaling_policies SET owns_map=0').run();
        expect(
            readMetrics(1, at + 30_000).maps.find((map) => map.game === 't5' && map.map === 'Moon')!
                .policy
        ).toMatchObject({ id: 'moon', mode: 'off', pausedReason: 'Operator paused.' });
        db().prepare("INSERT INTO settings(key,value) VALUES ('autoscaling_paused','1')").run();
        expect(
            readMetrics(1, at + 30_000).maps.find((map) => map.game === 't5' && map.map === 'Moon')!
                .policy?.pausedReason
        ).toBe('Autoscaling is globally paused. Operator paused.');
    });

    it('compares no-empty intervals with the current maximum, counting unknown lobbies in the lineup', async () => {
        const { recordMetrics, readMetrics } =
            await import('../../src/lib/server/fleet/metrics.js');
        const { db } = await import('../../src/lib/server/db/index.js');
        const at = Date.UTC(2026, 0, 3, 12);
        db()
            .prepare(
                `INSERT INTO autoscaling_policies
            (id,game,map_slug,settings,mode,owns_map,updated_at) VALUES (?,?,?,?,?,?,?)`
            )
            .run(
                'moon',
                't5',
                'moon',
                JSON.stringify({ minimum: 1, maximum: 2, spares: 1 }),
                'create-destroy',
                1,
                'now'
            );
        const one = { server: 'one', game: 't5', map: 'Moon', players: 1, capacity: null };
        const two = { ...one, server: 'two', players: null };
        recordMetrics([one], at);
        recordMetrics([one, two], at + 30_000);
        recordMetrics([one, two, { ...one, server: 'three' }], at + 60_000);
        recordMetrics([one, { ...two, players: 0 }], at + 90_000);
        recordMetrics([{ ...one, players: null }, two], at + 120_000);
        const result = readMetrics(1, at + 150_000);
        expect(result.maps[0].noEmpty * 3600).toBeCloseTo(90);
        expect(result.maps[0].noEmptyAtMaximum * 3600).toBeCloseTo(60);
        expect(result.maps[0].noEmptyBelowMaximum * 3600).toBeCloseTo(30);
        expect(result.maps[0].availabilityObserved * 3600).toBeCloseTo(120);
        expect(result.maps[0].availabilityUnknown * 3600).toBeCloseTo(30);
        db()
            .prepare("UPDATE autoscaling_policies SET settings=json_set(settings,'$.maximum',4)")
            .run();
        const revised = readMetrics(1, at + 150_000).maps[0];
        expect(revised.noEmptyAtMaximum).toBe(0);
        expect(revised.noEmptyBelowMaximum * 3600).toBeCloseTo(90);
    });

    it('compares adjacent equal windows and splits an observation at their shared boundary', async () => {
        const { recordMetrics, readMetrics } =
            await import('../../src/lib/server/fleet/metrics.js');
        const now = Date.UTC(2026, 0, 3, 12);
        const since = now - 86400_000;
        const sample = { server: 'one', game: 't5', map: 'Moon', players: 2, capacity: 4 };
        recordMetrics([sample], since - 15_000);
        recordMetrics([{ ...sample, players: 0 }], since + 15_000);
        const result = readMetrics(1, now);
        expect(result.previous.since).toBe(now - 2 * 86400_000);
        expect(result.previous.until).toBe(result.since);
        expect(result.previous.summary.active * 3600).toBeCloseTo(15);
        expect(result.summary.active * 3600).toBeCloseTo(15);
        expect(result.summary.idle * 3600).toBeCloseTo(90);
        expect(result.previous).toMatchObject({
            firstSampleAt: since - 15_000,
            lastSampleAt: since - 15_000,
            partialHistory: true
        });
    });

    it('returns the available prior evidence when a thirty-day comparison exceeds retained history', async () => {
        const { recordMetrics, readMetrics } =
            await import('../../src/lib/server/fleet/metrics.js');
        const now = Date.UTC(2026, 2, 3, 12);
        const day = 86400_000;
        const sample = { server: 'one', game: 't5', map: 'Moon', players: 2, capacity: 4 };
        recordMetrics([sample], now - 31 * day + 30_000);
        recordMetrics([{ ...sample, players: 0 }], now - 30 * day + 30_000);
        recordMetrics([sample], now - 30_000);
        const result = readMetrics(30, now);
        expect(result.previous).toMatchObject({
            since: now - 60 * day,
            until: now - 30 * day,
            partialHistory: true
        });
        expect(result.previous.summary.active * 3600).toBeCloseTo(90);
        expect(result.previous.firstSampleAt).toBe(now - 31 * day + 30_000);
        expect(result.summary.active * 3600).toBeCloseTo(30);
        expect(result.summary.idle * 3600).toBeCloseTo(90);
    });

    it('marks the retained start bound separately from gaps inside the previous window', async () => {
        const { recordMetrics, readMetrics } =
            await import('../../src/lib/server/fleet/metrics.js');
        const now = Date.UTC(2026, 0, 3, 12);
        const priorStart = now - 2 * 86400_000;
        const sample = { server: 'one', game: 't5', map: 'Moon', players: null, capacity: null };
        recordMetrics([sample], priorStart - 15_000);
        recordMetrics([sample], now - 30_000);
        const result = readMetrics(1, now);
        expect(result.previous.partialHistory).toBe(false);
        expect(result.previous.summary.unknown * 3600).toBeCloseTo(75);
        expect(result.previous.summary.observed).toBe(0);
        expect(result.previous.firstSampleAt).toBe(priorStart - 15_000);
        // Having the left edge says nothing about the uncaptured time after it.
        expect(result.previous.summary.unknown).toBeLessThan(24);
    });

    it('pools availability by known map-hours rather than lobby-hours or fleet elapsed time', async () => {
        const { recordMetrics, readMetrics } =
            await import('../../src/lib/server/fleet/metrics.js');
        const at = Date.UTC(2026, 0, 3, 12);
        const occupied = { server: 'one', game: 't5', map: 'Moon', players: 1, capacity: 4 };
        recordMetrics(
            [
                occupied,
                { ...occupied, server: 'two' },
                { ...occupied, server: 'three', map: 'Town', players: 0 },
                { ...occupied, server: 'four', map: 'Farm', players: 2, capacity: null },
                { ...occupied, server: 'five', map: 'Unknown', players: null }
            ],
            at
        );
        const result = readMetrics(1, at + 30_000);
        expect(result.pooledAvailability).toMatchObject({ coveredMaps: 3, totalMaps: 4 });
        expect(result.pooledAvailability.value).toBeCloseTo(200 / 3);
        expect(result.pooledAvailability.noEmptyMapHours * 3600).toBeCloseTo(60);
        expect(result.pooledAvailability.knownMapHours * 3600).toBeCloseTo(90);
        expect(result.pooledAvailability.unknownMapHours * 3600).toBeCloseTo(30);
        expect(result.summary.observed * 3600).toBeCloseTo(120);
        const empty = readMetrics(
            parseMetricsQuery(new URLSearchParams({ days: '1', game: 't5', map: 'Town' })),
            at + 30_000
        );
        expect(empty.pooledAvailability.value).toBe(0);
        const missingCapacity = readMetrics(
            parseMetricsQuery(new URLSearchParams({ days: '1', game: 't5', map: 'Farm' })),
            at + 30_000
        );
        expect(missingCapacity.pooledAvailability.value).toBe(100);
        const unknown = readMetrics(
            parseMetricsQuery(new URLSearchParams({ days: '1', game: 't5', map: 'Unknown' })),
            at + 30_000
        );
        expect(unknown.pooledAvailability.value).toBeNull();
    });

    it.each([
        { zone: 'America/New_York', at: '2026-03-08T06:59:45Z', first: [6, 1], second: [6, 3] },
        { zone: 'Asia/Kolkata', at: '2026-01-01T18:29:45Z', first: [3, 23], second: [4, 0] },
        { zone: 'Asia/Kathmandu', at: '2026-01-01T18:14:45Z', first: [3, 23], second: [4, 0] },
        { zone: 'Australia/Lord_Howe', at: '2026-10-03T15:29:45Z', first: [6, 1], second: [6, 2] }
    ])(
        'splits heatmap time across local boundaries in $zone',
        async ({ zone, at: timestamp, first, second }) => {
            const { recordMetrics, readMetrics } =
                await import('../../src/lib/server/fleet/metrics.js');
            const at = Date.parse(timestamp);
            recordMetrics(
                [{ server: 'one', game: 't5', map: 'Moon', players: 2, capacity: 4 }],
                at
            );
            const result = readMetrics(
                parseMetricsQuery(new URLSearchParams({ days: '1', timeZone: zone })),
                at + 30_000
            );
            expect(result.heatmap.timeZone).toBe(zone);
            expect(result.heatmap.cells).toHaveLength(168);
            for (const [weekday, hour] of [first, second]) {
                const cell = result.heatmap.cells.find(
                    (cell) => cell.weekday === weekday && cell.hour === hour
                )!;
                expect(cell.observed * 3600).toBeCloseTo(15);
                expect(cell.playerHours * 3600).toBeCloseTo(30);
                expect(cell.distinctDates).toBe(1);
            }
            expect(result.heatmap.cells.reduce((sum, cell) => sum + cell.observed, 0)).toBeCloseTo(
                result.summary.observed
            );
        }
    );

    it('weights repeated fall-back hours and counts their local date once', async () => {
        const { recordMetrics, readMetrics } =
            await import('../../src/lib/server/fleet/metrics.js');
        const at = Date.parse('2026-11-01T05:30:00Z');
        const sample = { server: 'one', game: 't5', map: 'Moon', players: 2, capacity: 4 };
        recordMetrics([sample], at);
        recordMetrics([{ ...sample, players: 0 }], at + 3600_000);
        const result = readMetrics(
            parseMetricsQuery(new URLSearchParams({ days: '1', timeZone: 'America/New_York' })),
            at + 3630_000
        );
        const cell = result.heatmap.cells.find((cell) => cell.weekday === 6 && cell.hour === 1)!;
        expect(cell.observed * 3600).toBeCloseTo(120);
        expect(cell.active * 3600).toBeCloseTo(90);
        expect(cell.idle * 3600).toBeCloseTo(30);
        expect(cell.distinctDates).toBe(1);
        expect(result.heatmap.cells.filter((cell) => cell.observed > 0)).toHaveLength(1);
    });

    it('counts unknown heatmap evidence and distinguishes retained names from current registrations', async () => {
        const { recordMetrics, readMetrics } =
            await import('../../src/lib/server/fleet/metrics.js');
        const { db } = await import('../../src/lib/server/db/index.js');
        const at = Date.UTC(2026, 0, 3, 12);
        const sample = { server: 'reused', game: 't5', map: 'Moon', players: null, capacity: null };
        recordMetrics(
            [sample, { ...sample, server: 'removed' }, { ...sample, server: 'tombstone' }],
            at
        );
        // A newly registered name can link to the current server without asserting
        // that its earlier historical observations belong to this registration.
        db()
            .prepare('INSERT INTO servers (name, created_at) VALUES (?, ?)')
            .run('reused', new Date(at + 15_000).toISOString());
        db()
            .prepare('INSERT INTO servers (name, destroyed_at) VALUES (?, ?)')
            .run('tombstone', new Date(at).toISOString());
        const result = readMetrics(1, at + 30_000);
        expect(result.servers.find((server) => server.server === 'reused')!.currentRegistered).toBe(
            true
        );
        expect(
            result.servers
                .filter((server) => server.server !== 'reused')
                .every((server) => !server.currentRegistered)
        ).toBe(true);
        expect(
            result.heatmap.cells.reduce((sum, cell) => sum + cell.unknown, 0) * 3600
        ).toBeCloseTo(90);
        expect(result.heatmap.cells.reduce((sum, cell) => sum + cell.observed, 0)).toBe(0);
        expect(result.heatmap.cells.find((cell) => cell.unknown > 0)!.distinctDates).toBe(1);
    });
});