import { afterEach, beforeEach, expect, it, vi } from 'vitest';
import { newFixture, type Fixture } from '../helpers/fixture.js';
import { prepareNativeHost } from '../helpers/native-host.js';
import { gameEvent } from '../helpers/telemetry.js';
import { scalingSettings, type ScalingPolicy } from '../../src/lib/autoscaling.js';
import type { GameEvent } from '../../src/lib/telemetry.js';

let fixture: Fixture;
beforeEach(async () => {
    vi.resetModules();
    fixture = await newFixture([]);
});
afterEach(async () => {
    vi.useRealTimers();
    await fixture.cleanup();
});
const town = 't6_zombie_town_1',
    farm = 't6_zombie_farm_1';
const policy: ScalingPolicy = {
    ...scalingSettings({ game: 't6', mapSlug: 'town', maximum: 4, mode: 'create-destroy' }),
    id: 'policy',
    revision: 1,
    pausedReason: null,
    updatedAt: ''
};

it('separates variants, deduplicates pending identities, and initializes additive schema', async () => {
    await prepareNativeHost([town, farm]);
    const { db } = await import('../../src/lib/server/db/index.js');
    const { scalingSnapshot } = await import('../../src/lib/server/autoscaling/snapshot.js');
    const { ensureAutoscalingSchema } = await import('../../src/lib/server/autoscaling/schema.js');
    ensureAutoscalingSchema(db());
    ensureAutoscalingSchema(db());
    const at = new Date().toISOString();
    for (const server of [town, farm])
        db()
            .prepare(
                `INSERT INTO servers(name,container_state,container_checked_at,last_seen_at,last_checked_at,last_players) VALUES(?,'running',?,?,?,0)`
            )
            .run(server, at, at, at);
    expect(scalingSnapshot(policy).members.map((m) => [m.name, m.state])).toEqual([
        [town, 'empty']
    ]);
    db()
        .prepare(
            `INSERT INTO server_deployments(id,server,action,state,stage,started_at,triggered_by) VALUES('create',?,'create','queued','Awaiting placement',?,'test')`
        )
        .run(town, at);
    db()
        .prepare(
            `INSERT INTO server_creation_jobs(deployment_id,server,game_mode,map_slug,expected_map) VALUES('create',?,'zombie','town','zm_transit')`
        )
        .run(town);
    expect(
        scalingSnapshot({ ...policy, mapSlug: '*' })
            .members.map((m) => m.name)
            .sort()
    ).toEqual([farm, town]);
    const snapshot = scalingSnapshot(policy);
    expect(snapshot.members).toHaveLength(1);
    expect(snapshot.members[0].state).toBe('creating');
    expect(snapshot.members[0].round).toBeNull();
    expect(snapshot.reservedNames).toEqual([town]);
});

async function occupiedLobby() {
    vi.useFakeTimers({ toFake: ['Date'] });
    await prepareNativeHost([town]);
    const { db } = await import('../../src/lib/server/db/index.js');
    const { scalingSnapshot } = await import('../../src/lib/server/autoscaling/snapshot.js');
    const now = Date.now();
    const iso = (offset = 0) => new Date(now + offset).toISOString();
    db()
        .prepare(
            `INSERT INTO servers(name,game,map,map_slug,container_state,container_checked_at,last_seen_at,last_checked_at,last_players,active_since,game_started_at)
            VALUES(?,'t6','zm_transit','town','running',?,?,?,1,?,?)`
        )
        .run(town, iso(), iso(), iso(), iso(-120_000), iso(-60_000));
    const report = (event: GameEvent['event'], round = 2, offset = -1000, players = 1) => {
        const payload = {
            ...gameEvent(event, round, players, town, 'zm_transit'),
            receivedAt: iso(offset)
        };
        db()
            .prepare(
                `INSERT OR REPLACE INTO server_telemetry(server,round,players,received_at,payload) VALUES(?,?,?,?,?)`
            )
            .run(town, round, players, payload.receivedAt, JSON.stringify(payload));
    };
    return { db, now, iso, report, member: () => scalingSnapshot(policy, now).members[0] };
}

it.each(['round_change', 'heartbeat'] as const)(
    'exposes the current occupied round from fresh %s reports',
    async (event) => {
        const { member, report } = await occupiedLobby();
        expect(member()).toMatchObject({ state: 'occupied', source: 'rcon', round: null });
        report(event, 1);
        expect(member()).toMatchObject({ state: 'occupied', round: 1 });
        report(event, 2);
        expect(member()).toMatchObject({ state: 'occupied', round: 2 });
    }
);

it('does not borrow stale or future rounds while fresh RCON still proves occupancy', async () => {
    const { member, report } = await occupiedLobby();
    for (const offset of [-91_000, 500]) {
        report('heartbeat', 12, offset);
        expect(member()).toMatchObject({ state: 'occupied', source: 'rcon', round: null });
    }
});

it('clears round evidence at match boundaries and when the lobby empties', async () => {
    const { db, member, report } = await occupiedLobby();
    report('heartbeat', 12);
    expect(member().round).toBe(12);
    for (const event of ['game_start', 'game_end'] as const) {
        report(event, 12);
        expect(member()).toMatchObject({ state: 'occupied', round: null });
    }
    report('heartbeat', 12, -1000, 0);
    // A positive RCON safety veto must not turn an empty report's round into demand.
    expect(member()).toMatchObject({ state: 'occupied', round: null });
    db().prepare('UPDATE servers SET last_players=0 WHERE name=?').run(town);
    expect(member()).toMatchObject({ state: 'empty', round: null });
});

it('rejects round evidence from before the current occupancy, match, or instance lifecycle', async () => {
    const { db, iso, member, report } = await occupiedLobby();
    report('heartbeat', 12);
    for (const field of ['active_since', 'game_started_at', 'game_ended_at']) {
        db().prepare(`UPDATE servers SET ${field}=? WHERE name=?`).run(iso(), town);
        expect(member()).toMatchObject({ state: 'occupied', round: null });
        db()
            .prepare(`UPDATE servers SET ${field}=? WHERE name=?`)
            .run(field === 'game_ended_at' ? null : iso(-120_000), town);
    }
    db()
        .prepare('UPDATE native_instances SET generation_reconciled_at=? WHERE server=?')
        .run(iso(-500), town);
    expect(member()).toMatchObject({ state: 'occupied', source: 'rcon', round: null });
    report('heartbeat', 2, 0);
    expect(member().round).toBe(2);
});

it('does not create schema mutations or host work when planning an empty map', async () => {
    const { db } = await import('../../src/lib/server/db/index.js');
    const { scalingSnapshot } = await import('../../src/lib/server/autoscaling/snapshot.js');
    const { planScaling } = await import('../../src/lib/server/autoscaling/planner.js');
    db()
        .prepare("INSERT INTO server_keys(id,game,pluto_key) VALUES('key-8','t6','private-key')")
        .run();
    expect(planScaling(policy, scalingSnapshot(policy), Date.now()).server).toBe(
        't6_zombie_town_1'
    );
    expect(db().prepare('SELECT COUNT(*) AS n FROM server_deployments').get()).toEqual({ n: 0 });
});