import { DEFAULT_TIME_ZONE, validTimeZone } from './time-zone.js';

export type MetricsDays = 1 | 7 | 30;

export function parseMetricsDays(value: string | null | undefined): MetricsDays {
    const days = Number(value ?? 7);
    return days === 1 || days === 7 || days === 30 ? days : 7;
}

export interface MetricsScope {
    game: string | null;
    map: string | null;
    timeZone: string;
}

export interface MetricsQuery extends MetricsScope {
    days: MetricsDays;
}

/** A map is an exact recorded label within a game, never a cross-game match. */
export function parseMetricsQuery(params: URLSearchParams): MetricsQuery {
    const requestedGame = params.get('game')?.trim() ?? '';
    const game = /^[a-z0-9_-]{1,32}$/.test(requestedGame) ? requestedGame : null;
    const requestedMap = params.get('map');
    const map = game && requestedMap && requestedMap.trim() && requestedMap.length <= 200 && !/[\u0000-\u001f\u007f]/.test(requestedMap)
        ? requestedMap : null;
    const requestedZone = params.get('timeZone');
    return { days: parseMetricsDays(params.get('days')), game, map,
        timeZone: validTimeZone(requestedZone) ? requestedZone : DEFAULT_TIME_ZONE };
}

/** All durations are hours. Observed is known server time, not collection coverage. */
export interface Utilization {
    observed: number;
    active: number;
    idle: number;
    unknown: number;
    playerHours: number;
}

export interface ServerMetrics extends Utilization {
    server: string;
    /** A current registration with this name exists; historical identity may differ. */
    currentRegistered: boolean;
}

export interface MapMetrics extends Utilization {
    game: string;
    map: string;
    /** Map wall time, not summed server time. */
    full: number;
    capacityObserved: number;
}

export interface MetricPoint extends Utilization {
    /** UTC bucket boundary, including when the selected interval starts later. */
    at: number;
    startAt: number;
    endAt: number;
    partial: boolean;
}

export interface PreviousMetrics {
    since: number;
    until: number;
    summary: Utilization;
    firstSampleAt: number | null;
    lastSampleAt: number | null;
    /** Retained scope evidence starts late or is absent, not a completeness guarantee. */
    partialHistory: boolean;
}

export interface HeatmapCell extends Utilization {
    /** Monday = 0, Sunday = 6. */
    weekday: number;
    hour: number;
    /** Distinct local dates with any captured time, including unknown status. */
    distinctDates: number;
}

export interface PooledPressure {
    /** Share of known map-hours with every tracked lobby full, from 0 to 100. */
    value: number | null;
    fullMapHours: number;
    knownMapHours: number;
    coveredMaps: number;
    totalMaps: number;
}

export interface MetricsData {
    days: MetricsDays;
    since: number;
    now: number;
    /** Retained sample timestamps describe collection, not gameplay freshness. */
    firstRetainedSampleAt: number | null;
    latestSampleAt: number | null;
    registeredServerCount: number;
    scope: MetricsScope;
    scopeOptions: { games: string[]; maps: { game: string; map: string }[] };
    scopeFirstSampleAt: number | null;
    scopeLatestSampleAt: number | null;
    summary: Utilization;
    servers: ServerMetrics[];
    maps: MapMetrics[];
    points: MetricPoint[];
    previous: PreviousMetrics;
    heatmap: { timeZone: string; cells: HeatmapCell[] };
    pooledPressure: PooledPressure;
}