/**
 * Shared types for the Strommix-Live-Widget.
 *
 * The aggregator route at `/api/strommix` builds this payload from the
 * four CMS external collections; the `StrommixBlock.svelte` component
 * consumes it.
 */

/** Default percentage thresholds (Wind+Solar / Last × 100) for bucket
 *  classification. Single source of truth — both the CMS schema
 *  (`live_strommix.json5`) and the block (`StrommixBlock.svelte`) read
 *  these. Editor can override per-instance via `threshold_*` fields. */
export const STROMMIX_DEFAULT_THRESHOLDS = {
  dunkelflaute: 15,
  niedrig: 35,
  mittel: 60,
} as const;

export type StrommixResponse = {
  // Production-snapshot timestamp (Unix sec) — used as the "anchor" for
  // the rest of the values. Cross-border + prices may have their own,
  // earlier or later, timestamps.
  measuredAtUnix: number | null;
  /** Where production + load came from. `smard` = pure SMARD (canonical);
   *  `smard+energy-charts` = SMARD with Energy-Charts as per-field
   *  fallback for filters SMARD couldn't resolve at the snapshot's slot
   *  (typically the load filter when SMARD's pipeline lags more than
   *  the production filters); `energy-charts` = SMARD entirely
   *  unreachable, full fallback. */
  dataSource: "smard" | "smard+energy-charts" | "energy-charts";
  // Production (MW)
  windOnshoreMw: number;
  windOffshoreMw: number;
  solarMw: number;
  biomassMw: number;
  hydroMw: number;
  ligniteMw: number;
  hardCoalMw: number;
  gasMw: number;
  nuclearMw: number;
  // Aggregates (MW)
  loadMw: number;
  weatherRenewableMw: number;
  conventionalMw: number;
  // Cross-border (GW; positive = net export from DE, negative = import)
  netFlowGw: number;
  /** When was the cross-border saldo last reported by upstream? cbpf
   *  typically lags 1–2 h behind real time. Widget compares to
   *  `measuredAtUnix` to decide whether to show "Stand HH:MM". */
  crossborderMeasuredAtUnix: number | null;
  flowsByCountry: Record<string, number>;
  // Prices (EUR/MWh; null if upstream unavailable). Picked from the
  // 15-min day-ahead slot whose interval contains "now", not the last
  // non-null cell of the array.
  priceDeEurMwh: number | null;
  priceFrEurMwh: number | null;
  /** Unix sec of the price-slot start that produced `priceDeEurMwh`. */
  priceMeasuredAtUnix: number | null;
  // Stale flags surfaced from the CMS' `x-rustycms-external-stale` header
  staleStrommix: boolean;
  staleCrossborder: boolean;
  stalePrice: boolean;

  // ---------------------------------------------------------------------
  // Historical aggregates (sourced from CMS `_history` endpoint over
  // raw upstream snapshots; null = no data yet for this widget).
  // ---------------------------------------------------------------------

  /** Today's residual-load curve. One entry per upstream slot (typically
   *  15 min). `loadMw - weatherRenewableMw` = the gap conventional plants
   *  + imports must fill. `null` when history backend is empty / disabled. */
  todayHourly: ResidualLoadPoint[] | null;

  /** Negative-price hours year-to-date (DE-LU, day-ahead). Counted by
   *  iterating history snapshots and summing 15-min slots whose price
   *  was below 0. */
  negPriceHoursYtd: number | null;

  /** Cross-border net balance YTD in GWh (positive = net export from DE,
   *  negative = net import). */
  netCrossborderGwhYtd: number | null;

  /** Per-country YTD balance, same sign convention as `netFlowGw`. */
  crossborderByCountryGwhYtd: Record<string, number> | null;

  /** Cross-border balance for *today only*, GWh per country and total.
   *  Same sign convention. `null` when crossborder history is empty. */
  crossborderTodayGwh: { total: number; perCountry: Record<string, number> } | null;

  /** Most recent contiguous run of `(wind+solar) / load < 10%`. `null`
   *  when no such run exists in retained history. `endedHoursAgo: 0`
   *  means the run is still ongoing (last slot is within the threshold). */
  lastDunkelflaute: DunkelflautePhase | null;

  /** Top 5 longest Dunkelflaute phases in retained history, newest first
   *  if equal length. Empty array when history exists but no qualifying
   *  phase found. `null` when history is unavailable. */
  worstDunkelflauten: DunkelflautePhase[] | null;
};

/** One upstream slot in the residual-load series. */
export type ResidualLoadPoint = {
  /** Unix seconds at the start of the slot. */
  unix: number;
  /** Total electrical load on the German grid (MW). */
  loadMw: number;
  /** Wind onshore + wind offshore + solar (MW). */
  weatherRenewableMw: number;
};

/** A contiguous low-renewables run, computed from history snapshots. */
export type DunkelflautePhase = {
  /** Unix sec of the first slot below the threshold. */
  startUnix: number;
  /** Run duration in hours (slot count × slot length). */
  durationH: number;
  /** Lowest Wind+Solar share observed during the run, percentage of load. */
  minPct: number;
  /** Hours since the run ended (0 = ongoing). */
  endedHoursAgo: number;
};