import type { GameDefinition, GameSymbol, SymbolStyle, SymbolTier } from "./types";

type Optional = "payScale" | "tags" | "rules" | "featureNames" | "id" | "minBet" | "maxBet" | "betDivisor";

/** `defineGame` fills defaults and derives feature names from the configured mechanics. */
export function defineGame(input: Omit<GameDefinition, Optional> & Partial<Pick<GameDefinition, Optional>>): GameDefinition {
  const def: GameDefinition = {
    id: input.id ?? input.slug,
    minBet: input.minBet ?? 10,
    maxBet: input.maxBet ?? 1000,
    payScale: input.payScale ?? 1,
    betDivisor: input.betDivisor ?? (input.payModel.type === "lines" ? input.payModel.lines.length : input.grid.reels >= 6 ? 50 : 25),
    tags: input.tags ?? [],
    rules: input.rules ?? [],
    featureNames: input.featureNames ?? [],
    ...input,
  } as GameDefinition;
  if (def.featureNames.length === 0) def.featureNames = deriveFeatureNames(def);
  return def;
}

export function deriveFeatureNames(def: GameDefinition): string[] {
  const f: string[] = [];
  if (def.payModel.type === "ways") f.push(`${waysCount(def)} ways`);
  else f.push(`${def.payModel.lines.length} paylines`);
  if (def.wild?.expanding) f.push("Expanding wilds");
  if (def.wild?.sticky) f.push("Sticky wilds");
  if (def.wild?.stacked) f.push("Stacked wilds");
  if (def.wild?.exploding) f.push("Exploding wilds");
  if (def.wild?.moving) f.push("Moving wilds");
  if (def.wild?.floating) f.push("Random wilds");
  if (def.wild?.multiplier) f.push("Multiplier wilds");
  if (def.cascades) f.push("Cascades");
  if (def.scatter) f.push("Free spins");
  if (def.spinCollect) f.push("Collect multiplier");
  if (def.holdRespin) f.push("Hold & respin");
  if (def.pickBonuses?.length) f.push("Bonus game");
  if (def.meter) f.push("Charge meter");
  if (def.heat) f.push("Heat meter");
  if (def.mystery) f.push("Mystery symbols");
  if (def.randomFeatures) f.push("Feature drops");
  if (def.quantum) f.push("Quantum split");
  if (def.dynamicGrid) f.push("Dynamic grid");
  if (def.jackpot || def.holdRespin) f.push("Jackpots");
  return f;
}

export function waysCount(def: GameDefinition): number {
  return Math.pow(def.grid.rows, def.grid.reels);
}

/** Helper for concise symbol declarations. */
export function sym(
  id: string,
  name: string,
  tier: SymbolTier,
  pays: Record<number, number> | null,
  weight: number | number[],
  style: SymbolStyle,
  extra: Partial<GameSymbol> = {},
): GameSymbol {
  return {
    id,
    name,
    kind: extra.kind ?? "regular",
    tier,
    pays: pays ?? undefined,
    weight,
    style,
    ...extra,
  };
}

export const wildSym = (id: string, name: string, weight: number | number[], style: SymbolStyle, extra: Partial<GameSymbol> = {}): GameSymbol =>
  sym(id, name, "special", null, weight, style, { kind: "wild", ...extra });

export const scatterSym = (id: string, name: string, weight: number | number[], style: SymbolStyle, scatterPays?: Record<number, number>, extra: Partial<GameSymbol> = {}): GameSymbol =>
  sym(id, name, "special", null, weight, style, { kind: "scatter", scatterPays, ...extra });