import type {
  Api,
  Model,
  SimpleStreamOptions,
  StreamOptions,
  ThinkingBudgets,
  ThinkingLevel,
} from "../types.js";

export function buildBaseOptions(
  model: Model<Api>,
  options?: SimpleStreamOptions,
  apiKey?: string,
): StreamOptions {
  return {
    temperature: options?.temperature,
    maxTokens: options?.maxTokens || Math.min(model.maxTokens, 32000),
    signal: options?.signal,
    apiKey: apiKey || options?.apiKey,
    cacheRetention: options?.cacheRetention,
    sessionId: options?.sessionId,
    headers: options?.headers,
    onPayload: options?.onPayload,
    maxRetryDelayMs: options?.maxRetryDelayMs,
    metadata: options?.metadata,
  };
}

export function clampReasoning(
  effort: ThinkingLevel | undefined,
): Exclude<ThinkingLevel, "xhigh"> | undefined {
  return effort === "xhigh" ? "high" : effort;
}

export function adjustMaxTokensForThinking(
  baseMaxTokens: number,
  modelMaxTokens: number,
  reasoningLevel: ThinkingLevel,
  customBudgets?: ThinkingBudgets,
): { maxTokens: number; thinkingBudget: number } {
  const defaultBudgets: ThinkingBudgets = {
    minimal: 1024,
    low: 2048,
    medium: 8192,
    high: 16384,
  };
  const budgets = { ...defaultBudgets, ...customBudgets };

  const minOutputTokens = 1024;
  const level = clampReasoning(reasoningLevel)!;
  let thinkingBudget = budgets[level]!;
  const maxTokens = Math.min(baseMaxTokens + thinkingBudget, modelMaxTokens);

  if (maxTokens <= thinkingBudget) {
    thinkingBudget = Math.max(0, maxTokens - minOutputTokens);
  }

  return { maxTokens, thinkingBudget };
}