import type { AiTaskContext } from "@/lib/ai-task-context";

export const MAX_DAILY_AI_TASKS = 5;

export type AiTaskGenerationOptions = {
  excludeLabels?: string[];
  maxCount?: number;
};

export function getGenerationSlotCount(
  carryOverCount: number,
  maxCount = MAX_DAILY_AI_TASKS,
) {
  return Math.max(0, maxCount - carryOverCount);
}

export function buildGenerationUserPrompt(
  context: AiTaskContext,
  options?: AiTaskGenerationOptions,
) {
  const maxCount = options?.maxCount ?? MAX_DAILY_AI_TASKS;
  const excludeLabels = options?.excludeLabels ?? [];

  if (excludeLabels.length === 0) {
    return `Generate today's personalized habit task labels as a JSON array of up to ${maxCount} strings.`;
  }

  return [
    `Generate exactly ${maxCount} NEW habit task labels as a JSON array of strings.`,
    "Do not repeat or rephrase any of these existing tasks the user already has:",
    ...excludeLabels.map((label) => `- ${label}`),
    "Use different wording only for genuinely different activities.",
  ].join("\n");
}