import { prisma } from "@/lib/db";
import type { TokenUsage } from "./types";

// Rough 2026 unit prices (USD). Tune in one place; admin cost dashboards read AiCostLog.
const PRICE = {
  gptInputPer1k: 0.0025,
  gptOutputPer1k: 0.01,
  elevenPer1kChars: 0.3,
  dallePerImage: 0.04,
};

export function scriptCostUsd(usage: TokenUsage): number {
  return round4(
    (usage.inputTokens / 1000) * PRICE.gptInputPer1k +
      (usage.outputTokens / 1000) * PRICE.gptOutputPer1k
  );
}

export function audioCostUsd(characters: number): number {
  return round4((characters / 1000) * PRICE.elevenPer1kChars);
}

export function artCostUsd(images: number): number {
  return round4(images * PRICE.dallePerImage);
}

export interface CostEntry {
  provider: "openai" | "elevenlabs";
  operation: "script" | "audio" | "art" | "repurpose";
  units: number;
  costUsd: number;
  episodeId?: string;
  userId?: string;
}

/** Record an AI usage/cost line for the admin monitoring dashboard. */
export async function recordCost(entry: CostEntry): Promise<void> {
  await prisma.aiCostLog.create({
    data: {
      provider: entry.provider,
      operation: entry.operation,
      units: entry.units,
      costUsd: entry.costUsd.toFixed(4),
      episodeId: entry.episodeId,
      userId: entry.userId,
    },
  });
}

function round4(n: number): number {
  return Math.round(n * 10000) / 10000;
}