/**
 * Server-side catalog of the V2 seconds-based subscription plans.
 *
 * FlatRender charges by **render-seconds**, not by number of videos. Each plan
 * grants a monthly bucket of render-seconds (`secondsCharge`); a render consumes
 * seconds equal to the video's length × a resolution multiplier (see
 * RESOLUTION_MULTIPLIERS). Plans live in the Identity service and are read here
 * from the gateway so prices/quotas are editable in admin without code changes.
 */

import { gatewayUrl } from "@/lib/api/gateway";

// ── Resolution multipliers: render-seconds = videoLengthSec × multiplier ───────
// Baseline is 720p (×1). Higher resolutions cost proportionally more seconds.
export const RESOLUTION_MULTIPLIERS: Record<string, number> = {
  "360p": 0.5,
  "540p": 0.75,
  "720p": 1,
  "1080p": 2,
  "2K": 3,
  "4K": 4,
};

export const RESOLUTION_ORDER = ["360p", "540p", "720p", "1080p", "2K", "4K"];

/** Multiplier for a resolution label, defaulting to 1 for unknown labels. */
export function resolutionMultiplier(resolution: string): number {
  return RESOLUTION_MULTIPLIERS[resolution] ?? 1;
}

/** Render-seconds a single render consumes at the given length + resolution. */
export function renderSecondsCost(lengthSec: number, resolution: string): number {
  return Math.ceil(lengthSec * resolutionMultiplier(resolution));
}

// ── Types ──────────────────────────────────────────────────────────────────

export interface SecondsPlan {
  id: string;
  code: string;
  name: string;
  description?: string | null;
  /** Display price in Toman (price_minor is stored in Rial = Toman × 10). */
  priceTomans: number;
  beforePriceTomans?: number | null;
  currency: string;
  /** Render-seconds granted per billing period. */
  secondsCharge: number;
  monthlyRendersQuota?: number | null;
  storageGb: number;
  parallelRenders: number;
  maxResolution: string;
  renderSpeedFactor: number;
  isFeatured: boolean;
  color?: string | null;
  /** True when renders are watermarked (free tier). */
  watermark: boolean;
}

interface V2PlanRow {
  id: string;
  code: string;
  name: string;
  description?: string | null;
  price_minor: number;
  before_price_minor?: number | null;
  currency: string;
  seconds_charge: number;
  monthly_renders_quota?: number | null;
  storage_gb: number;
  parallel_renders: number;
  max_resolution: string;
  render_speed_factor: number | string;
  is_featured: boolean;
  color?: string | null;
  features?: Record<string, unknown> | null;
}

function mapPlan(p: V2PlanRow): SecondsPlan {
  return {
    id: p.id,
    code: p.code,
    name: p.name,
    description: p.description,
    priceTomans: Math.round((p.price_minor ?? 0) / 10),
    beforePriceTomans:
      p.before_price_minor != null ? Math.round(p.before_price_minor / 10) : null,
    currency: p.currency,
    secondsCharge: p.seconds_charge,
    monthlyRendersQuota: p.monthly_renders_quota,
    storageGb: p.storage_gb,
    parallelRenders: p.parallel_renders,
    maxResolution: p.max_resolution,
    renderSpeedFactor: Number(p.render_speed_factor),
    isFeatured: p.is_featured,
    color: p.color,
    watermark: Boolean(p.features?.watermark),
  };
}

/**
 * Fetch the active plans from the Identity service (public, ISR-cached).
 * Returns an empty array when the gateway is unset/unreachable so the page can
 * render a graceful empty state instead of throwing.
 */
export async function fetchPlans(): Promise<SecondsPlan[]> {
  // Retry once: a single slow/cold gateway response shouldn't blank the page.
  for (let attempt = 0; attempt < 2; attempt++) {
    try {
      const res = await fetch(gatewayUrl("/v1/plans"), {
        headers: { Accept: "application/json" },
        signal: AbortSignal.timeout(6000),
        next: { revalidate: 60 },
      });
      if (!res.ok) continue;
      const json = (await res.json().catch(() => null)) as {
        data?: V2PlanRow[];
      } | null;
      const rows = json?.data ?? [];
      return rows.map(mapPlan).sort((a, b) => a.priceTomans - b.priceTomans);
    } catch {
      // fall through to the next attempt, then to the empty fallback
    }
  }
  return [];
}

/** Format a Toman amount with locale digit grouping. */
export function formatToman(amount: number, locale: string): string {
  return new Intl.NumberFormat(locale === "fa" ? "fa-IR" : "en-US").format(amount);
}