import { eq } from "drizzle-orm"
import { db } from "@/lib/db"
import { profiles } from "@/lib/db/schema"
import { PLAN_LIMITS } from "@/lib/stripe/plans"
import { getUserStorageBytes } from "@/lib/storage"
import type { Plan } from "@/types"

/**
 * Server-side plan-limit enforcement helpers. Single source of truth is
 * PLAN_LIMITS in lib/stripe/plans.ts — never hardcode limit numbers in routes.
 */

/** The user's current plan (defaults to "starter" if no profile row). */
export async function getUserPlan(userId: string): Promise<Plan> {
  const profile = await db.query.profiles.findFirst({
    where: eq(profiles.id, userId),
    columns: { plan: true },
  })
  return (profile?.plan ?? "starter") as Plan
}

/**
 * Returns an error message if storing `incomingBytes` more would exceed the
 * user's plan storage cap, otherwise null. Reads actual usage from the storage
 * backend so it stays accurate regardless of which tables reference the files.
 */
export async function checkStorageLimit(
  userId: string,
  incomingBytes: number
): Promise<string | null> {
  const plan = await getUserPlan(userId)
  const maxBytes = PLAN_LIMITS[plan].maxStorageMB * 1024 * 1024
  if (!Number.isFinite(maxBytes)) return null // unlimited plan

  const used = await getUserStorageBytes(userId)
  if (used + incomingBytes > maxBytes) {
    const limitMb = PLAN_LIMITS[plan].maxStorageMB
    return `Storage limit reached (${limitMb} MB on your plan). Upgrade for more space.`
  }
  return null
}