"use server";

import { revalidatePath } from "next/cache";
import { redirect } from "next/navigation";
import { auth } from "@/lib/auth";
import { prisma } from "@/lib/prisma";
import { rcon } from "@/lib/services/rcon";
import { sendCurrency } from "@/lib/services/send-currency";
import { siteSettings } from "@/lib/services/site-settings";

/**
 * Buy a published community-drawn badge for the SIGNED-IN user. Faithful to
 * AtomCMS's DrawBadgeController buy flow:
 *   - the buyer id is re-read from the session (auth()), NEVER from FormData,
 *     so a crafted form can't purchase on another account;
 *   - only PUBLISHED badges are purchasable;
 *   - the price is a flat, configurable amount (website_settings → the same
 *     `drawbadge.price` key AtomCMS uses), with a safe default;
 *   - the buyer must hold at least `price` credits, which are then deducted;
 *   - the badge is granted live via the emulator (givebadge RCON) and persisted
 *     into users_badges so it survives a relog (mirrors admin giveBadge).
 *
 * website_drawbadges has no price/code columns — the price comes from settings
 * and the emulator badge code is derived from the badge's stored `badge_path`
 * (the sprite filename, e.g. `album1584/MYBADGE.gif` → `MYBADGE`).
 */

const DEFAULT_PRICE = 50;

// The emulator badge code is the badge_path filename without its directory or
// extension, restricted to the code charset the client accepts.
function badgeCodeFromPath(badgePath: string): string {
  const base = badgePath.split(/[\\/]/).pop() ?? badgePath;
  const noExt = base.replace(/\.[^.]+$/, "");
  return noExt.replace(/[^A-Za-z0-9_-]/g, "").slice(0, 32);
}

async function resolvePrice(): Promise<number> {
  const raw = await siteSettings.get("drawbadge.price", String(DEFAULT_PRICE));
  const n = Number(raw);
  return Number.isFinite(n) && n >= 0 ? Math.floor(n) : DEFAULT_PRICE;
}

export async function buyBadge(formData: FormData): Promise<void> {
  const session = await auth();
  if (!session?.user?.id) redirect("/login");

  const userId = Number(session.user.id);
  if (!Number.isFinite(userId)) redirect("/login");

  // The form posts the badge row id; everything else (price, code) is resolved
  // server-side from trusted data — never from the client.
  const rawId = String(formData.get("id") ?? "").trim();
  if (!/^\d+$/.test(rawId)) redirect("/draw-badge?error=invalid");

  let outcome: "bought" | "invalid" | "credits" | "fail" = "fail";
  let boughtCode = "";

  try {
    const badge = await prisma.websiteDrawbadges.findUnique({
      where: { id: BigInt(rawId) },
      select: { id: true, badgePath: true, published: true },
    });

    if (!badge || !badge.published) {
      outcome = "invalid";
    } else {
      const code = badgeCodeFromPath(badge.badgePath);
      if (code.length === 0) {
        outcome = "invalid";
      } else {
        const price = await resolvePrice();

        // Re-read the buyer's live credit balance and verify it covers the cost.
        const buyer = await prisma.user.findUnique({
          where: { id: userId },
          select: { credits: true },
        });
        if (!buyer || buyer.credits < price) {
          outcome = "credits";
        } else {
          // Deduct first, then grant. sendCurrency falls back to a direct DB
          // write when RCON is offline; a negative amount is not supported, so
          // the debit is an atomic credits decrement and the credit (grant) is
          // the badge itself.
          if (price > 0) {
            await prisma.user.update({
              where: { id: userId },
              data: { credits: { decrement: price } },
            });
          }

          // Grant the badge live so it appears immediately for online users.
          await rcon.giveBadge(userId, code);

          // Persist it so it survives a relog / offline grant. users_badges has
          // no unique (user_id, badge_code) constraint, so guard duplicates and
          // compute the next free slot ourselves (mirrors admin giveBadge).
          try {
            const existing = await prisma.usersBadges.findFirst({
              where: { userId, badgeCode: code },
              select: { id: true },
            });
            if (!existing) {
              const max = await prisma.usersBadges.aggregate({
                where: { userId },
                _max: { slotId: true },
              });
              const slotId = (max._max.slotId ?? 0) + 1;
              await prisma.usersBadges.create({
                data: { userId, slotId, badgeCode: code },
              });
            }
          } catch {
            // Best-effort: the RCON grant already succeeded for online users.
          }

          outcome = "bought";
          boughtCode = code;
        }
      }
    }
  } catch {
    outcome = "fail";
  }

  revalidatePath("/draw-badge");

  // redirect() throws — it must live OUTSIDE the try/catch.
  if (outcome === "bought") {
    redirect(`/draw-badge?bought=${encodeURIComponent(boughtCode)}`);
  }
  redirect(`/draw-badge?error=${outcome}`);
}