import { NextRequest, NextResponse } from "next/server";
import { getServerSession } from "@/lib/auth";
import { db } from "@/lib/db";
import { campaigns, bingoItems, marks, users } from "@/lib/db/schema";
import { eq, inArray, desc } from "drizzle-orm";

export async function GET(req: NextRequest, { params }: { params: Promise<{ campaignId: string }> }) {
  const session = await getServerSession();
  if (!session) return NextResponse.json({ error: "Unauthorized" }, { status: 401 });

  try {
    const { campaignId } = await params;
    const campaign = db.select().from(campaigns).where(eq(campaigns.id, campaignId)).get();
    if (!campaign) return NextResponse.json({ error: "Campaign not found" }, { status: 404 });

    const items = db.select().from(bingoItems).where(eq(bingoItems.campaignId, campaignId)).orderBy(bingoItems.gridIndex).all();
    const allMarks = db.select().from(marks).where(eq(marks.campaignId, campaignId)).orderBy(desc(marks.createdAt)).all();

    const userIds = [...new Set(allMarks.map(m => m.userId))];
    const userMap: Record<string, string> = {};
    if (userIds.length > 0) {
      const markedUsers = db.select({ id: users.id, nickname: users.nickname })
        .from(users).where(inArray(users.id, userIds)).all();
      markedUsers.forEach(u => { userMap[u.id] = u.nickname; });
    }

    const itemMap: Record<string, typeof items[0]> = {};
    items.forEach(it => { itemMap[it.id] = it; });

    const markedItemIds = allMarks.map(m => m.itemId);
    const markCountMap: Record<string, number> = {};
    const markUsersMap: Record<string, string[]> = {};
    for (const m of allMarks) {
      markCountMap[m.itemId] = (markCountMap[m.itemId] || 0) + 1;
      if (!markUsersMap[m.itemId]) markUsersMap[m.itemId] = [];
      if (!markUsersMap[m.itemId].includes(userMap[m.userId] || "???")) {
        markUsersMap[m.itemId].push(userMap[m.userId] || "???");
      }
    }

    const activityLog = allMarks.slice(0, 20).map(m => {
      const nickname = userMap[m.userId] || "???";
      const item = itemMap[m.itemId];
      const emoji = item?.emoji || "💀";
      const text = item?.text || "unknown";
      const time = new Date(m.createdAt).toLocaleTimeString();
      return `${time} ${nickname} marked ${emoji} "${text}"`;
    });

    const totalCells = campaign.gridSize * campaign.gridSize;
    const grid: Array<{
      index: number;
      item: typeof items[0] | null;
      marked: boolean;
      markedBy: string[];
      markCount: number;
    }> = [];

    for (let i = 0; i < totalCells; i++) {
      const item = items.find(it => it.gridIndex === i) || null;
      grid.push({
        index: i,
        item,
        marked: markedItemIds.includes(item?.id || ""),
        markedBy: markUsersMap[item?.id || ""] || [],
        markCount: markCountMap[item?.id || ""] || 0,
      });
    }

    return NextResponse.json({ campaign, grid, activityLog });
  } catch {
    return NextResponse.json({ error: "Failed to load game state" }, { status: 500 });
  }
}