import { NextRequest, NextResponse } from "next/server";
import { eq, desc, sql, and } from "drizzle-orm";
import { db } from "@/lib/db";
import { lobsters, tasks } from "@/lib/db/schema";
import { getActiveLobsterIds } from "@/lib/redis";

export async function GET(req: NextRequest) {
  try {
    const { searchParams } = new URL(req.url);
    const limitParam = parseInt(searchParams.get("limit") ?? "50", 10);
    const limit = Math.min(Math.max(1, limitParam), 200);
    const region = searchParams.get("region");

    const conditions = [];
    if (region) {
      conditions.push(eq(lobsters.region, region));
    }

    const whereClause = conditions.length > 0 ? and(...conditions) : undefined;

    const lobsterRows = await db
      .select()
      .from(lobsters)
      .where(whereClause)
      .orderBy(desc(lobsters.lastHeartbeat))
      .limit(limit);

    const totalResult = await db
      .select({ count: sql<number>`count(*)` })
      .from(lobsters)
      .where(whereClause);
    const total = totalResult[0]?.count ?? 0;

    const activeLobsterIds = await getActiveLobsterIds();
    const activeSet = new Set(activeLobsterIds);

    const lobsterList = await Promise.all(
      lobsterRows.map(async (lobster) => {
        const latestTaskRows = await db
          .select({
            summary: tasks.summary,
            timestamp: tasks.timestamp,
            durationMs: tasks.durationMs,
          })
          .from(tasks)
          .where(eq(tasks.lobsterId, lobster.id))
          .orderBy(desc(tasks.timestamp))
          .limit(1);

        const lastTask = latestTaskRows[0] ?? null;

        return {
          id: lobster.id,
          name: lobster.name,
          model: lobster.model,
          platform: lobster.platform,
          city: lobster.city,
          country: lobster.country,
          isOnline: activeSet.has(lobster.id),
          lastTask,
        };
      })
    );

    return NextResponse.json({ lobsters: lobsterList, total });
  } catch (error) {
    console.error("Lobsters error:", error);
    return NextResponse.json(
      { error: "Internal server error" },
      { status: 500 }
    );
  }
}