import { redirect } from "next/navigation";

import { getSession } from "@/lib/auth";
import { prisma } from "@/lib/prisma";
import { ShellPage } from "@/components/page-templates";
import { TablePlaceholder } from "@/components/placeholders";

const AVERAGE_RESPONSE_DIVISOR = 1;

function formatDuration(ms: number | null) {
  if (!ms || ms < 0) {
    return "-";
  }

  const totalMinutes = Math.floor(ms / 60000);
  const minutes = totalMinutes % 60;
  const seconds = Math.floor((ms % 60000) / 1000);

  if (totalMinutes < 60) {
    return `${totalMinutes}m ${seconds}s`;
  }

  const hours = Math.floor(totalMinutes / 60);
  return `${hours}h ${minutes}m`;
}

export default async function TeamPerformancePage() {
  const session = await getSession();
  if (!session) {
    redirect("/login");
  }

  if (session.role !== "admin_client") {
    redirect("/unauthorized");
  }

  const agents = await prisma.user.findMany({
    where: {
      tenantId: session.tenantId,
      role: { code: "AGENT" }
    },
    include: {
      assignedConversations: {
        select: {
          status: true,
          firstMessageAt: true,
          lastOutboundAt: true
        }
      }
    },
    orderBy: { fullName: "asc" }
  });

  const rows = agents.map((agent) => {
    const handled = agent.assignedConversations.length;
    const resolved = agent.assignedConversations.filter((item) => item.status === "RESOLVED").length;
    const workload = agent.assignedConversations.filter((item) => item.status === "OPEN" || item.status === "PENDING").length;

    const responseSamples = agent.assignedConversations
      .filter((item) => item.firstMessageAt && item.lastOutboundAt)
      .map((item) => {
        if (!item.firstMessageAt || !item.lastOutboundAt) {
          return null;
        }

        return item.lastOutboundAt.getTime() - item.firstMessageAt.getTime();
      })
      .filter((item): item is number => item !== null && item >= 0);

    const avgResponse =
      responseSamples.length > 0
        ? formatDuration(
            responseSamples.reduce((sum, value) => sum + value, 0) /
              Math.max(AVERAGE_RESPONSE_DIVISOR, responseSamples.length)
          )
        : "-";

    return [agent.fullName, String(handled), avgResponse, String(resolved), `${workload} open`];
  });

  return (
    <ShellPage shell="admin" title="Team Performance" description="Leaderboard performa agent dan workload snapshot.">
      <TablePlaceholder
        title="Performance table"
        columns={["Agent", "Handled", "Avg response", "Resolved", "Workload"]}
        rows={rows}
      />
    </ShellPage>
  );
}