"use client";

import { useMemo } from "react";

import { Badge } from "@/components/ui/badge";
import { api } from "@/lib/trpc";

export interface OverviewViewProps {
  workspaceId?: string;
  spaceId?: string;
}

function formatUpdatedAt(value: Date | string): string {
  const date = value instanceof Date ? value : new Date(value);
  if (Number.isNaN(date.getTime())) return String(value);
  return date.toLocaleString();
}

export function OverviewView({ workspaceId, spaceId }: OverviewViewProps) {
  const spaceQuery = api.objects.getById.useQuery(
    { id: spaceId! },
    { enabled: Boolean(spaceId) },
  );

  const childrenQuery = api.objects.list.useQuery(
    {
      workspaceId: workspaceId!,
      parentId: spaceId ?? undefined,
      limit: 200,
    },
    { enabled: Boolean(workspaceId) },
  );

  const statusCounts = useMemo(() => {
    const counts = { open: 0, in_progress: 0, done: 0 };
    for (const row of childrenQuery.data?.objects ?? []) {
      const s = row.status;
      if (s === "in_progress") counts.in_progress += 1;
      else if (s === "done") counts.done += 1;
      else counts.open += 1;
    }
    return counts;
  }, [childrenQuery.data?.objects]);

  const recentChildren = useMemo(() => {
    const rows = childrenQuery.data?.objects ?? [];
    return [...rows]
      .sort((a, b) => {
        const ta = new Date(a.updatedAt).getTime();
        const tb = new Date(b.updatedAt).getTime();
        return tb - ta;
      })
      .slice(0, 10);
  }, [childrenQuery.data?.objects]);

  const isLoading = spaceQuery.isLoading || childrenQuery.isLoading;
  const children = childrenQuery.data?.objects ?? [];
  const hasChildren = children.length > 0;
  const space = spaceQuery.data as { title: string } | undefined;

  return (
    <div className="h-full overflow-auto p-6">
      {spaceQuery.isLoading ? (
        <div className="text-sm text-muted-foreground">Loading space…</div>
      ) : space ? (
        <h1 className="text-2xl font-semibold tracking-tight">{space.title}</h1>
      ) : null}

      <div className="mt-8 space-y-8">
        <section>
          <h2 className="text-sm font-semibold">By status</h2>
          <div className="mt-3 grid grid-cols-3 gap-4">
            {(
              [
                { key: "open" as const, label: "Open" },
                { key: "in_progress" as const, label: "In progress" },
                { key: "done" as const, label: "Done" },
              ] as const
            ).map(({ key, label }) => (
              <div
                key={key}
                className="rounded-lg border border-border bg-card p-4 shadow-sm"
              >
                <div className="text-sm text-muted-foreground">{label}</div>
                <div className="mt-1 text-2xl font-semibold tabular-nums">
                  {isLoading ? "—" : statusCounts[key]}
                </div>
              </div>
            ))}
          </div>
        </section>

        <section>
          <h2 className="text-sm font-semibold">Recent activity</h2>
          {childrenQuery.isLoading ? (
            <p className="mt-3 text-sm text-muted-foreground">Loading…</p>
          ) : !hasChildren ? (
            <div className="mt-4 rounded-lg border border-dashed border-border bg-muted/30 p-10 text-center text-sm text-muted-foreground">
              No items in this space yet.
            </div>
          ) : (
            <ul className="mt-3 divide-y divide-border rounded-lg border border-border bg-card shadow-sm">
              {recentChildren.map((obj) => (
                <li
                  key={obj.id}
                  className="flex items-center justify-between gap-3 px-4 py-3"
                >
                  <span className="min-w-0 truncate font-medium">
                    {obj.title}
                  </span>
                  <div className="flex shrink-0 items-center gap-2">
                    <Badge variant="outline">{obj.type}</Badge>
                    <span className="text-xs text-muted-foreground tabular-nums">
                      {formatUpdatedAt(obj.updatedAt)}
                    </span>
                  </div>
                </li>
              ))}
            </ul>
          )}
        </section>
      </div>
    </div>
  );
}