"use client";

import { useState } from "react";
import Link from "next/link";
import { useParams } from "next/navigation";
import {
  ArrowRight,
  CheckCircle2,
  CircleDashed,
  ClipboardList,
  FileText,
  FolderKanban,
  LayoutDashboard,
  LayoutGrid,
  Plus,
  Presentation,
  Sparkles,
  type LucideIcon,
} from "lucide-react";

import { CreateObjectDialog } from "@/components/objects";
import { Badge } from "@/components/ui/badge";
import { Button } from "@/components/ui/button";
import { Separator } from "@/components/ui/separator";
import { Skeleton } from "@/components/ui/skeleton";
import { api } from "@/lib/trpc";
import { usePanelStore } from "@/lib/stores/panel-store";
import { useWorkspaceStore } from "@/lib/stores/workspace-store";
import { cn } from "@/lib/utils";

/**
 * Minimal "X ago" formatter. We avoid pulling in date-fns or a Yjs-aware
 * relative-time helper for a single use site; the home page just needs
 * coarse-grained recency labels.
 */
function relativeTime(value: Date | string): string {
  const date = value instanceof Date ? value : new Date(value);
  const ms = Date.now() - date.getTime();
  if (Number.isNaN(ms)) return String(value);
  const secs = Math.max(1, Math.round(ms / 1000));
  if (secs < 60) return `${secs}s ago`;
  const mins = Math.round(secs / 60);
  if (mins < 60) return `${mins}m ago`;
  const hours = Math.round(mins / 60);
  if (hours < 24) return `${hours}h ago`;
  const days = Math.round(hours / 24);
  if (days < 7) return `${days}d ago`;
  return date.toLocaleDateString();
}

const TYPE_LABELS: Record<string, string> = {
  task: "Task",
  document: "Document",
  whiteboard: "Whiteboard",
  space: "Space",
  project: "Project",
  group: "Group",
  form: "Form",
};

const TYPE_ICONS: Record<string, LucideIcon> = {
  task: ClipboardList,
  document: FileText,
  whiteboard: Presentation,
  space: LayoutGrid,
  project: FolderKanban,
  group: FolderKanban,
  form: ClipboardList,
};

function isDoneStatus(status: string | null): boolean {
  return status === "done" || status === "closed";
}

export default function WorkspaceHomePage() {
  const params = useParams();
  const workspaceSlug =
    typeof params?.workspaceSlug === "string" ? params.workspaceSlug : undefined;

  const workspace = useWorkspaceStore((s) => s.currentWorkspace);
  const openPanel = usePanelStore((s) => s.open);

  const [createOpen, setCreateOpen] = useState(false);
  const [createType, setCreateType] = useState<string | undefined>(undefined);

  const statsQuery = api.objects.stats.useQuery(
    { workspace: workspaceSlug! },
    { enabled: Boolean(workspaceSlug) },
  );

  const recentQuery = api.objects.listRecent.useQuery(
    { workspace: workspaceSlug!, limit: 5 },
    { enabled: Boolean(workspaceSlug) },
  );

  const name = workspace?.name ?? "Workspace";
  const recent = recentQuery.data?.objects ?? [];

  return (
    <div className="flex min-h-full flex-col bg-background">
      <header className="relative overflow-hidden border-b border-border px-6 py-10 sm:px-10">
        <div
          className={cn(
            "absolute inset-0 bg-gradient-primary opacity-90",
            "dark:opacity-100",
          )}
          aria-hidden
        />
        <div className="absolute inset-0 bg-[radial-gradient(ellipse_at_top_right,_rgba(255,255,255,0.12),_transparent_55%)]" />
        <div className="relative flex flex-col gap-3">
          <div className="flex flex-wrap items-center gap-2 text-primary-foreground/90">
            <LayoutDashboard className="size-5" />
            <span className="text-xs font-semibold uppercase tracking-widest">
              Home
            </span>
          </div>
          <h1 className="text-3xl font-bold tracking-tight text-primary-foreground sm:text-4xl">
            {name}
          </h1>
          <p className="max-w-2xl text-sm text-primary-foreground/85 sm:text-base">
            Your command center for tasks, docs, and boards. Pick up where you
            left off or open the assistant to plan the day.
          </p>
          <div className="flex flex-wrap gap-2 pt-2">
            <Button
              type="button"
              size="sm"
              variant="secondary"
              className="gap-2 bg-primary-foreground/15 text-primary-foreground hover:bg-primary-foreground/25"
              onClick={() => openPanel("ai-chat")}
            >
              <Sparkles className="size-4" />
              Open AI assistant
            </Button>
            <Button
              type="button"
              size="sm"
              variant="secondary"
              className="gap-2 bg-primary-foreground/15 text-primary-foreground hover:bg-primary-foreground/25"
              onClick={() => {
                setCreateType("task");
                setCreateOpen(true);
              }}
            >
              <Plus className="size-4" />
              New task
            </Button>
          </div>
        </div>
      </header>

      <div className="mx-auto flex w-full max-w-5xl flex-1 flex-col gap-8 px-6 py-8 sm:px-10">
        <section>
          <h2 className="text-sm font-semibold text-foreground">Quick stats</h2>
          <p className="mt-1 text-sm text-muted-foreground">
            A snapshot of what&apos;s live in this workspace right now.
          </p>
          <div className="mt-4 grid gap-3 sm:grid-cols-2">
            <StatCard
              label="Open tasks"
              value={statsQuery.data?.openTasks}
              hint="Excludes done and closed"
              isLoading={statsQuery.isLoading}
            />
            <StatCard
              label="Projects, spaces & groups"
              value={statsQuery.data?.containers}
              hint="All container objects"
              isLoading={statsQuery.isLoading}
            />
          </div>
        </section>

        <Separator />

        <section>
          <div className="flex items-center justify-between gap-2">
            <div>
              <h2 className="text-sm font-semibold text-foreground">
                Recent activity
              </h2>
              <p className="mt-1 text-sm text-muted-foreground">
                Latest updates across this workspace.
              </p>
            </div>
            <Badge variant="secondary" className="shrink-0">
              Live
            </Badge>
          </div>

          {recentQuery.isLoading ? (
            <ul className="mt-4 divide-y divide-border rounded-lg border border-border bg-card">
              {[0, 1, 2].map((i) => (
                <li key={i} className="flex items-start gap-3 px-4 py-3">
                  <Skeleton className="mt-0.5 size-4 rounded-full" />
                  <div className="min-w-0 flex-1 space-y-2">
                    <Skeleton className="h-4 w-2/3" />
                    <Skeleton className="h-3 w-1/3" />
                  </div>
                  <Skeleton className="h-5 w-16" />
                </li>
              ))}
            </ul>
          ) : recent.length === 0 ? (
            <EmptyRecent
              onCreate={() => {
                setCreateType("task");
                setCreateOpen(true);
              }}
            />
          ) : (
            <ul className="mt-4 divide-y divide-border rounded-lg border border-border bg-card">
              {recent.map((item) => {
                if (!workspaceSlug) return null;
                const Icon = TYPE_ICONS[item.type] ?? ClipboardList;
                const typeLabel = TYPE_LABELS[item.type] ?? item.type;
                const done = isDoneStatus(item.status);
                return (
                  <li
                    key={item.id}
                    className="first:rounded-t-lg last:rounded-b-lg"
                  >
                    <Link
                      href={`/${workspaceSlug}/${item.id}`}
                      className="flex items-start gap-3 px-4 py-3 transition-colors hover:bg-muted/40"
                    >
                      <span className="mt-0.5 text-muted-foreground">
                        {done ? (
                          <CheckCircle2 className="size-4 text-teal" />
                        ) : (
                          <Icon className="size-4" />
                        )}
                      </span>
                      <div className="min-w-0 flex-1">
                        <p className="truncate font-medium text-foreground">
                          {item.title || "Untitled"}
                        </p>
                        <p className="text-xs text-muted-foreground">
                          {typeLabel} · Updated {relativeTime(item.updatedAt)}
                        </p>
                      </div>
                      <Badge
                        variant={done ? "secondary" : "outline"}
                        className="shrink-0 capitalize"
                      >
                        {done
                          ? "Done"
                          : item.status?.replace("_", " ") ?? "Active"}
                      </Badge>
                      <ArrowRight className="mt-0.5 size-4 shrink-0 text-muted-foreground/60" />
                    </Link>
                  </li>
                );
              })}
            </ul>
          )}
        </section>
      </div>

      <CreateObjectDialog
        open={createOpen}
        onOpenChange={setCreateOpen}
        defaultType={createType}
      />
    </div>
  );
}

function StatCard({
  label,
  value,
  hint,
  isLoading,
}: {
  label: string;
  value: number | undefined;
  hint: string;
  isLoading: boolean;
}) {
  return (
    <div className="rounded-lg border border-border bg-card p-4 shadow-sm">
      <p className="text-xs font-medium text-muted-foreground">{label}</p>
      {isLoading ? (
        <Skeleton className="mt-2 h-8 w-16" />
      ) : (
        <p className="mt-2 text-2xl font-semibold tabular-nums text-foreground">
          {value ?? 0}
        </p>
      )}
      <p className="mt-1 text-xs text-muted-foreground">{hint}</p>
    </div>
  );
}

function EmptyRecent({ onCreate }: { onCreate: () => void }) {
  return (
    <div className="mt-4 flex flex-col items-center gap-3 rounded-lg border border-dashed border-border bg-card px-6 py-10 text-center">
      <CircleDashed className="size-6 text-muted-foreground" />
      <div>
        <p className="text-sm font-medium text-foreground">
          Nothing here yet
        </p>
        <p className="mt-1 text-xs text-muted-foreground">
          Create your first task to see recent activity here.
        </p>
      </div>
      <Button size="sm" onClick={onCreate} className="gap-1">
        <Plus className="size-4" />
        New task
      </Button>
    </div>
  );
}