"use client";

import { usePathname, useRouter } from "next/navigation";
import { useState, useTransition } from "react";
import { MoreHorizontal, Plus, Star, Trash2, PenLine } from "lucide-react";
import {
  createDashboard,
  deleteDashboard,
  renameDashboard,
  setDefaultDashboard,
} from "@/app/d/actions";
import type { DashboardMeta } from "@/app/d/actions";
import {
  DropdownMenu,
  DropdownMenuContent,
  DropdownMenuItem,
  DropdownMenuSeparator,
  DropdownMenuTrigger,
} from "@/components/ui/dropdown-menu";

export function DashboardSwitcher({ dashboards }: { dashboards: DashboardMeta[] }) {
  const pathname = usePathname();
  const router = useRouter();
  const [, startTransition] = useTransition();
  const [creatingNew, setCreatingNew] = useState(false);
  const [newName, setNewName] = useState("");

  function activeSlug() {
    const m = pathname.match(/^\/d\/([^/]+)/);
    return m?.[1] ?? null;
  }

  function handleCreate() {
    if (!newName.trim()) return;
    startTransition(async () => {
      const created = await createDashboard(newName.trim());
      setCreatingNew(false);
      setNewName("");
      router.push(`/d/${created.slug}`);
    });
  }

  return (
    <div className="flex items-center gap-1">
      {/* Active tab highlights — overlay on top of the server-rendered links */}
      {dashboards.map((d) => {
        const isActive = activeSlug() === d.slug;
        return (
          <span
            key={d.id}
            aria-hidden
            className={`absolute pointer-events-none border-b-2 transition-colors ${
              isActive ? "border-primary" : "border-transparent"
            }`}
            style={{ display: "none" }}
          />
        );
      })}

      {creatingNew ? (
        <form
          onSubmit={(e) => {
            e.preventDefault();
            handleCreate();
          }}
          className="flex items-center gap-1 ml-1"
        >
          <input
            autoFocus
            value={newName}
            onChange={(e) => setNewName(e.target.value)}
            placeholder="Dashboard name"
            className="h-7 rounded border border-input bg-background px-2 text-sm focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring"
            onKeyDown={(e) => e.key === "Escape" && setCreatingNew(false)}
          />
          <button
            type="submit"
            className="text-xs text-muted-foreground hover:text-foreground px-1"
          >
            Add
          </button>
          <button
            type="button"
            onClick={() => setCreatingNew(false)}
            className="text-xs text-muted-foreground hover:text-foreground px-1"
          >
            Cancel
          </button>
        </form>
      ) : (
        <button
          type="button"
          onClick={() => setCreatingNew(true)}
          className="shrink-0 flex items-center gap-1 px-2 py-2 text-sm text-muted-foreground hover:text-foreground transition-colors"
          aria-label="New dashboard"
        >
          <Plus className="size-3.5" />
        </button>
      )}

      {dashboards.map((d) => {
        const isActive = activeSlug() === d.slug;
        if (!isActive) return null;
        return <DashboardKebab key={d.id} dashboard={d} canDelete={dashboards.length > 1} />;
      })}
    </div>
  );
}

function DashboardKebab({
  dashboard,
  canDelete,
}: {
  dashboard: DashboardMeta;
  canDelete: boolean;
}) {
  const [, startTransition] = useTransition();
  const [renaming, setRenaming] = useState(false);
  const [newName, setNewName] = useState(dashboard.name);

  function handleRename() {
    if (!newName.trim() || newName === dashboard.name) {
      setRenaming(false);
      return;
    }
    startTransition(async () => {
      await renameDashboard(dashboard.id, newName.trim());
      setRenaming(false);
    });
  }

  if (renaming) {
    return (
      <form
        onSubmit={(e) => {
          e.preventDefault();
          handleRename();
        }}
        className="flex items-center gap-1 ml-1"
      >
        <input
          autoFocus
          value={newName}
          onChange={(e) => setNewName(e.target.value)}
          className="h-7 rounded border border-input bg-background px-2 text-sm focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring"
          onKeyDown={(e) => e.key === "Escape" && setRenaming(false)}
        />
        <button type="submit" className="text-xs text-muted-foreground hover:text-foreground px-1">
          Save
        </button>
        <button
          type="button"
          onClick={() => setRenaming(false)}
          className="text-xs text-muted-foreground hover:text-foreground px-1"
        >
          Cancel
        </button>
      </form>
    );
  }

  return (
    <DropdownMenu>
      <DropdownMenuTrigger
        className="shrink-0 flex items-center px-1 py-2 text-muted-foreground hover:text-foreground transition-colors"
        aria-label="Dashboard options"
      >
        <MoreHorizontal className="size-4" />
      </DropdownMenuTrigger>
      <DropdownMenuContent align="end">
        <DropdownMenuItem onSelect={() => setRenaming(true)}>
          <PenLine className="size-4 mr-2" />
          Rename
        </DropdownMenuItem>
        {!dashboard.isDefault && (
          <DropdownMenuItem
            onSelect={() => startTransition(() => setDefaultDashboard(dashboard.id))}
          >
            <Star className="size-4 mr-2" />
            Set as default
          </DropdownMenuItem>
        )}
        {canDelete && (
          <>
            <DropdownMenuSeparator />
            <DropdownMenuItem
              className="text-destructive focus:text-destructive"
              onSelect={() => startTransition(() => deleteDashboard(dashboard.id))}
            >
              <Trash2 className="size-4 mr-2" />
              Delete
            </DropdownMenuItem>
          </>
        )}
      </DropdownMenuContent>
    </DropdownMenu>
  );
}