"use client"

import Link from "next/link"
import { usePathname } from "next/navigation"

import { PAGES_NEW } from "@/lib/docs"
import { showMcpDocs } from "@/lib/flags"
import type { source } from "@/lib/source"
import {
  Sidebar,
  SidebarContent,
  SidebarGroup,
  SidebarGroupContent,
  SidebarGroupLabel,
  SidebarMenu,
  SidebarMenuButton,
  SidebarMenuItem,
} from "@/registry/new-york-v4/ui/sidebar"

type PageTreeNode = (typeof source.pageTree)["children"][number]
type PageTreeFolder = Extract<PageTreeNode, { type: "folder" }>
type PageTreePage = Extract<PageTreeNode, { type: "page" }>

const TOP_LEVEL_SECTIONS = [
  { name: "Get Started", href: "/docs" },
  {
    name: "Components",
    href: "/docs/components",
  },
  {
    name: "Directory",
    href: "/docs/directory",
  },
  {
    name: "MCP Server",
    href: "/docs/mcp",
  },
  {
    name: "Forms",
    href: "/docs/forms",
  },
  {
    name: "Changelog",
    href: "/docs/changelog",
  },
]
const EXCLUDED_SECTIONS = ["installation", "dark-mode"]
const EXCLUDED_PAGES = ["/docs", "/docs/changelog"]

// Recursively find all pages in a folder tree.
function getAllPagesFromFolder(folder: PageTreeFolder): PageTreePage[] {
  const pages: PageTreePage[] = []

  for (const child of folder.children) {
    if (child.type === "page") {
      pages.push(child)
    } else if (child.type === "folder") {
      pages.push(...getAllPagesFromFolder(child))
    }
  }

  return pages
}

// Get the pages from a folder, handling nested base folders (radix/base).
function getPagesFromFolder(
  folder: PageTreeFolder,
  currentBase: string
): PageTreePage[] {
  // For the components folder, find the base subfolder.
  if (folder.$id === "components" || folder.name === "Components") {
    for (const child of folder.children) {
      if (child.type === "folder") {
        // Match by $id or by name.
        const isRadix = child.$id === "radix" || child.name === "Radix UI"
        const isBase = child.$id === "base" || child.name === "Base UI"

        if (
          (currentBase === "radix" && isRadix) ||
          (currentBase === "base" && isBase)
        ) {
          return child.children.filter(
            (c): c is PageTreePage => c.type === "page"
          )
        }
      }
    }

    // Fallback: return all pages from nested folders.
    return getAllPagesFromFolder(folder).filter(
      (page) => !page.url.endsWith("/components")
    )
  }

  // For other folders, return direct page children.
  return folder.children.filter(
    (child): child is PageTreePage => child.type === "page"
  )
}

export function DocsSidebar({
  tree,
  ...props
}: React.ComponentProps<typeof Sidebar> & { tree: typeof source.pageTree }) {
  const pathname = usePathname()

  // Detect current base from URL (radix or base).
  const baseMatch = pathname.match(/\/docs\/components\/(radix|base)\//)
  const currentBase = baseMatch ? baseMatch[1] : "radix" // Default to radix.

  return (
    <Sidebar
      className="sticky top-[calc(var(--header-height)+1px)] z-30 hidden h-[calc(100svh-var(--footer-height)-4rem)] overscroll-none bg-transparent lg:flex"
      collapsible="none"
      {...props}
    >
      <SidebarContent className="no-scrollbar overflow-x-hidden px-2">
        <div className="from-background via-background/80 to-background/50 sticky -top-1 z-10 h-8 shrink-0 bg-gradient-to-b blur-xs" />
        <SidebarGroup>
          <SidebarGroupLabel className="text-muted-foreground font-medium">
            Sections
          </SidebarGroupLabel>
          <SidebarGroupContent>
            <SidebarMenu>
              {TOP_LEVEL_SECTIONS.map(({ name, href }) => {
                if (!showMcpDocs && href.includes("/mcp")) {
                  return null
                }
                return (
                  <SidebarMenuItem key={name}>
                    <SidebarMenuButton
                      asChild
                      isActive={
                        href === "/docs"
                          ? pathname === href
                          : pathname.startsWith(href)
                      }
                      className="data-[active=true]:bg-accent data-[active=true]:border-accent 3xl:fixed:w-full 3xl:fixed:max-w-48 relative h-[30px] w-fit overflow-visible border border-transparent text-[0.8rem] font-medium after:absolute after:inset-x-0 after:-inset-y-1 after:z-0 after:rounded-md"
                    >
                      <Link href={href}>
                        <span className="absolute inset-0 flex w-(--sidebar-width) bg-transparent" />
                        {name}
                      </Link>
                    </SidebarMenuButton>
                  </SidebarMenuItem>
                )
              })}
            </SidebarMenu>
          </SidebarGroupContent>
        </SidebarGroup>
        {tree.children.map((item) => {
          if (EXCLUDED_SECTIONS.includes(item.$id ?? "")) {
            return null
          }

          return (
            <SidebarGroup key={item.$id}>
              <SidebarGroupLabel className="text-muted-foreground font-medium">
                {item.name}
              </SidebarGroupLabel>
              <SidebarGroupContent>
                {item.type === "folder" && (
                  <SidebarMenu className="gap-0.5">
                    {getPagesFromFolder(item, currentBase).map((page) => {
                      if (!showMcpDocs && page.url.includes("/mcp")) {
                        return null
                      }

                      if (EXCLUDED_PAGES.includes(page.url)) {
                        return null
                      }

                      return (
                        <SidebarMenuItem key={page.url}>
                          <SidebarMenuButton
                            asChild
                            isActive={page.url === pathname}
                            className="data-[active=true]:bg-accent data-[active=true]:border-accent 3xl:fixed:w-full 3xl:fixed:max-w-48 relative h-[30px] w-fit overflow-visible border border-transparent text-[0.8rem] font-medium after:absolute after:inset-x-0 after:-inset-y-1 after:z-0 after:rounded-md"
                          >
                            <Link href={page.url}>
                              <span className="absolute inset-0 flex w-(--sidebar-width) bg-transparent" />
                              {page.name}
                              {PAGES_NEW.includes(page.url) && (
                                <span
                                  className="flex size-2 rounded-full bg-blue-500"
                                  title="New"
                                />
                              )}
                            </Link>
                          </SidebarMenuButton>
                        </SidebarMenuItem>
                      )
                    })}
                  </SidebarMenu>
                )}
              </SidebarGroupContent>
            </SidebarGroup>
          )
        })}
        <div className="from-background via-background/80 to-background/50 sticky -bottom-1 z-10 h-16 shrink-0 bg-gradient-to-t blur-xs" />
      </SidebarContent>
    </Sidebar>
  )
}