'use client'

import Link from 'next/link'
import { useEffect, useState } from 'react'
import { usePathname } from 'next/navigation'
import { HugeiconsIcon } from '@hugeicons/react'
import { ChevronRightIcon, UserIcon } from '@hugeicons/core-free-icons'

import {
  Sidebar,
  SidebarContent,
  SidebarFooter,
  SidebarGroup,
  SidebarHeader,
  SidebarMenu,
  SidebarMenuButton,
  SidebarMenuItem,
  SidebarMenuSub,
  SidebarMenuSubButton,
  SidebarMenuSubItem,
  SidebarRail,
} from '@/components/ui/sidebar'
import {
  Collapsible,
  CollapsibleContent,
  CollapsibleTrigger,
} from '@/components/ui/collapsible'
import {
  Tooltip,
  TooltipContent,
  TooltipTrigger,
} from '@/components/ui/tooltip'
import { Button } from '@/components/ui/button'
import { useAuth } from '@/contexts/auth-context'
import { DASHBOARD_ITEM, CONFIGURATION_ITEM, NAV_GROUPS, type NavGroup, type NavItem } from '@/config/nav'

function canSee(item: NavItem, permissions: Set<string>): boolean {
  if (!item.permission) return true
  return permissions.has(item.permission)
}

function isGroupVisible(group: NavGroup, permissions: Set<string>): boolean {
  return group.items.some((item) => canSee(item, permissions))
}

export function AppSidebar() {
  const { user, permissions, logout } = useAuth()
  const pathname = usePathname()

  const dashboardActive = pathname === DASHBOARD_ITEM.href
  const configurationActive =
    pathname === CONFIGURATION_ITEM.href || pathname.startsWith(CONFIGURATION_ITEM.href + '/')
  const [openGroups, setOpenGroups] = useState<Record<string, boolean>>({})

  useEffect(() => {
    setOpenGroups((prev) => {
      const next = { ...prev }

      for (const group of NAV_GROUPS) {
        if (!isGroupVisible(group, permissions)) continue

        const visibleItems = group.items.filter((item) => canSee(item, permissions))
        const groupActive = visibleItems.some(
          (item) =>
            pathname === item.href ||
            (item.href !== '/' && pathname.startsWith(item.href)),
        )

        if (groupActive) {
          next[group.title] = true
        } else if (!(group.title in next)) {
          next[group.title] = false
        }
      }

      return next
    })
  }, [pathname, permissions])

  return (
    <Sidebar collapsible="icon">
      <SidebarHeader>
        <div className="flex items-center gap-2 px-2 py-1">
          <div className="flex h-8 w-8 shrink-0 items-center justify-center rounded-lg bg-primary text-primary-foreground text-sm font-bold">
            D
          </div>
          <span className="truncate font-semibold text-sidebar-foreground group-data-[collapsible=icon]:hidden">
            Distribution
          </span>
        </div>
      </SidebarHeader>

      <SidebarContent className="gap-0">
        {/* Dashboard — standalone, not inside a collapsible group */}
        <SidebarGroup className="py-1">
          <SidebarMenu>
            <SidebarMenuItem>
              <SidebarMenuButton
                render={<Link href={DASHBOARD_ITEM.href} />}
                isActive={dashboardActive}
                tooltip={DASHBOARD_ITEM.title}
              >
                <HugeiconsIcon icon={DASHBOARD_ITEM.icon} size={18} />
                <span>{DASHBOARD_ITEM.title}</span>
              </SidebarMenuButton>
            </SidebarMenuItem>
          </SidebarMenu>
        </SidebarGroup>

        {/* Collapsible groups */}
        {NAV_GROUPS.map((group) => {
          if (!isGroupVisible(group, permissions)) return null

          const visibleItems = group.items.filter((item) =>
            canSee(item, permissions),
          )
          const groupActive = visibleItems.some(
            (item) =>
              pathname === item.href ||
              (item.href !== '/' && pathname.startsWith(item.href)),
          )

          return (
            <Collapsible
              key={group.title}
              open={openGroups[group.title] ?? groupActive}
              onOpenChange={(open) =>
                setOpenGroups((prev) => ({ ...prev, [group.title]: open }))
              }
              className="group/collapsible"
            >
              <SidebarGroup className="py-0">
                <SidebarMenu>
                  <SidebarMenuItem>
                    <SidebarMenuButton
                      render={<CollapsibleTrigger />}
                      isActive={groupActive}
                      tooltip={group.title}
                    >
                      <HugeiconsIcon icon={group.icon} size={18} />
                      <span>{group.title}</span>
                      <HugeiconsIcon
                        icon={ChevronRightIcon}
                        size={14}
                        className="ml-auto shrink-0 transition-transform duration-200 group-data-[open]/collapsible:rotate-90 group-data-[collapsible=icon]:hidden"
                      />
                    </SidebarMenuButton>
                  </SidebarMenuItem>

                  <CollapsibleContent>
                    <SidebarMenuSub>
                      {visibleItems.map((item) => {
                        const isActive =
                          pathname === item.href ||
                          (item.href !== '/' &&
                            pathname.startsWith(item.href))
                        return (
                          <Tooltip key={item.href}>
                            <SidebarMenuSubItem>
                              <SidebarMenuSubButton
                                render={<TooltipTrigger render={<Link href={item.href} />} />}
                                isActive={isActive}
                              >
                                <HugeiconsIcon icon={item.icon} size={15} />
                                <span>{item.title}</span>
                              </SidebarMenuSubButton>
                            </SidebarMenuSubItem>
                            <TooltipContent side="right">{item.description ?? item.title}</TooltipContent>
                          </Tooltip>
                        )
                      })}
                    </SidebarMenuSub>
                  </CollapsibleContent>
                </SidebarMenu>
              </SidebarGroup>
            </Collapsible>
          )
        })}

        {/* Configuration — standalone, no sub-nav */}
        {canSee(CONFIGURATION_ITEM, permissions) && (
          <SidebarGroup className="py-1">
            <SidebarMenu>
              <SidebarMenuItem>
                <SidebarMenuButton
                  render={<Link href={CONFIGURATION_ITEM.href} />}
                  isActive={configurationActive}
                  tooltip={CONFIGURATION_ITEM.title}
                >
                  <HugeiconsIcon icon={CONFIGURATION_ITEM.icon} size={18} />
                  <span>{CONFIGURATION_ITEM.title}</span>
                </SidebarMenuButton>
              </SidebarMenuItem>
            </SidebarMenu>
          </SidebarGroup>
        )}
      </SidebarContent>

      <SidebarFooter>
        <div className="flex items-center gap-2 px-2 py-1 group-data-[collapsible=icon]:justify-center">
          <div className="flex h-8 w-8 shrink-0 items-center justify-center rounded-full bg-muted text-muted-foreground">
            <HugeiconsIcon icon={UserIcon} size={16} />
          </div>
          <div className="flex min-w-0 flex-1 flex-col group-data-[collapsible=icon]:hidden">
            <span className="truncate text-sm font-medium text-sidebar-foreground">
              {user?.username ?? '—'}
            </span>
            <Button
              variant="ghost"
              size="sm"
              onClick={logout}
              className="h-auto justify-start p-0 text-xs text-muted-foreground hover:text-foreground hover:bg-transparent"
            >
              Sign out
            </Button>
          </div>
        </div>
      </SidebarFooter>

      <SidebarRail />
    </Sidebar>
  )
}