import { Link, NavLink, Outlet, useLocation } from 'react-router-dom'
import { ChevronDown, Circle, type LucideIcon } from 'lucide-react'
import * as Icons from 'lucide-react'
import { useState } from 'react'
import { useAuth } from '@/contexts/AuthContext'
import { TopBar } from '@/components/TopBar'
import type { MenuNode } from '@/types/menu'
import { cn } from '@/lib/cn'

function getIcon(name: string | null): LucideIcon {
  if (!name) return Circle
  const candidate = (Icons as unknown as Record<string, LucideIcon>)[name]
  return candidate ?? Circle
}

// Map contract type code → ContractType int enum value (mirrors
// Domain/Contracts/ContractType.cs for URL filter).
const TYPE_CODE_TO_INT: Record<string, number> = {
  ThauPhu: 1,
  GiaoKhoan: 2,
  NhaCungCap: 3,
  DichVu: 4,
  MuaBan: 5,
  NguyenTacNcc: 6,
  NguyenTacDv: 7,
}

// Resolve menu key → route. Static map for top-level items, pattern for
// Ct_<Type>_<Action> sub-menu entries.
function resolvePath(key: string): string | null {
  const staticMap: Record<string, string> = {
    Dashboard: '/dashboard',
    Suppliers: '/master/suppliers',
    Projects: '/master/projects',
    Departments: '/master/departments',
    Contracts: '/contracts',
    Forms: '/forms',
    Reports: '/reports',
    Users: '/system/users',
    Roles: '/system/roles',
    Permissions: '/system/permissions',
    MenuVisibility: '/system/menu-visibility',
    Workflows: '/system/workflows',
    CatalogUnits: '/master/catalogs/units',
    CatalogMaterials: '/master/catalogs/materials',
    CatalogServices: '/master/catalogs/services',
    CatalogWorkItems: '/master/catalogs/work-items',
    PurchaseEvaluations: '/purchase-evaluations',
    PeWorkflows: '/system/pe-workflows',
    Budgets: '/budgets',
    Bg_List: '/budgets',
    Bg_Create: '/budgets/new',
    Bg_Pending: '/budgets?phase=Pending',
    // [Phase 10.1 G-H1 S33 2026-05-26] Module Hồ sơ Nhân sự (Mig 34). LESSON
    // Plan CA Hotfix 1 gotcha #50: PHẢI mirror staticMap khi thêm page mới
    // — nếu thiếu, MenuLeaf line ~198 `if (!path) return null` → sidebar drop silent.
    Hrm_HoSo: '/employees',
    // [Phase 10.2 G-O1 S34 2026-05-27] Module Văn phòng số — Danh bạ nội bộ.
    // 4-place mirror Pattern 16-bis: types/ + pages/ + App.tsx + menuKeys + staticMap.
    Off_DanhBa: '/directory',
  }
  if (staticMap[key]) return staticMap[key]

  const match = key.match(/^Ct_([^_]+)_(List|Create|Pending)$/)
  if (match) {
    const [, code, action] = match
    const typeInt = TYPE_CODE_TO_INT[code]
    if (!typeInt) return null
    if (action === 'List') return `/contracts?type=${typeInt}`
    if (action === 'Create') return `/contracts/new?type=${typeInt}`
    if (action === 'Pending') return `/contracts?type=${typeInt}&pendingMe=1`
  }

  // Workflow admin per ContractType: Wf_<Code> → /system/workflows/<code>
  const wfMatch = key.match(/^Wf_(.+)$/)
  if (wfMatch) {
    const code = wfMatch[1]
    if (TYPE_CODE_TO_INT[code]) return `/system/workflows/${code}`
  }

  // Pe_<Code>_<Action> cho module Duyệt NCC
  const peMatch = key.match(/^Pe_([^_]+)_(List|Create|Pending)$/)
  if (peMatch) {
    const [, code, action] = peMatch
    const PE_CODE_TO_INT: Record<string, number> = { DuyetNcc: 1, DuyetNccPhuongAn: 2 }
    const typeInt = PE_CODE_TO_INT[code]
    if (!typeInt) return null
    if (action === 'List') return `/purchase-evaluations?type=${typeInt}`
    // "Thao tác" leaf → workspace 2-panel (Q4 2026-05-07): pick + create + sửa
    // tables inline. Header-only `/new` page giữ tồn tại cho deep-link cũ
    // (PeDetailTabs "Sửa header" button vẫn navigate sang đó).
    if (action === 'Create') return `/purchase-evaluations/workspace?type=${typeInt}`
    if (action === 'Pending') return `/purchase-evaluations?type=${typeInt}&pendingMe=1`
  }
  // PE workflow admin leaf: PeWf_<Code> → /system/pe-workflows/<code>
  const peWfMatch = key.match(/^PeWf_(.+)$/)
  if (peWfMatch) {
    const code = peWfMatch[1]
    if (code === 'DuyetNcc' || code === 'DuyetNccPhuongAn') return `/system/pe-workflows/${code}`
  }

  // Quy trình duyệt MỚI (Mig 22 — Session 17): root = group bowed, leaf =
  // type-specific designer. Sau UAT thay thế PeWorkflows + Workflows cũ.
  if (key === 'ApprovalWorkflowsV2') return '/system/approval-workflows-v2'
  const awV2Match = key.match(/^AwV2_(.+)$/)
  if (awV2Match) {
    const code = awV2Match[1]
    if (code === 'DuyetNcc' || code === 'DuyetNccPhuongAn' || code === 'Contract') {
      return `/system/approval-workflows-v2/${code}`
    }
  }

  return null
}

// Admin side: hide the per-ContractType contract submenu (Ct_*) — that's a
// user-app concern. Keep Wf_* workflow-admin leaves.
// [Plan CA S29 2026-05-22] cũng hide "Cấu hình danh mục dùng chung" (Master +
// Catalogs) — đã move sang fe-user/eoffice. Admin vẫn phân quyền role × menu ×
// CRUD qua /system/permissions (Permission Matrix tự reflect 9 menu key này).
const ADMIN_HIDDEN_MASTER_KEYS = new Set([
  'Master', 'Suppliers', 'Projects', 'Departments',
  'Catalogs', 'CatalogUnits', 'CatalogMaterials', 'CatalogServices', 'CatalogWorkItems',
])

function isAdminHidden(key: string): boolean {
  return key.startsWith('Ct_') || ADMIN_HIDDEN_MASTER_KEYS.has(key)
}

function filterForAdmin(nodes: MenuNode[]): MenuNode[] {
  return nodes
    .filter(n => !isAdminHidden(n.key))
    .map(n => ({ ...n, children: filterForAdmin(n.children) }))
}

function MenuNodeRenderer({ node, depth = 0 }: { node: MenuNode; depth?: number }) {
  const hasChildren = node.children.length > 0
  if (hasChildren) return <MenuGroup node={node} depth={depth} />
  return <MenuLeaf node={node} depth={depth} />
}

function MenuGroup({ node, depth }: { node: MenuNode; depth: number }) {
  // Top-level groups expanded by default, nested ones collapsed to reduce noise
  const [open, setOpen] = useState(depth === 0)
  const Icon = getIcon(node.icon)
  const isTopLevel = depth === 0

  return (
    <div>
      <button
        onClick={() => setOpen(o => !o)}
        className={cn(
          'relative block w-full rounded-md text-left transition',
          isTopLevel
            ? 'px-3 py-2 pr-7 text-[11px] font-semibold uppercase tracking-wide text-slate-500 hover:bg-slate-100 whitespace-nowrap'
            : 'px-3 py-1.5 pr-7 text-[12px] font-medium leading-snug text-slate-600 hover:bg-slate-100 hover:text-slate-900',
        )}
      >
        {/* [Plan AA S24 t2 wrap fix] inline-block icon + inline text — label
            dài wrap về đầu hàng (under icon, KHÔNG indent sau icon). Mirror
            fe-user rule §3.9. ChevronDown absolute right. */}
        <Icon className="mr-1.5 -mt-0.5 inline-block h-4 w-4 align-middle" />
        <span className="align-middle" title={node.label}>{node.label}</span>
        <ChevronDown className={cn(
          'absolute right-2 top-2 h-3.5 w-3.5 text-slate-400 transition',
          !open && '-rotate-90',
        )} />
      </button>
      {open && (
        <div className={cn(
          'mt-0.5 space-y-0.5',
          depth === 0 ? 'pl-2' : 'ml-3 mt-1 border-l border-slate-100 pl-3',
        )}>
          {node.children.map(c => (
            <MenuNodeRenderer key={c.key} node={c} depth={depth + 1} />
          ))}
        </div>
      )}
    </div>
  )
}

// Transient query keys — không phải "navigation identity", strip trước khi
// compare để menu giữ highlight khi user select row / search / filter.
// Ví dụ leaf "Danh sách" `?type=1` vẫn highlight khi user click phiếu →
// `?type=1&id=abc`. Trước đó exact-set match → mất highlight (bug UAT 2026-05-08).
const TRANSIENT_QUERY_KEYS = new Set(['id', 'q', 'editHeader', 'page', 'phase', 'awId'])

// So sánh 2 query string dạng key-value set (thứ tự param không quan trọng,
// transient keys ignored). Fix bug: /contracts?type=1 và ?type=1&pendingMe=1
// cùng highlight vì NavLink built-in `end` prop chỉ match pathname.
function queryMatches(current: string, target: string): boolean {
  const a = new URLSearchParams(current)
  const b = new URLSearchParams(target)
  const aKeys = [...a.keys()].filter(k => !TRANSIENT_QUERY_KEYS.has(k)).sort()
  const bKeys = [...b.keys()].filter(k => !TRANSIENT_QUERY_KEYS.has(k)).sort()
  if (aKeys.length !== bKeys.length) return false
  return aKeys.every((k, i) => bKeys[i] === k && a.get(k) === b.get(k))
}

function MenuLeaf({ node, depth }: { node: MenuNode; depth: number }) {
  const Icon = getIcon(node.icon)
  const path = resolvePath(node.key)
  const location = useLocation()
  if (!path) return null
  const isDeep = depth >= 2

  const [targetPath, targetQuery = ''] = path.split('?')
  const isActive = location.pathname === targetPath
    && queryMatches(location.search.replace(/^\?/, ''), targetQuery)

  return (
    <NavLink
      to={path}
      title={node.label}
      className={cn(
        'block rounded-md leading-snug transition',
        isDeep ? 'px-3 py-1 text-[11px]' : 'px-3 py-2 text-[12px] font-medium',
        isActive
          ? 'bg-brand-50 text-brand-700'
          : 'text-slate-600 hover:bg-slate-100 hover:text-slate-900',
      )}
    >
      {/* [Plan AA S24 t2 wrap fix] inline-block icon + inline text → mirror fe-user. */}
      <Icon className={cn('mr-2 -mt-0.5 inline-block align-middle', isDeep ? 'h-3.5 w-3.5' : 'h-4 w-4')} />
      <span className="align-middle">{node.label}</span>
    </NavLink>
  )
}

export function Layout() {
  const { menu } = useAuth()

  return (
    <div className="flex h-screen">
      <aside className="flex w-72 flex-col border-r border-slate-200 bg-white xl:w-80">
        <div className="flex h-16 items-center border-b border-slate-200 px-5">
          <Link to="/dashboard" className="flex items-center gap-2.5">
            <img src="/logo.png" alt="Solutions" className="h-8 w-auto" />
            <span className="text-[11px] font-semibold uppercase tracking-wider text-slate-400">Admin</span>
          </Link>
        </div>
        <nav className="flex-1 space-y-1 overflow-y-auto p-3">
          {filterForAdmin(menu).map(n => (
            <MenuNodeRenderer key={n.key} node={n} depth={0} />
          ))}
        </nav>
      </aside>
      <div className="flex flex-1 flex-col overflow-hidden">
        <TopBar />
        <main className="flex-1 overflow-auto">
          <Outlet />
        </main>
      </div>
    </div>
  )
}