import { useState } from 'react'
import { NavLink } from 'react-router-dom'
import { Command, Activity, FolderKanban, Monitor, Settings, Menu, X, Wifi, WifiOff, Loader } from 'lucide-react'
import { useSSEContext } from '../contexts/SSEContext'
import type { SSEStatus } from '../hooks/useSSE'

const navItems = [
  { to: '/', icon: Command, label: 'Hub' },
  { to: '/logs', icon: Activity, label: 'Logs' },
  { to: '/projects', icon: FolderKanban, label: 'Projects' },
  { to: '/sessions', icon: Monitor, label: 'Sessions' },
  { to: '/settings', icon: Settings, label: 'Settings' },
]

/** Small status pill shown in the sidebar footer and mobile header. */
function SSEStatusBadge({ status, showLabel = false }: { status: SSEStatus; showLabel?: boolean }) {
  const cfg = {
    connected: { icon: Wifi, color: 'text-green-500', label: 'Live' },
    connecting: { icon: Loader, color: 'text-yellow-500 animate-spin', label: 'Connecting' },
    reconnecting: { icon: Loader, color: 'text-yellow-500 animate-spin', label: 'Reconnecting' },
    error: { icon: WifiOff, color: 'text-red-500', label: 'Disconnected' },
  }[status]

  const Icon = cfg.icon

  return (
    <div className="flex items-center gap-1.5" title={cfg.label}>
      <Icon size={14} className={cfg.color} />
      {showLabel && <span className={`text-xs ${cfg.color}`}>{cfg.label}</span>}
    </div>
  )
}

export default function Layout({ children }: { children: React.ReactNode }) {
  const [expanded, setExpanded] = useState(false)
  const [mobileOpen, setMobileOpen] = useState(false)
  const { sseStatus } = useSSEContext()

  return (
    <div className="flex min-h-screen bg-surface-darkest text-on-surface">
      {/* Desktop Nav Rail */}
      <aside
        className={`hidden md:flex flex-col border-r border-surface-light transition-all duration-200 ${
          expanded ? 'w-64' : 'w-18'
        }`}
        onMouseEnter={() => setExpanded(true)}
        onMouseLeave={() => setExpanded(false)}
      >
        <div className="flex items-center gap-3 px-4 h-16 border-b border-surface-light">
          <Command size={24} className="text-primary shrink-0" />
          {expanded && <span className="font-bold text-lg whitespace-nowrap">Control Center</span>}
        </div>
        <nav className="flex-1 py-4 space-y-1">
          {navItems.map((item) => (
            <NavLink
              key={item.to}
              to={item.to}
              className={({ isActive }) =>
                `flex items-center gap-3 px-4 py-3 mx-2 rounded-lg transition-colors ${
                  isActive
                    ? 'bg-primary/10 text-primary'
                    : 'text-on-surface-variant hover:bg-surface-light hover:text-on-surface'
                }`
              }
            >
              <item.icon size={20} className="shrink-0" />
              {expanded && <span className="whitespace-nowrap">{item.label}</span>}
            </NavLink>
          ))}
        </nav>
        {/* SSE connection status — footer of sidebar */}
        <div className="px-4 py-3 border-t border-surface-light flex items-center gap-2">
          <SSEStatusBadge status={sseStatus} />
          {expanded && (
            <span className="text-xs text-on-surface-muted whitespace-nowrap">
              {sseStatus === 'connected' ? 'Live updates on' : sseStatus}
            </span>
          )}
        </div>
      </aside>

      {/* Mobile Header + Bottom Nav */}
      <div className="flex-1 flex flex-col md:ml-0">
        <header className="md:hidden flex items-center justify-between h-16 px-4 border-b border-surface-light bg-surface-dark">
          <div className="flex items-center gap-2">
            <Command size={22} className="text-primary" />
            <span className="font-bold">Control Center</span>
            <SSEStatusBadge status={sseStatus} />
          </div>
          <button onClick={() => setMobileOpen(!mobileOpen)} className="p-2">
            {mobileOpen ? <X size={22} /> : <Menu size={22} />}
          </button>
        </header>

        {/* Mobile drawer */}
        {mobileOpen && (
          <div className="md:hidden fixed inset-0 z-50 bg-surface-dark/95 backdrop-blur">
            <div className="flex flex-col p-4 space-y-2">
              {navItems.map((item) => (
                <NavLink
                  key={item.to}
                  to={item.to}
                  onClick={() => setMobileOpen(false)}
                  className={({ isActive }) =>
                    `flex items-center gap-3 px-4 py-3 rounded-lg ${
                      isActive
                        ? 'bg-primary/10 text-primary'
                        : 'text-on-surface-variant'
                    }`
                  }
                >
                  <item.icon size={20} />
                  {item.label}
                </NavLink>
              ))}
            </div>
          </div>
        )}

        <main className="flex-1 p-4 md:p-6 overflow-auto">{children}</main>

        {/* Mobile Bottom Nav */}
        <nav className="md:hidden flex items-center justify-around h-16 border-t border-surface-light bg-surface-dark">
          {navItems.slice(0, 5).map((item) => (
            <NavLink
              key={item.to}
              to={item.to}
              className={({ isActive }) =>
                `flex flex-col items-center gap-1 p-2 text-xs ${
                  isActive ? 'text-primary' : 'text-on-surface-variant'
                }`
              }
            >
              <item.icon size={20} />
              <span>{item.label}</span>
            </NavLink>
          ))}
        </nav>
      </div>
    </div>
  )
}