import { APP_CONFIGS } from '@/frontend/config/appMenus'
import { useLogout, useSession } from '@/frontend/hooks/useAuth'
import React from 'react'
import {
  ActionIcon,
  Alert,
  AppShell,
  Avatar,
  Box,
  Burger,
  Button,
  Center,
  Group,
  Loader,
  LoadingOverlay,
  Menu,
  NavLink,
  Select,
  Stack,
  Text,
  ThemeIcon,
  Title,
  useComputedColorScheme,
  useMantineColorScheme
} from '@mantine/core'
import { useDisclosure } from '@mantine/hooks'
import { useQuery } from '@tanstack/react-query'
import { Link, useLocation, useMatches, useNavigate, useParams } from '@tanstack/react-router'
import {
  TbAlertTriangle,
  TbApps,
  TbArrowLeft,
  TbChevronRight,
  TbClock,
  TbDashboard,
  TbDeviceMobile,
  TbHistory,
  TbLogout,
  TbMoon,
  TbSettings,
  TbSun,
  TbUser,
  TbUserCircle
} from 'react-icons/tb'

interface DashboardLayoutProps {
  children: React.ReactNode
}

export function DashboardLayout({ children }: DashboardLayoutProps) {
  const [mobileOpened, { toggle: toggleMobile }] = useDisclosure()
  const [desktopOpened, { toggle: toggleDesktop }] = useDisclosure(true)
  const { toggleColorScheme } = useMantineColorScheme()
  const computedColorScheme = useComputedColorScheme('light', { getInitialValueInEffect: true })
  const location = useLocation()
  const navigate = useNavigate()
  const { appId } = useParams({ strict: false }) as { appId?: string }

  const matches = useMatches()
  const currentPath = matches[matches.length - 1]?.pathname

  // ─── Connect to auth system ──────────────────────────
  const { data: sessionData, isLoading: sessionLoading } = useSession()
  const user = sessionData?.user
  const logout = useLogout()

  // Redirect USER role to profile (pending approval)
  React.useEffect(() => {
    if (!sessionLoading && user?.role === 'USER') {
      navigate({ to: '/profile' })
    }
  }, [user?.role, sessionLoading, navigate])

  // ─── Fetch registered apps from database ─────────────
  const { data: appsData } = useQuery({
    queryKey: ['apps'],
    queryFn: () => fetch('/api/apps', { credentials: 'include' }).then((r) => r.json()),
    staleTime: 60_000,
  })

  // ─── Fetch system status from database ───────────────
  const { data: systemStatus } = useQuery({
    queryKey: ['system', 'status'],
    queryFn: () => fetch('/api/system/status', { credentials: 'include' }).then((r) => r.json()),
    refetchInterval: 30_000, // refresh every 30 seconds
    staleTime: 15_000,
  })

  const globalNav = [
    { label: 'Dashboard', icon: TbDashboard, to: '/dashboard' },
    { label: 'Applications', icon: TbApps, to: '/apps' },
    { label: 'Log Activity', icon: TbHistory, to: '/logs' },
    { label: 'Error Reports', icon: TbAlertTriangle, to: '/bug-reports' },
    { label: 'Users', icon: TbUser, to: '/users' },
  ]

  const activeApp = appId ? APP_CONFIGS[appId] : null
  const navLinks = activeApp ? activeApp.menus : globalNav

  // Build app selector data from API
  const appSelectData = (appsData || []).map((app: any) => ({
    value: app.id,
    label: app.name,
  }))

  // System status indicator
  const isOperational = systemStatus?.status === 'operational'
  const statusColor = isOperational ? '#10b981' : '#f59e0b'
  const statusText = isOperational ? 'All Systems Operational' : 'System Degraded'

  const handleLogout = () => {
    logout.mutate()
  }

  // Prevent dashboard flash for USER role while redirect is happening
  if (sessionLoading || user?.role === 'USER') {
    return (
      <Center mih="100vh">
        <LoadingOverlay visible />
      </Center>
    )
  }

  return (
    <AppShell
      header={{ height: 70 }}
      navbar={{
        width: 260,
        breakpoint: 'sm',
        collapsed: { mobile: !mobileOpened, desktop: !desktopOpened },
      }}
      padding="xl"
      styles={(theme) => ({
        main: {
          backgroundColor: computedColorScheme === 'dark' ? theme.colors.dark[9] : theme.colors.gray[0],
          transition: 'background-color 0.2s ease',
        },
      })}
    >
      <AppShell.Header px="xl">
        <Group h="100%" justify="space-between">
          <Group>
            <Burger opened={mobileOpened} onClick={toggleMobile} hiddenFrom="sm" size="sm" />
            <Burger opened={desktopOpened} onClick={toggleDesktop} visibleFrom="sm" size="sm" />
            <Group gap="xs">
              <ThemeIcon
                size={34}
                radius="md"
                variant="gradient"
                gradient={{ from: '#2563EB', to: '#7C3AED', deg: 135 }}
              >
                <TbDeviceMobile size={18} />
              </ThemeIcon>
              <Text
                size="lg"
                fw={700}
                className="gradient-text"
                style={{ letterSpacing: '-0.5px' }}
              >
                Monitoring System
              </Text>
            </Group>
          </Group>

          <Group gap="md">
            <ActionIcon
              onClick={() => toggleColorScheme()}
              variant="default"
              size="lg"
              aria-label="Toggle color scheme"
            >
              {computedColorScheme === 'dark' ? <TbSun size={18} /> : <TbMoon size={18} />}
            </ActionIcon>
            <Menu shadow="md" width={200} position="bottom-end">
              <Menu.Target>
                <Avatar
                  src={undefined}
                  alt={user?.name || 'User'}
                  color="brand-blue"
                  radius="xl"
                  style={{ cursor: 'pointer' }}
                >
                  {user?.name?.charAt(0).toUpperCase()}
                </Avatar>
              </Menu.Target>

              <Menu.Dropdown>
                {user && (
                  <>
                    <Menu.Label>
                      <Text size="sm" fw={600} truncate>{user.name}</Text>
                      <Text size="xs" c="dimmed" truncate>{user.email}</Text>
                    </Menu.Label>
                    <Menu.Divider />
                  </>
                )}
                <Menu.Label>Application</Menu.Label>
                <Menu.Item
                  leftSection={<TbUserCircle size={16} />}
                  onClick={() => navigate({ to: '/profile' })}
                >
                  Profile
                </Menu.Item>
                <Menu.Divider />
                <Menu.Label>Danger Zone</Menu.Label>
                <Menu.Item
                  color="red"
                  leftSection={<TbLogout size={16} />}
                  onClick={handleLogout}
                  disabled={logout.isPending}
                >
                  {logout.isPending ? 'Logging out...' : 'Logout'}
                </Menu.Item>
              </Menu.Dropdown>
            </Menu>
          </Group>
        </Group>
      </AppShell.Header>

      <AppShell.Navbar p="md">
        <Stack gap="xs" mt="md">
          {activeApp && (
            <NavLink
              label="Back to Dashboard"
              leftSection={<TbArrowLeft size={20} />}
              component={Link}
              to="/dashboard"
              styles={(theme) => ({
                root: {
                  borderRadius: theme.radius.md,
                  opacity: 0.7,
                  '&:hover': { opacity: 1 },
                },
              })}
            />
          )}

          {
            activeApp &&
            <Select
              label="Selected Application"
              value={appId}
              data={appSelectData.length > 0 ? appSelectData : [
                { value: 'desa-plus', label: 'Desa+' },
              ]}
              onChange={(val) => val && navigate({ to: '/apps/$appId', params: { appId: val } })}
              radius="md"
              size="sm"
              w={220}
              mb={"md"}
              variant="filled"
              styles={(theme) => ({
                input: { border: computedColorScheme === 'dark' ? '1px solid rgba(255,255,255,0.1)' : '1px solid rgba(0,0,0,0.1)' }
              })}
            />
          }



          {/* {activeApp && (
            <Text size="xs" fw={700} c="dimmed" px="md" mb="xs" style={{ textTransform: 'uppercase' }}>
              {activeApp.name} Context
            </Text>
          )} */}

          {navLinks.map((link: any) => {
            const isActive = currentPath === link.to

            return (
              <NavLink
                key={link.label}
                component={Link}
                to={link.to}
                activeOptions={{ exact: true }}
                label={link.label}
                leftSection={<link.icon size={20} />}
                rightSection={<TbChevronRight size={14} />}
                active={isActive}
                variant="filled"
                color="brand-blue"
                className="sidebar-nav-item"
              />
            )
          })}
        </Stack>

        <Box style={{ marginTop: 'auto' }}>
          <Stack gap="xs">
            <Box
              p="md"
              className="glass"
              style={{ borderRadius: '12px', border: computedColorScheme === 'dark' ? '1px solid rgba(255,255,255,0.05)' : '1px solid rgba(0,0,0,0.05)' }}
            >
              <Text size="xs" c="dimmed" fw={600} mb="xs">SYSTEM STATUS</Text>
              <Group gap="xs">
                <Box style={{ width: 8, height: 8, borderRadius: '50%', background: statusColor, boxShadow: `0 0 6px ${statusColor}` }} />
                <Text size="sm" fw={500}>{statusText}</Text>
              </Group>
              {systemStatus && (
                <Text size="xs" c="dimmed" mt={4}>
                  {systemStatus.activeSessions} active session{systemStatus.activeSessions !== 1 ? 's' : ''}
                </Text>
              )}
            </Box>

            <Button
              variant="light"
              color="red"
              fullWidth
              leftSection={logout.isPending ? <Loader size={16} color="red" /> : <TbLogout size={16} />}
              mt="md"
              onClick={handleLogout}
              disabled={logout.isPending}
            >
              {logout.isPending ? 'Logging out...' : 'Log out'}
            </Button>
          </Stack>
        </Box>
      </AppShell.Navbar>

      <AppShell.Main>
        {children}
      </AppShell.Main>
    </AppShell>
  )
}