import React from 'react';
import { Box, Card, CardContent, Skeleton, Stack, Paper } from '@mui/material';

/**
 * Skeleton loader for activity cards
 */
export function ActivityCardSkeleton() {
  return (
    <Card sx={{ mb: 2 }}>
      <CardContent>
        <Box sx={{ display: 'flex', alignItems: 'center', mb: 2 }}>
          <Skeleton variant="circular" width={40} height={40} sx={{ mr: 2 }} />
          <Box sx={{ flex: 1 }}>
            <Skeleton variant="text" width="60%" height={24} />
            <Skeleton variant="text" width="40%" height={20} />
          </Box>
        </Box>
        <Skeleton variant="text" width="80%" />
        <Skeleton variant="text" width="50%" />
      </CardContent>
    </Card>
  );
}

/**
 * Skeleton loader for activity list
 */
export function ActivityListSkeleton({ count = 3 }: { count?: number }) {
  return (
    <>
      {Array.from({ length: count }).map((_, index) => (
        <ActivityCardSkeleton key={index} />
      ))}
    </>
  );
}

/**
 * Skeleton loader for stat cards
 */
export function StatCardSkeleton() {
  return (
    <Paper sx={{ p: 3 }}>
      <Skeleton variant="text" width="40%" height={20} sx={{ mb: 1 }} />
      <Skeleton variant="text" width="60%" height={32} sx={{ mb: 1 }} />
      <Skeleton variant="text" width="50%" height={16} />
    </Paper>
  );
}

/**
 * Skeleton loader for stat grid
 */
export function StatGridSkeleton({ count = 4 }: { count?: number }) {
  return (
    <Box
      sx={{
        display: 'grid',
        gridTemplateColumns: {
          xs: '1fr',
          sm: 'repeat(2, 1fr)',
          md: 'repeat(4, 1fr)',
        },
        gap: 2,
        mb: 3,
      }}
    >
      {Array.from({ length: count }).map((_, index) => (
        <StatCardSkeleton key={index} />
      ))}
    </Box>
  );
}

/**
 * Skeleton loader for charts
 */
export function ChartSkeleton({ height = 300 }: { height?: number }) {
  return (
    <Paper sx={{ p: 3 }}>
      <Skeleton variant="text" width="40%" height={24} sx={{ mb: 3 }} />
      <Skeleton variant="rectangular" width="100%" height={height} />
      <Box sx={{ display: 'flex', justifyContent: 'space-around', mt: 2 }}>
        <Skeleton variant="text" width={60} />
        <Skeleton variant="text" width={60} />
        <Skeleton variant="text" width={60} />
        <Skeleton variant="text" width={60} />
      </Box>
    </Paper>
  );
}

/**
 * Skeleton loader for child profile card
 */
export function ChildProfileSkeleton() {
  return (
    <Card sx={{ mb: 2 }}>
      <CardContent>
        <Box sx={{ display: 'flex', alignItems: 'center', mb: 2 }}>
          <Skeleton variant="circular" width={60} height={60} sx={{ mr: 2 }} />
          <Box sx={{ flex: 1 }}>
            <Skeleton variant="text" width="50%" height={28} />
            <Skeleton variant="text" width="30%" height={20} />
          </Box>
        </Box>
        <Skeleton variant="text" width="70%" />
        <Skeleton variant="text" width="60%" />
      </CardContent>
    </Card>
  );
}

/**
 * Skeleton loader for form fields
 */
export function FormSkeleton() {
  return (
    <Stack spacing={3}>
      <Box>
        <Skeleton variant="text" width={100} height={20} sx={{ mb: 1 }} />
        <Skeleton variant="rectangular" width="100%" height={56} />
      </Box>
      <Box>
        <Skeleton variant="text" width={100} height={20} sx={{ mb: 1 }} />
        <Skeleton variant="rectangular" width="100%" height={56} />
      </Box>
      <Box>
        <Skeleton variant="text" width={100} height={20} sx={{ mb: 1 }} />
        <Skeleton variant="rectangular" width="100%" height={56} />
      </Box>
      <Skeleton variant="rectangular" width={120} height={42} />
    </Stack>
  );
}

/**
 * Skeleton loader for table rows
 */
export function TableRowSkeleton({ columns = 4 }: { columns?: number }) {
  return (
    <Box sx={{ display: 'flex', gap: 2, py: 2, borderBottom: 1, borderColor: 'divider' }}>
      {Array.from({ length: columns }).map((_, index) => (
        <Skeleton key={index} variant="text" width={`${100 / columns}%`} height={20} />
      ))}
    </Box>
  );
}

/**
 * Skeleton loader for table
 */
export function TableSkeleton({ rows = 5, columns = 4 }: { rows?: number; columns?: number }) {
  return (
    <Paper sx={{ p: 2 }}>
      {/* Header */}
      <Box sx={{ display: 'flex', gap: 2, py: 2, borderBottom: 2, borderColor: 'divider', mb: 2 }}>
        {Array.from({ length: columns }).map((_, index) => (
          <Skeleton key={index} variant="text" width={`${100 / columns}%`} height={24} />
        ))}
      </Box>
      {/* Rows */}
      {Array.from({ length: rows }).map((_, index) => (
        <TableRowSkeleton key={index} columns={columns} />
      ))}
    </Paper>
  );
}

/**
 * Skeleton loader for list items
 */
export function ListItemSkeleton() {
  return (
    <Box sx={{ display: 'flex', alignItems: 'center', py: 2, borderBottom: 1, borderColor: 'divider' }}>
      <Skeleton variant="circular" width={40} height={40} sx={{ mr: 2 }} />
      <Box sx={{ flex: 1 }}>
        <Skeleton variant="text" width="70%" height={20} />
        <Skeleton variant="text" width="40%" height={16} />
      </Box>
      <Skeleton variant="rectangular" width={80} height={32} />
    </Box>
  );
}

/**
 * Skeleton loader for list
 */
export function ListSkeleton({ count = 5 }: { count?: number }) {
  return (
    <Paper sx={{ p: 2 }}>
      {Array.from({ length: count }).map((_, index) => (
        <ListItemSkeleton key={index} />
      ))}
    </Paper>
  );
}

/**
 * Skeleton loader for dashboard summary
 */
export function DashboardSummarySkeleton() {
  return (
    <Box>
      {/* Header */}
      <Box sx={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between', mb: 3 }}>
        <Skeleton variant="text" width={200} height={40} />
        <Skeleton variant="rectangular" width={120} height={40} />
      </Box>

      {/* Stats Grid */}
      <StatGridSkeleton count={4} />

      {/* Recent Activities */}
      <Paper sx={{ p: 3, mb: 3 }}>
        <Skeleton variant="text" width={150} height={28} sx={{ mb: 2 }} />
        <ActivityListSkeleton count={3} />
      </Paper>

      {/* Charts */}
      <Box sx={{ display: 'grid', gridTemplateColumns: { xs: '1fr', md: 'repeat(2, 1fr)' }, gap: 3 }}>
        <ChartSkeleton height={250} />
        <ChartSkeleton height={250} />
      </Box>
    </Box>
  );
}

/**
 * Skeleton loader for chat messages
 */
export function ChatMessageSkeleton({ isUser = false }: { isUser?: boolean }) {
  return (
    <Box
      sx={{
        display: 'flex',
        justifyContent: isUser ? 'flex-end' : 'flex-start',
        mb: 2,
      }}
    >
      {!isUser && <Skeleton variant="circular" width={40} height={40} sx={{ mr: 2 }} />}
      <Box sx={{ maxWidth: '70%' }}>
        <Skeleton variant="rounded" width={200} height={60} />
        <Skeleton variant="text" width={100} height={16} sx={{ mt: 0.5 }} />
      </Box>
      {isUser && <Skeleton variant="circular" width={40} height={40} sx={{ ml: 2 }} />}
    </Box>
  );
}

/**
 * Skeleton loader for chat conversation
 */
export function ChatSkeleton({ messageCount = 4 }: { messageCount?: number }) {
  return (
    <Box sx={{ p: 2 }}>
      {Array.from({ length: messageCount }).map((_, index) => (
        <ChatMessageSkeleton key={index} isUser={index % 2 === 0} />
      ))}
    </Box>
  );
}

/**
 * Skeleton loader for page content
 */
export function PageSkeleton() {
  return (
    <Box>
      {/* Page header */}
      <Box sx={{ display: 'flex', alignItems: 'center', mb: 3 }}>
        <Skeleton variant="circular" width={40} height={40} sx={{ mr: 2 }} />
        <Skeleton variant="text" width={250} height={40} />
      </Box>

      {/* Content */}
      <Paper sx={{ p: 3 }}>
        <Skeleton variant="text" width="60%" height={28} sx={{ mb: 2 }} />
        <Skeleton variant="text" width="100%" />
        <Skeleton variant="text" width="100%" />
        <Skeleton variant="text" width="80%" sx={{ mb: 3 }} />

        <Skeleton variant="rectangular" width="100%" height={200} sx={{ mb: 2 }} />

        <Skeleton variant="text" width="100%" />
        <Skeleton variant="text" width="90%" />
      </Paper>
    </Box>
  );
}

/**
 * Full page loading overlay with spinner
 */
export function LoadingOverlay({ message = 'Loading...' }: { message?: string }) {
  return (
    <Box
      sx={{
        position: 'fixed',
        top: 0,
        left: 0,
        right: 0,
        bottom: 0,
        display: 'flex',
        flexDirection: 'column',
        alignItems: 'center',
        justifyContent: 'center',
        bgcolor: 'rgba(255, 255, 255, 0.9)',
        zIndex: 9999,
      }}
    >
      <Skeleton variant="circular" width={60} height={60} sx={{ mb: 2 }} />
      <Skeleton variant="text" width={150} height={24} />
    </Box>
  );
}