import type { ReactNode } from "react";
import { useNavigate } from "react-router-dom";
import AddIcon from "@mui/icons-material/Add";
import CheckCircleOutlineIcon from "@mui/icons-material/CheckCircleOutline";
import FolderOpenOutlinedIcon from "@mui/icons-material/FolderOpenOutlined";
import ScheduleOutlinedIcon from "@mui/icons-material/ScheduleOutlined";
import {
  Alert,
  Box,
  CircularProgress,
  Paper,
  Stack,
  Table,
  TableBody,
  TableCell,
  TableContainer,
  TableHead,
  TableRow,
  Typography,
} from "@mui/material";
import { useDashboardStats } from "@/domain/dashboard/use-cases/use-dashboard-stats";

const INVOICE_STATUSES = ["Draft", "Challenged", "Pending Approval", "Approved", "Paid"] as const;

const PRIORITY_LEVELS = [5, 4, 3, 2, 1] as const;

interface KpiCardProps {
  title: string;
  description?: string;
  value?: string | number;
  icon: ReactNode;
  color: "success" | "primary" | "info" | "warning";
  onClick: () => void;
  loading?: boolean;
}

function KpiCard({ title, description, value, icon, color, onClick, loading }: KpiCardProps) {
  const colorMap = {
    success: "success.main",
    primary: "primary.main",
    info: "info.main",
    warning: "warning.main",
  } as const;

  return (
    <Paper
      variant="outlined"
      onClick={onClick}
      className="flex min-h-[140px] flex-1 cursor-pointer transition-shadow hover:shadow-md"
      sx={{
        borderLeftWidth: 4,
        borderLeftStyle: "solid",
        borderLeftColor: colorMap[color],
      }}
    >
      <Box className="flex w-full gap-4 p-4">
        <Box
          className="flex h-12 w-12 shrink-0 items-center justify-center rounded-full"
          sx={{ bgcolor: `${colorMap[color]}22`, color: colorMap[color] }}
        >
          {icon}
        </Box>

        <Box className="flex min-w-0 flex-col justify-center gap-1">
          <Typography variant="subtitle1" className="font-semibold">
            {title}
          </Typography>
          {value !== undefined && (
            <Typography variant="h4" component="p" className="font-bold leading-tight">
              {loading ? "..." : typeof value === "number" ? value.toLocaleString() : value}
            </Typography>
          )}
          {description && (
            <Typography variant="body2" color="text.secondary">
              {description}
            </Typography>
          )}
        </Box>
      </Box>
    </Paper>
  );
}

export default function DashboardPage() {
  const navigate = useNavigate();
  const { data: stats, isLoading, isFetching, error } = useDashboardStats();

  const formatStat = (value: number | undefined) => (isLoading ? undefined : (value ?? 0));

  return (
    <Box className="flex flex-col gap-4 p-4">
      <Stack direction="row" spacing={2} alignItems="baseline">
        <Typography variant="h5" component="h1">
          Dashboard
        </Typography>
        {isFetching && !isLoading && <CircularProgress size={16} />}
      </Stack>

      {error && (
        <Alert severity="error">
          {error instanceof Error ? error.message : "Failed to load dashboard stats"}
        </Alert>
      )}

      <Stack direction={{ xs: "column", lg: "row" }} spacing={2} useFlexGap flexWrap="wrap">
        <KpiCard
          title="Create a Work Order"
          description="Report a problem you need fixed"
          icon={<AddIcon />}
          color="success"
          onClick={() => navigate("/workorders/new")}
        />
        <KpiCard
          title="Open Work Orders"
          value={formatStat(stats?.open)}
          icon={<FolderOpenOutlinedIcon />}
          color="primary"
          loading={isLoading}
          onClick={() => navigate("/workorders")}
        />
        <KpiCard
          title="Not Dispatched"
          value={formatStat(stats?.notDispatched)}
          icon={<ScheduleOutlinedIcon />}
          color="info"
          loading={isLoading}
          onClick={() => navigate("/workorders")}
        />
        <KpiCard
          title="Completed Orders"
          value={formatStat(stats?.completed)}
          icon={<CheckCircleOutlineIcon />}
          color="warning"
          loading={isLoading}
          onClick={() => navigate("/workorders")}
        />
      </Stack>

      <Paper variant="outlined" className="overflow-hidden">
        <Box className="border-b border-border px-4 py-3">
          <Typography variant="h6" component="h2">
            Priority Analysis
          </Typography>
          <Typography variant="body2" color="text.secondary">
            Age of open Work Orders by Priority
          </Typography>
        </Box>

        <TableContainer>
          <Table size="small">
            <TableHead>
              <TableRow>
                <TableCell className="font-semibold">Priority</TableCell>
                <TableCell align="right" className="font-semibold">
                  Total
                </TableCell>
                <TableCell align="right" className="font-semibold">
                  0-14 Days
                </TableCell>
                <TableCell align="right" className="font-semibold">
                  15-29 Days
                </TableCell>
                <TableCell align="right" className="font-semibold">
                  30-59 Days
                </TableCell>
                <TableCell align="right" className="font-semibold">
                  60+ Days
                </TableCell>
              </TableRow>
            </TableHead>
            <TableBody>
              {PRIORITY_LEVELS.map((priority) => (
                <TableRow key={priority}>
                  <TableCell>{priority}</TableCell>
                  <TableCell align="right">—</TableCell>
                  <TableCell align="right">—</TableCell>
                  <TableCell align="right">—</TableCell>
                  <TableCell align="right">—</TableCell>
                  <TableCell align="right">—</TableCell>
                </TableRow>
              ))}
            </TableBody>
          </Table>
        </TableContainer>
      </Paper>

      <Paper variant="outlined" className="overflow-hidden">
        <Box className="border-b border-border px-4 py-3">
          <Typography variant="h6" component="h2">
            Invoice Analysis
          </Typography>
        </Box>

        <TableContainer>
          <Table size="small">
            <TableHead>
              <TableRow>
                <TableCell className="font-semibold">Status</TableCell>
                <TableCell align="right" className="font-semibold">
                  Count
                </TableCell>
                <TableCell align="right" className="font-semibold">
                  Amount
                </TableCell>
              </TableRow>
            </TableHead>
            <TableBody>
              {INVOICE_STATUSES.map((status) => (
                <TableRow key={status}>
                  <TableCell>{status}</TableCell>
                  <TableCell align="right">0</TableCell>
                  <TableCell align="right">$0.00</TableCell>
                </TableRow>
              ))}
            </TableBody>
          </Table>
        </TableContainer>
      </Paper>
    </Box>
  );
}