import type { ReactNode } from "react";
import { useNavigate } from "react-router";
import { Alert, Box, Button, CircularProgress, Paper, Stack, Typography } from "@mui/material";
import { VendorPortalTokenPanel } from "./vendor-portal-token-panel";
import { VendorRosterConflictAlert } from "./vendor-roster-conflict-alert";
import { VendorRosterFormFields } from "./vendor-roster-form-fields";
import { VendorRosterLoadErrorAlert } from "./vendor-roster-load-error";
import { useVendorRosterForm } from "./use-vendor-roster-form";

interface VendorRosterPageProps {
  vendorId?: string;
  companyId?: string;
}

function PageShell({
  title,
  subtitle,
  children,
}: {
  title: string;
  subtitle: string;
  children: ReactNode;
}) {
  return (
    <Box className="mx-auto max-w-4xl p-4">
      <Paper variant="outlined" className="p-6">
        <Stack spacing={4}>
          <Box>
            <Typography variant="h5" component="h1">
              {title}
            </Typography>
            <Typography variant="body2" sx={{ color: "text.secondary", mt: 0.5 }}>
              {subtitle}
            </Typography>
          </Box>
          {children}
        </Stack>
      </Paper>
    </Box>
  );
}

export default function VendorRosterPage({ vendorId, companyId }: VendorRosterPageProps) {
  const navigate = useNavigate();
  const isEdit = vendorId !== undefined || companyId !== undefined;
  const form = useVendorRosterForm({
    mode: isEdit ? "update" : "create",
    vendorId,
    companyId,
    onSuccess: () => navigate("/vendors"),
  });

  if (isEdit && form.isLoading) {
    return (
      <Box className="flex justify-center p-10">
        <CircularProgress />
      </Box>
    );
  }

  if (isEdit && form.isError) {
    return (
      <PageShell title="Vendor company" subtitle="Edit the company and its technicians.">
        <Alert severity="error">Failed to load vendor company. Try again.</Alert>
        <Stack direction="row" sx={{ justifyContent: "flex-end" }}>
          <Button variant="outlined" onClick={() => navigate("/vendors")}>
            Back to vendors
          </Button>
        </Stack>
      </PageShell>
    );
  }

  if (isEdit && !form.roster) {
    return null;
  }

  const title = isEdit ? "Edit Vendor Company" : "Add Vendor Company";
  const subtitle = isEdit
    ? "Update company details and technicians in one save."
    : "Register a company and add zero, one, or multiple technicians.";
  const companySelectionProps = isEdit
    ? {}
    : {
        companies: form.companies,
        selectedCompanyId: form.selectedCompanyId,
        onSelectCompany: form.selectCompany,
        onClearSelectedCompany: form.clearSelectedCompany,
      };

  return (
    <PageShell title={title} subtitle={subtitle}>
      <Box component="form" onSubmit={form.handleSubmit(form.submit)}>
        <Stack spacing={3}>
          {form.loadErrorMessage !== null && (
            <VendorRosterLoadErrorAlert message={form.loadErrorMessage} onRetry={form.retryLoad} />
          )}

          {form.conflict !== null && (
            <VendorRosterConflictAlert conflict={form.conflict} onReload={form.reload} />
          )}

          <VendorRosterFormFields
            control={form.control}
            errors={form.errors}
            tradeOptions={form.trades}
            {...companySelectionProps}
          />

          {isEdit && vendorId !== undefined && vendorId !== "" && (
            <VendorPortalTokenPanel vendorId={vendorId} />
          )}

          <Stack direction="row" spacing={2} sx={{ justifyContent: "flex-end" }}>
            <Button
              variant="outlined"
              onClick={() => navigate("/vendors")}
              disabled={form.isSaving}
            >
              Cancel
            </Button>
            <Button type="submit" variant="contained" disabled={form.isSaving || !form.isValid}>
              {form.isSaving ? "Saving..." : isEdit ? "Save" : "Create"}
            </Button>
          </Stack>
        </Stack>
      </Box>
    </PageShell>
  );
}