'use client';

import { useState, useCallback } from 'react';
import { Badge } from '@/components/ui/badge';
import { Input } from '@/components/ui/input';
import { Button } from '@/components/ui/button';
import {
  Dialog,
  DialogContent,
  DialogHeader,
  DialogTitle,
} from '@/components/ui/dialog';
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from '@/components/ui/table';
import { Search, CheckCircle2, XCircle, Loader2, ExternalLink, Package } from 'lucide-react';
import { useUserTimezone } from '@/lib/hooks/use-user-timezone';

interface ComplianceMismatch {
  id: number;
  company_id: number | null;
  company_name: string | null;
  configuration_item_id: number | null;
  veeam_workload_uid: string | null;
  mismatch_type: string;
  backup_type_udf: string | null;
  device_name: string;
  contract_name: string | null;
  veeam_workload_name: string | null;
  billing_covered: boolean | null;
  billing_contract_name: string | null;
  billing_contracted_qty: number | null;
  billing_contract_id: number | null;
  coverage_source: string | null;
}

interface ContractService {
  id: number;
  service_id: number | null;
  display_name: string;
  description: string | null;
  unit_price: number | null;
  unit_cost: number | null;
  quantity: number | null;
  adjusted_price: number | null;
  period_label: string | null;
  start_date: string | null;
  end_date: string | null;
}

interface ContractDetail {
  id: number;
  contract_name: string;
  company_name: string;
  status: number;
  contract_type: number | null;
  start_date: string | null;
  end_date: string | null;
  description: string | null;
}

interface ComplianceDetailTableProps {
  mismatches: ComplianceMismatch[];
}

const BACKUP_SERVICE_PATTERNS = [
  /workstation.*backup/i,
  /w\/ backup/i,
  /windows server/i,
  /server virtual/i,
  /server phys/i,
  /esxi host/i,
  /wulf 365 it complete (endpoint|server)/i,
  /wulf it complete \((server|endpoint)\)/i,
];

function isBackupService(name: string): boolean {
  return BACKUP_SERVICE_PATTERNS.some((re) => re.test(name));
}

function ContractCoverageModal({
  contractId,
  companyName,
  open,
  onClose,
  tz,
}: {
  contractId: number | null;
  companyName: string | null;
  open: boolean;
  onClose: () => void;
  tz: string;
}) {
  const [data, setData] = useState<{ contract: ContractDetail; services: ContractService[] } | null>(null);
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const [loadedId, setLoadedId] = useState<number | null>(null);

  const load = useCallback(async (id: number) => {
    if (loadedId === id) return;
    setLoading(true);
    setError(null);
    try {
      const res = await fetch(`/api/data/contracts/${id}/services`);
      if (!res.ok) throw new Error('Failed to load contract details');
      const json = await res.json();
      setData(json);
      setLoadedId(id);
    } catch (e) {
      setError(e instanceof Error ? e.message : 'Unknown error');
    } finally {
      setLoading(false);
    }
  }, [loadedId]);

  if (open && contractId && loadedId !== contractId && !loading) {
    load(contractId);
  }

  const contract = data?.contract;
  const services = data?.services ?? [];
  const backupServices = services.filter((s) => isBackupService(s.display_name));
  const otherServices = services.filter((s) => !isBackupService(s.display_name));

  return (
    <Dialog open={open} onOpenChange={(v) => !v && onClose()}>
      <DialogContent className="max-w-2xl max-h-[80vh] overflow-y-auto">
        <DialogHeader>
          <DialogTitle className="flex items-center gap-2">
            <Package className="h-4 w-4 text-muted-foreground" />
            Contract Coverage
            {contract && (
              <span className="text-muted-foreground font-normal text-sm ml-1">— {contract.company_name}</span>
            )}
          </DialogTitle>
        </DialogHeader>

        {loading && (
          <div className="flex items-center justify-center py-12">
            <Loader2 className="h-5 w-5 animate-spin text-muted-foreground" />
          </div>
        )}

        {error && (
          <p className="text-sm text-red-500 py-4">{error}</p>
        )}

        {!loading && !error && contract && (
          <div className="space-y-5">
            {/* Contract header */}
            <div className="rounded-lg border bg-muted/30 p-4 space-y-2">
              <div className="flex items-start justify-between gap-4">
                <div>
                  <p className="font-semibold text-base">{contract.contract_name}</p>
                  <p className="text-sm text-muted-foreground">{contract.company_name}</p>
                </div>
                <a
                  href={`https://ww1.autotask.net/contracts/views/contractView.asp?contractID=${contract.id}`}
                  target="_blank"
                  rel="noopener noreferrer"
                  className="flex items-center gap-1 text-xs text-blue-500 hover:text-blue-600 shrink-0 mt-0.5"
                >
                  View in Autotask <ExternalLink className="h-3 w-3" />
                </a>
              </div>
              <div className="flex flex-wrap gap-x-6 gap-y-1 text-xs text-muted-foreground">
                {contract.start_date && (
                  <span>Start: {new Date(contract.start_date).toLocaleDateString(undefined, { timeZone: tz })}</span>
                )}
                {contract.end_date && (
                  <span>End: {new Date(contract.end_date).toLocaleDateString(undefined, { timeZone: tz })}</span>
                )}
                <span className="flex items-center gap-1">
                  <span className={`inline-block h-1.5 w-1.5 rounded-full ${contract.status === 1 ? 'bg-green-500' : 'bg-gray-400'}`} />
                  {contract.status === 1 ? 'Active' : 'Inactive'}
                </span>
              </div>
            </div>

            {/* Backup-relevant services */}
            {backupServices.length > 0 && (
              <div className="space-y-2">
                <p className="text-xs font-semibold uppercase tracking-wide text-green-600 dark:text-green-400">Backup-Covered Services</p>
                <ServiceTable services={backupServices} highlight />
              </div>
            )}

            {/* Other services */}
            {otherServices.length > 0 && (
              <div className="space-y-2">
                <p className="text-xs font-semibold uppercase tracking-wide text-muted-foreground">All Services ({services.length})</p>
                <ServiceTable services={otherServices} />
              </div>
            )}

            {services.length === 0 && (
              <p className="text-sm text-muted-foreground text-center py-4">No service lines found for this contract.</p>
            )}
          </div>
        )}
      </DialogContent>
    </Dialog>
  );
}

function ServiceTable({ services, highlight }: { services: ContractService[]; highlight?: boolean }) {
  return (
    <div className="rounded-md border overflow-hidden">
      <Table>
        <TableHeader>
          <TableRow className="bg-muted/40">
            <TableHead className="text-xs">Service</TableHead>
            <TableHead className="text-xs w-28 text-right">Unit Price</TableHead>
            <TableHead className="text-xs w-28 text-right">Unit Cost</TableHead>
          </TableRow>
        </TableHeader>
        <TableBody>
          {services.map((s) => (
            <TableRow key={s.id} className={highlight ? 'bg-green-500/5' : undefined}>
              <TableCell className="text-sm py-2">
                {highlight && <CheckCircle2 className="inline h-3 w-3 text-green-500 mr-1.5 shrink-0" />}
                {s.display_name}
              </TableCell>
              <TableCell className="text-sm py-2 text-right">
                {s.unit_price != null ? `$${Number(s.unit_price).toFixed(2)}` : '—'}
              </TableCell>
              <TableCell className="text-sm py-2 text-right text-muted-foreground">
                {s.unit_cost != null ? `$${Number(s.unit_cost).toFixed(2)}` : '—'}
              </TableCell>
            </TableRow>
          ))}
        </TableBody>
      </Table>
    </div>
  );
}

export function ComplianceDetailTable({ mismatches }: ComplianceDetailTableProps) {
  const tz = useUserTimezone();
  const [search, setSearch] = useState('');
  const [typeFilter, setTypeFilter] = useState<string>('all');
  const [modalContractId, setModalContractId] = useState<number | null>(null);
  const [modalCompanyName, setModalCompanyName] = useState<string | null>(null);
  const [modalOpen, setModalOpen] = useState(false);

  const openModal = (contractId: number, companyName: string | null) => {
    setModalContractId(contractId);
    setModalCompanyName(companyName);
    setModalOpen(true);
  };

  const filtered = mismatches.filter((m) => {
    const matchesSearch =
      (m.device_name || '').toLowerCase().includes(search.toLowerCase()) ||
      (m.company_name || '').toLowerCase().includes(search.toLowerCase());
    const matchesType =
      typeFilter === 'all' || m.mismatch_type === typeFilter;
    return matchesSearch && matchesType;
  });

  return (
    <div className="space-y-4">
      <div className="flex items-center gap-4">
        <div className="relative flex-1 max-w-sm">
          <Search className="absolute left-3 top-1/2 -translate-y-1/2 h-4 w-4 text-muted-foreground" />
          <Input
            placeholder="Search devices or companies..."
            value={search}
            onChange={(e) => setSearch(e.target.value)}
            className="pl-9"
          />
        </div>
        <div className="flex gap-2">
          {[
            { key: 'all', label: 'All' },
            { key: 'contracted_not_backed_up', label: 'Missing Backup' },
            { key: 'backed_up_not_contracted', label: 'No Contract' },
          ].map((f) => (
            <Button
              key={f.key}
              variant={typeFilter === f.key ? 'default' : 'outline'}
              size="sm"
              onClick={() => setTypeFilter(f.key)}
            >
              {f.label}
            </Button>
          ))}
        </div>
      </div>

      <div className="rounded-md border">
        <Table>
          <TableHeader>
            <TableRow>
              <TableHead>Company</TableHead>
              <TableHead>Device</TableHead>
              <TableHead>Issue</TableHead>
              <TableHead>Backup UDF</TableHead>
              <TableHead>Contract Coverage</TableHead>
              <TableHead>Veeam Workload</TableHead>
            </TableRow>
          </TableHeader>
          <TableBody>
            {filtered.length === 0 ? (
              <TableRow>
                <TableCell colSpan={6} className="text-center text-muted-foreground py-8">
                  {mismatches.length === 0
                    ? 'No compliance issues found — all clear!'
                    : 'No matching results'}
                </TableCell>
              </TableRow>
            ) : (
              filtered.map((m) => (
                <TableRow key={m.id}>
                  <TableCell className="font-medium">{m.company_name || '-'}</TableCell>
                  <TableCell>{m.device_name}</TableCell>
                  <TableCell>
                    <Badge
                      className={
                        m.mismatch_type === 'contracted_not_backed_up'
                          ? 'bg-red-500/10 text-red-500'
                          : 'bg-yellow-500/10 text-yellow-500'
                      }
                    >
                      {m.mismatch_type === 'contracted_not_backed_up'
                        ? 'Missing Backup'
                        : 'No Contract'}
                    </Badge>
                  </TableCell>
                  <TableCell className="text-sm">{m.backup_type_udf || '-'}</TableCell>
                  <TableCell className="text-sm">
                    {m.billing_covered && m.billing_contract_id ? (
                      <button
                        onClick={() => openModal(m.billing_contract_id!, m.company_name)}
                        className="flex items-center gap-1.5 text-left hover:underline cursor-pointer group"
                      >
                        <CheckCircle2 className="h-3.5 w-3.5 text-green-500 shrink-0" />
                        <span className="text-green-700 dark:text-green-400 font-medium group-hover:underline">
                          {m.billing_contract_name || 'Active'}
                        </span>
                        {m.billing_contracted_qty != null && (
                          <span className="text-muted-foreground">({m.billing_contracted_qty} seats)</span>
                        )}
                      </button>
                    ) : m.billing_covered ? (
                      <div className="flex items-center gap-1.5">
                        <CheckCircle2 className="h-3.5 w-3.5 text-green-500 shrink-0" />
                        <span className="text-green-700 dark:text-green-400 font-medium">
                          {m.billing_contract_name || 'Active'}
                        </span>
                      </div>
                    ) : (
                      <div className="flex items-center gap-1.5">
                        <XCircle className="h-3.5 w-3.5 text-red-500 shrink-0" />
                        <span className="text-red-700 dark:text-red-400">No backup contract</span>
                      </div>
                    )}
                  </TableCell>
                  <TableCell className="text-sm">{m.veeam_workload_name || '-'}</TableCell>
                </TableRow>
              ))
            )}
          </TableBody>
        </Table>
      </div>

      <ContractCoverageModal
        contractId={modalContractId}
        companyName={modalCompanyName}
        open={modalOpen}
        onClose={() => setModalOpen(false)}
        tz={tz}
      />
    </div>
  );
}