'use client';

import { useState } from 'react';
import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
import { format } from 'date-fns';
import { Download, FileDown, Loader2, Mail } from 'lucide-react';
import { toast } from 'sonner';

import { Button } from '@/components/ui/button';
import { Checkbox } from '@/components/ui/checkbox';
import { Input } from '@/components/ui/input';
import { Label } from '@/components/ui/label';
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
  DialogTrigger,
} from '@/components/ui/dialog';
import { Badge } from '@/components/ui/badge';
import { usePermissions } from '@/hooks/use-permissions';
import { apiFetch } from '@/lib/api/client';
import { toastError } from '@/lib/api/toast-error';

interface ExportRow {
  id: string;
  status: 'pending' | 'building' | 'ready' | 'sent' | 'failed';
  storageKey: string | null;
  sizeBytes: number | null;
  createdAt: string;
  readyAt: string | null;
  sentAt: string | null;
  sentTo: string | null;
  error: string | null;
}

interface ListResp {
  data: ExportRow[];
}

const STATUS_VARIANT: Record<ExportRow['status'], 'secondary' | 'outline' | 'destructive'> = {
  pending: 'outline',
  building: 'outline',
  ready: 'secondary',
  sent: 'secondary',
  failed: 'destructive',
};

export function GdprExportButton({
  clientId,
  variant = 'button',
}: {
  clientId: string;
  /** `button` = standalone outline button (default). `icon` = compact icon-only
   *  trigger for the detail-header top-right action cluster (CM-4). */
  variant?: 'button' | 'icon';
}) {
  const { can, isSuperAdmin } = usePermissions();
  const qc = useQueryClient();
  const [open, setOpen] = useState(false);
  const [emailToClient, setEmailToClient] = useState(false);
  const [emailOverride, setEmailOverride] = useState('');

  const allowed = isSuperAdmin || can('clients', 'gdpr_export');

  const queryKey = ['gdpr-exports', clientId];
  const { data, isLoading } = useQuery<ListResp>({
    queryKey,
    queryFn: () => apiFetch<ListResp>(`/api/v1/clients/${clientId}/gdpr-export`),
    enabled: open && allowed,
    // Poll only when the user is watching AND a job is in flight. GDPR
    // exports take ~30s; 15s is the rule-of-thumb minimum that doesn't
    // burn CPU. When everything's already settled, stop polling.
    refetchInterval: (q) => {
      if (!open || !allowed) return false;
      const rows = q.state.data?.data ?? [];
      const hasInFlight = rows.some((r) => r.status === 'pending' || r.status === 'building');
      return hasInFlight ? 15_000 : false;
    },
  });

  const request = useMutation({
    mutationFn: () =>
      apiFetch(`/api/v1/clients/${clientId}/gdpr-export`, {
        method: 'POST',
        body: {
          emailToClient,
          emailOverride: emailOverride.trim() || null,
        },
      }),
    onSuccess: () => {
      toast.success('Export queued - refresh in ~30 seconds');
      qc.invalidateQueries({ queryKey });
      setEmailOverride('');
    },
    onError: (err: unknown) => {
      toastError(err);
    },
  });

  if (!allowed) return null;

  async function downloadById(exportId: string) {
    try {
      const res = await apiFetch<{ data: { url: string } }>(
        `/api/v1/clients/${clientId}/gdpr-export/${exportId}`,
      );
      window.open(res.data.url, '_blank', 'noopener');
    } catch (err) {
      toastError(err);
    }
  }

  const rows = data?.data ?? [];

  return (
    <Dialog open={open} onOpenChange={setOpen}>
      <DialogTrigger asChild>
        {variant === 'icon' ? (
          <button
            type="button"
            aria-label="GDPR export"
            title="GDPR export"
            className="shrink-0 rounded-md p-1.5 text-muted-foreground/70 transition-colors hover:bg-foreground/5 hover:text-foreground"
          >
            <FileDown className="size-4" aria-hidden />
          </button>
        ) : (
          <Button variant="outline" size="sm" className="h-8">
            <FileDown className="mr-1.5 h-3.5 w-3.5" aria-hidden />
            GDPR export
          </Button>
        )}
      </DialogTrigger>
      <DialogContent className="max-w-2xl">
        <DialogHeader>
          <DialogTitle>Personal data export</DialogTitle>
          <DialogDescription>
            Bundles every record we hold about this client (profile, contacts, addresses, yachts,
            companies, interests, tenancies, invoices, documents, audit log) into a ZIP with JSON
            and HTML copies. Used to satisfy GDPR Article 15 access requests.
          </DialogDescription>
        </DialogHeader>

        <div className="space-y-4">
          <div className="flex items-start gap-2 rounded-lg border border-border bg-muted/30 p-3">
            <Checkbox
              id="email-to-client"
              checked={emailToClient}
              onCheckedChange={(v) => setEmailToClient(v === true)}
            />
            <div className="space-y-2 flex-1 min-w-0">
              <Label htmlFor="email-to-client" className="text-sm font-medium">
                Email the bundle when ready
              </Label>
              <p className="text-xs text-muted-foreground">
                Sends a 7-day signed download link to the client&apos;s primary email - or to the
                override below.
              </p>
              {emailToClient ? (
                <Input
                  type="email"
                  placeholder="optional override (defaults to primary contact)"
                  value={emailOverride}
                  onChange={(e) => setEmailOverride(e.target.value)}
                  className="h-8 text-sm"
                />
              ) : null}
            </div>
          </div>

          <Button onClick={() => request.mutate()} disabled={request.isPending}>
            {request.isPending ? (
              <Loader2 className="mr-1.5 h-3.5 w-3.5 animate-spin" aria-hidden />
            ) : (
              <FileDown className="mr-1.5 h-3.5 w-3.5" aria-hidden />
            )}
            Queue export
          </Button>

          <div>
            <h4 className="text-sm font-medium mb-2">Recent exports</h4>
            {isLoading ? (
              <p className="text-sm text-muted-foreground">Loading…</p>
            ) : rows.length === 0 ? (
              <p className="text-sm text-muted-foreground">No exports yet.</p>
            ) : (
              <ul className="text-sm divide-y border rounded-lg">
                {rows.map((r) => (
                  <li key={r.id} className="flex items-center gap-2 py-2 px-3 hover:bg-muted/50">
                    <Badge variant={STATUS_VARIANT[r.status]} className="capitalize text-xs">
                      {r.status}
                    </Badge>
                    <div className="flex-1 min-w-0">
                      <div className="text-xs">
                        Requested {format(new Date(r.createdAt), 'MMM d, yyyy HH:mm')}
                      </div>
                      {r.sentTo ? (
                        <div className="text-xs text-muted-foreground inline-flex items-center gap-1">
                          <Mail className="h-3 w-3" aria-hidden />
                          Sent to {r.sentTo}
                        </div>
                      ) : null}
                      {r.error ? (
                        <div className="text-xs text-destructive truncate">{r.error}</div>
                      ) : null}
                    </div>
                    {(r.status === 'ready' || r.status === 'sent') && r.storageKey ? (
                      <Button
                        type="button"
                        variant="ghost"
                        size="sm"
                        onClick={() => downloadById(r.id)}
                      >
                        <Download className="h-3.5 w-3.5" aria-hidden />
                      </Button>
                    ) : null}
                  </li>
                ))}
              </ul>
            )}
          </div>
        </div>

        <DialogFooter>
          <Button variant="ghost" onClick={() => setOpen(false)}>
            Close
          </Button>
        </DialogFooter>
      </DialogContent>
    </Dialog>
  );
}
