'use client';

import { useCallback, useEffect, useState } from 'react';
import { useTranslations } from 'next-intl';
import {
  type SearchProviderResponse,
  addSearchProvider,
  fetchSearchProviders,
  removeSearchProvider,
} from '@/lib/dashboard-api';

/**
 * SearchProviderForm (D-15).
 * Lists current search providers (defaults read-only, custom deletable)
 * plus an add form for creating custom providers with client-side
 * validation that urlTemplate contains {query}.
 */
export function SearchProviderForm() {
  const t = useTranslations('widgets');
  const [providers, setProviders] = useState<SearchProviderResponse[]>([]);
  const [isLoading, setIsLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);

  // Add form state
  const [newName, setNewName] = useState('');
  const [newUrlTemplate, setNewUrlTemplate] = useState('');
  const [validationError, setValidationError] = useState<string | null>(null);
  const [isSubmitting, setIsSubmitting] = useState(false);

  const loadProviders = useCallback(async () => {
    try {
      const data = await fetchSearchProviders();
      setProviders(data);
      setError(null);
    } catch {
      setError('Failed to load search providers');
    } finally {
      setIsLoading(false);
    }
  }, []);

  useEffect(() => {
    loadProviders();
  }, [loadProviders]);

  const handleAdd = useCallback(async () => {
    // Client-side validation: urlTemplate must contain {query}
    if (!newName.trim()) {
      setValidationError('Name is required');
      return;
    }
    if (!newUrlTemplate.includes('{query}')) {
      setValidationError('URL template must contain {query}');
      return;
    }

    setValidationError(null);
    setIsSubmitting(true);
    try {
      const created = await addSearchProvider({
        name: newName.trim(),
        urlTemplate: newUrlTemplate.trim(),
      });
      setProviders((prev) => [...prev, created]);
      setNewName('');
      setNewUrlTemplate('');
    } catch {
      setValidationError('Failed to add provider');
    } finally {
      setIsSubmitting(false);
    }
  }, [newName, newUrlTemplate]);

  const handleDelete = useCallback(async (id: string) => {
    try {
      await removeSearchProvider(id);
      setProviders((prev) => prev.filter((p) => p.id !== id));
    } catch {
      // Silent fail — provider stays in list
    }
  }, []);

  if (isLoading) {
    return (
      <p className="text-sm text-muted-foreground">Loading providers...</p>
    );
  }

  if (error) {
    return <p className="text-sm text-destructive">{error}</p>;
  }

  return (
    <div className="space-y-4">
      {/* Existing providers list */}
      <div className="space-y-2">
        <h3 className="text-sm font-medium text-foreground">
          {t('search.providers')}
        </h3>

        {providers.length === 0 ? (
          <p className="text-sm text-muted-foreground">No providers found.</p>
        ) : (
          <ul className="space-y-1">
            {providers.map((provider) => (
              <li
                key={provider.id}
                className="flex items-center justify-between rounded border border-border bg-background px-3 py-2 text-sm"
              >
                <div className="min-w-0 flex-1">
                  <span className="font-medium text-foreground">
                    {provider.name}
                  </span>
                  {provider.isDefault && (
                    <span className="ml-2 text-xs text-muted-foreground">
                      (Default)
                    </span>
                  )}
                  <p className="truncate text-xs text-muted-foreground">
                    {provider.urlTemplate}
                  </p>
                </div>

                {/* Only custom (non-default) providers can be deleted */}
                {!provider.isDefault && (
                  <button
                    type="button"
                    onClick={() => handleDelete(provider.id)}
                    className="ml-3 shrink-0 rounded p-1 text-muted-foreground hover:bg-destructive/10 hover:text-destructive transition-colors"
                    aria-label={`Remove ${provider.name}`}
                  >
                    <svg
                      xmlns="http://www.w3.org/2000/svg"
                      width="14"
                      height="14"
                      viewBox="0 0 24 24"
                      fill="none"
                      stroke="currentColor"
                      strokeWidth="2"
                      strokeLinecap="round"
                      strokeLinejoin="round"
                    >
                      <polyline points="3 6 5 6 21 6" />
                      <path d="M19 6v14a2 2 0 0 1-2 2H7a2 2 0 0 1-2-2V6m3 0V4a2 2 0 0 1 2-2h4a2 2 0 0 1 2 2v2" />
                    </svg>
                  </button>
                )}
              </li>
            ))}
          </ul>
        )}
      </div>

      {/* Add new provider form */}
      <div className="space-y-3 rounded border border-border bg-muted/30 p-3">
        <h3 className="text-sm font-medium text-foreground">
          {t('search.addProvider')}
        </h3>

        <div>
          <label
            htmlFor="provider-name"
            className="mb-1 block text-xs text-muted-foreground"
          >
            Name
          </label>
          <input
            id="provider-name"
            type="text"
            placeholder="e.g. GitHub"
            className="h-8 w-full rounded border border-border bg-background px-3 text-sm text-foreground placeholder:text-muted-foreground"
            value={newName}
            onChange={(e) => {
              setNewName(e.target.value);
              setValidationError(null);
            }}
          />
        </div>

        <div>
          <label
            htmlFor="provider-url"
            className="mb-1 block text-xs text-muted-foreground"
          >
            URL Template
          </label>
          <input
            id="provider-url"
            type="text"
            placeholder="https://example.com/search?q={query}"
            className="h-8 w-full rounded border border-border bg-background px-3 text-sm text-foreground placeholder:text-muted-foreground"
            value={newUrlTemplate}
            onChange={(e) => {
              setNewUrlTemplate(e.target.value);
              setValidationError(null);
            }}
          />
          <p className="mt-1 text-xs text-muted-foreground">
            Must contain <code className="rounded bg-muted px-1">{'{query}'}</code> as
            placeholder for the search term.
          </p>
        </div>

        {validationError && (
          <p className="text-xs text-destructive">{validationError}</p>
        )}

        <button
          type="button"
          onClick={handleAdd}
          disabled={isSubmitting || !newName.trim() || !newUrlTemplate.trim()}
          className="h-8 rounded bg-primary px-4 text-sm font-medium text-primary-foreground hover:bg-primary/90 disabled:cursor-not-allowed disabled:opacity-50 transition-colors"
        >
          {isSubmitting ? 'Adding...' : t('search.addProviderButton')}
        </button>
      </div>
    </div>
  );
}