import { inject, Injectable, signal } from '@angular/core';
import { HttpClient, HttpParams } from '@angular/common/http';
import { Observable } from 'rxjs';
import { finalize } from 'rxjs/operators';

/**
 * Search hit from Meilisearch with highlighting
 */
export interface SearchHit {
  id: string;
  title: string;
  path: string;
  file: string;
  tags?: string[];
  properties?: Record<string, unknown>;
  updatedAt?: number;
  createdAt?: number;
  excerpt?: string;
  _formatted?: {
    title?: string;
    content?: string;
  };
}

/**
 * Search response from Meilisearch API
 */
export interface SearchResponse {
  hits: SearchHit[];
  estimatedTotalHits: number;
  facetDistribution?: Record<string, Record<string, number>>;
  processingTimeMs: number;
  query: string;
}

/**
 * Search options
 */
export interface SearchOptions {
  limit?: number;
  offset?: number;
  sort?: string;
  highlight?: boolean;
}

/**
 * Service for server-side search using Meilisearch
 */
@Injectable({ providedIn: 'root' })
export class SearchMeilisearchService {
  private http = inject(HttpClient);
  
  /** Loading state signal */
  loading = signal(false);

  /**
   * Execute a search query
   */
  search(q: string, opts?: SearchOptions): Observable<SearchResponse> {
    this.loading.set(true);
    
    let params = new HttpParams().set('q', q);
    
    if (opts?.limit !== undefined) {
      params = params.set('limit', String(opts.limit));
    }
    if (opts?.offset !== undefined) {
      params = params.set('offset', String(opts.offset));
    }
    if (opts?.sort) {
      params = params.set('sort', opts.sort);
    }
    if (opts?.highlight === false) {
      params = params.set('highlight', 'false');
    }

    const url = `/api/search?${params.toString()}`;
    console.log('[SearchMeilisearchService] Sending request:', url);

    return this.http
      .get<SearchResponse>('/api/search', { params })
      .pipe(
        finalize(() => {
          console.log('[SearchMeilisearchService] Request completed');
          this.loading.set(false);
        })
      );
  }

  /**
   * Trigger a full reindex of the vault
   */
  reindex(): Observable<{ ok: boolean; indexed: boolean; count: number; elapsedMs: number }> {
    this.loading.set(true);
    
    return this.http
      .post<{ ok: boolean; indexed: boolean; count: number; elapsedMs: number }>(
        '/api/reindex',
        {}
      )
      .pipe(finalize(() => this.loading.set(false)));
  }
}