package ru.mcs.sopds.service;

import org.springframework.data.jpa.repository.Query;
import ru.mcs.sopds.entity.*;
import ru.mcs.sopds.repository.*;
import lombok.RequiredArgsConstructor;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Pageable;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
@RequiredArgsConstructor
public class BookService {

    private final BookRepository bookRepository;
    private final AuthorRepository authorRepository;
    private final GenreRepository genreRepository;
    private final SeriesRepository seriesRepository;

    public Long getBooksCount() {
        return bookRepository.count();
    }

    public Long getAuthorsCount() {
        return authorRepository.count();
    }

    public Long getSeriesCount() {
        return seriesRepository.count();
    }

    public Long getGenresCount() {
        return genreRepository.count();
    }

    public List<Book> getRecentBooks(int limit) {
        return bookRepository.findTopNByOrderByRegisterDateDesc(PageRequest.of(0, limit));
    }

    public List<Genre> getPopularGenres(int limit) {
        List<Genre> genres = genreRepository.findPopularGenres(limit);
        // Для нативных запросов нам нужно установить bookCount вручную
        // или использовать Projection/DTO
        return genres;
    }

    public Page<Book> getAllBooks(Pageable pageable) {
        return bookRepository.findAll(pageable);
    }

    public Page<Author> getAllAuthors(Pageable pageable) {
        return authorRepository.findAll(pageable);
    }

    public Page<Author> getAuthorsByLetter(String letter, Pageable pageable) {
        return authorRepository.findByFullNameStartingWith(letter, pageable);
    }

    public List<Genre> getAllGenres() {
        return genreRepository.findAll();
    }

    public Page<Series> getAllSeries(Pageable pageable) {
        return seriesRepository.findAll(pageable);
    }

    public Book getBookById(Long id) {
        return bookRepository.findById(id).orElse(null);
    }

    public Author getAuthorById(Long id) {
        return authorRepository.findById(id).orElse(null);
    }

    public Series getSeriesById(Long id) {
        return seriesRepository.findById(id).orElse(null);
    }

    public Genre getGenreById(Long id) {
        return genreRepository.findById(id).orElse(null);
    }

    public Page<Book> getBooksByAuthor(Long authorId, Pageable pageable) {
        return bookRepository.findByAuthorsId(authorId, pageable);
    }

    public Page<Book> getBooksBySeries(Long seriesId, Pageable pageable) {
        return bookRepository.findBySeriesId(seriesId, pageable);
    }

    public Page<Book> getBooksByGenre(Long genreId, Pageable pageable) {
        return bookRepository.findByGenresId(genreId, pageable);
    }

    public Page<Book> searchBooks(String query, Pageable pageable) {
        return bookRepository.findByTitleContainingIgnoreCase(query, pageable);
    }

    public Page<Book> getBooksByLanguage(String lang, Pageable pageable) {
        return bookRepository.findByLang(lang, pageable);
    }

    public Page<Author> getAuthorsByLanguage(String lang, Pageable pageable) {
        return authorRepository.findByBooksLang(lang, pageable);
    }

    public Page<Series> getSeriesByLanguage(String lang, Pageable pageable) {
        return seriesRepository.findByBooksLang(lang, pageable);
    }
}