package internal

import (
	"fmt"
	"path/filepath"

	"github.com/blevesearch/bleve/v2"
	log "github.com/sirupsen/logrus"
)

type Indexer interface {
	Index(entry *Entry) error
	Size() int64
	Search(q string, p int) (*bleve.SearchResult, error)
}

type indexer struct {
	conf *Config
	idx  bleve.Index
}

func NewIndexer(conf *Config) (Indexer, error) {
	var (
		idx bleve.Index
		err error
	)

	fn := filepath.Join(conf.Data, "spyda.bleve")

	if FileExists(fn) {
		idx, err = bleve.Open(fn)
	} else {
		mapping := bleve.NewIndexMapping()
		idx, err = bleve.New(fn, mapping)
	}
	if err != nil {
		log.WithError(err).Error("error creating indexer")
		return nil, err
	}

	return &indexer{conf: conf, idx: idx}, nil
}

func (i *indexer) Size() int64 {
	count, err := i.idx.DocCount()
	if err != nil {
		log.WithError(err).Warn("error getting index size")
		return 0
	}
	return int64(count)
}

func (i *indexer) Index(entry *Entry) error {
	return i.idx.Index(entry.Hash(), entry)
}

func (i *indexer) Search(q string, p int) (*bleve.SearchResult, error) {
	query := bleve.NewMatchQuery(q)
	searchRequest := bleve.NewSearchRequest(query)
	searchRequest.Fields = []string{"URL", "Title", "Author", "Summary", "Length"}
	searchRequest.Highlight = bleve.NewHighlight()
	searchRequest.Size = i.conf.ResultsPerPage
	searchRequest.From = searchRequest.Size * (p - 1)
	searchResults, err := i.idx.Search(searchRequest)
	if err != nil {
		log.WithError(err).Error("error searching index")
		return nil, fmt.Errorf("error searching index: %w", err)
	}

	return searchResults, nil
}