refine.go

package liber

import (
	"bufio"
	"bytes"
	"errors"
	"fmt"
	"io"
	"log"
	"os"
)

func (db *Database) RefineFunc(dir string, chooser MetadataChooserFunc) func(*Book) error {
	storage := NewFileStorage(dir)
	refiners := defaultMetadataRefiners

	return func(book *Book) error {
		if err := refineMetadata(book, "", storage, refiners, chooser); err == nil {
			log.Printf("%s: updated metadata", book.Id)
			return db.PutBook(book)
		}
		return nil
	}
}

// ListBooks writes IDs of books that match any of a series of
// functions to an io.Writer.
func (db *Database) ListBooks(w io.Writer, matchFuncs ...func(book *Book) bool) error {
	return db.onAllBooks(func(book *Book) error {
		ok := false
		for _, f := range matchFuncs {
			if f(book) {
				ok = true
				break
			}
		}
		if ok {
			fmt.Fprintf(w, "%s\n", book.Id)
		}
		return nil
	})
}

// WithBookIDs calls a function on books whose IDs are read from the
// specified io.Reader.
func (db *Database) WithBookIDs(r io.Reader, f func(book *Book) error) error {
	scanner := bufio.NewScanner(r)
	for scanner.Scan() {
		id := ParseID(string(bytes.TrimSpace(scanner.Bytes())))
		book, err := db.GetBook(id)
		if err != nil {
			log.Printf("error: no such book %s", id)
			continue
		}
		if err := f(book); err != nil {
			log.Printf("error: %s: %v", id, err)
			// Stop?
		}
	}
	return scanner.Err()
}

// Local path is a hint for generating the cover image.
func findCoverImage(book *Book, path string, refiners []MetadataRefiner, storage *FileStorage) error {
	if book.CoverPath != "" {
		return nil
	}

	localCoverPath := path + ".cover.png"
	for _, refiner := range refiners {