const { xmlToJSON } = require('./index')
const { stripHtml } = require("string-strip-html")
function parseCreators(metadata) {
if (!metadata['dc:creator']) return null
var creators = metadata['dc:creator']
if (!creators.length) return null
return creators.map(c => {
if (typeof c !== 'object' || !c['$'] || !c['_']) return false
return {
value: c['_'],
role: c['$']['opf:role'] || null,
fileAs: c['$']['opf:file-as'] || null
}
})
}
function fetchCreator(creators, role) {
if (!creators || !creators.length) return null
var creator = creators.find(c => c.role === role)
return creator ? creator.value : null
}
function fetchTagString(metadata, tag) {
if (!metadata[tag] || !metadata[tag].length) return null
var tag = metadata[tag][0]
if (typeof tag !== 'string') return null
return tag
}
function fetchDate(metadata) {
var date = fetchTagString(metadata, 'dc:date')
if (!date) return null
var dateSplit = date.split('-')
if (!dateSplit.length || dateSplit[0].length !== 4 || isNaN(dateSplit[0])) return null
return dateSplit[0]
}
function fetchPublisher(metadata) {
return fetchTagString(metadata, 'dc:publisher')
}
function fetchISBN(metadata) {
if (!metadata['dc:identifier'] || !metadata['dc:identifier'].length) return null
var identifiers = metadata['dc:identifier']
var isbnObj = identifiers.find(i => i['$'] && i['$']['opf:scheme'] === 'ISBN')
return isbnObj ? isbnObj['_'] || null : null
}
function fetchTitle(metadata) {
return fetchTagString(metadata, 'dc:title')
}
function fetchDescription(metadata) {
var description = fetchTagString(metadata, 'dc:description')
if (!description) return null
// check if description is HTML or plain text. only plain text allowed
// calibre stores < and > as < and >
description = description.replace(/</g, '<').replace(/>/g, '>')
if (description.match(/<!DOCTYPE html>|<\/?\s*[a-z-][^>]*\s*>|(\&(?:[\w\d]+|#\d+|#x[a-f\d]+);)/)) return stripHtml(description).result
return description
}
function fetchGenres(metadata) {
if (!metadata['dc:subject'] || !metadata['dc:subject'].length) return []
return metadata['dc:subject'].map(g => typeof g === 'string' ? g : null).filter(g => !!g)
}
function fetchLanguage(metadata) {
return fetchTagString(metadata, 'dc:language')
}
function fetchSeries(metadata) {
if (typeof metadata.meta == "undefined") return null
return fetchTagString(metadata.meta, "calibre:series")
}
function fetchVolumeNumber(metadata) {
if (typeof metadata.meta == "undefined") return null
return fetchTagString(metadata.meta, "calibre:series_index")
}
function fetchNarrators(creators, metadata) {
var roleNrt = fetchCreator(creators, 'nrt')
if (typeof metadata.meta == "undefined" || roleNrt != null) return roleNrt
try {
var narratorsJSON = JSON.parse(fetchTagString(metadata.meta, "calibre:user_metadata:#narrators").replace(/"/g, '"'))
return narratorsJSON["#value#"].join(", ")
} catch {
return null
}
}
module.exports.parseOpfMetadataXML = async (xml) => {
var json = await xmlToJSON(xml)
if (!json || !json.package || !json.package.metadata) return null
var metadata = json.package.metadata
if (Array.isArray(metadata)) {
if (!metadata.length) return null
metadata = metadata[0]
}
if (typeof metadata.meta != "undefined") {
metadata.meta = {}
for (var match of xml.matchAll(/<meta name="(?<name>.+)" content="(?<content>.+)"\/>/g)) {
metadata.meta[match.groups['name']] = [match.groups['content']]
}
}
var creators = parseCreators(metadata)
var data = {
title: fetchTitle(metadata),
author: fetchCreator(creators, 'aut'),
narrator: fetchNarrators(creators, metadata),
publishedYear: fetchDate(metadata),
publisher: fetchPublisher(metadata),
isbn: fetchISBN(metadata),
description: fetchDescription(metadata),
genres: fetchGenres(metadata),
language: fetchLanguage(metadata),
series: fetchSeries(metadata),
sequence: fetchVolumeNumber(metadata)
}
return data
}