package parser

import (
	"regexp"
	"strings"

	"github.com/meskio/epubgo"
)

type MetaData map[string]interface{}

func EpubMetadata(epub *epubgo.Epub) MetaData {
	metadata := MetaData{}
	for _, m := range epub.MetadataFields() {
		data, err := epub.Metadata(m)
		if err != nil {
			continue
		}
		switch m {
		case "creator":
			metadata["author"] = parseAuthr(data)
		case "description":
			metadata[m] = parseDescription(data)
		case "subject":
			metadata[m] = parseSubject(data)
		case "date":
			metadata[m] = parseDate(data)
		case "language":
			metadata["lang"] = GuessLang(epub, data)
		case "title", "contributor", "publisher":
			metadata[m] = cleanStr(strings.Join(data, ", "))
		case "identifier":
			attr, _ := epub.MetadataAttr(m)
			for i, d := range data {
				if attr[i]["scheme"] == "ISBN" {
					isbn := ISBN(d)
					if isbn != "" {
						metadata["isbn"] = isbn
					}
				}
			}
		default:
			metadata[m] = strings.Join(data, ", ")
		}
	}
	return metadata
}

func cleanStr(str string) string {
	str = strings.Replace(str, "'", "'", -1)
	exp, _ := regexp.Compile("&[^;]*;")
	str = exp.ReplaceAllString(str, "")
	exp, _ = regexp.Compile("[ ,]*$")
	str = exp.ReplaceAllString(str, "")
	return str
}

func parseAuthr(creator []string) []string {
	exp1, _ := regexp.Compile("^(.*\\( *([^\\)]*) *\\))*$")
	exp2, _ := regexp.Compile("^[^:]*: *(.*)$")
	res := make([]string, len(creator))
	for i, s := range creator {
		auth := exp1.FindStringSubmatch(s)
		if auth != nil {
			res[i] = cleanStr(strings.Join(auth[2:], ", "))
		} else {
			auth := exp2.FindStringSubmatch(s)
			if auth != nil {
				res[i] = cleanStr(auth[1])
			} else {
				res[i] = cleanStr(s)
			}
		}
	}
	return res
}

func parseDescription(description []string) string {
	str := cleanStr(strings.Join(description, "\n"))
	str = strings.Replace(str, "</p>", "\n", -1)
	exp, _ := regexp.Compile("<[^>]*>")
	str = exp.ReplaceAllString(str, "")
	str = strings.Replace(str, "&amp;", "&", -1)
	str = strings.Replace(str, "&lt;", "<", -1)
	str = strings.Replace(str, "&gt;", ">", -1)
	str = strings.Replace(str, "\\n", "\n", -1)
	return str
}

func parseSubject(subject []string) []string {
	var res []string
	for _, s := range subject {
		res = append(res, strings.Split(s, " / ")...)
	}
	return res
}

func parseDate(date []string) string {
	if len(date) == 0 {
		return ""
	}
	return strings.Replace(date[0], "Unspecified: ", "", -1)
}