"use strict";

const DocUtils = require("./docUtils");
const extensionRegex = /[^.]+\.([^.]+)/;

const rels = {
	getPrefix(fileType) {
		return fileType === "docx" ? "word" : "ppt";
	},
	getFileTypeName(fileType) {
		return fileType === "docx" ? "document" : "presentation";
	},
	getRelsFileName(fileName) {
		return fileName.replace(/^.*?([a-zA-Z0-9]+)\.xml$/, "$1") + ".xml.rels";
	},
	getRelsFilePath(fileName, fileType) {
		const relsFileName = rels.getRelsFileName(fileName);
		const prefix = fileType === "pptx" ? "ppt/slides" : "word";
		return `${prefix}/_rels/${relsFileName}`;
	},
};

module.exports = class ImgManager {
	constructor(zip, fileName, xmlDocuments, fileType) {
		this.fileName = fileName;
		this.prefix = rels.getPrefix(fileType);
		this.zip = zip;
		this.xmlDocuments = xmlDocuments;
		this.fileTypeName = rels.getFileTypeName(fileType);
		this.mediaPrefix = fileType === "pptx" ? "../media" : "media";
		const relsFilePath = rels.getRelsFilePath(fileName, fileType);
		this.relsDoc = xmlDocuments[relsFilePath] || this.createEmptyRelsDoc(xmlDocuments, relsFilePath);
	}
	createEmptyRelsDoc(xmlDocuments, relsFileName) {
		const mainRels = this.prefix + "/_rels/" + (this.fileTypeName) + ".xml.rels";
		const doc = xmlDocuments[mainRels];
		if (!doc) {
			const err = new Error("Could not copy from empty relsdoc");
			err.properties = {
				mainRels,
				relsFileName,
				files: Object.keys(this.zip.files),
			};
			throw err;
		}
		const relsDoc = DocUtils.str2xml(DocUtils.xml2str(doc));
		const relationships = relsDoc.getElementsByTagName("Relationships")[0];
		const relationshipChilds = relationships.getElementsByTagName("Relationship");
		for (let i = 0, l = relationshipChilds.length; i < l; i++) {
			relationships.removeChild(relationshipChilds[i]);
		}
		xmlDocuments[relsFileName] = relsDoc;
		return relsDoc;
	}
	loadImageRels() {
		const iterable = this.relsDoc.getElementsByTagName("Relationship");
		return Array.prototype.reduce.call(iterable, function (max, relationship) {
			const id = relationship.getAttribute("Id");
			if (/^rId[0-9]+$/.test(id)) {
				return Math.max(max, parseInt(id.substr(3), 10));
			}
			return max;
		}, 0);
	}
// Add an extension type in the [Content_Types.xml], is used if for example you want word to be able to read png files (for every extension you add you need a contentType)
	addExtensionRels(contentType, extension) {
		const contentTypeDoc = this.xmlDocuments["[Content_Types].xml"];
		const defaultTags = contentTypeDoc.getElementsByTagName("Default");
		const extensionRegistered = Array.prototype.some.call(defaultTags, function (tag) {
			return tag.getAttribute("Extension") === extension;
		});
		if (extensionRegistered) {
			return;
		}
		const types = contentTypeDoc.getElementsByTagName("Types")[0];
		const newTag = contentTypeDoc.createElement("Default");
		newTag.namespaceURI = null;
		newTag.setAttribute("ContentType", contentType);
		newTag.setAttribute("Extension", extension);
		types.appendChild(newTag);
	}
	// Add an image and returns it's Rid
	addImageRels(imageName, imageData, i) {
		if (i == null) {
			i = 0;
		}
		const realImageName = i === 0 ? imageName : imageName + `(${i})`;
		const imagePath = `${this.prefix}/media/${realImageName}`;
		if (this.zip.files[imagePath] != null) {
			return this.addImageRels(imageName, imageData, i + 1);
		}
		const image = {
			name: imagePath,
			data: imageData,
			options: {
				binary: true,
			},
		};
		this.zip.file(image.name, image.data, image.options);
		const extension = realImageName.replace(extensionRegex, "$1");
		this.addExtensionRels(`image/${extension}`, extension);
		const relationships = this.relsDoc.getElementsByTagName("Relationships")[0];
		const newTag = this.relsDoc.createElement("Relationship");
		newTag.namespaceURI = null;
		const maxRid = this.loadImageRels() + 1;
		newTag.setAttribute("Id", `rId${maxRid}`);
		newTag.setAttribute("Type", "http://schemas.openxmlformats.org/officeDocument/2006/relationships/image");
		newTag.setAttribute("Target", `${this.mediaPrefix}/${realImageName}`);
		relationships.appendChild(newTag);
		return maxRid;
	}
};