export const PrismjsType = {
	PlainText: "PlainText",
	Markdown: "Markdown",
	JavaScript: "JavaScript",
	TypeScript: "TypeScript",
	Initialization: "Initialization",
	PHP: "PHP",
	SQL: "SQL",
	XML: "XML",
	CSS: "CSS",
	VUE: "VUE",
	LESS: "LESS",
	Markup: "Markup",
	YAML: "YAML",
	Json: "Json",
	Java: "Java",
	Properties: "Properties",
	NginxConf: "NginxConf",
	ApacheConf: "ApacheConf"
} as const;

export type PrismjsType = (typeof PrismjsType)[keyof typeof PrismjsType];

export type PrismjsProperties = {

	extensions: string[]
	prismjs: string;
	viewer: PrismjsViewer;
}

export const PrismjsViewer = {

	MARKDOWN: "MARKDOWN",

	CODE: "CODE",

	TEXT: "TEXT"
} as const;

export type PrismjsViewer = (typeof PrismjsViewer)[keyof typeof PrismjsViewer];

export default class Prismjs {

	private static instance: Prismjs;

	map = new Map<PrismjsType, PrismjsProperties>();

	private constructor() {
		this.map.set(PrismjsType.PlainText,      {extensions: ["txt"],                 prismjs: "",           viewer: PrismjsViewer.TEXT});
		this.map.set(PrismjsType.Markdown,       {extensions: ["md"],                  prismjs: "md",         viewer: PrismjsViewer.MARKDOWN});
		this.map.set(PrismjsType.JavaScript,     {extensions: ["js"],                  prismjs: "js",         viewer: PrismjsViewer.CODE});
		this.map.set(PrismjsType.VUE,            {extensions: ["vue"],                 prismjs: "html",       viewer: PrismjsViewer.CODE});
		this.map.set(PrismjsType.TypeScript,     {extensions: ["ts"],                  prismjs: "ts",         viewer: PrismjsViewer.CODE});
		this.map.set(PrismjsType.Initialization, {extensions: ["ini"],                 prismjs: "ini",        viewer: PrismjsViewer.CODE});
		this.map.set(PrismjsType.PHP,            {extensions: ["php"],                 prismjs: "php",        viewer: PrismjsViewer.CODE});
		this.map.set(PrismjsType.SQL,            {extensions: ["sql"],                 prismjs: "sql",        viewer: PrismjsViewer.CODE});
		this.map.set(PrismjsType.XML,            {extensions: ["xml", "fxml", "wxml"], prismjs: "xml",        viewer: PrismjsViewer.CODE});
		this.map.set(PrismjsType.CSS,            {extensions: ["css", "wxss"],         prismjs: "css",        viewer: PrismjsViewer.CODE});
		this.map.set(PrismjsType.LESS,           {extensions: ["less"],                prismjs: "less",       viewer: PrismjsViewer.CODE});
		this.map.set(PrismjsType.Markup,         {extensions: ["htm", "html"],         prismjs: "markup",     viewer: PrismjsViewer.CODE});
		this.map.set(PrismjsType.YAML,           {extensions: ["yml", "yaml"],         prismjs: "yaml",       viewer: PrismjsViewer.CODE});
		this.map.set(PrismjsType.Json,           {extensions: ["json"],                prismjs: "json",       viewer: PrismjsViewer.CODE});
		this.map.set(PrismjsType.Java,           {extensions: ["java"],                prismjs: "java",       viewer: PrismjsViewer.CODE});
		this.map.set(PrismjsType.Properties,     {extensions: ["properties"],          prismjs: "properties", viewer: PrismjsViewer.CODE});
		this.map.set(PrismjsType.NginxConf,      {extensions: [],                      prismjs: "nginx",      viewer: PrismjsViewer.CODE});
		this.map.set(PrismjsType.ApacheConf,     {extensions: [],                      prismjs: "apacheconf", viewer: PrismjsViewer.CODE});
	}

	private static getInstance(): Prismjs {
		if (!Prismjs.instance) {
			Prismjs.instance = new Prismjs();
		}
		return Prismjs.instance;
	}

	public static typeFromFileName(fileName: string): PrismjsType | undefined {
		const ext = fileName.substring(fileName.lastIndexOf(".") + 1);
		if (!ext) {
			return undefined;
		}
		const map = Prismjs.getInstance().map;
		for (const key of map.keys()) {
			const value = map.get(key);
			if (value) {
				const extensions = value.extensions;
				for (let i = 0; i < extensions.length; i++) {
					const extension = extensions[i];
					if (extension === ext) {
						return key;
					}
				}
			}
		}
		return undefined;
	}

	public static getFileProperties(type: PrismjsType): PrismjsProperties | undefined {
		return Prismjs.getInstance().map.get(type);
	}
}