const stringRegex =  /(.*?)(@(.*))?:(.*)/

class ObjID {
	public bucket: string
	public key: string
	public version?: string

	constructor(bucket: string, key: string, version?: string) {
		this.bucket = bucket
		if(!key){
			this.key = "/"
		}else{
			this.key = key
		}
		if (version){
			this.version = version
		}

		this.normalize()
	}
	
	public toString(): string {
		if (this.version) {
			return `${this.bucket}@${this.version}:${this.key}`
		}else{
			return `${this.bucket}:${this.key}`
		}
	}

	public normalize(): void{
		if (!this.key.startsWith("/")){
			this.key = "/" + this.key
		}
	}

	public isDirectory(): boolean {
		return this.key.endsWith("/")
	}

	public toURI(): string {
		return `/f/${this.bucket}${this.key}`
	}

	public toJSON(): string{
		// HACK: toJSON is required so that apollo can parse the ObjID back to a string
		// that can be used in gql query
		return this.toString()
	}

	public rename(name: string): ObjID{
		const parts = this.key.split("/")
		parts[parts.length - (this.isDirectory()?2:1)] = name
		return new ObjID(this.bucket,parts.join("/"))
	}

	/**
	 * Get the parent of the object. If Obj is a file then the containing directory
	 * if Obj is a directory it returns the parent
	 * @returns parent ObjID or null if already at root
	 */
	public parent(): ObjID | null {
		if (this.key == "/") {
			// Already at root. We dont have a parent
			return null
		}
	
		if (this.isDirectory()) {
			const parts = this.key.split("/")
			const parent = new ObjID(this.bucket, parts.slice(0,-2).join("/") + "/")
			parent.normalize()
			return parent
		} else {
			const parts = this.key.split("/")
			const parent = new ObjID(this.bucket, parts.slice(0,-1).join("/")  + "/")
			parent.normalize()
			return parent
		}
	}

	public static fromString(from: string): ObjID{
		const match = stringRegex.exec(from)

		if (!match){
			throw new Error("Failed to parse ObjID")
		}

		return new ObjID(match[1],match[4],match[3])
	}

	public static fromURI(uri: string): ObjID{
		let uri2 = uri

		if (!uri2.endsWith("/")){
			uri2 += "/"
		}

		const parts = uri2.split("/")

		const bucket = parts[2]
		const key = parts.slice(3).join("/")

		return new ObjID(bucket,key)
	}
}

export default ObjID