import { generateId } from '../utils/GeneratorHelpers'

const prefix = 'did:op:'

/**
 * Decentralized ID.
 */
export default class DID {
    /**
     * Parses a DID from a string.
     * @param  {string} didString DID in string.
     * @return {DID}
     */
    public static parse(didString: string): DID {
        let did: DID
        const didMatch = didString.match(/^did:op:([a-f0-9]{64})$/i)

        if (didMatch) {
            did = new DID(didMatch[1])
        }

        if (!did) {
            throw new Error(`Parsing DID failed, ${didString}`)
        }

        return did
    }

    /**
     * Returns a new DID.
     * @return {DID}
     */
    public static generate(): DID {
        return new DID(generateId())
    }

    /**
     * ID.
     * @type {string}
     */
    private id: string

    private constructor(id: string) {
        this.id = id
    }

    /**
     * Returns the DID.
     * @return {string}
     */
    public getDid(): string {
        return `${prefix}${this.id}`
    }

    /**
     * Returns the ID.
     * @return {string}
     */
    public getId(): string {
        return this.id
    }
}