/**
 * A laravel error response
 */
class ErrorResponse {
    constructor()
    {
        this._message = '';
        this._errors = {};
    }

    /**
     * @param {string} json
     * @return {ErrorResponse|null}
     */
    static fromJsonString(json) {
        if(!this.is(json)) {
            return null;
        }
        let jsonObject = JSON.parse(json);

        let instance = new this;
        instance._message = jsonObject.message;
        instance._errors = jsonObject.errors;

        return instance;
    }

    /**
     * Checks that the given json string represents a ErrorResponse
     *
     * @param {string} json
     * @param {boolean} logErrors
     * @return {boolean}
     */
    static is(json, logErrors = true)
    {
        let jsonObject = null;
        try {
            jsonObject = JSON.parse(json);
            if(!jsonObject) return false;
        } catch (e) {
            if(logErrors) console.error('ErrorResponse: The given json does not represent a valid ErrorResponse since the json string was not a valid json');
            return false;
        }

        if(!jsonObject.hasOwnProperty('message') || typeof jsonObject.message !== 'string') {
            if(logErrors) console.error('ErrorResponse: The response object must have an message property that is a string. Object:', jsonObject);
            return false;
        }

        if(!jsonObject.hasOwnProperty('errors') || typeof jsonObject.errors !== 'object') {
            if(logErrors) console.error('ErrorResponse: The response object must have an errors object that represents valid laravel field errors. Object:', jsonObject);
            return false;
        }

        for(let fieldName in jsonObject.errors) {
            if(jsonObject.errors.hasOwnProperty(fieldName) && !Array.isArray(jsonObject.errors[fieldName])) {
                if(logErrors) console.error('ErrorResponse: The property "'+fieldName+'" in the errors array must have have array as value containing errors strings. Object:', jsonObject);
                return false;
            }
        }

        return true;
    }

    /**
     * Retrurns a comprehensive error message for all the fields.
     *
     * @return {string}
     */
    get message() {
        return this._message;
    }

    /**
     * @return {Object} returns an object where the property are field names. and the values are arrays containing errors for those field names.
     */
    get errors() {
        return this._errors;
    }
}

export { ErrorResponse }