class PasswordGenerator{
    constructor(options){
        const defaultOptions = {
            minLength: 6,
            maxLength: 32,
            minLower: 2,
            minUpper: 2,
            minNum: 2,
            minSpecial: 3,
            specialChars: "!@#$%^&*()_+~`|}{[]:;?><,./-=",
        };
        this.options = { ...defaultOptions, ...options };
    }

    Generate(){
        // Generate random password that complies with the options
        const { minLength, maxLength, minLower, minUpper, minNum, minSpecial, specialChars } = this.options;

        let pass = "";

        let lowerRegex = /[a-z]/g;
        let upperRegex = /[A-Z]/g;
        let numRegex = /[0-9]/g;

        // Generate password
        //generate random length
        let length = Math.floor(Math.random() * (maxLength - minLength + 1) + minLength);
        //generate random length for each character type
        let lowerLength = Math.floor(Math.random() * (length - minLower - minUpper - minNum - minSpecial + 1) + minLower);
        let upperLength = Math.floor(Math.random() * (length - lowerLength - minUpper - minNum - minSpecial + 1) + minUpper);
        let numLength = Math.floor(Math.random() * (length - lowerLength - upperLength - minNum - minSpecial + 1) + minNum);
        let specialLength = Math.floor(Math.random() * (length - lowerLength - upperLength - numLength - minSpecial + 1) + minSpecial);

        //generate random characters
        for(let i = 0; i < lowerLength; i++){
            pass += lowerRegex[Math.floor(Math.random() * lowerRegex.length)];
        }

        for(let i = 0; i < upperLength; i++){
            pass += upperRegex[Math.floor(Math.random() * upperRegex.length)];
        }

        for(let i = 0; i < numLength; i++){
            pass += numRegex[Math.floor(Math.random() * numRegex.length)];
        }

        for(let i = 0; i < specialLength; i++){
            pass += specialChars[Math.floor(Math.random() * specialChars.length)];
        }

        //shuffle password
        pass = pass.split('').sort(function(){return 0.5-Math.random()}).join('');
    }
}

module.exports = PasswordGenerator;