/*
 * 计算密码复杂度
 */

function gettype(str, i) {
    if (str.charCodeAt(i) >= 48 && str.charCodeAt(i) <= 57) {
        return 1;
    } else if (str.charCodeAt(i) >= 97 && str.charCodeAt(i) <= 122) {
        return 2;
    } else if (str.charCodeAt(i) >= 65 && str.charCodeAt(i) <= 90) {
        return 3;
    }

    return 4;
}

function isregular(cur, pre, type) {
    var curCode = cur.charCodeAt(0);
    var preCode = pre.charCodeAt(0);

    if (curCode - preCode === 0) {
        return true;
    }

    if (type !== 4 && (curCode - preCode === 1 || curCode - preCode === -1)) {
        return true;
    }

    return false;
}

function getcomplex(curType, preType) {
    if (preType === 0 || curType === preType) {
        return 0;
    } else if (curType === 4 || preType === 4) {
        return 2;
    } else {
        return 1;
    }
}

function computeComplex(password) {
    var complex = 0,
        length = password.length,
        pre = '',
        preType = 0,
        i = 0,
        cur,
        curType;


    for (i = 0; i < length; i++) {
        cur = password.charAt(i);
        curType = gettype(password, i);

        if (preType !== curType || !isregular(cur, pre, curType)) {
            complex += curType + getcomplex(curType, preType);
        }

        pre = cur;
        preType = curType;
    }

    return complex;
}

module.exports = computeComplex;