// "use strict" is not required in ES6 modules as they are always in strict mode

// Exporting functions and constants as named exports and default export

/**
 * RegExp to match cookie-name in RFC 6265 sec 4.1.1
 * This refers out to the obsoleted definition of token in RFC 2616 sec 2.2
 * which has been replaced by the token definition in RFC 7230 appendix B.
 *
 * cookie-name       = token
 * token             = 1*tchar
 * tchar             = "!" / "#" / "$" / "%" / "&" / "'" /
 *                     "*" / "+" / "-" / "." / "^" / "_" /
 *                     "`" / "|" / "~" / DIGIT / ALPHA
 *
 * Note: Allowing more characters - https://github.com/jshttp/cookie/issues/191
 * Allow same range as cookie value, except `=`, which delimits end of name.
 */
const cookieNameRegExp = /^[\u0021-\u003A\u003C\u003E-\u007E]+$/;
/**
 * RegExp to match cookie-value in RFC 6265 sec 4.1.1
 *
 * cookie-value      = *cookie-octet / ( DQUOTE *cookie-octet DQUOTE )
 * cookie-octet      = %x21 / %x23-2B / %x2D-3A / %x3C-5B / %x5D-7E
 *                     ; US-ASCII characters excluding CTLs,
 *                     ; whitespace DQUOTE, comma, semicolon,
 *                     ; and backslash
 *
 * Allowing more characters: https://github.com/jshttp/cookie/issues/191
 * Comma, backslash, and DQUOTE are not part of the parsing algorithm.
 */
const cookieValueRegExp = /^[\u0021-\u003A\u003C-\u007E]*$/;
/**
 * RegExp to match domain-value in RFC 6265 sec 4.1.1
 *
 * domain-value      = <subdomain>
 *                     ; defined in [RFC1034], Section 3.5, as
 *                     ; enhanced by [RFC1123], Section 2.1
 * <subdomain>       = <label> | <subdomain> "." <label>
 * <label>           = <let-dig> [ [ <ldh-str> ] <let-dig> ]
 *                     Labels must be 63 characters or less.
 *                     'let-dig' not 'letter' in the first char, per RFC1123
 * <ldh-str>         = <let-dig-hyp> | <let-dig-hyp> <ldh-str>
 * <let-dig-hyp>     = <let-dig> | "-"
 * <let-dig>         = <letter> | <digit>
 * <letter>          = any one of the 52 alphabetic characters A through Z in
 *                     upper case and a through z in lower case
 * <digit>           = any one of the ten digits 0 through 9
 *
 * Keep support for leading dot: https://github.com/jshttp/cookie/issues/173
 *
 * > (Note that a leading %x2E ("."), if present, is ignored even though that
 * character is not permitted, but a trailing %x2E ("."), if present, will
 * cause the user agent to ignore the attribute.)
 */
const domainValueRegExp = /^([.]?[a-z0-9]([a-z0-9-]{0,61}[a-z0-9])?)([.][a-z0-9]([a-z0-9-]{0,61}[a-z0-9])?)*$/i;
/**
 * RegExp to match path-value in RFC 6265 sec 4.1.1
 *
 * path-value        = <any CHAR except CTLs or ";">
 * CHAR              = %x01-7F
 *                     ; defined in RFC 5234 appendix B.1
 */
const pathValueRegExp = /^[\u0020-\u003A\u003D-\u007E]*$/;
const __toString = Object.prototype.toString;
const NullObject = (() => {
    const C = function () {
    };
    C.prototype = Object.create(null);
    return C;
})();

/**
 * Parse a cookie header.
 *
 * Parse the given cookie header string into an object
 * The object has the various cookies as keys(names) => values
 */
export function parse(input, options) {
    const obj = new NullObject();
    const dec = options?.decode || decode;

    // If input is an array, process each string
    const headers = Array.isArray(input) ? input : [input];
    // console.log(headers);
    for (const str of headers) {
        const len = str.length;
        if (len < 2) continue;

        let index = 0;
        do {
            const eqIdx = str.indexOf("=", index);
            if (eqIdx === -1) break;
            const colonIdx = str.indexOf(";", index);
            const endIdx = colonIdx === -1 ? len : colonIdx;

            if (eqIdx > endIdx) {
                index = str.lastIndexOf(";", eqIdx - 1) + 1;
                continue;
            }

            const keyStartIdx = startIndex(str, index, eqIdx);
            const keyEndIdx = endIndex(str, eqIdx, keyStartIdx);
            const key = str.slice(keyStartIdx, keyEndIdx); // Keep original case

            let valStartIdx = startIndex(str, eqIdx + 1, endIdx);
            let valEndIdx = endIndex(str, endIdx, valStartIdx);
            const value = dec(str.slice(valStartIdx, valEndIdx));

            // Always overwrite with the latest value for the same key
            obj[key] = value;

            index = endIdx + 1;
        } while (index < len);
    }

    return obj;
}


function startIndex(str, index, max) {
    do {
        const code = str.charCodeAt(index);
        if (code !== 0x20 && code !== 0x09) return index;
    } while (++index < max);
    return max;
}

function endIndex(str, index, min) {
    while (index > min) {
        const code = str.charCodeAt(--index);
        if (code !== 0x20 && code !== 0x09) return index + 1;
    }
    return min;
}

/**
 * Serialize data into a cookie header.
 *
 * Serialize a name value pair into a cookie string suitable for
 * http headers. An optional options object specifies cookie parameters.
 */
export function serialize(name, val, options) {
    const enc = options?.encode || encodeURIComponent;
    if (!cookieNameRegExp.test(name)) {
        throw new TypeError(`argument name is invalid: ${name}`);
    }
    const value = enc(val);
    if (!cookieValueRegExp.test(value)) {
        throw new TypeError(`argument val is invalid: ${val}`);
    }
    let str = name + "=" + value;
    if (!options) return str;
    if (options.maxAge !== undefined) {
        if (!Number.isInteger(options.maxAge)) {
            throw new TypeError(`option maxAge is invalid: ${options.maxAge}`);
        }
        str += "; Max-Age=" + options.maxAge;
    }
    if (options.domain) {
        if (!domainValueRegExp.test(options.domain)) {
            throw new TypeError(`option domain is invalid: ${options.domain}`);
        }
        str += "; Domain=" + options.domain;
    }
    if (options.path) {
        if (!pathValueRegExp.test(options.path)) {
            throw new TypeError(`option path is invalid: ${options.path}`);
        }
        str += "; Path=" + options.path;
    }
    if (options.expires) {
        if (!isDate(options.expires) || !Number.isFinite(options.expires.valueOf())) {
            throw new TypeError(`option expires is invalid: ${options.expires}`);
        }
        str += "; Expires=" + options.expires.toUTCString();
    }
    if (options.httpOnly) {
        str += "; HttpOnly";
    }
    if (options.secure) {
        str += "; Secure";
    }
    if (options.partitioned) {
        str += "; Partitioned";
    }
    if (options.priority) {
        const priority = typeof options.priority === "string" ? options.priority.toLowerCase() : undefined;
        switch (priority) {
            case "low":
                str += "; Priority=Low";
                break;
            case "medium":
                str += "; Priority=Medium";
                break;
            case "high":
                str += "; Priority=High";
                break;
            default:
                throw new TypeError(`option priority is invalid: ${options.priority}`);
        }
    }
    if (options.sameSite) {
        const sameSite = typeof options.sameSite === "string" ? options.sameSite.toLowerCase() : options.sameSite;
        switch (sameSite) {
            case true:
            case "strict":
                str += "; SameSite=Strict";
                break;
            case "lax":
                str += "; SameSite=Lax";
                break;
            case "none":
                str += "; SameSite=None";
                break;
            default:
                throw new TypeError(`option sameSite is invalid: ${options.sameSite}`);
        }
    }
    return str;
}

/**
 * URL-decode string value. Optimized to skip native call when no %.
 */
function decode(str) {
    if (str.indexOf("%") === -1) return str;
    try {
        return decodeURIComponent(str);
    } catch (e) {
        return str;
    }
}

/**
 * Determine if value is a Date.
 */
function isDate(val) {
    return __toString.call(val) === "[object Date]";
}

export function stringify(obj, encode = 0) {
    return Object.entries(obj)
        .map(([key, value]) => encode ? serialize(key, value) : decodeURIComponent(serialize(key, value)))
        .join("; ")
}


// Export as default object for named and default usage
const COOKIE = {parse, serialize, stringify};
export default COOKIE;
