import {ValidationResult, ValidatorFunction, ValidatorFunctionParams} from './types'
import {isJSON} from '../../util'

/**
 * String-related validation rules.
 */
const regexes: {[key: string]: RegExp} = {
    'string.is.alpha': /[a-zA-Z]*/,
    'string.is.alpha_num': /[a-zA-Z0-9]*/,
    'string.is.alpha_dash': /[a-zA-Z-]*/,
    'string.is.alpha_score': /[a-zA-Z_]*/,
    'string.is.alpha_num_dash_score': /[a-zA-Z\-_0-9]*/,
    'string.is.email': /(?:[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*|"(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])*")@(?:(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?|\[(?:(?:(2(5[0-5]|[0-4][0-9])|1[0-9][0-9]|[1-9]?[0-9]))\.){3}(?:(2(5[0-5]|[0-4][0-9])|1[0-9][0-9]|[1-9]?[0-9])|[a-z0-9-]*[a-z0-9]:(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])+)])/,  // eslint-disable-line no-control-regex
    'string.is.ip': /((^\s*((([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5]))\s*$)|(^\s*((([0-9A-Fa-f]{1,4}:){7}([0-9A-Fa-f]{1,4}|:))|(([0-9A-Fa-f]{1,4}:){6}(:[0-9A-Fa-f]{1,4}|((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3})|:))|(([0-9A-Fa-f]{1,4}:){5}(((:[0-9A-Fa-f]{1,4}){1,2})|:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3})|:))|(([0-9A-Fa-f]{1,4}:){4}(((:[0-9A-Fa-f]{1,4}){1,3})|((:[0-9A-Fa-f]{1,4})?:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){3}(((:[0-9A-Fa-f]{1,4}){1,4})|((:[0-9A-Fa-f]{1,4}){0,2}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){2}(((:[0-9A-Fa-f]{1,4}){1,5})|((:[0-9A-Fa-f]{1,4}){0,3}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){1}(((:[0-9A-Fa-f]{1,4}){1,6})|((:[0-9A-Fa-f]{1,4}){0,4}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(:(((:[0-9A-Fa-f]{1,4}){1,7})|((:[0-9A-Fa-f]{1,4}){0,5}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:)))(%.+)?\s*$))/,
    'string.is.ip.v4': /(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}/,
    'string.is.ip.v6': /(([0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,7}:|([0-9a-fA-F]{1,4}:){1,6}:[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,5}(:[0-9a-fA-F]{1,4}){1,2}|([0-9a-fA-F]{1,4}:){1,4}(:[0-9a-fA-F]{1,4}){1,3}|([0-9a-fA-F]{1,4}:){1,3}(:[0-9a-fA-F]{1,4}){1,4}|([0-9a-fA-F]{1,4}:){1,2}(:[0-9a-fA-F]{1,4}){1,5}|[0-9a-fA-F]{1,4}:((:[0-9a-fA-F]{1,4}){1,6})|:((:[0-9a-fA-F]{1,4}){1,7}|:)|fe80:(:[0-9a-fA-F]{0,4}){0,4}%[0-9a-zA-Z]+|::(ffff(:0{1,4})?:)?((25[0-5]|(2[0-4]|1?[0-9])?[0-9])\.){3}(25[0-5]|(2[0-4]|1?[0-9])?[0-9])|([0-9a-fA-F]{1,4}:){1,4}:((25[0-5]|(2[0-4]|1?[0-9])?[0-9])\.){3}(25[0-5]|(2[0-4]|1?[0-9])?[0-9]))/,
    'string.is.mime': /^(?=[-a-z]{1,127}\/[-.a-z0-9]{1,127}$)[a-z]+(-[a-z]+)*\/[a-z0-9]+([-.][a-z0-9]+)*$/,
    'string.is.url': /((([A-Za-z]{3,9}:(?:\/\/)?)(?:[-;:&=+$,\w]+@)?[A-Za-z0-9.-]+|(?:www\.|[-;:&=+$,\w]+@)[A-Za-z0-9.-]+)((?:\/[+~%/.\w\-_]*)?\??(?:[-+=&;%@.\w_]*)#?(?:[.!/\\\w]*))?)/,
    'string.is.uuid': /^[0-9a-fA-F]{8}\b-[0-9a-fA-F]{4}\b-[0-9a-fA-F]{4}\b-[0-9a-fA-F]{4}\b-[0-9a-fA-F]{12}$/,
}

function validateRex(key: string, inputValue: unknown, message: string): ValidationResult {
    if ( regexes[key].test(String(inputValue)) ) {
        return { valid: true }
    }

    return {
        valid: false,
        message,
    }
}

/** Requires the input value to be alphabetical characters only. */
function alpha(fieldName: string, inputValue: unknown): ValidationResult {
    return validateRex('string.is.alpha', inputValue, 'must be alphabetical only')
}

/** Requires the input value to be alphanumeric characters only. */
function alphaNum(fieldName: string, inputValue: unknown): ValidationResult {
    return validateRex('string.is.alpha_num', inputValue, 'must be alphanumeric only')
}

/** Requires the input value to be alphabetical characters or the "-" character only. */
function alphaDash(fieldName: string, inputValue: unknown): ValidationResult {
    return validateRex('string.is.alpha_dash', inputValue, 'must be alphabetical and dashes only')
}

/** Requires the input value to be alphabetical characters or the "_" character only. */
function alphaScore(fieldName: string, inputValue: unknown): ValidationResult {
    return validateRex('string.is.alpha_score', inputValue, 'must be alphabetical and underscores only')
}

/** Requires the input value to be alphabetical characters, numeric characters, "-", or "_" only. */
function alphaNumDashScore(fieldName: string, inputValue: unknown): ValidationResult {
    return validateRex('string.is.alpha_num_dash_score', inputValue, 'must be alphanumeric, dashes, and underscores only')
}

/** Requires the input value to be a valid RFC email address format. */
function email(fieldName: string, inputValue: unknown): ValidationResult {
    return validateRex('string.is.email', inputValue, 'must be an email address')
}

/** Requires the input value to be a valid IPv4 or IPv6 address. */
function ip(fieldName: string, inputValue: unknown): ValidationResult {
    return validateRex('string.is.ip', inputValue, 'must be a valid IP address')
}

/** Requires the input value to be a valid IPv4 address. */
function ipv4(fieldName: string, inputValue: unknown): ValidationResult {
    return validateRex('string.is.ip.v4', inputValue, 'must be a valid IP version 4 address')
}

/** Requires the input value to be a valid IPv6 address. */
function ipv6(fieldName: string, inputValue: unknown): ValidationResult {
    return validateRex('string.is.ip.v6', inputValue, 'must be a valid IP version 6 address')
}

/** Requires the input value to be a valid file MIME type. */
function mime(fieldName: string, inputValue: unknown): ValidationResult {
    return validateRex('string.is.mime', inputValue, 'must be a valid MIME-type')
}

/** Requires the input value to be a valid RFC URL format. */
function url(fieldName: string, inputValue: unknown): ValidationResult {
    return validateRex('string.is.url', inputValue, 'must be a valid URL')
}

/** Requires the input value to be a valid RFC UUID format. */
function uuid(fieldName: string, inputValue: unknown): ValidationResult {
    return validateRex('string.is.uuid', inputValue, 'must be a valid UUID')
}

/**
 * Builds a validation function that requires the input value to match the given regex.
 * @param rex
 */
function regex(rex: RegExp): ValidatorFunction {
    return (fieldName: string, inputValue: unknown): ValidationResult => {
        if ( rex.test(String(inputValue)) ) {
            return { valid: true }
        }

        return {
            valid: false,
            message: 'is not valid',
        }
    }
}

/**
 * Builds a validation function that requires the input to NOT match the given regex.
 * @param rex
 */
function notRegex(rex: RegExp): ValidatorFunction {
    return (fieldName: string, inputValue: unknown): ValidationResult => {
        if ( !rex.test(String(inputValue)) ) {
            return { valid: true }
        }

        return {
            valid: false,
            message: 'is not valid',
        }
    }
}

/**
 * Builds a validation function that requires the given input to end with the substring.
 * @param substr
 */
function ends(substr: string): ValidatorFunction {
    return (fieldName: string, inputValue: unknown): ValidationResult => {
        if ( String(inputValue).endsWith(substr) ) {
            return { valid: true }
        }

        return {
            valid: false,
            message: `must end with "${substr}"`,
        }
    }
}

/**
 * Builds a validation function that requires the given input to begin with the substring.
 * @param substr
 */
function begins(substr: string): ValidatorFunction {
    return (fieldName: string, inputValue: unknown): ValidationResult => {
        if ( String(inputValue).startsWith(substr) ) {
            return { valid: true }
        }

        return {
            valid: false,
            message: `must begin with "${substr}"`,
        }
    }
}

/** Requires the input value to be a valid JSON string. */
function json(fieldName: string, inputValue: unknown): ValidationResult {
    if ( isJSON(String(inputValue)) ) {
        return { valid: true }
    }

    return {
        valid: false,
        message: 'must be valid JSON',
    }
}

/**
 * Builds a validator function that requires the input value to have exactly len many characters.
 * @param len
 */
function length(len: number): ValidatorFunction {
    return (fieldName: string, inputValue: unknown): ValidationResult => {
        if ( String(inputValue).length === len ) {
            return { valid: true }
        }

        return {
            valid: false,
            message: `must be exactly of length ${len}`,
        }
    }
}

/**
 * Builds a validator function that requires the input value to have at least len many characters.
 * @param len
 */
function lengthMin(len: number): ValidatorFunction {
    return (fieldName: string, inputValue: unknown): ValidationResult => {
        if ( String(inputValue).length >= len ) {
            return { valid: true }
        }

        return {
            valid: false,
            message: `must be at least length ${len}`,
        }
    }
}

/**
 * Builds a validator function that requires the input value to have at most len many characters.
 * @param len
 */
function lengthMax(len: number): ValidatorFunction {
    return (fieldName: string, inputValue: unknown): ValidationResult => {
        if ( String(inputValue).length <= len ) {
            return { valid: true }
        }

        return {
            valid: false,
            message: `must be at most length ${len}`,
        }
    }
}

/**
 * Validator function that requires the input value to match a `${field}Confirm` field's value.
 * @param fieldName
 * @param inputValue
 * @param params
 */
function confirmed(fieldName: string, inputValue: unknown, params: ValidatorFunctionParams): ValidationResult {
    const confirmedFieldName = `${fieldName}Confirm`
    if ( inputValue === params.data[confirmedFieldName] ) {
        return { valid: true }
    }

    return {
        valid: false,
        message: `confirmation does not match`,
    }
}

export const Str = {
    alpha,
    alphaNum,
    alphaDash,
    alphaScore,
    alphaNumDashScore,
    email,
    ip,
    ipv4,
    ipv6,
    mime,
    url,
    uuid,
    regex,
    notRegex,
    ends,
    begins,
    json,
    length,
    lengthMin,
    lengthMax,
    confirmed,
}