SwiftLint/Source/SwiftLintBuiltInRules/Rules/RuleConfigurations/ExpiringTodoConfiguration.swift

import SwiftLintCore

@AutoConfigParser
struct ExpiringTodoConfiguration: RuleConfiguration {
    typealias Severity = SeverityConfiguration<Parent>

    struct DelimiterConfiguration: Equatable, AcceptableByConfigurationElement {
        static let `default`: DelimiterConfiguration = .init(opening: "[", closing: "]")

        fileprivate(set) var opening: String
        fileprivate(set) var closing: String

        init(fromAny value: Any, context ruleID: String) throws(Issue) {
            guard let dateDelimiters = value as? [String: String],
                  let openingDelimiter = dateDelimiters["opening"],
                  let closingDelimiter = dateDelimiters["closing"] else {
                throw .invalidConfiguration(ruleID: ruleID)
            }
            self.init(opening: openingDelimiter, closing: closingDelimiter)
        }

        init(opening: String, closing: String) {
            self.opening = opening
            self.closing = closing
        }

        func asOption() -> OptionType {
            .nest {
                "opening" => .string(opening)
                "closing" => .string(closing)
            }
        }
    }

    @ConfigurationElement(key: "approaching_expiry_severity")
    private(set) var approachingExpirySeverity = Severity(.warning)
    @ConfigurationElement(key: "expired_severity")
    private(set) var expiredSeverity = Severity(.error)
    @ConfigurationElement(key: "bad_formatting_severity")
    private(set) var badFormattingSeverity = Severity(.error)

    // swiftlint:disable:next todo
    /// The number of days prior to expiry before the TODO emits a violation
    @ConfigurationElement(key: "approaching_expiry_threshold")
    private(set) var approachingExpiryThreshold = 15
    /// The opening/closing characters used to surround the expiry-date string
    @ConfigurationElement(key: "date_delimiters")
    private(set) var dateDelimiters = DelimiterConfiguration.default
    /// The format which should be used to the expiry-date string into a `Date` object
    @ConfigurationElement(key: "date_format")
    private(set) var dateFormat = "MM/dd/yyyy"
    /// The separator used for regex detection of the expiry-date string
    @ConfigurationElement(key: "date_separator")
    private(set) var dateSeparator = "/"
}