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//
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//  CachedResponseHandler.swift
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//
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//  Copyright (c) 2019 Alamofire Software Foundation (http://alamofire.org/)
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//
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//  Permission is hereby granted, free of charge, to any person obtaining a copy
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//  of this software and associated documentation files (the "Software"), to deal
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//  in the Software without restriction, including without limitation the rights
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//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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//  copies of the Software, and to permit persons to whom the Software is
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//  furnished to do so, subject to the following conditions:
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//
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//  The above copyright notice and this permission notice shall be included in
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//  all copies or substantial portions of the Software.
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//
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//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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//  THE SOFTWARE.
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//
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import Foundation
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/// A type that handles whether the data task should store the HTTP response in the cache.
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public protocol CachedResponseHandler {
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    /// Determines whether the HTTP response should be stored in the cache.
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    ///
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    /// The `completion` closure should be passed one of three possible options:
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    ///
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    ///   1. The cached response provided by the server (this is the most common use case).
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    ///   2. A modified version of the cached response (you may want to modify it in some way before caching).
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    ///   3. A `nil` value to prevent the cached response from being stored in the cache.
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    ///
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    /// - Parameters:
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    ///   - task:       The data task whose request resulted in the cached response.
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    ///   - response:   The cached response to potentially store in the cache.
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    ///   - completion: The closure to execute containing cached response, a modified response, or `nil`.
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    func dataTask(_ task: URLSessionDataTask,
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                  willCacheResponse response: CachedURLResponse,
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                  completion: @escaping (CachedURLResponse?) -> Void)
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}
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// MARK: -
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/// `ResponseCacher` is a convenience `CachedResponseHandler` making it easy to cache, not cache, or modify a cached
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/// response.
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public struct ResponseCacher {
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    /// Defines the behavior of the `ResponseCacher` type.
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    public enum Behavior {
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        /// Stores the cached response in the cache.
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        case cache
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        /// Prevents the cached response from being stored in the cache.
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        case doNotCache
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        /// Modifies the cached response before storing it in the cache.
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        case modify((URLSessionDataTask, CachedURLResponse) -> CachedURLResponse?)
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    }
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    /// Returns a `ResponseCacher` with a `.cache` `Behavior`.
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    public static let cache = ResponseCacher(behavior: .cache)
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    /// Returns a `ResponseCacher` with a `.doNotCache` `Behavior`.
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    public static let doNotCache = ResponseCacher(behavior: .doNotCache)
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    /// The `Behavior` of the `ResponseCacher`.
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    public let behavior: Behavior
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    /// Creates a `ResponseCacher` instance from the `Behavior`.
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    ///
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    /// - Parameter behavior: The `Behavior`.
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    public init(behavior: Behavior) {
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        self.behavior = behavior
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    }
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}
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extension ResponseCacher: CachedResponseHandler {
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    public func dataTask(_ task: URLSessionDataTask,
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                         willCacheResponse response: CachedURLResponse,
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                         completion: @escaping (CachedURLResponse?) -> Void) {
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        switch behavior {
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        case .cache:
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            completion(response)
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        case .doNotCache:
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            completion(nil)
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        case let .modify(closure):
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            let response = closure(task, response)
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            completion(response)
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        }
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    }
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}
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#if swift(>=5.5)
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extension CachedResponseHandler where Self == ResponseCacher {
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    /// Provides a `ResponseCacher` which caches the response, if allowed. Equivalent to `ResponseCacher.cache`.
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    public static var cache: ResponseCacher { .cache }
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    /// Provides a `ResponseCacher` which does not cache the response. Equivalent to `ResponseCacher.doNotCache`.
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    public static var doNotCache: ResponseCacher { .doNotCache }
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    /// Creates a `ResponseCacher` which modifies the proposed `CachedURLResponse` using the provided closure.
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    ///
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    /// - Parameter closure: Closure used to modify the `CachedURLResponse`.
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    /// - Returns:           The `ResponseCacher`.
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    public static func modify(using closure: @escaping ((URLSessionDataTask, CachedURLResponse) -> CachedURLResponse?)) -> ResponseCacher {
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        ResponseCacher(behavior: .modify(closure))
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    }
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}
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#endif