FileAccessorFake.swift

// Copyright (c) 2021 Spotify AB.
//
// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

import Foundation
@testable import XCRemoteCache

enum FileAccessorFakeError: Error {
    case itemDoesntExist
}

class FileAccessorFake: FileAccessor {
    enum Mode {
        case normal
        case strict
    }

    private var storage: [String: (content: Data?, mdate: Date)] = [:]
    private let mode: Mode

    init(mode: Mode) {
        self.mode = mode
    }

    func contents(atPath path: String) throws -> Data? {
        return storage[path]?.content
    }

    func fileExists(atPath path: String) -> Bool {
        return storage.keys.contains(path)
    }

    func write(toPath path: String, contents: Data?) throws {
        storage[path] = (contents, Date())
    }

    func removeItem(atPath path: String) throws {
        if mode == .strict && storage[path] == nil {
            throw FileAccessorFakeError.itemDoesntExist
        }
        storage[path] = nil
    }

    func fileMDate(atPath path: String) -> Date? {
        return storage[path]?.mdate
    }
}

extension FileAccessorFake: DirScanner {
    func itemType(atPath path: String) throws -> ItemType {
        if storage[path] != nil {
            return .file
        }
        if try !recursiveItems(at: URL(fileURLWithPath: path)).isEmpty {
            return .dir
        }
        return .nonExisting
    }

    func items(at dir: URL) throws -> [URL] {
        storage.keys.map(URL.init(fileURLWithPath:)).filter {
            $0.deletingLastPathComponent() == dir
        }
    }

    func recursiveItems(at dir: URL) throws -> [URL] {
        let paths = storage.keys.filter {
            $0.hasPrefix(dir.path)
        }
        return paths.map(URL.init(fileURLWithPath:))
    }
}