// Copyright (c) 2017 Hèctor Marquès Ranea
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

import Foundation

public enum TaskFailure: Error
{
    case stillRunning             (domain: String, code: Int)
    case nonzeroTerminationStatus (domain: String, code: Int, terminationStatus: Int, uncaughtSignal: Bool)
    case emptyOutput              (domain: String, code: Int)

    public init?(result: TaskResult, domain: String = #function, code: Int = #line)
    {
        guard let terminationStatus = result.terminationStatus else {
            self = TaskFailure.stillRunning(
                domain: domain,
                code: code
            ); return
        }
        guard terminationStatus == 0 else {
            self = TaskFailure.nonzeroTerminationStatus(
                domain: domain,
                code: code,
                terminationStatus: terminationStatus,
                uncaughtSignal: result.terminatedDueUncaughtSignal
            ); return
        }
        guard !result.standardOutput.isEmpty else {
            self = TaskFailure.emptyOutput(
                domain: domain,
                code: code
            ); return
        }
        return nil
    }
}
