//
//  FilePath.swift
//  Freetime
//
//  Created by Ryan Nystrom on 12/3/17.
//  Copyright © 2017 Ryan Nystrom. All rights reserved.
//

import Foundation

struct FilePath {

    static private let joiner = "/"

    let components: [String]

    var baseComponents: [String]? {
        let count = components.count
        guard count > 1 else { return nil }
        return Array(components[0..<count-1])
    }

    var path: String {
        return components.joined(separator: FilePath.joiner)
    }

    var basePath: String? {
        return baseComponents?.joined(separator: FilePath.joiner)
    }

    var current: String? {
        return components.last
    }

    var fileExtension: String? {
        let components = current?.components(separatedBy: ".") ?? []
        if components.count > 1 {
            return components.last
        } else {
            return nil
        }
    }

    func appending(_ component: String) -> FilePath {
        return FilePath(components: components + [component])
    }

}

// MARK: - FilePath (BinaryFile) -

extension FilePath {

    private static let supportedBinaries = [
        "pdf": "application/pdf"
    ]

    // MARK: Public API

    /// A Boolean value indicating whether a string has binary file suffix.
    ///
    /// Supported types: **pdf**.
    var hasBinarySuffix: Bool {
        return binarySuffix != nil
    }

    /// Returns mime type for the supported binary files.
    var mimeType: String? {
        guard let type = binarySuffix else { return nil }

        return FilePath.supportedBinaries[type]
    }

    // MARK: Private API

    private var binarySuffix: String? {
        return FilePath.supportedBinaries.keys.first(where: { path.hasSuffix($0) })
    }

}