//
//  IntercommSystem.swift
//  io.privado.main.hive
//
//  Created by Juraldinio on 6/21/20.
//  Copyright © 2020 Privado. All rights reserved.
//

import Foundation

final class IntercommSystem {
    
    enum Constants {
        static let sudoPath = "/usr/bin/sudo"
        static let ifconfigPath = "/sbin/ifconfig"
        static let networksetupPath = "/usr/sbin/networksetup"
        static let dscacheutilPath = "/usr/bin/dscacheutil"
    }
    
    private weak var client: HiveIntercommConsole?
    
    init(client: HiveIntercommConsole?) {
        self.client = client
    }
    
    // MARK: - Extractor methods
    
    private func extractHardwarePorts(from stdout: String) -> [HardwarePort] {
        
        guard let regExp = try? NSRegularExpression(pattern: #"(\([\d]+\)) ([\w]+)\n\(Hardware Port: ([\w]+), Device: ([\w]+)\)"#, options: []) else {
            return []
        }
        
        return stdout
            .components(separatedBy: "\n\n")
            .map { String($0) }
            .compactMap { value -> HardwarePort? in
                guard let match = regExp.firstMatch(in: value, options: [], range: NSRange(location: 0, length: value.count))
                    , match.numberOfRanges > 4
                    , let port = value.substring(using: match.range(at: 3))
                    , let device = value.substring(using: match.range(at: 4)) else {
                        return nil
                }
                
                return HardwarePort(port: port, device: device)
            }
            .filter { $0.isValid }
    }
    
    private func extractIp(domain: String, from stdout: String) -> String? {
        let results = stdout
            .split(separator: "\n")
            .map { String($0) }
        
        guard results.contains(where: { $0.contains(domain) }) else { return nil }
        
        guard let ipAddress = results.filter({ $0.contains("ip_address") }).first?.split(separator: " ")
            , ipAddress.count > 1 else {
                return nil
        }
        
        return String(ipAddress[1])
    }
    
    /*private func extractIFConfigSettings(from stdout: String) -> [InterfaceConfiguration] {
        
        guard let regExp = try? NSRegularExpression(pattern: #"([\w\d]+): .+\n([ ]+inet ([\d\.]+) netmask .+\n|[ ]+inet6 [\w:]+.+\n|.+\n)+.+"#, options: []) else {
            return []
        }
        
        return []
    }*/
    
}

extension IntercommSystem: IntercommSystemType {
    
    func updateRequired(short: String, bundle: String, completion: @escaping (Bool) -> Void) {
        completion(false)
    }

    func version(completion: @escaping (String, String) -> Void) {
        let shortVersion = Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String ?? "1.0"
        let bundleVersion = Bundle.main.infoDictionary?["CFBundleVersion"] as? String ?? "1"
        completion(shortVersion, bundleVersion)
    }
    
    func ping(completion: @escaping () -> Void) {
        completion()
    }

    func ifconfig(completion: @escaping (String) -> Void) {
        let result = main.run(Constants.ifconfigPath)
        completion(result.stdout)
    }

    func hardwarePorts(completion: @escaping ([HardwarePort]) -> Void) {
        let result = main.run(Constants.networksetupPath, ["-listnetworkserviceorder"])
        self.client?.console(message: "hardwarePorts stdout: \(result.stdout)")
        let ports = self.extractHardwarePorts(from: result.stdout)
        completion(ports)
    }
    
    func flushDNS(completion: @escaping (Bool) -> Void) {
        
        let arguments: [String]
            
        let os = ProcessInfo().operatingSystemVersion
        
        switch (os.majorVersion, os.minorVersion, os.patchVersion) {
        case let (_, minor, _) where minor >= 12:
            arguments = ["killall -HUP mDNSResponder",
                         "killall mDNSResponderHelper",
                         "dscacheutil -flushcache"]
        case let (_, minor, _) where minor >= 11:
            arguments = ["killall -HUP mDNSResponder"]
        case let (_, 10, patch) where patch >= 4:
            arguments = ["dscacheutil -flushcache",
                         "killall -HUP mDNSResponder"]
        default:
            arguments = []
        }
        
        guard !arguments.isEmpty else {
            completion(false)
            return
        }
        
        do {
            try arguments.forEach {
                let result = main.run(Constants.sudoPath, $0.split(separator: " ").map({ String($0) }))
                guard result.succeeded else { throw NSError() }
                //self.client?.console(message: "flushDNS stdout: \(result.stdout)")
                if !result.stderror.isEmpty { self.client?.console(message: "flushDNS stderror: \(result.stderror)") }
            }
        } catch {
            completion(false)
            return
        }
        
        completion(true)
    }
    
    func resolveDNS(name: String, completion: @escaping (String) -> Void) {
        let arguments = ["-q", "host", "-a", "name", name]
        let result = main.run(Constants.dscacheutilPath, arguments)
        let ipAddress = self.extractIp(domain: name, from: result.stdout) ?? ""
        completion(ipAddress)
    }
    
    func changeDNS(servers: [String], hardware: String, completion: @escaping (Bool) -> Void) {
        var arguments = ["-setdnsservers", hardware]
        arguments.append(contentsOf: servers)
        
        let result = main.run(Constants.networksetupPath, arguments)
        completion(result.error == nil)
    }
    
    func currentDNS(hardware: [String], completion: @escaping ([String: [String]]) -> Void) {
        
        let dns = hardware.reduce([String: [String]]()) { dns, hardware in
            
            var dns = dns
            let arguments = ["-getdnsservers", hardware]
            
            let result = main.run(Constants.networksetupPath, arguments)
            if result.error == nil {
                if result.stdout.contains("aren't any DNS") {
                    dns[hardware] = []
                } else {
                    dns[hardware] = result.stdout
                        .split(separator: "\n")
                        .map { String($0) }
                }
            }
            
            return dns
        }
        
        completion(dns)
    }
    
    func removeUninstaller(completion: @escaping () -> Void) {
        
        [
            ["launchctl", "unload", "/Library/LaunchDaemons/io.privado.main.uninstaller.plist"],
            ["rm", "/Library/LaunchDaemons/io.privado.main.uninstaller.plist"],
            ["rm", "/Library/PrivilegedHelperTools/io.privado.main.uninstaller"]
        ].forEach { arguments in
            main.run(Constants.sudoPath, arguments)
        }
        
        completion()
        
    }
    
}