/*

    Copyright (C) 2016 Apple Inc. All Rights Reserved.

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    This file contains the ControlExtension class. The ControlExtension class is a sub-class of NEFilterControlProvider, and is responsible for downloading content filter rules from a web service.

*/

import NetworkExtension

import Foundation

import SimpleTunnelServices

/// A NEFitlerControlProvider sub-class that implements logic for downloading rules from a web server.

class ControlExtension : NEFilterControlProvider {

    // MARK: Properties

    /// The default rules, in the event that 

    let defaultRules: [String: [String: AnyObject]] = [

        "www.apple.com" : [

            "kRule" : FilterRuleAction.block.rawValue as AnyObject,

            "kRemediationKey" : "Remediate1" as AnyObject

        ]

    ]

    /// An integer to use as the context for key-value observing.

    var observerContext = 0

    // MARK: Interface

    /// Update the filter based on changes to the configuration

    func updateFromConfiguration() {

        guard let serverAddress = filterConfiguration.serverAddress else { return }

        FilterUtilities.defaults?.setValue(defaultRules, forKey: "rules")

        FilterUtilities.fetchRulesFromServer(filterConfiguration.serverAddress)

        let remediationURL = "https://\(serverAddress)/remediate/?url=\(NEFilterProviderRemediationURLFlowURLHostname)&organization=\(NEFilterProviderRemediationURLOrganization)&username=\(NEFilterProviderRemediationURLUsername)"

        simpleTunnelLog("Remediation url is \(remediationURL)")

        remediationMap =

            [

                NEFilterProviderRemediationMapRemediationURLs : [ "Remediate1" : remediationURL as NSObject ],

                NEFilterProviderRemediationMapRemediationButtonTexts :

                    [

                        "RemediateButton1" : "Request Access" as NSObject,

                        "RemediateButton2" : "\"<script>alert('wooo hoooooo');</script>" as NSObject,

                        "RemediateButton3" : "Request Access 3" as NSObject,

                ]

            ]

        self.urlAppendStringMap = [ "SafeYes" : "safe=yes", "Adult" : "adult=yes"]

        simpleTunnelLog("Remediation map set")

    }

    // MARK: Initializers

    override init() {

        super.init()

        updateFromConfiguration()

        FilterUtilities.defaults?.setValue(defaultRules, forKey: "rules")

        FilterUtilities.fetchRulesFromServer(self.filterConfiguration.serverAddress)

        self.addObserver(self, forKeyPath: "filterConfiguration", options: [.initial, .new], context: &observerContext)

    }

    // MARK: NSObject

    /// Observe changes to the configuration.

    override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {

        if keyPath == "filterConfiguration" && context == &observerContext {

            simpleTunnelLog("configuration changed")

            updateFromConfiguration()

        } else {

            super.observeValue(forKeyPath: keyPath, of: object, change: change, context: context)

        }

    }

    // MARK: NEFilterControlProvider

    /// Handle a new flow of network data

    override func handleNewFlow(_ flow: NEFilterFlow, completionHandler: @escaping (NEFilterControlVerdict) -> Void) {

        simpleTunnelLog("Handle new flow called")

        var controlVerdict = NEFilterControlVerdict.updateRules()

        let (ruleType, hostname, _) = FilterUtilities.getRule(flow)

        switch ruleType {

            case .needMoreRulesAndAllow:

                simpleTunnelLog("\(hostname) is set to be Allowed")

                controlVerdict = NEFilterControlVerdict.allow(withUpdateRules: false)

            case .needMoreRulesAndBlock:

                simpleTunnelLog("\(hostname) is set to be blocked")

                controlVerdict = NEFilterControlVerdict.drop(withUpdateRules: false)

            default:

                simpleTunnelLog("\(hostname) is not set for need more rules")

        }

        completionHandler(controlVerdict)

    }

}