//
//  XCallbackURL.swift
//  Tusker
//
//  Created by Shadowfacts on 9/23/18.
//  Copyright © 2018 Shadowfacts. All rights reserved.
//

import UIKit

typealias XCBAction = (_ url: XCallbackURL, _ session: XCBSession, _ silent: Bool?) -> Void

struct XCallbackURLSpec {
    
    let path: String
    let type: XCBActionType
    let arguments: [String: Bool]
    let canRunSilently: Bool
    let action: XCBAction
    
    init(type: XCBActionType, arguments: [String: Bool], canRunSilently: Bool, action: @escaping XCBAction) {
        self.path = type.path
        self.type = type
        self.canRunSilently = canRunSilently
        self.action = action
        var arguments = arguments
        if canRunSilently {
            arguments["silent"] = true
        }
        self.arguments = arguments
    }
    
    func handle(url: XCallbackURL) -> Bool {
        let session = XCBManager.createSession(type: type, url: url)
        if canRunSilently && url.silent {
            if let source = url.source {
                let permission = Preferences.shared.silentActions[source] ?? .undecided
                switch permission {
                case .accepted:
                    action(url, session, true)
                case .rejected:
                    action(url, session, false)
                case .undecided:
                    let alert = UIAlertController(title: "\(source) wants to perform actions silently", message: "Accepting will allow \(source) to perform actions without your confirmation, rejecting will always prompt for confirmation.", preferredStyle: .alert)
                    alert.addAction(UIAlertAction(title: "Accept", style: .default, handler: { (_) in
                        Preferences.shared.silentActions[source] = .accepted
                        self.action(url, session, true)
                    }))
                    alert.addAction(UIAlertAction(title: "Reject", style: .default, handler: { (_) in
                        Preferences.shared.silentActions[source] = .rejected
                        self.action(url, session, false)
                    }))
                    UIApplication.shared.keyWindow!.rootViewController!.present(alert, animated: true)
                }
            } else {
                session.complete(with: .error, additionalData: [
                    "error": "Cannot perform silent action without source app, x-source parameter must be specified"
                    ])
            }
        } else {
            action(url, session, nil)
        }
        return true
    }
    
}

struct XCallbackURL {
    let path: String
    let arguments: [String: String]
    let silent: Bool
    let source: String?
    let success: URL?
    let error: URL?
    let cancel: URL?
    
    init(spec: XCallbackURLSpec, components: URLComponents) {
        self.path = spec.path
        let queryItems = components.queryItems!
        self.arguments = spec.arguments.reduce(into: [String: String](), { (result, el) in
            if let value = queryItems.first(where: { $0.name == el.key })?.value {
                result[el.key] = value
            }
        })
        if spec.canRunSilently {
            silent = Bool(arguments["silent"] ?? "false") ?? false
        } else {
            silent = false
        }
        source = queryItems.first(where: { $0.name == "x-source" }).flatMap { $0.value }
        success = queryItems.first(where: { $0.name == "x-success" }).flatMap { $0.value }.flatMap { URL(string: $0) }
        error = queryItems.first(where: { $0.name == "x-error" }).flatMap { $0.value }.flatMap { URL(string: $0) }
        cancel = queryItems.first(where: { $0.name == "x-cancel" }).flatMap { $0.value }.flatMap { URL(string: $0) }
    }
}

extension XCallbackURLSpec {
    func matches(_ components: URLComponents) -> Bool {
        guard path == components.path else { return false }
        for (name, optional) in arguments {
            if (!optional && components.queryItems?.first(where: { $0.name == name }) == nil) {
                return false
            }
        }
        return true
    }
}