//
//  MongoController.swift
//  MongoView
//
//  Created by Shadowfacts on 1/8/20.
//  Copyright © 2020 Shadowfacts. All rights reserved.
//

import Foundation
import MongoSwift
import NIO
import Combine

class MongoController {
    let connectionString: String
    
    var group: EventLoopGroup!
    
    var client: MongoClient!
    
    @Published var statusManager = StatusManager()
    @Published private(set) var status: ConnectionStatus {
        didSet {
            statusManager.set(messageFor(status: status), for: .connection)
        }
    }

    init(connectionString: String) {
        self.connectionString = connectionString
        self.status = .connecting
        self.statusManager.set(messageFor(status: .connecting), for: .connection)
    }
    
    deinit {
        try! group.syncShutdownGracefully()
        cleanupMongoSwift()
    }
    
    func setup() {
        print("setting up mongo")
        
        group = MultiThreadedEventLoopGroup(numberOfThreads: 1)
        
        do {
            client = try MongoClient(connectionString, using: group)
            status = .connected
        } catch {
            status = .failed
            print("Failed to connect to Mongo: \(error)")
        }
    }
    
    func db(for collection: DatabaseCollection) -> MongoDatabase {
        return client.db(collection.database)
    }
    
    func collection(_ collection: DatabaseCollection) -> MongoCollection<BSONDocument> {
        return db(for: collection).collection(collection.name)
    }
    
    private func messageFor(status: ConnectionStatus) -> String {
        switch status {
        case .connecting:
            return "Connecting..."
        case .connected:
            return "Connected to \(connectionString)"
        case .failed:
            return "Failed to connect"
        }
    }

}

extension MongoController {
    enum ConnectionStatus {
        case connecting, connected, failed
    }
}