//
//  RemoteProfileViewModel.swift
//  Mastodon
//
//  Created by MainasuK Cirno on 2021-4-2.
//

import os.log
import Foundation
import Combine
import CoreDataStack
import MastodonSDK

final class RemoteProfileViewModel: ProfileViewModel {
    
    init(context: AppContext, userID: Mastodon.Entity.Account.ID) {
        super.init(context: context, optionalMastodonUser: nil)
        
        guard let activeMastodonAuthenticationBox = context.authenticationService.activeMastodonAuthenticationBox.value else {
            return
        }
        let domain = activeMastodonAuthenticationBox.domain
        let authorization = activeMastodonAuthenticationBox.userAuthorization
        context.apiService.accountInfo(
            domain: domain,
            userID: userID,
            authorization: authorization
        )
        .retry(3)
        .sink { completion in
            switch completion {
            case .failure(let error):
                // TODO: handle error
                os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s: remote user %s fetch failed: %s", ((#file as NSString).lastPathComponent), #line, #function, userID, error.localizedDescription)
            case .finished:
                os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s: remote user %s fetched", ((#file as NSString).lastPathComponent), #line, #function, userID)
            }
        } receiveValue: { [weak self] response in
            guard let self = self else { return }
            let managedObjectContext = context.managedObjectContext
            let request = MastodonUser.sortedFetchRequest
            request.fetchLimit = 1
            request.predicate = MastodonUser.predicate(domain: domain, id: response.value.id)
            guard let mastodonUser = managedObjectContext.safeFetch(request).first else {
                assertionFailure()
                return
            }
            self.mastodonUser.value = mastodonUser
        }
        .store(in: &disposeBag)
    }
    
    init(context: AppContext, notificationID: Mastodon.Entity.Notification.ID) {
        super.init(context: context, optionalMastodonUser: nil)

        guard let activeMastodonAuthenticationBox = context.authenticationService.activeMastodonAuthenticationBox.value else {
            return
        }
        let domain = activeMastodonAuthenticationBox.domain
        let authorization = activeMastodonAuthenticationBox.userAuthorization

        context.apiService.notification(
            notificationID: notificationID,
            mastodonAuthenticationBox: activeMastodonAuthenticationBox
        )
        .compactMap { [weak self] response -> AnyPublisher<Mastodon.Response.Content<Mastodon.Entity.Account>, Error>? in
            let userID = response.value.account.id
            // TODO: use .account directly
            return context.apiService.accountInfo(
                domain: domain,
                userID: userID,
                authorization: authorization
            )
        }
        .switchToLatest()
        .retry(3)
        .sink { completion in
            switch completion {
            case .failure(let error):
                // TODO: handle error
                os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s: remote notification %s user fetch failed: %s", ((#file as NSString).lastPathComponent), #line, #function, notificationID, error.localizedDescription)
            case .finished:
                os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s: remote notification %s user fetched", ((#file as NSString).lastPathComponent), #line, #function, notificationID)
            }
        } receiveValue: { [weak self] response in
            guard let self = self else { return }
            let managedObjectContext = context.managedObjectContext
            let request = MastodonUser.sortedFetchRequest
            request.fetchLimit = 1
            request.predicate = MastodonUser.predicate(domain: domain, id: response.value.id)
            guard let mastodonUser = managedObjectContext.safeFetch(request).first else {
                assertionFailure()
                return
            }
            self.mastodonUser.value = mastodonUser
        }
        .store(in: &disposeBag)
    }
    
}