Vernissage/MastodonKit/Sources/MastodonKit/MastodonClient+Convenience.swift

//
//  https://mczachurski.dev
//  Copyright © 2022 Marcin Czachurski and the repository contributors.
//  Licensed under the MIT License.
//

import Foundation
import OAuthSwift

public extension MastodonClient {
    func createApp(named name: String,
                          redirectUri: String = "urn:ietf:wg:oauth:2.0:oob",
                          scopes: Scopes,
                          website: URL) async throws -> App {
        
        let request = try Self.request(
            for: baseURL,
            target: Mastodon.Apps.register(
                clientName: name,
                redirectUris: redirectUri,
                scopes: scopes.reduce("") { $0 == "" ? $1 : $0 + " " + $1},
                website: website.absoluteString
            )
        )
        
        return try await downloadJson(App.self, request: request)
    }
    
    func authenticate(app: App, scope: Scopes) async throws -> OAuthSwiftCredential { // todo: we should not load OAuthSwift objects here
        oauthClient = OAuth2Swift(
            consumerKey: app.clientId,
            consumerSecret: app.clientSecret,
            authorizeUrl: baseURL.appendingPathComponent("oauth/authorize"),
            accessTokenUrl: baseURL.appendingPathComponent("oauth/token"),
            responseType: "code"
        )
        
        return try await withCheckedThrowingContinuation { [weak self] continuation in
            self?.oAuthContinuation = continuation
            oAuthHandle = oauthClient?.authorize(
                withCallbackURL: app.redirectUri,
                scope: scope.asScopeString,
                state: "MASToDON_AUTH",
                completionHandler: { result in
                    switch result {
                    case let .success((credentials, _, _)):
                        continuation.resume(with: .success(credentials))
                    case let .failure(error):
                        continuation.resume(throwing: error)
                    }
                    self?.oAuthContinuation = nil
                }
            )
        }
    }
    
    static func handleOAuthResponse(url: URL) {
        OAuthSwift.handle(url: url)
    }

    @available(*, deprecated, message: "The password flow is discoured and won't support 2FA. Please use authentiate(app:, scope:)")
    func getToken(withApp app: App,
                         username: String,
                         password: String,
                         scope: Scopes) async throws -> AccessToken {

        let request = try Self.request(
            for: baseURL,
            target: Mastodon.OAuth.authenticate(app, username, password, scope.asScopeString)
        )
        
        return try await downloadJson(AccessToken.self, request: request)
    }
}

private extension [String] {
    var asScopeString: String {
        joined(separator: " ")
    }
}