//
//  PushSubscription.swift
//  Pachyderm
//
//  Created by Shadowfacts on 9/9/18.
//  Copyright © 2018 Shadowfacts. All rights reserved.
//

import Foundation

public struct PushSubscription: Decodable, Sendable {
    public var id: String
    public var endpoint: URL
    public var serverKey: String
    public var alerts: Alerts
    public var policy: Policy
    
    public init(from decoder: any Decoder) throws {
        let container = try decoder.container(keyedBy: CodingKeys.self)
        // id is documented as being a string, but mastodon returns a json number
        if let s = try? container.decode(String.self, forKey: .id) {
            self.id = s
        } else {
            let i = try container.decode(Int.self, forKey: .id)
            self.id = i.description
        }
        self.endpoint = try container.decode(URL.self, forKey: .endpoint)
        self.serverKey = try container.decode(String.self, forKey: .serverKey)
        self.alerts = try container.decode(PushSubscription.Alerts.self, forKey: .alerts)
        // added in mastodon 4.1.0
        self.policy = try container.decodeIfPresent(PushSubscription.Policy.self, forKey: .policy) ?? .all
    }
    
    public static func create(endpoint: URL, publicKey: Data, authSecret: Data, alerts: Alerts, policy: Policy) -> Request<PushSubscription> {
        return Request(method: .post, path: "/api/v1/push/subscription", body: ParametersBody([
            "subscription[endpoint]" => endpoint.absoluteString,
            "subscription[keys][p256dh]" => publicKey.base64EncodedString(),
            "subscription[keys][auth]" => authSecret.base64EncodedString(),
            "data[alerts][mention]" => alerts.mention,
            "data[alerts][status]" => alerts.status,
            "data[alerts][reblog]" => alerts.reblog,
            "data[alerts][follow]" => alerts.follow,
            "data[alerts][follow_request]" => alerts.followRequest,
            "data[alerts][favourite]" => alerts.favourite,
            "data[alerts][poll]" => alerts.poll,
            "data[alerts][update]" => alerts.update,
            "data[alerts][pleroma:emoji_reaction]" => alerts.emojiReaction,
            "data[policy]" => policy.rawValue,
        ]))
    }
    
    public static func update(alerts: Alerts, policy: Policy) -> Request<PushSubscription> {
        return Request(method: .put, path: "/api/v1/push/subscription", body: ParametersBody([
            "data[alerts][mention]" => alerts.mention,
            "data[alerts][status]" => alerts.status,
            "data[alerts][reblog]" => alerts.reblog,
            "data[alerts][follow]" => alerts.follow,
            "data[alerts][follow_request]" => alerts.followRequest,
            "data[alerts][favourite]" => alerts.favourite,
            "data[alerts][poll]" => alerts.poll,
            "data[alerts][update]" => alerts.update,
            "data[alerts][pleroma:emoji_reaction]" => alerts.emojiReaction,
            "data[policy]" => policy.rawValue,
        ]))
    }
    
    public static func delete() -> Request<Empty> {
        return Request(method: .delete, path: "/api/v1/push/subscription")
    }
    
    private enum CodingKeys: String, CodingKey {
        case id
        case endpoint
        case serverKey = "server_key"
        case alerts
        case policy
    }
}

extension PushSubscription {
    public struct Alerts: Decodable, Sendable {
        public let mention: Bool
        public let status: Bool
        public let reblog: Bool
        public let follow: Bool
        public let followRequest: Bool
        public let favourite: Bool
        public let poll: Bool
        public let update: Bool
        public let emojiReaction: Bool

        public init(
            mention: Bool,
            status: Bool,
            reblog: Bool,
            follow: Bool,
            followRequest: Bool,
            favourite: Bool,
            poll: Bool,
            update: Bool,
            emojiReaction: Bool
        ) {
            self.mention = mention
            self.status = status
            self.reblog = reblog
            self.follow = follow
            self.followRequest = followRequest
            self.favourite = favourite
            self.poll = poll
            self.update = update
            self.emojiReaction = emojiReaction
        }
        
        public init(from decoder: any Decoder) throws {
            let container: KeyedDecodingContainer<PushSubscription.Alerts.CodingKeys> = try decoder.container(keyedBy: PushSubscription.Alerts.CodingKeys.self)
            self.mention = try container.decode(Bool.self, forKey: PushSubscription.Alerts.CodingKeys.mention)
            // status added in mastodon 3.3.0
            self.status = try container.decodeIfPresent(Bool.self, forKey: PushSubscription.Alerts.CodingKeys.status) ?? false
            self.reblog = try container.decode(Bool.self, forKey: PushSubscription.Alerts.CodingKeys.reblog)
            self.follow = try container.decode(Bool.self, forKey: PushSubscription.Alerts.CodingKeys.follow)
            // follow_request added in 3.1.0
            self.followRequest = try container.decodeIfPresent(Bool.self, forKey: PushSubscription.Alerts.CodingKeys.followRequest) ?? false
            self.favourite = try container.decode(Bool.self, forKey: PushSubscription.Alerts.CodingKeys.favourite)
            self.poll = try container.decode(Bool.self, forKey: PushSubscription.Alerts.CodingKeys.poll)
            // update added in mastodon 3.5.0
            self.update = try container.decodeIfPresent(Bool.self, forKey: PushSubscription.Alerts.CodingKeys.update) ?? false
            // pleroma/akkoma only
            self.emojiReaction = try container.decodeIfPresent(Bool.self, forKey: .emojiReaction) ?? false
        }
        
        private enum CodingKeys: String, CodingKey {
            case mention
            case status
            case reblog
            case follow
            case followRequest = "follow_request"
            case favourite
            case poll
            case update
            case emojiReaction = "pleroma:emoji_reaction"
        }
    }
}

extension PushSubscription {
    public enum Policy: String, Decodable, Sendable {
        case all
        case followed
        case followers
        case none
    }
}