//
//  Draft.swift
//  ComposeUI
//
//  Created by Shadowfacts on 8/18/20.
//  Copyright © 2020 Shadowfacts. All rights reserved.
//

import Foundation
import Combine
import Pachyderm

public class Draft: Codable, Identifiable, ObservableObject {
    public let id: UUID
    var lastModified: Date
    
    @Published public var accountID: String
    @Published public var text: String
    @Published public var contentWarningEnabled: Bool
    @Published public var contentWarning: String
    @Published public var attachments: [DraftAttachment]
    @Published public var inReplyToID: String?
    @Published public var visibility: Visibility
    @Published public var poll: Poll?
    @Published public var localOnly: Bool
    
    var initialText: String
    
    public var hasContent: Bool {
        (!text.isEmpty && text != initialText) ||
            (contentWarningEnabled && !contentWarning.isEmpty) ||
            attachments.count > 0 ||
            poll?.hasContent == true
    }
    
    public init(
        accountID: String,
        text: String,
        contentWarning: String,
        inReplyToID: String?,
        visibility: Visibility,
        localOnly: Bool
    ) {
        self.id = UUID()
        self.lastModified = Date()
        
        self.accountID = accountID
        self.text = text
        self.contentWarning = contentWarning
        self.contentWarningEnabled = !contentWarning.isEmpty
        self.attachments = []
        self.inReplyToID = inReplyToID
        self.visibility = visibility
        self.localOnly = localOnly
        
        self.initialText = text
    }
    
    public required init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: CodingKeys.self)
        
        self.id = try container.decode(UUID.self, forKey: .id)
        self.lastModified = try container.decode(Date.self, forKey: .lastModified)
        
        self.accountID = try container.decode(String.self, forKey: .accountID)
        self.text = try container.decode(String.self, forKey: .text)
        self.contentWarningEnabled = try container.decode(Bool.self, forKey: .contentWarningEnabled)
        self.contentWarning = try container.decode(String.self, forKey: .contentWarning)
        self.attachments = try container.decode([DraftAttachment].self, forKey: .attachments)
        self.inReplyToID = try container.decode(String?.self, forKey: .inReplyToID)
        self.visibility = try container.decode(Visibility.self, forKey: .visibility)
        self.poll = try container.decode(Poll?.self, forKey: .poll)
        self.localOnly = try container.decodeIfPresent(Bool.self, forKey: .localOnly) ?? false
        
        self.initialText = try container.decode(String.self, forKey: .initialText)
    }
    
    public func encode(to encoder: Encoder) throws {
        var container = encoder.container(keyedBy: CodingKeys.self)
        
        try container.encode(id, forKey: .id)
        try container.encode(lastModified, forKey: .lastModified)
        
        try container.encode(accountID, forKey: .accountID)
        try container.encode(text, forKey: .text)
        try container.encode(contentWarningEnabled, forKey: .contentWarningEnabled)
        try container.encode(contentWarning, forKey: .contentWarning)
        try container.encode(attachments, forKey: .attachments)
        try container.encode(inReplyToID, forKey: .inReplyToID)
        try container.encode(visibility, forKey: .visibility)
        try container.encode(poll, forKey: .poll)
        try container.encode(localOnly, forKey: .localOnly)
        
        try container.encode(initialText, forKey: .initialText)
    }
}

extension Draft: Equatable {
    public static func ==(lhs: Draft, rhs: Draft) -> Bool {
        return lhs.id == rhs.id
    }
}

extension Draft {
    enum CodingKeys: String, CodingKey {
        case id
        case lastModified
        
        case accountID
        case text
        case contentWarningEnabled
        case contentWarning
        case attachments
        case inReplyToID
        case visibility
        case poll
        case localOnly
        
        case initialText
    }
}

extension Draft {
    public class Poll: Codable, ObservableObject {
        @Published public var options: [Option]
        @Published public var multiple: Bool
        @Published public var duration: TimeInterval
        
        var hasContent: Bool {
            options.contains { !$0.text.isEmpty }
        }
        
        public init() {
            self.options = [Option(""), Option("")]
            self.multiple = false
            self.duration = 24 * 60 * 60 // 1 day
        }
        
        public required init(from decoder: Decoder) throws {
            let container = try decoder.container(keyedBy: CodingKeys.self)
            self.options = try container.decode([Option].self, forKey: .options)
            self.multiple = try container.decode(Bool.self, forKey: .multiple)
            self.duration = try container.decode(TimeInterval.self, forKey: .duration)
        }
        
        public func encode(to encoder: Encoder) throws {
            var container = encoder.container(keyedBy: CodingKeys.self)
            try container.encode(options, forKey: .options)
            try container.encode(multiple, forKey: .multiple)
            try container.encode(duration, forKey: .duration)
        }
        
        private enum CodingKeys: String, CodingKey {
            case options
            case multiple
            case duration
        }
        
        public class Option: Identifiable, Codable, ObservableObject {
            public let id = UUID()
            @Published public var text: String
            
            init(_ text: String) {
                self.text = text
            }
            
            public required init(from decoder: Decoder) throws {
                self.text = try decoder.singleValueContainer().decode(String.self)
            }
            
            public func encode(to encoder: Encoder) throws {
                var container = encoder.singleValueContainer()
                try container.encode(text)
            }
        }
    }
}