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

import Foundation
import Pachyderm

class Draft: Codable, ObservableObject {
    let id: UUID
    var lastModified: Date
    
    @Published var accountID: String
    @Published var text: String
    @Published var contentWarningEnabled: Bool
    @Published var contentWarning: String
    @Published var attachments: [CompositionAttachment]
    @Published var inReplyToID: String?
    @Published var visibility: Status.Visibility
    
    var initialText: String
    
    var hasContent: Bool {
        (!text.isEmpty && text != initialText) ||
            (contentWarningEnabled && !contentWarning.isEmpty) ||
            attachments.count > 0
    }
    
    init(accountID: String) {
        self.id = UUID()
        self.lastModified = Date()
        
        self.accountID = accountID
        self.text = ""
        self.contentWarningEnabled = false
        self.contentWarning = ""
        self.attachments = []
        self.inReplyToID = nil
        self.visibility = Preferences.shared.defaultPostVisibility
        
        self.initialText = ""
    }
    
    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)
        if let enabled = try? container.decode(Bool.self, forKey: .contentWarningEnabled) {
            self.contentWarningEnabled = enabled
            self.contentWarning = try container.decode(String.self, forKey: .contentWarning)
        } else {
            // todo: temporary until migration away from old drafts manager is complete
            let cw = try container.decode(String?.self, forKey: .contentWarning)
            if let cw = cw {
                self.contentWarningEnabled = !cw.isEmpty
                self.contentWarning = cw
            } else {
                self.contentWarningEnabled = false
                self.contentWarning = ""
            }
        }
        self.attachments = try container.decode([CompositionAttachment].self, forKey: .attachments)
        self.inReplyToID = try container.decode(String?.self, forKey: .inReplyToID)
        self.visibility = try container.decode(Status.Visibility.self, forKey: .visibility)
        
        self.initialText = try container.decode(String.self, forKey: .initialText)
    }
    
    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(initialText, forKey: .initialText)
    }
}

extension Draft: Equatable {
    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 initialText
    }
}

extension MastodonController {
    
    func createDraft(inReplyToID: String? = nil, mentioningAcct: String? = nil) -> Draft {
        var acctsToMention = [String]()
        
        var visibility = Preferences.shared.defaultPostVisibility
        var contentWarning = ""
        
        if let inReplyToID = inReplyToID,
           let inReplyTo = persistentContainer.status(for: inReplyToID) {
            acctsToMention.append(inReplyTo.account.acct)
            acctsToMention.append(contentsOf: inReplyTo.mentions.map(\.acct))
            visibility = inReplyTo.visibility
            
            if !inReplyTo.spoilerText.isEmpty {
                switch Preferences.shared.contentWarningCopyMode {
                case .doNotCopy:
                    break
                case .asIs:
                    contentWarning = inReplyTo.spoilerText
                case .prependRe:
                    if inReplyTo.spoilerText.lowercased().starts(with: "re:") {
                        contentWarning = inReplyTo.spoilerText
                    } else {
                        contentWarning = "re: \(inReplyTo.spoilerText)"
                    }
                }
            }
        }
        if let mentioningAcct = mentioningAcct {
            acctsToMention.append(mentioningAcct)
        }
        if let ownAccount = self.account {
            acctsToMention.removeAll(where: { $0 == ownAccount.acct })
        }
        acctsToMention = acctsToMention.uniques()
        
        let draft = Draft(accountID: accountInfo!.id)
        draft.inReplyToID = inReplyToID
        draft.text = acctsToMention.map { "@\($0) " }.joined()
        draft.initialText = draft.text
        draft.visibility = visibility
        draft.contentWarning = contentWarning
        draft.contentWarningEnabled = !contentWarning.isEmpty
        return draft
    }
    
}