// Copyright © 2022 Rangeproof Pty Ltd. All rights reserved.

import Foundation
import GRDB
import SessionUtilitiesKit

public final class VisibleMessage: Message {
    private enum CodingKeys: String, CodingKey {
        case syncTarget
        case text = "body"
        case attachmentIds = "attachments"
        case quote
        case linkPreview
        case profile
        case openGroupInvitation
    }
    
    /// In the case of a sync message, the public key of the person the message was targeted at.
    ///
    /// - Note: `nil` if this isn't a sync message.
    public var syncTarget: String?
    public let text: String?
    public var attachmentIds: [String]
    public let quote: Quote?
    public let linkPreview: LinkPreview?
    public var profile: Profile?
    public let openGroupInvitation: OpenGroupInvitation?

    public override var isSelfSendValid: Bool { true }
    
    // MARK: - Validation
    
    public override var isValid: Bool {
        guard super.isValid else { return false }
        if !attachmentIds.isEmpty { return true }
        if openGroupInvitation != nil { return true }
        if let text = text?.trimmingCharacters(in: .whitespacesAndNewlines), !text.isEmpty { return true }
        return false
    }
    
    // MARK: - Initialization
    
    public init(
        sentTimestamp: UInt64? = nil,
        recipient: String? = nil,
        groupPublicKey: String? = nil,
        syncTarget: String? = nil,
        text: String?,
        attachmentIds: [String] = [],
        quote: Quote? = nil,
        linkPreview: LinkPreview? = nil,
        profile: Profile? = nil,
        openGroupInvitation: OpenGroupInvitation? = nil
    ) {
        self.syncTarget = syncTarget
        self.text = text
        self.attachmentIds = attachmentIds
        self.quote = quote
        self.linkPreview = linkPreview
        self.profile = profile
        self.openGroupInvitation = openGroupInvitation
        
        super.init(
            sentTimestamp: sentTimestamp,
            recipient: recipient,
            groupPublicKey: groupPublicKey
        )
    }
    
    // MARK: - Codable
    
    required init(from decoder: Decoder) throws {
        let container: KeyedDecodingContainer<CodingKeys> = try decoder.container(keyedBy: CodingKeys.self)
        
        syncTarget = try? container.decode(String.self, forKey: .syncTarget)
        text = try? container.decode(String.self, forKey: .text)
        attachmentIds = ((try? container.decode([String].self, forKey: .attachmentIds)) ?? [])
        quote = try? container.decode(Quote.self, forKey: .quote)
        linkPreview = try? container.decode(LinkPreview.self, forKey: .linkPreview)
        profile = try? container.decode(Profile.self, forKey: .profile)
        openGroupInvitation = try? container.decode(OpenGroupInvitation.self, forKey: .openGroupInvitation)
        
        try super.init(from: decoder)
    }
    
    public override func encode(to encoder: Encoder) throws {
        try super.encode(to: encoder)
        
        var container: KeyedEncodingContainer<CodingKeys> = encoder.container(keyedBy: CodingKeys.self)
        
        try container.encodeIfPresent(syncTarget, forKey: .syncTarget)
        try container.encodeIfPresent(text, forKey: .text)
        try container.encodeIfPresent(attachmentIds, forKey: .attachmentIds)
        try container.encodeIfPresent(quote, forKey: .quote)
        try container.encodeIfPresent(linkPreview, forKey: .linkPreview)
        try container.encodeIfPresent(profile, forKey: .profile)
        try container.encodeIfPresent(openGroupInvitation, forKey: .openGroupInvitation)
    }

    // MARK: - Proto Conversion
    
    public override class func fromProto(_ proto: SNProtoContent, sender: String) -> VisibleMessage? {
        guard let dataMessage = proto.dataMessage else { return nil }
        
        return VisibleMessage(
            syncTarget: dataMessage.syncTarget,
            text: dataMessage.body,
            attachmentIds: [],    // Attachments are handled in MessageReceiver
            quote: dataMessage.quote.map { Quote.fromProto($0) },
            linkPreview: dataMessage.preview.first.map { LinkPreview.fromProto($0) },
            profile: Profile.fromProto(dataMessage),
            openGroupInvitation: dataMessage.openGroupInvitation.map { OpenGroupInvitation.fromProto($0) }
        )
    }

    public override func toProto(_ db: Database) -> SNProtoContent? {
        let proto = SNProtoContent.builder()
        var attachmentIds = self.attachmentIds
        let dataMessage: SNProtoDataMessage.SNProtoDataMessageBuilder
        
        // Profile
        if let profile = profile, let profileProto = profile.toProto() {
            dataMessage = profileProto.asBuilder()
        }
        else {
            dataMessage = SNProtoDataMessage.builder()
        }
        
        // Text
        if let text = text { dataMessage.setBody(text) }
        
        // Quote
        
        if let quotedAttachmentID = quote?.attachmentID, let index = attachmentIDs.firstIndex(of: quotedAttachmentID) {
            attachmentIDs.remove(at: index)
        }
        
        if let quote = quote, let quoteProto = quote.toProto(db) {
            dataMessage.setQuote(quoteProto)
        }
        
        // Link preview
        if let linkPreviewAttachmentId = linkPreview?.attachmentId, let index = attachmentIds.firstIndex(of: linkPreviewAttachmentId) {
            attachmentIds.remove(at: index)
        }
        
        if let linkPreview = linkPreview, let linkPreviewProto = linkPreview.toProto(db) {
            dataMessage.setPreview([ linkPreviewProto ])
        }
        
        // Attachments
        
        let attachments: [SessionMessagingKit.Attachment]? = try? SessionMessagingKit.Attachment.fetchAll(db, ids: self.attachmentIds)
        
        if !(attachments ?? []).allSatisfy({ $0.state == .uploaded }) {
            #if DEBUG
            preconditionFailure("Sending a message before all associated attachments have been uploaded.")
            #endif
        }
        let attachmentProtos = (attachments ?? []).compactMap { $0.buildProto() }
        dataMessage.setAttachments(attachmentProtos)
        
        // Open group invitation
        if let openGroupInvitation = openGroupInvitation, let openGroupInvitationProto = openGroupInvitation.toProto() { dataMessage.setOpenGroupInvitation(openGroupInvitationProto) }
        
        // Group context
        do {
            try setGroupContextIfNeeded(db, on: dataMessage)
        } catch {
            SNLog("Couldn't construct visible message proto from: \(self).")
            return nil
        }
        // Sync target
        if let syncTarget = syncTarget {
            dataMessage.setSyncTarget(syncTarget)
        }
        // Build
        do {
            proto.setDataMessage(try dataMessage.build())
            return try proto.build()
        } catch {
            SNLog("Couldn't construct visible message proto from: \(self).")
            return nil
        }
    }
    
    // MARK: - Description
    
    public var description: String {
        """
        VisibleMessage(
            text: \(text ?? "null"),
            attachmentIds: \(attachmentIds),
            quote: \(quote?.description ?? "null"),
            linkPreview: \(linkPreview?.description ?? "null"),
            profile: \(profile?.description ?? "null")
            "openGroupInvitation": \(openGroupInvitation?.description ?? "null")
        )
        """
    }
}

// MARK: - Database Type Conversion

public extension VisibleMessage {
    static func from(_ db: Database, interaction: Interaction) -> VisibleMessage {
        let result = VisibleMessage()
        result.sentTimestamp = UInt64(interaction.timestampMs)
        result.recipient = (try? interaction.recipientStates.fetchOne(db))?.recipientId
        
        if let thread: SessionThread = try? interaction.thread.fetchOne(db), thread.variant == .closedGroup {
            result.groupPublicKey = thread.id
        }
        
        result.text = interaction.body
        result.attachmentIDs = ((try? interaction.attachments.fetchAll(db)) ?? []).map { $0.id }
        result.quote = (try? interaction.quote.fetchOne(db))
            .map { VisibleMessage.Quote.from(db, quote: $0) }
        
        if let linkPreview: SessionMessagingKit.LinkPreview = try? interaction.linkPreview.fetchOne(db) {
            switch linkPreview.variant {
                case .standard:
                    result.linkPreview = VisibleMessage.LinkPreview.from(db, linkPreview: linkPreview)
                    
                case .openGroupInvitation:
                    result.openGroupInvitation = VisibleMessage.OpenGroupInvitation.from(
                        db,
                        linkPreview: linkPreview
                    )
            }
        }
        
        return result
    }
}