session-ios/SessionMessagingKit/Database/Models/ClosedGroup.swift

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

import Foundation
import GRDB
import SessionUtilitiesKit

public struct ClosedGroup: Codable, Identifiable, FetchableRecord, PersistableRecord, TableRecord, ColumnExpressible {
    public static var databaseTableName: String { "closedGroup" }
    internal static let threadForeignKey = ForeignKey([Columns.threadId], to: [SessionThread.Columns.id])
    private static let thread = belongsTo(SessionThread.self, using: threadForeignKey)
    private static let keyPairs = hasMany(
        ClosedGroupKeyPair.self,
        using: ClosedGroupKeyPair.closedGroupForeignKey
    )
    public static let members = hasMany(GroupMember.self, using: GroupMember.closedGroupForeignKey)
    
    public typealias Columns = CodingKeys
    public enum CodingKeys: String, CodingKey, ColumnExpression {
        case threadId
        case name
        case formationTimestamp
    }
    
    public var id: String { threadId }  // Identifiable
    public var publicKey: String { threadId }

    /// The id for the thread this closed group belongs to
    ///
    /// **Note:** This value will always be publicKey for the closed group
    public let threadId: String
    public let name: String
    public let formationTimestamp: TimeInterval
    
    // MARK: - Relationships
    
    public var thread: QueryInterfaceRequest<SessionThread> {
        request(for: ClosedGroup.thread)
    }
    
    public var keyPairs: QueryInterfaceRequest<ClosedGroupKeyPair> {
        request(for: ClosedGroup.keyPairs)
    }
    
    public var allMembers: QueryInterfaceRequest<GroupMember> {
        request(for: ClosedGroup.members)
    }
    
    public var members: QueryInterfaceRequest<GroupMember> {
        request(for: ClosedGroup.members)
            .filter(GroupMember.Columns.role == GroupMember.Role.standard)
    }
    
    public var zombies: QueryInterfaceRequest<GroupMember> {
        request(for: ClosedGroup.members)
            .filter(GroupMember.Columns.role == GroupMember.Role.zombie)
    }
    
    public var moderators: QueryInterfaceRequest<GroupMember> {
        request(for: ClosedGroup.members)
            .filter(GroupMember.Columns.role == GroupMember.Role.moderator)
    }
    
    public var admins: QueryInterfaceRequest<GroupMember> {
        request(for: ClosedGroup.members)
            .filter(GroupMember.Columns.role == GroupMember.Role.admin)
    }
    
    // MARK: - Initialization
    
    public init(
        threadId: String,
        name: String,
        formationTimestamp: TimeInterval
    ) {
        self.threadId = threadId
        self.name = name
        self.formationTimestamp = formationTimestamp
    }
    
    // MARK: - Custom Database Interaction
    
    public func delete(_ db: Database) throws -> Bool {
        // Delete all 'GroupMember' records associated with this ClosedGroup (can't
        // have a proper ForeignKey constraint as 'GroupMember' is reused for the
        // 'OpenGroup' table as well)
        try request(for: ClosedGroup.members).deleteAll(db)
        return try performDelete(db)
    }
}

// MARK: - Mutation

public extension ClosedGroup {
    func with(name: String) -> ClosedGroup {
        return ClosedGroup(
            threadId: threadId,
            name: name,
            formationTimestamp: formationTimestamp
        )
    }
}

// MARK: - GRDB Interactions

public extension ClosedGroup {
    func fetchLatestKeyPair(_ db: Database) throws -> ClosedGroupKeyPair? {
        return try keyPairs
            .order(ClosedGroupKeyPair.Columns.receivedTimestamp.desc)
            .fetchOne(db)
    }
}