UserData.swift

//
//  UserData.swift
//

import Cocoa
import Combine
import ForumsKit

class UserData: NSObject, ObservableObject, NSFetchedResultsControllerDelegate {

    @Published var users = [FKUser]()
    @Published var showQueryEditor = false

    var onChange: ((Event) -> ())?

    enum Event {
        case count(Int)
    }

    var sortFields = [
        ("id", "ID"),
        ("points", "Points"),
        ("name", "Name"),
        ("domain", "Domain"),
        ("dateInserted", "Joined"),
        ("dateLastActive", "Active")
    ]

    var csv: Data? {
        get {
            let columns = ["ID", "Type", "Points", "Name", "Rank", "Email", "Domain", "Inserted", "Updated", "Last active", "Roles"].joined(separator: ",")

            func row(_ user: FKUser) -> String {
                let row: [Quotable] = [
                    Int(user.id),
                    user.type ?? "",
                    Int(user.points),
                    user.name ?? "",
                    user.rank?.name ?? "",
                    user.email ?? "",
                    user.domain ?? "",
                    user.dateInserted.preferredDateString(),
                    user.dateUpdated.preferredDateString(),
                    user.dateLastActive.preferredDateString(),
                    user.roleDescription
                ]
                return row.map { $0.quote() }
                    .joined(separator: ",")
            }

            let csvText = ([columns] + users.map { row($0) }).joined(separator: "\n")
            return csvText.data(using: .utf8)
        }
    }

    var predicateTemplates = TemplateBuilder()
        .template(path: \FKUser.name)
        .template(path: \FKUser.domain)
        .template(path: \FKUser.dateInserted)
        .template(path: \FKUser.dateUpdated)
        .template(path: \FKUser.dateLastActive)
        .template(path: \FKUser.rank?.name, modifier: .any)
        .template(path: "roles.name", modifier: .any)
        .template(path: \FKUser.points)
        .template(path: \FKUser.id)
        .all()

    var predicateChanges = PassthroughSubject<NSPredicate?, Never>()

    private var fetchController: NSFetchedResultsController<FKUser>?

    override init() {
        super.init()
        fetchController = ForumsKit.usersFetchedResultsController()
        fetchController?.delegate = self
        reload()
    }

    private func reload() {
        do {
            try fetchController?.performFetch()
            users = fetchController?.fetchedObjects ?? []
            onChange?(.count(users.count))
        }
        catch {
            print("ERROR: \(error)")
        }
    }

    func update(predicate: NSPredicate?) {
        showQueryEditor = predicate != nil
        fetchController?.fetchRequest.predicate = predicate
        reload()
    }

    func update(sort: NSSortDescriptor) {
        fetchController?.fetchRequest.sortDescriptors = [sort]
        reload()
    }

    func update(filter: String) {
        let value = filter.trim()
        var predicate: NSPredicate? = nil
        if !value.isEmpty {
            let query = """
                (name contains[cd] %@) or                
                (any roles.name contains[cd] %@) or
                (any rank.name contains[cd] %@) or
                (points contains[cd] %@) or
                (id contains[cd] %@)
            """
            predicate = NSPredicate(format: query, value, value, value, value, value, value)
        }
        fetchController?.fetchRequest.predicate = predicate
        reload()
    }

    // MARK: NSFetchedResultsControllerDelegate

    func controllerDidChangeContent(_ controller: NSFetchedResultsController<NSFetchRequestResult>) {
        reload()
    }
}