// SPDX-FileCopyrightText: 2026 Kaede Akino
// SPDX-License-Identifier: GPL-3.0-only

import Foundation
import SwiftData
import TermindApplication
import TermindDomain

public enum TermindSchemaV32DeviceModels {
    @Model
    public final class PersistentDeviceRecord {
        @Attribute(.unique) public var id = UUID()
        public var displayName = ""

        public init(_ value: DeviceRecord) {
            id = value.id
            displayName = value.displayName
        }

        public var value: DeviceRecord {
            DeviceRecord(id: id, displayName: displayName)
        }
    }
}

public typealias PersistentDeviceRecord = TermindSchemaV32DeviceModels.PersistentDeviceRecord

@MainActor
public final class SwiftDataDeviceDirectoryRepository: DeviceDirectoryRepository {
    private let context: ModelContext
    public var didRecordHistoryChanges: ((HistoryMutationSet) -> Void)?

    public init(context: ModelContext) { self.context = context }

    public func devices() throws -> [DeviceRecord] {
        try context.fetch(FetchDescriptor<PersistentDeviceRecord>()).map(\.value)
    }

    public func registerIfNeeded(_ device: DeviceRecord) throws {
        let journal = HistorySyncJournal(context: context, kind: .device)
        // Launch registration is not an explicit rename/recreation of a remotely deleted directory entry.
        guard try journal.envelope(for: .init(kind: .device, id: device.id))?.isDeleted != true else { return }
        try upsert(device)
    }

    public func upsert(_ device: DeviceRecord) throws {
        var mutations = HistoryMutationSet.empty
        try context.commit {
            try HistorySyncJournal(context: context).bootstrapIfNeeded()
            let id = device.id
            var descriptor = FetchDescriptor<PersistentDeviceRecord>(
                predicate: #Predicate { $0.id == id })
            descriptor.fetchLimit = 1
            if let existing = try context.fetch(descriptor).first {
                guard existing.displayName != device.displayName else { return }
                existing.displayName = device.displayName
            } else {
                context.insert(PersistentDeviceRecord(device))
            }
            mutations = try HistorySyncJournal(context: context).recordCurrentSnapshot()
        }
        if !mutations.isEmpty { didRecordHistoryChanges?(mutations) }
    }
}