import Foundation
import Observation

@MainActor @Observable
final class ARProjectsViewModel {
    private(set) var supplied: [ARProject] = []
    private(set) var custom: [ARProject] = []
    private(set) var isLoading = true
    var errorMessage: String?
    private let service: any ARProjectsProviding

    init(service: any ARProjectsProviding) {
        self.service = service
    }

    func load() {
        isLoading = true
        defer { isLoading = false }
        do {
            let projects = try service.loadProjects()
            supplied = projects.filter { $0.source == .supplied }
            custom = projects.filter { $0.source == .custom }
        } catch { errorMessage = error.localizedDescription }
    }

    func update(id: UUID, name: String, tank: Tank) -> ARProject? {
        do {
            let project = try service.updateProject(id: id, name: name, tank: tank)
            if let index = custom.firstIndex(where: { $0.id == id }) { custom[index] = project }
            return project
        } catch {
            errorMessage = error.localizedDescription
            return nil
        }
    }

    func delete(id: UUID) {
        do {
            try service.deleteProject(id: id)
            supplied.removeAll { $0.id == id }
            custom.removeAll { $0.id == id }
        } catch { errorMessage = error.localizedDescription }
    }

    func create(name: String, tank: Tank) -> ARProject? {
        do {
            let project = try service.createProject(name: name, tank: tank)
            custom.insert(project, at: 0)
            return project
        } catch {
            errorMessage = error.localizedDescription
            return nil
        }
    }
}