import Foundation
import Observation
import SwiftData

@MainActor
@Observable
final class CategoryViewModel {
    private(set) var categories: [Category] = []
    private var context: ModelContext?

    static let presetColors: [String] = [
        "#2EB852", "#F5DC1F", "#4A90D9", "#F5A623",
        "#9B59B6", "#E74C3C", "#1ABC9C", "#F39C12"
    ]

    func setup(context: ModelContext) {
        self.context = context
        fetchCategories()
    }

    func fetchCategories() {
        guard let context else { return }
        let descriptor = FetchDescriptor<Category>(sortBy: [SortDescriptor(\.name)])
        categories = (try? context.fetch(descriptor)) ?? []
    }

    func addCategory(name: String, colorHex: String) {
        guard let context else { return }
        let category = Category(name: name, colorHex: colorHex)
        context.insert(category)
        try? context.save()
        fetchCategories()
    }

    func deleteCategory(_ category: Category) {
        guard let context else { return }
        context.delete(category)
        try? context.save()
        fetchCategories()
    }

    func taskCount(for category: Category) -> Int {
        category.tasks.count
    }
}