TodosApp/Todos/Model/Project.swift

//
//  Project.swift
//  Todos
//
//  Created by Sam Jaffe on 2/28/26.
//

import Foundation
import SwiftData
import SwiftUI

@Model
final class Project: Codable, Ordered, Aggregate {
  typealias Element = Task

  var sortOrder: Int = 0
  var timestamp: Date
  var name: String = "New Project"
  var category: String = ""
  @Relationship(deleteRule: .cascade, inverse: \Task.project)
  var tasks: [Task] = []

  init(timestamp: Date) {
    self.timestamp = timestamp
  }

  func move(fromOffsets: IndexSet, toOffset: Int) {
    tasks.move(fromOffsets: fromOffsets, toOffset: toOffset)
    reindex()
  }

  func remove(_ item: Element) {
    tasks.removeAll(where: { $0.id == item.id })
    reindex()
  }

  func reindex() {
    for (index, item) in tasks.enumerated() {
      item.sortOrder = index
    }
  }

  func yaml(_ indent: Int = 0) -> String {
    let hdr = String(repeating: "  ", count: indent)
    var rval = hdr + "\(name):\n"
    if !category.isEmpty {
      rval += hdr + "  # In Category: \(category)\n"
    }
    rval += tasks.map({ $0.yaml(indent + 1) }).joined()
    return rval
  }

  enum CodingKeys: CodingKey { case timestamp, category, name, tasks }

  required init(from decoder: any Decoder) throws {
    let container = try decoder.container(keyedBy: CodingKeys.self)
    timestamp = try container.decode(Date.self, forKey: .timestamp)
    category = try container.decode(String.self, forKey: .category)
    name = try container.decode(String.self, forKey: .name)
    tasks = try container.decode([Task].self, forKey: .tasks)
    tasks.forEach({ $0.project = self })
  }

  func encode(to encoder: any Encoder) throws {
    var container = encoder.container(keyedBy: CodingKeys.self)
    try container.encode(timestamp, forKey: .timestamp)
    try container.encode(category, forKey: .category)
    try container.encode(tasks, forKey: .tasks)
    try container.encode(name, forKey: .name)
  }
}