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

import Foundation
import SwiftData

enum Status: String, CaseIterable, Identifiable, Codable {
  case Todo = " "
  case Complete = "V"
  case InProgress = "C"
  case Hiatus = "H"
  case Waiting = "R"

  var id: Self { self }
  var description: String { self.rawValue }
  var isStrong: Bool {
    self == .Complete || self == .Hiatus || self == .Waiting
  }
  var label: String {
    switch self {
    case .Todo: return "square.and.pencil"
    case .Complete: return "checkmark"
    case .InProgress: return "ellipsis.circle"
    case .Hiatus: return "clock.badge.questionmark"
    case .Waiting: return "airplane.circle"
    }
  }
}

@Model
final class SubTask: Codable, Ordered {
  var sortOrder: Int = 0
  var name: String
  var task: Task?
  var notes: String = ""
  var status: Status = Status.Todo

  init(name: String, parent: Task? = nil) {
    self.name = name
    self.task = parent
  }

  func yaml(_ indent: Int = 0) -> String {
    let hdr = String(repeating: "  ", count: indent)
    let subhdr = hdr + "  # "
    var rval = hdr + "- [\(status.rawValue)] \(name)\n"
    if !notes.isEmpty {
      rval += subhdr + notes.replacingOccurrences(of: "\n", with: "\n" + subhdr) + "\n"
    }
    return rval
  }

  enum CodingKeys: CodingKey { case name, notes, status }

  required init(from decoder: any Decoder) throws {
    let container = try decoder.container(keyedBy: CodingKeys.self)
    name = try container.decode(String.self, forKey: .name)
    notes = try container.decode(String.self, forKey: .notes)
    status = try container.decode(Status.self, forKey: .status)
  }

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

@Model
final class Tag: Codable {
  var id: String
  var task: Task?

  init(id: String, parent: Task? = nil) {
    self.id = id
    self.task = parent
  }

  func like(_ str: String) -> Bool {
    return id.caseInsensitiveCompare(str) == .orderedSame
  }

  required init(from decoder: any Decoder) throws {
    id = try decoder.singleValueContainer().decode(String.self)
  }

  func encode(to encoder: any Encoder) throws {
    var single = encoder.singleValueContainer()
    try single.encode(id)
  }
}

@Model
final class Task: Codable, Ordered {
  var sortOrder: Int = 0
  var name: String
  var project: Project?
  var category: String = ""
  @Relationship(deleteRule: .cascade, inverse: \Tag.task)
  var tags: [Tag] = []
  @Relationship(deleteRule: .cascade, inverse: \SubTask.task)
  var subtasks: [SubTask] = []
  var notes: String = ""
  var status: Status = Status.Todo

  init(name: String, parent: Project? = nil) {
    self.name = name
    self.project = parent
    self.category = parent?.category ?? ""
  }

  func yaml(_ indent: Int = 0) -> String {
    let hdr = String(repeating: "  ", count: indent)
    let subhdr = hdr + "  # "
    var rval = hdr + "[\(status.rawValue)] \(name) "
    rval += "(\(tags.map(\.id).joined(separator: " ")))\n"
    if !notes.isEmpty {
      rval += subhdr + notes.replacingOccurrences(of: "\n", with: "\n" + subhdr) + "\n"
    }
    rval += subtasks.map({ $0.yaml(indent + 1) }).joined()
    return rval
  }

  enum CodingKeys: CodingKey { case name, category, tags, subtasks, notes, status }

  required init(from decoder: any Decoder) throws {
    let container = try decoder.container(keyedBy: CodingKeys.self)
    name = try container.decode(String.self, forKey: .name)
    category = try container.decode(String.self, forKey: .category)
    tags = try container.decode([Tag].self, forKey: .tags)
    subtasks = try container.decode([SubTask].self, forKey: .subtasks)
    notes = try container.decode(String.self, forKey: .notes)
    status = try container.decode(Status.self, forKey: .status)
    tags.forEach({ $0.task = self })
    subtasks.forEach({ $0.task = self })
  }

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