/*
 * Keyman is copyright (C) SIL Global. MIT License.
 *
 * Created by Shawn Schantz on 2025-12-19
 *
 * Value object for loading a package from kmp.json
 *
 */


import Foundation

let defaultHelpFilename = "welcome.htm"
let defaultReadmeFilename = "readme.htm"

public struct PackageSource: Identifiable, Decodable, Hashable, Equatable {
  public var id = UUID()
  let system: SystemInfo
  let options: Options
  let info: Info
  let files: [PackageFile]?
  let keyboards: [KeyboardSource]?
  
  // computed properties for convenience
  var packageName: String {
    return info.name.description
  }
  var packageVersion: String {
    return info.version.description
  }
  var copyright: String? {
    return info.copyright?.description
  }
  var readmeFilename: String? {
    if let filename = options.readmeFile {
      return filename
    }
    if let fileArray = self.files {
      if fileArray.contains(where: { $0.name == defaultReadmeFilename }) {
        return defaultReadmeFilename
      }
    }
    return nil
  }
  var helpFilename: String? {
    if let filename = options.welcomeFile { return filename }

    if let fileArray = self.files {
      if fileArray.contains(where: { $0.name == defaultHelpFilename }) {
        return defaultHelpFilename
      }
    }
    
    return nil
  }
  var graphicFilename: String? {
    return options.graphicFile
  }
  
  enum CodingKeys: String, CodingKey {
    case system
    case options
    case info
    case files
    case keyboards
  }
  
  public init(from decoder: Decoder) throws {
    let container = try decoder.container(keyedBy: CodingKeys.self)
    
    self.info = try container.decode(Info.self, forKey: .info)
    self.keyboards = try container.decodeIfPresent([KeyboardSource].self, forKey: .keyboards)
    self.system = try container.decode(SystemInfo.self, forKey: .system)
    self.options = try container.decode(Options.self, forKey: .options)
    self.files = try container.decodeIfPresent([PackageFile].self, forKey: .files)
    
    if files?.isEmpty ?? true {
      throw LoadPackageError.containsNoFiles
    }

    if keyboards?.isEmpty ?? true {
      throw LoadPackageError.containsNoKeyboards
    }
  }
  
  public func hash(into hasher: inout Hasher) {
    hasher.combine(id) // only combine the unique ID
  }
  
  // Custom Equatable conformance (required by Hashable)
  public static func == (lhs: PackageSource, rhs: PackageSource) -> Bool {
    return lhs.id == rhs.id // only compare unique IDs
  }
}

struct Info: Decodable {
  let name: DescribedValue
  let version: DescribedValue
  let copyright: DescribedValue?
  let author: Author?
  let website: Website?
  
  enum CodingKeys: String, CodingKey {
    case name
    case copyright
    case author
    case version
    case website
  }
}

struct DescribedValue: Decodable {
  let description: String
  
  enum CodingKeys: String, CodingKey {
    case description
  }
}

struct Author: Decodable {
  let description: String?
  let url: String?
  
  enum CodingKeys: String, CodingKey {
    case description
    case url
  }
}

struct Website: Decodable {
  let description: String?
  let url: String?
  
  enum CodingKeys: String, CodingKey {
    case description
    case url
  }
}

struct SystemInfo: Decodable {
  let keymanDeveloperVersion: String?
  let fileVersion: String
  
  enum CodingKeys: String, CodingKey {
    case keymanDeveloperVersion
    case fileVersion
  }
}

struct Options: Decodable {
  let readmeFile: String?
  let graphicFile: String?
  let licenseFile: String?
  let welcomeFile: String?

  enum CodingKeys: String, CodingKey {
    case readmeFile
    case graphicFile
    case licenseFile
    case welcomeFile
  }
}

struct PackageFile: Decodable {
  let name: String?
  let description: String?
  
  enum CodingKeys: String, CodingKey {
    case name
    case description
  }
}