import ArgumentParser
import CliClient
import Dependencies
import Foundation
import Logging

struct CreateCommand: AsyncParsableCommand {

  static let commandName = "create"

  static let configuration = CommandConfiguration.playbook(
    commandName: commandName,
    abstract: "Create a home performance assesment project.",
    examples: (
      label: "Create Assesment",
      example: "\(commandName) /new/assement/path"
    )
  )

  @OptionGroup var globals: GlobalOptions

  @Option(
    name: .shortAndLong,
    help: "The template repository to use."
  )
  var repo: String?

  @Option(
    name: .shortAndLong,
    help: "The repo branch or version to use."
  )
  var branch: String?

  @Option(
    name: .shortAndLong,
    help: "Path to local template directory to use.",
    completion: .directory
  )
  var templateDir: String?

  @Flag(
    name: .shortAndLong,
    help: "Force using a local template directory."
  )
  var localTemplateDir = false

  @Argument(
    help: "Path to the project directory.",
    completion: .directory
  )
  var projectDir: String

  @Argument(
    help: "Extra arguments passed to the playbook."
  )
  var extraArgs: [String] = []

  mutating func run() async throws {
    try await _run()
  }

  private func _run() async throws {
    try await withSetupLogger(commandName: Self.commandName, globals: globals) {
      @Dependency(\.cliClient) var cliClient
      @Dependency(\.logger) var logger

      let encoder = cliClient.encoder()

      let configuration = try cliClient.loadConfiguration()

      logger.debug("Configuration: \(configuration)")

      let jsonData = try parseOptions(
        command: self,
        configuration: configuration,
        logger: logger,
        encoder: encoder
      )

      guard let jsonString = String(data: jsonData, encoding: .utf8) else {
        throw CreateError.encodingError
      }

      logger.debug("JSON string: \(jsonString)")

      try await runPlaybook(
        commandName: Self.commandName,
        globals: self.globals,
        configuration: configuration,
        extraArgs: extraArgs,
        "--tags", "setup-project",
        "--extra-vars", "project_dir=\(self.projectDir)",
        "--extra-vars", "'\(jsonString)'"
      )
    }
  }
}

private func parseOptions(
  command: CreateCommand,
  configuration: Configuration,
  logger: Logger,
  encoder: JSONEncoder
) throws -> Data {
  let templateDir = command.templateDir ?? configuration.templateDir
  let templateRepo = command.repo ?? configuration.templateRepo
  let version = (command.branch ?? configuration.templateRepoVersion) ?? "main"

  logger.debug("""
    (\(command.localTemplateDir), \(String(describing: templateDir)), \(String(describing: templateRepo)))
  """)

  switch (command.localTemplateDir, templateDir, templateRepo) {
  case (true, .none, _):
    // User supplied they wanted to use a local template directory, but we could not find
    // the path set from command line or in configuration.
    throw CreateError.templateDirNotFound
  case let (false, _, .some(repo)):
    // User did not supply they wanted to use a local template directory, and we found a repo url that was
    // either set by the command line or found in the configuration.
    logger.debug("Using repo.")
    return try encoder.encode(TemplateRepo(repo: repo, version: version))
  case let (true, .some(templateDir), _):
    // User supplied they wanted to use a local template directory, and we found the template directory
    // either set by the command line or in the configuration.
    logger.debug("Using template directory.")
    return try encoder.encode(TemplateDirJson(path: templateDir))
  case let (false, .some(templateDir), _):
    // User supplied they did not wanted to use a local template directory, and we found the template directory
    // either set by the command line or in the configuration, and no repo was found / handled previously.
    logger.debug("Using template directory.")
    return try encoder.encode(TemplateDirJson(path: templateDir))
  case (_, .none, .none):
    // We could not find a repo or template directory.
    throw CreateError.templateDirOrRepoNotSpecified
  }
}

private struct TemplateDirJson: Encodable {

  let template: Template

  init(path: String) {
    self.template = .init(path: path)
  }

  struct Template: Encodable {
    let path: String
  }
}

private struct TemplateRepo: Encodable {

  let template: Template

  init(repo: String, version: String?) {
    self.template = .init(repo: repo, version: version ?? "main")
  }

  struct Template: Encodable {
    let repo: String
    let version: String
  }
}

enum CreateError: Error {
  case encodingError
  case templateDirNotFound
  case templateDirOrRepoNotSpecified
}