# frozen_string_literal: true

module Mediamtx
  # Rimuove path MediaMTX live/match_{uuid} lasciati attivi dopo fine diretta.
  class CleanupOrphanPaths
    Result = Struct.new(:removed, :skipped, keyword_init: true)

    SESSION_PATH = %r{\Alive/match_([0-9a-f-]{36})(?:_air)?\z}i

    ACTIVE_SESSION_STATUSES = %w[live paused connecting reconnecting].freeze
    PROCESSING_GRACE = -> { ENV.fetch("RECORDINGS_LOCAL_PROCESSING_GRACE_HOURS", "6").to_i.hours }

    def initialize(client: Client.new, logger: Rails.logger)
      @client = client
      @logger = logger
      @removed = 0
      @skipped = 0
      @deleted_session_ids = Set.new
    end

    def call
      online = @client.online_path_names

      @client.list_paths.each do |item|
        name = item["name"].to_s
        session_id = session_id_from_path(name)
        unless session_id
          @skipped += 1
          next
        end

        if online.include?(name) || item["online"]
          @skipped += 1
          next
        end

        next unless removable?(session_id)

        remove_session_paths(session_id, name)
      end

      Result.new(removed: @removed, skipped: @skipped)
    end

    def removable?(session_id)
      session = StreamSession.find_by(id: session_id)
      return true if session.nil?

      return false if ACTIVE_SESSION_STATUSES.include?(session.status)

      recording = Recording.find_by(stream_session: session)
      return true if recording.nil?

      return false if recording.status == "processing" && processing_within_grace?(session)

      true
    end

    private

    def session_id_from_path(path_name)
      match = path_name.match(SESSION_PATH)
      match&.[](1)
    end

    def processing_within_grace?(session)
      ended_at = session.ended_at || session.updated_at
      ended_at.nil? || ended_at >= PROCESSING_GRACE.call.ago
    end

    def remove_session_paths(session_id, path_name)
      return if @deleted_session_ids.include?(session_id)

      session = StreamSession.find_by(id: session_id)
      if session
        @client.delete_path(session)
      else
        delete_orphan_path_names(session_id)
      end

      @deleted_session_ids.add(session_id)
      @removed += 1
      @logger.info("[Mediamtx::CleanupOrphanPaths] removed paths for session #{session_id} (from #{path_name})")
    rescue Client::Error, Faraday::Error => e
      @skipped += 1
      @logger.warn("[Mediamtx::CleanupOrphanPaths] skip #{path_name}: #{e.message}")
    end

    def delete_orphan_path_names(session_id)
      @client.delete_path_name("live/match_#{session_id}")
      @client.delete_path_name("live/match_#{session_id}_air")
    end
  end
end