# frozen_string_literal: true

module Api
  class RulesController < ApplicationController
    skip_before_action :verify_authenticity_token
    before_action :authenticate_project!
    before_action :check_project_enabled

    # GET /api/:public_key/rules/version
    # Quick version check - returns latest updated_at timestamp
    def version
      current_sampling = HubLoad.current_sampling
      response.headers['X-Sample-Rate'] = current_sampling[:allowed_requests].to_s

      render json: {
        version: Rule.latest_version,
        count: Rule.active.count,
        sampling: current_sampling
      }
    end

    # GET /api/:public_key/rules?since=1730646186272060
    # Incremental sync - returns rules updated since timestamp (microsecond Unix timestamp)
    # GET /api/:public_key/rules
    # Full sync - returns all active rules
    def index
      rules = if params[:since].present?
        # Incremental sync
        since_time = parse_timestamp(params[:since])
        Rule.since(since_time)
      else
        # Full sync - only return enabled rules
        Rule.active.sync_order
      end

      current_sampling = HubLoad.current_sampling
      response.headers['X-Sample-Rate'] = current_sampling[:allowed_requests].to_s

      render json: {
        version: Rule.latest_version,
        sampling: current_sampling,
        rules: rules.map(&:to_agent_format)
      }
    rescue ArgumentError => e
      render json: { error: "Invalid timestamp format: #{e.message}" }, status: :bad_request
    end

    private

    def authenticate_project!
      public_key = params[:public_key] || params[:project_id]

      @project = Project.find_by(public_key: public_key)

      unless @project
        render json: { error: "Invalid project key" }, status: :unauthorized
        return
      end
    end

    def check_project_enabled
      unless @project.enabled?
        render json: { error: "Project is disabled" }, status: :forbidden
      end
    end

    def parse_timestamp(timestamp_str)
      # Parse microsecond Unix timestamp
      unless timestamp_str.match?(/^\d+$/)
        raise ArgumentError, "Invalid timestamp format. Expected microsecond Unix timestamp (e.g., 1730646186272060)"
      end

      total_microseconds = timestamp_str.to_i
      seconds = total_microseconds / 1_000_000
      microseconds = total_microseconds % 1_000_000
      Time.at(seconds, microseconds)
    rescue ArgumentError => e
      raise ArgumentError, "Invalid timestamp format: #{e.message}. Use microsecond Unix timestamp (e.g., 1730646186272060)"
    end
  end
end