電気代を毎日連絡してくれるLINEbotを作る(3)：graphql-clientを使って、RailsからオクトパスエナジーのGraphQL APIを叩く

require "graphql/client"
require "graphql/client/http"

class GetOctopusTokenService
  HTTP = GraphQL::Client::HTTP.new("https://api.oejp-kraken.energy/v1/graphql/")
  Schema = GraphQL::Client.load_schema(HTTP)
  Client = GraphQL::Client.new(schema: Schema, execute: HTTP)
  LOGIN_QUERY = Client.parse <<~'GRAPHQL'
    mutation Login($input: ObtainJSONWebTokenInput!) {
      obtainKrakenToken(input: $input) {
        token
        refreshToken
      }
    }
  GRAPHQL

  def perform
    res = Client.query(LOGIN_QUERY::Login, variables: {
      "input": {
        "email": ENV['OCTOPUS_EMAIL'],
        "password": ENV['OCTOPUS_PASSWORD']
      }
    })
    res.original_hash.dig("data", "obtainKrakenToken", "token")
  end

end

require "graphql/client"
require "graphql/client/http"

module OctopusGraphql
  # Configure GraphQL endpoint using the basic HTTP network adapter.
  HTTP = GraphQL::Client::HTTP.new("https://api.oejp-kraken.energy/v1/graphql/") do
    def headers(context)
      { "Authorization": GetOctopusTokenService.new.perform }
    end
  end
  # Fetch latest schema on init, this will make a network request
  Schema = GraphQL::Client.load_schema(HTTP)
  Client = GraphQL::Client.new(schema: Schema, execute: HTTP)
end

class OctopusController < ApplicationController

  QUERY = OctopusGraphql::Client.parse <<~'GRAPHQL'
    query HalfHourlyReadings($accountNumber: String!, $fromDatetime: DateTime, $toDatetime: DateTime) {
      account(accountNumber: $accountNumber) {
        properties {
          electricitySupplyPoints {
            halfHourlyReadings(fromDatetime: $fromDatetime, toDatetime: $toDatetime) {
              startAt
              endAt
              version
              value
              costEstimate
            }
          }
        }
      }
    }
  GRAPHQL

  def index
    res = OctopusGraphql::Client.query(QUERY::HalfHourlyReadings, variables: {
      accountNumber: ENV['OCTOPUS_ACCOUNT_NUMBER'],
      fromDatetime: Date.yesterday.beginning_of_day.iso8601,
      toDatetime: Date.yesterday.end_of_day.iso8601
    })
    properties = res.original_hash.dig("data", "account", "properties")
    electricitySupplyPoints = properties.first["electricitySupplyPoints"]
    halfHourlyReadings = electricitySupplyPoints.first["halfHourlyReadings"]
    @start_at = halfHourlyReadings.pluck("startAt").min.to_time.localtime.strftime("%Y/%m/%d %H:%M")
    @end_at = halfHourlyReadings.pluck("endAt").max.to_time.localtime.strftime("%Y/%m/%d %H:%M")
    @kwh = halfHourlyReadings.pluck("value").map(&:to_f).sum
    @cost = halfHourlyReadings.pluck("costEstimate").map(&:to_i).sum
  end
end