68 lines
1.9 KiB
Ruby
68 lines
1.9 KiB
Ruby
# frozen_string_literal: true
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require "json"
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require "net/http"
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require "provider/adapters/adapter"
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class Provider
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module Adapters
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# Bank of Thailand. Fetches daily average commercial bank exchange rates
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# for 19 currencies against the Thai baht (THB). Uses mid_rate (midpoint
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# of buying transfer and selling). Some currencies are quoted per 100 or
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# 1,000 units — the adapter normalises to per-unit rates.
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# Requires BOT_API_KEY environment variable.
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class BOT < Adapter
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BASE_URL = "https://gateway.api.bot.or.th/Stat-ExchangeRate/v2/DAILY_AVG_EXG_RATE/"
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class << self
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def api_key = ENV["BOT_API_KEY"] || raise(Adapter::Unavailable, "no API key")
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def backfill_range = 30 # API enforces max 31-day period per request
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end
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def fetch(after: nil, upto: nil)
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uri = URI(BASE_URL)
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uri.query = URI.encode_www_form(
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start_period: after.strftime("%Y-%m-%d"),
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end_period: (upto || Date.today).strftime("%Y-%m-%d"),
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)
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response = Net::HTTP.get_response(uri, {
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"Authorization" => self.class.api_key,
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"Accept" => "application/json",
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})
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parse(response.body)
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end
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def parse(body)
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data = JSON.parse(body).dig("result", "data", "data_detail")
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return [] unless data
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data.filter_map do |record|
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mid = record["mid_rate"]
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next if mid.nil? || mid.to_s.empty?
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rate = Float(mid)
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next if rate.zero?
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currency = record["currency_id"]
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unit = extract_unit(record["currency_name_eng"])
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rate /= unit if unit > 1
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{ date: Date.parse(record["period"]), base: currency, quote: "THB", rate: }
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end
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end
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private
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def extract_unit(name)
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case name
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when /\(100 /i then 100
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when /\(1,000 /i then 1_000
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else 1
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end
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end
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end
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end
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end
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