62 lines
1.7 KiB
Ruby
62 lines
1.7 KiB
Ruby
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# frozen_string_literal: true
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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 Botswana. Publishes daily rates for ~7 currencies against BWP.
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# The CSV export only contains these columns.
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class BOB < Adapter
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CSV_URL = URI("https://www.bankofbotswana.bw/export/exchange-rates.csv?page&_format=csv")
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# Columns in the CSV mapped to ISO currency codes
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COLUMNS = {
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"CHN" => "CNY",
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"EUR" => "EUR",
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"GBP" => "GBP",
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"USD" => "USD",
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"YEN" => "JPY",
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"ZAR" => "ZAR",
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}.freeze
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class << self
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end
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def fetch(after: nil, upto: nil)
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records = parse(Net::HTTP.get(CSV_URL))
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after ? records.select { |r| r[:date] >= Date.parse(after.to_s) } : records
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end
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def parse(csv)
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csv = csv.dup.force_encoding(Encoding::UTF_8)
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rows = csv.delete_prefix("\uFEFF").lines(chomp: true)
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headers = rows.shift&.split(",")
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date_index = headers&.index("Date")
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return [] unless date_index
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column_indices = COLUMNS.each_with_object({}) do |(col, iso), map|
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idx = headers.index(col)
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map[iso] = idx if idx
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end
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rows.filter_map do |line|
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values = line.delete('"').split(",")
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date = Date.strptime(values[date_index].strip, "%d %b %Y")
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rates = column_indices.filter_map do |iso, idx|
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val = values[idx]
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next if val.nil? || val.empty?
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rate = Float(val)
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next if rate.zero?
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{ date:, base: "BWP", quote: iso, rate: }
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end
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rates.empty? ? nil : rates
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end.flatten.sort_by { |r| r[:date] }
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end
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end
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end
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end
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