#!/usr/bin/ruby

require 'net/http'
require 'json'

VERSION = "2.2.4"
BINARY_NAME = "units"

begin
    def get_crypto_id(currency_name)
        url = 'https://api.coinmarketcap.com/v1/ticker/?limit=0'
        uri = URI(url)
        response = Net::HTTP.get(uri)
        currencies = JSON.parse(response)
        currencies.each do |currency|
            if currency["id"].upcase == currency_name || currency["name"].upcase == currency_name || currency["symbol"].upcase == currency_name
                return currency["id"]
            end
        end
        return ""
    end

    def get_crypto_price(currency_name, convert_name)
        from_name = get_crypto_id(currency_name)
        if from_name == ""
            return "Error: Unknown unit '" + currency_name + "'"
        end
        url = 'https://api.coinmarketcap.com/v1/ticker/' + from_name + '/?convert=' + convert_name
        uri = URI(url)
        response = Net::HTTP.get(uri)
        currencies = JSON.parse(response)
        price = currencies[0]["price_" + convert_name.downcase]
        if !price
            return "Error: Incompatible units. Can't convert " + currency_name + " to " + convert_name
        end
        return price
    end

    args = ARGV.dup
    if args.empty?
       input = STDIN.gets
    else
        input = ""
        args.each do |arg|
            if input != ""
            input = input + " " + arg.dup
            else
                input = arg.dup
            end
        end
    end
    input.strip!
    if input == "-v" or input ==  "--version"
        puts "blaconvert v"+VERSION
        exit
    end
    mid = 0
    from = ""
    to = ""
    num = 0
    words = input.split(" ")
    for i in 0..words.length-1
        if words[i] == "in" or words[i] == "to"
            mid = i
        end
    end
    if words.length == 3 && mid == 0
        num = Float(words[0])
        from = words[1]
        to = words[2]
    elsif words.length == 2 && mid == 0
        num = 1
        from = words[0]
        to = words[1]
    elsif mid > 0
        for i in 1..mid-1
            from += words[i]
        end
        for i in mid+1..words.length-1
            to += words[i]
        end
        num = Float(words[0])
    else
        puts "Invalid input! Try !convert [amount] [from-unit] to [to-unit] e.g !convert 2 cm to inches"
        exit
    end
    if from.upcase == "F" && to.upcase == "C"
        temp = (num - 32) / 1.8
        puts "#{num} F = #{temp} C"
    elsif from.upcase == "C" && to.upcase == "F"
        temp = (num * 1.8) + 32
        puts "#{num} C = #{temp} F"
    else
    out = %x(#{BINARY_NAME} -t1 #{from} #{to})
    outs = out.split(" ")
    if outs[0] == "Unknown"
        from.upcase!
        out = %x(#{BINARY_NAME} -t1 #{from} #{to})
        outs = out.split(" ")
        if outs[0] == "Unknown"
            to.upcase!
            out = %x(#{BINARY_NAME} -t1 #{from} #{to})
            outs = out.split(" ")
            if outs[0] == "Unknown"
                out = "Error: " + out
                units_failed = true
            elsif outs[0] == "conformability"
                out = "Error: Incompatible units. Can't convert from #{from} to #{to}"
                units_failed = true
            end
        elsif outs[0] == "conformability"
            out = "Error: Incompatible units. Can't convert from #{from} to #{to}"
            units_failed = true
        end
    elsif outs[0] == "conformability"
        out = "Error: Incompatible units. Can't convert from #{from} to #{to}"
        units_failed = true
    end

    if units_failed
        units_error = out
        out = get_crypto_price(from, to)
        if out.split(" ")[0] == "Error:"
            reverse_out = get_crypto_price(to, from)
            if reverse_out.split(" ")[0] == "Error:"
                if units_error.split(" ")[1] == "Incompatible"
                    puts units_error
                else
                    puts out
                end
                exit
            else
                out = 1/Float(reverse_out)
            end
        end
    end

    puts "#{num} #{from} = #{num * Float(out)} #{to}"
    end
end