As the title says, I have built a Caesar Cipher in Ruby that utilizes ASCII for the encryption. I am not sure whether or not this was the best way to go about the task but this way made the most sense to me. My code is below. Please give me any feedback that comes to mind. Thanks

puts 'Please enter your string to be coded'
    string = gets.chomp.split("")

puts 'Please enter your number key'
    key = gets.chomp.to_i

    if (key > 26) 
        key = key % 26
    end

    string.map! do |i|
        i.ord
    end

    string.map! {|i| i = i + key}.map! {|i| 
        if (i > 122)
            then i = i - 26
        elsif (90 < i && i < 97)
            then i = i - 26
        elsif (i > 96 && (i - key) < 91 && (i - key) > 64)
            then i = i - 26
        elsif (i < 65 )
            then i = 32
        else
            i
        end
    }

    string.map! do |i|
        i.chr 
    end

    puts "Your coded word is #{string.join("")}"

puts 'Return back to original string? (Yes or No)'
    response = gets.chomp.downcase

    if response == 'yes'
        string.to_s.split("")
        string.map! do |i|
            i.ord
        end
    
        string.map! {|i| i - key}.map! {|i| 
            if (90 < i && i < 97)
                then i = i + 26
            elsif ((i+key) > 96 && i < 91 && i > 64)
                then i = i + 26
            elsif (i < 65 && (i+key) < 91 && (i + key) > 64)
                then i = i + 26
            elsif (i < 65)
                then i = 32
            else
                i
            end
        }

        string.map! do |i|
            i.chr
        end

        puts string.join("")
        
    end