From a71107597dc437aa59ac714042acbdc014c72ee9 Mon Sep 17 00:00:00 2001
From: Rebecca Roach <22301035+RebeccaRoach@users.noreply.github.com>
Date: Wed, 5 Feb 2020 10:27:03 -0800
Subject: [PATCH] This is the calculator project for day 2 homework

---
 Conversational_Commandline_Calculator.rb | 77 ++++++++++++++++++++++++
 1 file changed, 77 insertions(+)
 create mode 100644 Conversational_Commandline_Calculator.rb

diff --git a/Conversational_Commandline_Calculator.rb b/Conversational_Commandline_Calculator.rb
new file mode 100644
index 0000000..089c8ac
--- /dev/null
+++ b/Conversational_Commandline_Calculator.rb
@@ -0,0 +1,77 @@
+# Define get_valid_num to make sure the user enters a valid number to be utilized in the calculator (do_calculator method)
+def get_valid_num(prompt)
+    valid_entry = false
+    while !valid_entry
+      puts "#{prompt}" 
+      entered = gets.chomp
+      entry_to_check = entered.scan(/(-?\.?)\d+.?(\d+)?/)
+      if entry_to_check.length != 1
+        puts "Invalid number, please try again."
+      else
+        valid_entry = true
+        entered = entered.to_f
+      end
+    end
+    return entered
+end
+
+# Define do_calculator to get a valid operator from the user, handle 4 possible math operations with that operator,
+# and return the result of the calculation
+def do_calculator
+    puts "What kind of calculation do you want? (+, minus, multiply, division, etc!)"
+
+    valid_operators = ["add", "+", "plus", "addition", "subtract", "-", "minus", "subtraction", "*", "multiply", "x", "times", "multiplication", "divide", "/", "division"]
+    operator = gets.chomp.downcase
+
+    until valid_operators.include?(operator)
+        puts "Please provide a valid operator."
+        operator = gets.chomp.downcase
+    end
+
+    a = get_valid_num("What is the first number?")
+    b = get_valid_num("What is the second number?")
+
+    case operator
+    when "+", "add", "plus", "addition"
+        result = a + b
+    when "-", "subtract", "minus", "subtraction"
+        result = a - b
+    when "*", "multiply", "x", "times", "multiplication"
+        result = a * b
+    when "/", "divide", "division"
+        if b == 0
+            return "invalid because you divided by zero"
+        end
+        result = a / b
+    else
+        puts "I didn't understand. What kind of operation do you want?"
+        operator = gets.chomp
+    end
+    return result
+end
+
+# Program execution starts on line 55
+
+puts "Welcome to the Conversational Commandline Calculator!"
+
+# starts off true to enforce going through while loop once
+do_next_calculation = true
+while do_next_calculation
+    puts
+    puts "Do you want me to calculate something for you? (yay, nay, etc!)"
+    next_calculation = gets.chomp.downcase
+    valid_decision = %w[n no nope nay nah y yes yay yeah yep]
+
+    until valid_decision.include?(next_calculation)
+        puts "Sorry, I didn't understand that. Want me to do a calculation for ya?"
+        next_calculation = gets.chomp.downcase
+    end
+
+    case next_calculation
+        when "n", "no", "nay", "nope", "nah"
+            do_next_calculation = false
+            puts "Okay, see you next time!"
+        when "y", "yes", "yay", "yeah", "yep"
+            puts "Your result is #{do_calculator}."
+    end
+end