From 2ab0e88e2541391d372b940b53c922463b9c71a6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christoffer=20M=C3=BCller=20Madsen?=
 <christoffer@guava.space>
Date: Wed, 1 Feb 2017 13:43:05 +0100
Subject: [PATCH] functional clean-up

---
 invoice.rb | 103 ++++++++++++++++++++++++++++++++---------------------
 1 file changed, 62 insertions(+), 41 deletions(-)

diff --git a/invoice.rb b/invoice.rb
index 345d5ab..120fb78 100644
--- a/invoice.rb
+++ b/invoice.rb
@@ -8,7 +8,6 @@ load 'config.rb'
 Options = {}
 OptionParser.new do |opts|
   opts.banner = "Usage: invoice.rb [options]"
-  
   opts.on("-d", "--draft", "Generate invoices with 'DRAFT' watermark") do |d|
     Options[:draft] = d
   end
@@ -21,13 +20,30 @@ OptionParser.new do |opts|
   end
 end.parse!
 
+
 Transaction = Struct.new(:time, :person, :product, :amount)
+
 Product = Struct.new(:id, :description, :price) do
   def to_s
     "#{id} => #{description}, #{price}"
   end
 end
 
+class Person
+  def initialize(id, name)
+    @id = id
+    @name = name
+    @purchases = {}
+  end
+  
+  def to_s
+    id
+  end
+
+  attr_reader :id
+  attr_accessor :name, :purchases
+end
+
 def read_file(file)
   rows = Array.new
   CSV.foreach(file, col_sep: ';', converters: :float) do |row|
@@ -36,52 +52,69 @@ def read_file(file)
   rows
 end
 
-def read_db(db)
+def load_transactions_from_db(db)
   transactions = Array.new
-  db.query("SELECT * FROM Transactions").each do |trans|
-    if date_of_prev('monday').to_time < trans["time"]
-      transactions << Transaction.new(trans["time"], trans["buyer"],
-                          trans["product"], trans["amount"])
+  db.query("SELECT * FROM Transactions").each do |row|
+    if date_of_prev('monday').to_time < row["time"]
+      transactions << Transaction.new(row["time"], row["buyer"],
+                                      row["product"], row["amount"])
     end
   end
   return transactions
 end
 
-# Partition transactions into the persons who they belong to
-def partition_transactions(transactions)
-  persons = Hash.new
-  transactions.each do |trans|
-    # Initialize data structures if not already done
-    if !(persons[trans.person])
-      persons[trans.person] = {}
+def load_persons_from_db(db)
+  persons = {}
+  db.query("SELECT * FROM Persons").each do |row|
+    persons[row['id']] = Person.new(row['id'],row['name'])
+  end
+  return persons
+end
+
+def load_products_from_db(db)
+  products = {}
+  db.query("SELECT * FROM Products").each do |p|
+    product = Product.new(p['id'], p['description'], p['price'])
+    products[p['id']] = product
+    if Options[:verbose]
+      puts "Found product: #{product}"
     end
-    if !(persons[trans.person][trans.product])
-      persons[trans.person][trans.product] = 0
+  end
+  
+  return products
+end
+
+# Partition transactions into the persons who they belong to
+def partition_transactions(transactions,persons)
+  transactions.each do |t|
+    # Initialize data structures if not already done
+    if !(persons[t.person].purchases[t.product])
+      persons[t.person].purchases[t.product] = 0
     end
     
-    persons[trans.person][trans.product] += trans.amount
+    persons[t.person].purchases[t.product] += t.amount
   end
   
   return persons
 end
 
-def generate_receipt(persons,draft)
+def generate_receipt(persons,products,draft)
   counter = 0
 
   # Iterate through persons who have purchased something in the given timeframe
-  persons.each do |person, products|
+  persons.each do |id, person|
     counter += 1
 
     yaml = YAML_BASE.clone
-    yaml["to"] = Names[person]
+    yaml["to"] = person.name
     yaml["invoice-nr"] = Time.now.strftime('%Y%W') + "-" + counter.to_s
     
     # Iterate through products purchased and write data to yaml hash
-    products.each do |id, amount|
+    person.purchases.each do |id, amount|
       yaml["service"] = Array.new unless yaml["service"]
-      hash = {description: Products[id].description,
-              pieceprice: Products[id].price.to_i,
-              price: Products[id].price.to_i*amount, amount: amount}
+      hash = {description: products[id].description,
+              pieceprice: products[id].price.to_i,
+              price: products[id].price.to_i*amount, amount: amount}
 
       # Convert Symbols to Strings to ensure compatibility with pandoc
       yaml["service"] << Hash[hash.map{ |k, v| [k.to_s, v] }]
@@ -122,24 +155,12 @@ def date_of_prev(day)
   date - delta
 end
 
+#################
+
 db = Mysql2::Client.new(:host => DB_HOST, :username => DB_USER, :database => DB_DB)
 
-# Initialize product and member hashses
-Products = Hash.new
-Names = Hash.new
-Prices = Hash.new
-db.query("SELECT * FROM Products").each do |p|
-  product = Product.new(p['id'], p['description'], p['price'])
-  Products[p['id']] = product
-  
-  if Options[:verbose]
-    puts "Found product: #{product}"
-  end
-end
+transactions = load_transactions_from_db(db)
+persons = load_persons_from_db(db)
+products = load_products_from_db(db)
 
-db.query("SELECT * FROM Persons").each do |member|
-  Names[member['id']] = member['name']
-end
-
-partition = partition_transactions(read_db(db))
-generate_receipt(partition,Options[:draft])
+generate_receipt(partition_transactions(transactions,persons), products, Options[:draft])