From 2935964d64b422cad6de49e6e4738d8d2d822cf7 Mon Sep 17 00:00:00 2001
From: Mike Mattozzi <mike.mattozzi@gmail.com>
Date: Sat, 28 Sep 2013 17:17:13 -0400
Subject: [PATCH] Adding international currency support

---
 dist.ini               |   1 +
 lib/DDG/Goodie/Loan.pm | 349 +++++++++++++++++++++++++++++++++++++++--
 t/Loan.t               |  54 ++++++-
 3 files changed, 381 insertions(+), 23 deletions(-)

diff --git a/dist.ini b/dist.ini
index eebc89658..2562decb3 100644
--- a/dist.ini
+++ b/dist.ini
@@ -48,6 +48,7 @@ Games::Sudoku::Component = 0.02
 Data::RandomPerson = 0.4
 URI::Escape = 3.31
 Lingua::EN::Words2Nums = 0
+Locale::Currency::Format = 1.30
 
 [Prereqs / TestRequires]
 Test::More = 0.98
diff --git a/lib/DDG/Goodie/Loan.pm b/lib/DDG/Goodie/Loan.pm
index 6489865ca..10a2f8b3c 100644
--- a/lib/DDG/Goodie/Loan.pm
+++ b/lib/DDG/Goodie/Loan.pm
@@ -2,6 +2,7 @@ package DDG::Goodie::Loan;
 # ABSTRACT: Calculate monthly payment and total interest payment for a conventional mortgage loan
 
 use DDG::Goodie;
+use Locale::Currency::Format;
 
 triggers start => 'loan';
 
@@ -26,24 +27,76 @@ sub loan_monthly_payment {
 	return ($r / (1 - (1 + $r)**(-1 * $n))) * $p;
 }
 
+# A map of country code to currency code, filled in below
+my %country_to_currency;
+
+# A map of currency symbol to currency code, filled in below
+my %symbol_to_currency = ( );
+
+# From the symbol used, guess the currency (this will override any location data that comes in with the user). 
+# This is pretty imprecise. Assume USD if a $ is used. More assumptions can be added here later to priorize 
+# currency guessing. Perhaps location data can be used to break ties. 
+sub convert_symbol_to_currency {
+	my $symbol = shift;
+	if ($symbol eq "\$") {
+		return "USD";
+	} else {
+		return $symbol_to_currency{$symbol};
+	}
+}
+
+# Given the country code and currency formatting rules, the input can be made ready to convert
+# to a useable number. Examples: 
+# In USD: 400,000 => 400000
+# In EUR: 400.000,00 => 400000.00
+sub normalize_formatted_currency_string {
+	my ($str, $currency_code) = @_;
+	
+	my $thousands_separator = thousands_separator($currency_code);
+	my $decimal_separator = decimal_separator($currency_code);
+	
+	$str =~ s/\Q$thousands_separator//g;
+	if ($decimal_separator ne ".") {
+		$str =~ s/\Q$decimal_separator/\./g;
+	}
+	
+	return $str;
+}
+
 handle remainder => sub {
 	my $query = $_;
-
+	
 	# At a minimum, query should contain some amount of money and a percent interest rate
-	if ($query =~ /^\$?(\d+)\s(at\s)?(\d+.?\d*)%/) {
-		my $principal = $1;
-		my $rate = $3;
+	if ($query =~ /^(\p{Currency_Symbol})?([\d\.,]+)\s(at\s)?(\d+.?\d*)%/) {
+		my $symbol = $1;
+		my $principal = $2;
+		my $rate = $4;
 		my $downpayment = 0;
 		my $years = 30;
 
+		# Apply localization, default to US if unknown
+		my $currency_code = "USD";
+		if (defined $symbol) {
+			$currency_code = convert_symbol_to_currency($symbol);
+		} elsif (defined $loc->country_code) {
+			$currency_code = $country_to_currency{$loc->country_code} || $country_to_currency{"us"};
+			$symbol = currency_symbol($currency_code);
+		}
+
+		# Given the country code and currency formatting rules, the input can be made ready to convert
+		# to a useable number. 
+		$principal = normalize_formatted_currency_string($principal, $currency_code);
+
 		# Check if query contains downpayment information
-		if ($query =~ /\$?(\d+)(%)? down/) {
-			my $downpaymentIsInDollars = ! (defined $2);
-			my $downpaymentNoUnits = $1;
-			if ($downpaymentIsInDollars) {
-				$downpayment = $downpaymentNoUnits;
+		if ($query =~ /(\p{Currency_Symbol})?(\d+)(%)? down/) {
+			my $downpayment_is_in_cash = ! (defined $3);
+			my $downpayment_without_units = $2;
+			if ($downpayment_is_in_cash) {
+				# Downpayment expresses in an amount of currency
+				$downpayment = normalize_formatted_currency_string($downpayment_without_units, $currency_code);
 			} else {
-				$downpayment = $principal * .01 * $downpaymentNoUnits;
+				# Downpayment expressed as a percentage of principal
+				$downpayment = $principal * .01 * $downpayment_without_units;
 			}
 		}
 
@@ -52,15 +105,281 @@ handle remainder => sub {
 			$years = $1;
 		}
 
-		my $loanAmt = $principal - $downpayment;
-		my $monthlyPayment = loan_monthly_payment($loanAmt, $rate / 12 * .01, $years * 12);
-		my $totalInterest = ($monthlyPayment * 12 * $years) - $loanAmt;
+		my $loan_amount = $principal - $downpayment;
+		my $monthly_payment = loan_monthly_payment($loan_amount, $rate / 12 * .01, $years * 12);
+		my $total_interest = ($monthly_payment * 12 * $years) - $loan_amount;
 
-		return "Monthly Payment is \$" . sprintf("%.2f", $monthlyPayment) . 
-			" for $years years. Total interest paid is \$" . sprintf("%.2f", $totalInterest); 
+		return "Monthly Payment is " . currency_format($currency_code, $monthly_payment, FMT_SYMBOL) . 
+			" for $years years. Total interest paid is " . 
+			currency_format($currency_code, $total_interest, FMT_SYMBOL); 
 			
 	}
 	return;
 };
 
+# A map of 2 letter country code to 3 letter currency code. Copied from Locale::Object perl module 
+# (http://search.cpan.org/~jrobinson/Locale-Object/) which carries some extra baggage with it, and 
+# has also not been updated since 2007. If the mapping between any country and currency needs to be 
+# changed, this is where to change it. 
+%country_to_currency = (
+	'ad' => 'EUR',
+	'ae' => 'AED',
+	'af' => 'AFA',
+	'ag' => 'XCD',
+	'ai' => 'XCD',
+	'al' => 'ALL',
+	'am' => 'AMD',
+	'an' => 'ANG',
+	'ao' => 'AOA',
+	'aq' => '000',
+	'ar' => 'ARS',
+	'as' => 'USD',
+	'at' => 'EUR',
+	'au' => 'AUD',
+	'aw' => 'AWG',
+	'az' => 'AZM',
+	'ba' => 'BAM',
+	'bb' => 'BBD',
+	'bd' => 'BDT',
+	'be' => 'EUR',
+	'bf' => 'XOF',
+	'bg' => 'BGL',
+	'bh' => 'BHD',
+	'bi' => 'BIF',
+	'bj' => 'XOF',
+	'bm' => 'BMD',
+	'bn' => 'BND',
+	'bo' => 'BOB',
+	'br' => 'BRL',
+	'bs' => 'BSD',
+	'bt' => 'BTN',
+	'bv' => 'NOK',
+	'bw' => 'BWP',
+	'by' => 'BYR',
+	'bz' => 'BZD',
+	'ca' => 'CAD',
+	'cc' => 'AUD',
+	'cd' => 'CDF',
+	'cf' => 'XAF',
+	'cg' => 'XAF',
+	'ch' => 'CHF',
+	'ci' => 'XOF',
+	'ck' => 'NZD',
+	'cl' => 'CLP',
+	'cm' => 'XAF',
+	'cn' => 'CNY',
+	'co' => 'COP',
+	'cr' => 'CRC',
+	'cu' => 'CUP',
+	'cv' => 'CVE',
+	'cx' => 'AUD',
+	'cy' => 'CYP',
+	'cz' => 'CZK',
+	'de' => 'EUR',
+	'dj' => 'DJF',
+	'dk' => 'DKK',
+	'dm' => 'XCD',
+	'do' => 'DOP',
+	'dz' => 'DZD',
+	'ec' => 'ECS',
+	'ee' => 'EEK',
+	'eg' => 'EGP',
+	'eh' => 'MAD',
+	'er' => 'ERN',
+	'es' => 'EUR',
+	'et' => 'ETB',
+	'fi' => 'EUR',
+	'fj' => 'FJD',
+	'fk' => 'FKP',
+	'fm' => 'USD',
+	'fo' => 'DKK',
+	'fr' => 'EUR',
+	'fx' => 'EUR',
+	'ga' => 'XAF',
+	'gb' => 'GBP',
+	'gd' => 'XCD',
+	'ge' => 'GEL',
+	'gf' => 'EUR',
+	'gh' => 'GHC',
+	'gi' => 'GIP',
+	'gl' => 'DKK',
+	'gm' => 'GMD',
+	'gn' => 'GNF',
+	'gp' => 'EUR',
+	'gq' => 'GQE',
+	'gr' => 'EUR',
+	'gs' => 'GBP',
+	'gt' => 'GTQ',
+	'gu' => 'USD',
+	'gw' => 'XOF',
+	'gy' => 'GYD',
+	'hk' => 'HKD',
+	'hm' => 'AUD',
+	'hn' => 'HNL',
+	'hr' => 'HRK',
+	'ht' => 'HTG',
+	'hu' => 'HUF',
+	'id' => 'IDR',
+	'ie' => 'EUR',
+	'il' => 'ILS',
+	'in' => 'INR',
+	'io' => 'GBP',
+	'iq' => 'IQD',
+	'ir' => 'IRR',
+	'is' => 'ISK',
+	'it' => 'EUR',
+	'jm' => 'JMD',
+	'jo' => 'JOD',
+	'jp' => 'JPY',
+	'ke' => 'KES',
+	'kg' => 'KGS',
+	'kh' => 'KHR',
+	'ki' => 'AUD',
+	'km' => 'KMF',
+	'kn' => 'XCD',
+	'kp' => 'KPW',
+	'kr' => 'KRW',
+	'kw' => 'KWD',
+	'ky' => 'KYD',
+	'kz' => 'KZT',
+	'la' => 'LAK',
+	'lb' => 'LBP',
+	'lc' => 'XCD',
+	'li' => 'CHF',
+	'lk' => 'LKR',
+	'lr' => 'LRD',
+	'ls' => 'LSL',
+	'lt' => 'LTL',
+	'lu' => 'EUR',
+	'lv' => 'LVL',
+	'ly' => 'LYD',
+	'ma' => 'MAD',
+	'mc' => 'EUR',
+	'md' => 'MDL',
+	'me' => 'YUM',
+	'mg' => 'MGF',
+	'mh' => 'USD',
+	'mk' => 'MKD',
+	'ml' => 'XOF',
+	'mm' => 'MMK',
+	'mn' => 'MNT',
+	'mo' => 'MOP',
+	'mp' => 'USD',
+	'mq' => 'EUR',
+	'mr' => 'MRO',
+	'ms' => 'XCD',
+	'mt' => 'MTL',
+	'mu' => 'MUR',
+	'mv' => 'MVR',
+	'mw' => 'MWK',
+	'mx' => 'MXN',
+	'my' => 'MYR',
+	'mz' => 'MZM',
+	'na' => 'NAD',
+	'nc' => 'XPF',
+	'ne' => 'XOF',
+	'nf' => 'AUD',
+	'ng' => 'NGN',
+	'ni' => 'NIO',
+	'nl' => 'EUR',
+	'no' => 'NOK',
+	'np' => 'NPR',
+	'nr' => 'AUD',
+	'nu' => 'NZD',
+	'nz' => 'NZD',
+	'om' => 'OMR',
+	'pa' => 'PAB',
+	'pe' => 'PEN',
+	'pf' => 'XPF',
+	'pg' => 'PGK',
+	'ph' => 'PHP',
+	'pk' => 'PKR',
+	'pl' => 'PLN',
+	'pm' => 'EUR',
+	'pn' => 'NZD',
+	'pr' => 'USD',
+	'ps' => 'ILS',
+	'pt' => 'EUR',
+	'pw' => 'USD',
+	'py' => 'PYG',
+	'qa' => 'QAR',
+	're' => 'EUR',
+	'ro' => 'ROL',
+	'rs' => 'YUM',
+	'ru' => 'RUB',
+	'rw' => 'RWF',
+	'sa' => 'SAR',
+	'sb' => 'SBD',
+	'sc' => 'SCR',
+	'sd' => 'SDP',
+	'se' => 'SEK',
+	'sg' => 'SGD',
+	'sh' => 'SHP',
+	'si' => 'SIT',
+	'sj' => 'NOK',
+	'sk' => 'SKK',
+	'sl' => 'SLL',
+	'sm' => 'EUR',
+	'sn' => 'XOF',
+	'so' => 'SOS',
+	'sr' => 'SRG',
+	'st' => 'STD',
+	'sv' => 'SVC',
+	'sy' => 'SYP',
+	'sz' => 'SZL',
+	'tc' => 'USD',
+	'td' => 'XAF',
+	'tf' => 'EUR',
+	'tg' => 'XOF',
+	'th' => 'THB',
+	'tj' => 'TJS',
+	'tk' => 'NZD',
+	'tl' => 'IDR',
+	'tm' => 'TMM',
+	'tn' => 'TND',
+	'to' => 'TOP',
+	'tr' => 'TRL',
+	'tt' => 'TTD',
+	'tv' => 'AUD',
+	'tw' => 'TWD',
+	'tz' => 'TZS',
+	'ua' => 'UAH',
+	'ug' => 'UGX',
+	'um' => 'USD',
+	'us' => 'USD',
+	'uy' => 'UYU',
+	'uz' => 'UZS',
+	'va' => 'EUR',
+	'vc' => 'XCD',
+	've' => 'VEB',
+	'vg' => 'USD',
+	'vi' => 'USD',
+	'vn' => 'VND',
+	'vu' => 'VUV',
+	'wf' => 'XPF',
+	'ws' => 'WST',
+	'ye' => 'YER',
+	'yt' => 'EUR',
+	'yu' => 'YUM',
+	'za' => 'ZAR',
+	'zm' => 'ZMK',
+	'zr' => 'XAF',
+	'zw' => 'ZWD');
+
+# Build the mapping of symbol to currency name
+foreach my $code (values %country_to_currency) {
+	my $symbol_for_code = currency_symbol($code);
+	if (defined $symbol_for_code) {
+		$symbol_to_currency{$symbol_for_code} = $code;
+	}
+}
+
+# Add in uppercase version of country code to be safe
+my %uc_country_to_currency_map = ( );
+while (my($k, $v) = each %country_to_currency) {
+	$uc_country_to_currency_map{uc $k} = $v;
+}
+
+@country_to_currency{keys %uc_country_to_currency_map} = values %uc_country_to_currency_map;
+
 1;
diff --git a/t/Loan.t b/t/Loan.t
index 0e5b1fc8b..299e72ac5 100644
--- a/t/Loan.t
+++ b/t/Loan.t
@@ -2,9 +2,11 @@
 
 use strict;
 use warnings;
-
 use Test::More;
 use DDG::Test::Goodie;
+use DDG::Test::Location;
+use DDG::Request;
+use utf8;
 
 zci answer_type => 'loan';
 zci is_cached => 1;
@@ -14,19 +16,55 @@ ddg_goodie_test (
 		'DDG::Goodie::Loan'
 	],
 	'loan 400000 4.5%' =>
-		test_zci('Monthly Payment is $2026.74 for 30 years. Total interest paid is $329626.85'),
+		test_zci('Monthly Payment is $2,026.74 for 30 years. Total interest paid is $329,626.85'),
 	'loan $400000 at 4.5%' =>
-		test_zci('Monthly Payment is $2026.74 for 30 years. Total interest paid is $329626.85'),
+		test_zci('Monthly Payment is $2,026.74 for 30 years. Total interest paid is $329,626.85'),
 	'loan $500000 at 4.5% with 20% down' =>
-		test_zci('Monthly Payment is $2026.74 for 30 years. Total interest paid is $329626.85'),
+		test_zci('Monthly Payment is $2,026.74 for 30 years. Total interest paid is $329,626.85'),
 	'loan $500000 at 4.5% with $100000 down' =>
-		test_zci('Monthly Payment is $2026.74 for 30 years. Total interest paid is $329626.85'),
+		test_zci('Monthly Payment is $2,026.74 for 30 years. Total interest paid is $329,626.85'),
 	'loan $250000 3% interest 15 years' =>
-		test_zci('Monthly Payment is $1726.45 for 15 years. Total interest paid is $60761.74'),
+		test_zci('Monthly Payment is $1,726.45 for 15 years. Total interest paid is $60,761.74'),
 	'loan $300000 at 3% interest with $50000 downpayment for 15 years' =>
-		test_zci('Monthly Payment is $1726.45 for 15 years. Total interest paid is $60761.74'),
+		test_zci('Monthly Payment is $1,726.45 for 15 years. Total interest paid is $60,761.74'),
 	'loan $300000 3% $50000 down 15 year' =>
-		test_zci('Monthly Payment is $1726.45 for 15 years. Total interest paid is $60761.74')
+		test_zci('Monthly Payment is $1,726.45 for 15 years. Total interest paid is $60,761.74'),
+	'loan €400000 at 4.5%' =>
+		test_zci('Monthly Payment is €2.026,74 for 30 years. Total interest paid is €329.626,85'),
+	'loan £250000 3% interest 15 years' =>
+		test_zci('Monthly Payment is £1,726.45 for 15 years. Total interest paid is £60,761.74'),
+	'loan $400,000.00 at 4.5%' =>
+		test_zci('Monthly Payment is $2,026.74 for 30 years. Total interest paid is $329,626.85'),
+	'loan €250.000,00 3% interest 15 years' =>
+		test_zci('Monthly Payment is €1.726,45 for 15 years. Total interest paid is €60.761,74'),
+	# Test a few cases of inferring user's location
+	DDG::Request->new(query_raw => "loan 400000 4.5%", location => test_location("de")) =>
+		test_zci('Monthly Payment is €2.026,74 for 30 years. Total interest paid is €329.626,85'),
+	DDG::Request->new(query_raw => "loan 400000 4.5%", location => test_location("in")) =>
+		test_zci('Monthly Payment is ₨2,026.74 for 30 years. Total interest paid is ₨329,626.85'),
+	DDG::Request->new(query_raw => "loan 400000 4.5%", location => test_location("my")) =>
+		test_zci('Monthly Payment is 2,026.74 MYR for 30 years. Total interest paid is 329,626.85 MYR'),
+	# Test that symbol overrides user's location
+	DDG::Request->new(query_raw => "loan \$400,000 4.5%", location => test_location("de")) =>
+		test_zci('Monthly Payment is $2,026.74 for 30 years. Total interest paid is $329,626.85'),
+	# Imagine a new country later appears, test defaulting to USD because we don't know about it
+	DDG::Request->new(query_raw => "loan 400000 4.5%", location => DDG::Location->new(
+			{
+				country_code => 'LL',
+				country_code3 => 'LLA',
+				country_name => 'Llama Land',
+				region => '9',
+				region_name => 'Llama Region',
+				city => 'New Llama City',
+				latitude => '90.0000',
+				longitude => '0.0000',
+				time_zone => 'America/New_York',
+				area_code => 0,
+				continent_code => 'NA',
+				metro_code => 0
+			}
+		)) =>
+		test_zci('Monthly Payment is $2,026.74 for 30 years. Total interest paid is $329,626.85')
 );
 
 done_testing;