#!/usr/bin/perl

use Text::CSV;
use Data::Dumper;

# cw_products
# 0 id  1 sku  2 product_name

# cw_skus
# 0 sku_id  1 sku  2 product_id

# cw_orders
# 0 order_id  1 date  2 status  3 customer_id

# cw_order_skus
# 0 id  1 order_id  2 sku_id

# cw_customers
# 0 customer_id  1 customer_type  2 date_added  3 date_modified  4 first_name  5 last_name

@products   = load_csv("cw_products.csv");
@skus       = load_csv("cw_skus.csv");
@orders     = load_csv("cw_orders.csv");
@order_skus = load_csv("cw_order_skus.csv");
@customers  = load_csv("cw_customers.csv");

$product_name_lookup = {};
for $product (@products) {
  $sku  = $product->[1];
  $name = $product->[2];
  $product_name_lookup->{ $sku } = $name;
}

$customer_name_lookup = {};
for $customer (@customers) {
  $id = $customer->[0];
  $name = $customer->[5] . " " . $customer->[4];
  $customer_name_lookup->{ $id } = $name;
}

$sku_id_lookup = {};
for $sku (@skus) {
  $sku_id = $sku->[0];
  $sku_name = $sku->[1];
  $sku_id_lookup->{ $sku_id } = $sku_name;
}

$customers_seen = {};
for $order (@orders) {
  $order_id = $order->[0];
  $customer_id = $order->[3];
  if (exists( $customers_seen->{ $customer_id } )) {
    # print $customer_name_lookup->{ $customer_id } . "\n";
    $customers_seen->{ $customer_id } += 1;
  }
  else {
    $customers_seen->{ $customer_id } = 1;
  }
}

$repeat_customers = 0;
$total_customers = 0;
for $customer_id (keys %$customers_seen) {
  $count = $customers_seen->{ $customer_id };
  $total_customers += 1;
  if ( $count > 1 ) {
    # print $count . ": " . $customer_name_lookup->{ $customer_id } . "\n";
    $repeat_customers += 1;
  }
}

print "total customers: " . $total_customers . "\n";
print "repeat customers: " . $repeat_customers . "\n";


# print Dumper( $sku_id_lookup );















sub load_csv () {
  my $filename = shift;
  my @rows;
  my $csv = Text::CSV->new ( { binary => 1 } )  # should set binary attribute.
                 or die "Cannot use CSV: ".Text::CSV->error_diag ();
 
  open my $fh, "<:encoding(utf8)", $filename or die "$filename: $!";
  while ( my $row = $csv->getline( $fh ) ) {
    push @rows, $row;
  }
  $csv->eof or $csv->error_diag();
  close $fh;
  return @rows;
}