Manipulate some poorly delimited data into a useful CSV

A way to do it is to put everything in a hash.

# put values into a hash based on the id and tag
awk 'NR>1{n[$2","$4]+=$1}
END{
    # merge the same ids on the one line
    for(i in n){
        id=i;
        sub(/,.*/,"",id);
        a[id]=a[id]","n[i];
    }
    # print everyhing
    for(i in a){
        print i""a[i];
    }
}'

edit: my first answer didn't answer the question properly

Perl to the rescue:

#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

<>;  # Skip the header.

my %sum;
my %types;
while (<>) {
    my ($count, $id, $type) = grep length, split '[\s|]+';
    $sum{$id}{$type} += $count;
    $types{$type} = 1;
}

say join ',', 'id', sort keys %types;
for my $id (sort { $a <=> $b } keys %sum) {
    say join ',', $id, map $_ // q(), @{ $sum{$id} }{ sort keys %types };
}

It keeps two tables, table of types and table of ids. For each id, it stores the sum per type.

If GNU datamash is an option for you, then

awk 'NR>1 {print $1, $2, $4}' OFS=, file | datamash -t, -s --filler=0 crosstab 2,3 sum 1
,1,2,3
10,0,0,588
12,0,0,10
14,0,0,883
17,0,0,98
18,17,0,77598
2,0,0,17892
21,0,0,10000
23,0,0,20000
27,0,0,63
3,0,0,6
35,0,0,2446
4,15,253,19871
5,0,0,1000