#!/usr/bin/perl

use strict;
use warnings;

my $linenum = 0;

# sub nextline(): reads lines from INFILE until it gets to one that is not a
# comment or whitespace and returns the line.  also strips leading whitespace 
# and updates $linenum
sub nextline {
    my $line;
    if( eof( INFILE ) ) {
        print( STDERR "unexpected EOF\n" );
        exit;
    }
    $line = <INFILE>;
    $linenum++;
    while( $line =~ m/^\#/ || $line =~ m/^\s*$/ ) {
        $line = <INFILE>;
        $linenum++;
    }
    $line =~ s/^\s*//;
    return $line;
}
  
my ( $filename, $line, $numchords, $numstates, $numheaders, $next );
my ( @chords, @chordnames, @tmp, @table, @headers );
my $file = $ARGV[0];
open( INFILE, $file );
open( OUTFILE, ">$file.in" );
chomp( $line = nextline() );
unless( $line =~ m/^headers/ ) {
    print( STDERR "line 1 should read \"headers\"\n" );
    exit;
}
# headers in the input file are the same as the output, so just copy them over
$line = nextline();
$numheaders = 0;
while( !($line =~ m/^end/ ) ) {
    push( @headers, $line );
    $numheaders++;
    $line = nextline();
}
print( OUTFILE "$numheaders\n" );
foreach $next (@headers) {
    print( OUTFILE $next );
}

chomp( $line = nextline() );
unless( $line =~ m/chords/ ) {
    print( STDERR "line $linenum should read \"chords\"\n" );
    exit;
}
$line = nextline();
$numchords = 0;
while( !($line =~ m/^end/ ) ) {
    push( @chords, $line );
    @tmp = split( / /, $line );
    push( @chordnames, $tmp[0] );
    $numchords++;
    $line = nextline();
}
# print number of chords
print( OUTFILE "$numchords\n" );
# chord definition also has the same format, so just copy them over
foreach $next (@chords) {
    print( OUTFILE $next );
}

chomp( $line = nextline() );
unless( $line =~ s/states:// ) {
    print( STDERR "line $linenum should read \"states: <number of states>\"\n" );
    exit;
}
$line =~ s/\s*//;
$numstates = $line;
print( OUTFILE "$numstates\n" );
$numstates = $numstates * $numchords + 1;
my ( $col, $nextcol, $chordname, $subscript, $prob, $index, $rowtitle, $row );
my @probs;
$nextcol = -1;
$next = nextline();
for( my $i = 0; !($next =~ m/^end/); ++$i ) {
    for( my $j = 0; $j < $numstates; ++$j ) {
        $probs[$j] = 0;
    }
    if( $next =~ m/^\#/ ) {
        $next = nextline();
    }
    # Pick out the row title
    if( $next =~ s/^(.*):\s*// ) {
        $rowtitle = $1;
        if( $i == 0 ) {
            unless( $rowtitle =~ m/start/ ) {
                print( STDERR "expected \"start:\" at line $linenum\n" );
                exit;
            }
        }
        else {
            unless( $rowtitle =~ m/^(\w*)\((\d*)\)$/ ) {
                print( STDERR 
                       "\"$rowtitle\" produces a syntax error on line $linenum\n");
                exit;
            }

            $chordname = $1;
            $subscript = $2;
            for( my $k = 0; $k < @chordnames; ++$k ) {
                if( $chordname eq $chordnames[$k] ) {
                    $index = $k;
                }
            }
            # This calculates the row that the row title refers to.
            $row = ($index + 1) + (($subscript-1) * $numchords);
            # if $row != $i, then at least one row is missing from the input file.
            # Any rows missing from the input file have a 100 percent chance of
            # stopping.
            while( $row != $i ) {
                $probs[0] = 100;
                print( OUTFILE "@probs" );
                print( OUTFILE "\n" );
                $i++;
                $probs[0] = 0;
            }
        }
    }
    else {
        print( STDERR "syntax error on line $linenum\n" );
        exit;
    }

    if( $next =~ s/\[stop\s(\w*)\]\s*// ) {
        $probs[0] = $1;
    }
    # Go through all the chords, figure out what column they correspond to, and
    # fill in the appropiate entry in @prob
    while( $next =~ s/^\[(\w*)\((\d*)\)\s(\d*)\]\s*// ) {
        $chordname = $1;
        $subscript = $2;
        $prob = $3;
        for( my $k = 0; $k < @chordnames; ++$k ) {
            if( $chordname eq $chordnames[$k] ) {
                $index = $k;
            }
        }
        $col = ($index + 1) + (($subscript-1) * $numchords);
        $probs[$col] = $prob;
    }
    $tmp[0] = 0;
    foreach $prob (@probs) {
        $tmp[0] += $prob;
    }
    # Since a syntax error will cause the reg exp to fail in the above while loop,
    # failure to add up to 100 can either mean a user addition error, or a syntax
    # error
    if( $tmp[0] != 100 ) {
        print( STDERR 
               "line $linenum does not add up to 100 or has a syntax error\n" );
        exit;
    }
    print( OUTFILE "@probs" );
    print( OUTFILE "\n" );
    $next = nextline();
}
system( "./chord -f $file.in" );