use v6.e.PREVIEW;

use Pandoc;
use JSON::Class:auth<zef:vrurg>;
use File::Temp;

use DB::Post;

#| A literate, markdown, idris post

unit class IdrisPost does Post is json(:pretty);

#| Marker for disambiguation between post types in json representation, the
#| cheaty way
has Bool:D $.idris is json = True;

#| Location of the ipkg for the package containing the post
has IO::Path:D $.ipkg
    is required
    is json(
        :to-json(*.Str),
        :from-json(*.IO)
    );

method title(--> Str:D) {
       markdown-title($!source)
}

# Use katla to highlight our file, mangle the resulting output, and then pass it
# through to pandoc for html generation
method render-html(--> Str:D) {
    my $project-dir = $!ipkg.parent;
    indir $project-dir, {
        # Do a pack build to make sure we have the needed files
        # TODO: Figure out how to only do this once
        pack <build>;
        # First we have to find the location of the ttm file
        my $relative-path = $!source.extension('ttm').relative:
            $project-dir.add('src');
        my $ttc-dir = dir($project-dir.add('build/ttc/'))[0];
        my $ttm-path = $ttc-dir.add: $relative-path;
        # Run through katla
        my $output = katla 'markdown', $!source, $ttm-path;
        # Send output to pandoc through a temporary file
        my ($filename, $filehandle) = tempfile;
        $filehandle.spurt: $output, :close;
        markdown-to-html $filename.IO
    };
}

# Run a pack command, erroring on failure
sub pack(*@args) {
    my $pack = run 'pack', @args, :out, :err;
    my $pack-out = $pack.out.slurp: :close;
    my $pack-err = $pack.err.slurp: :close;
    die "Pack exited with {$pack.exitcode}\nout: $pack-out\nerr: $pack-err"
        unless $pack;
}

# Run a katla command, erroring on failure, returning the standard out, and
# mangling the output accordingly
sub katla(*@args --> Str:D) {
    my $katla = run 'katla', @args, :out, :err;
    my $katla-out = $katla.out.slurp: :close;
    my $katla-err = $katla.err.slurp: :close;
    die "Katla exited with {$katla.exitcode}\nout: $katla-out\nerr: $katla-err"
        unless $katla;
    # TODO modify output
    $katla-out
}