#!/usr/bin/env perl

package IkiWiki::Plugin::pandoc;

use warnings;
use strict;
use IkiWiki;
use FileHandle;
use IPC::Open2;
use JSON;

sub import {
    my $markdown_ext = $config{pandoc_markdown_ext} || "mdwn";

    # May be both a string with a single value, a string containing commas or an arrayref
    if ($markdown_ext =~ /,/) {
        $markdown_ext = [split /\s*,\s*/, $markdown_ext];
    }

    hook(type => "getsetup", id => "pandoc", call => \&getsetup);
    if (ref $markdown_ext eq 'ARRAY') {
        foreach my $mde (@$markdown_ext) {
            hook(type => 'htmlize', id => $mde,
                 call => sub{ htmlize("markdown", @_) });
        }
    } else {
        hook(type => "htmlize", id => $markdown_ext,
             call => sub { htmlize("markdown", @_) });
    }
    if ($config{pandoc_latex}) {
        hook(type => "htmlize", id => "tex",
             call => sub { htmlize("latex", @_) });
    }
    if ($config{pandoc_rst}) {
        hook(type => "htmlize", id => "rst",
             call => sub { htmlize("rst", @_) });
    }
    if ($config{pandoc_textile}) {
        hook(type => "htmlize", id => "textile",
             call => sub { htmlize("textile", @_) });
    }
    if ($config{pandoc_mediawiki}) {
        hook(type => "htmlize", id => "mediawiki",
             call => sub { htmlize("mediawiki", @_) });
    }
}


sub getsetup () {
    return
    plugin => {
        safe => 1,
        rebuild => 1,
    },
    pandoc_command => {
        type => "string",
        example => "/usr/local/bin/pandoc",
        description => "Path to pandoc executable",
        safe => 0,
        rebuild => 0,
    },
    pandoc_markdown_ext => {
        type => "string",
        example => "mdwn",
        description => "File extension for Markdown files",
        safe => 1,
        rebuild => 1,
    },
    pandoc_latex => {
        type => "boolean",
        example => 0,
        description => "Enable Pandoc processing of LaTeX documents",
        safe => 0,
        rebuild => 1,
    },
    pandoc_rst => {
        type => "boolean",
        example => 0,
        description => "Enable Pandoc processing of reStructuredText documents",
        safe => 0,
        rebuild => 1,
    },
    pandoc_textile => {
        type => "boolean",
        example => 0,
        description => "Enable Pandoc processing of Textile documents",
        safe => 0,
        rebuild => 1,
    },
    pandoc_mediawiki => {
        type => "boolean",
        example => 0,
        description => "Enable Pandoc processing of MediaWiki documents",
        safe => 0,
        rebuild => 1,
    },
    pandoc_smart => {
        type => "boolean",
        example => 1,
        description => "Use smart quotes, dashes, and ellipses",
        safe => 1,
        rebuild => 1,
    },
    pandoc_obfuscate => {
        type => "boolean",
        example => 1,
        description => "Obfuscate emails",
        safe => 1,
        rebuild => 1,
    },
    pandoc_html5 => {
        type => "boolean",
        example => 0,
        description => "Generate HTML5",
        safe => 1,
        rebuild => 1,
    },
    pandoc_ascii => {
        type => "boolean",
        example => 0,
        description => "Generate ASCII instead of UTF8",
        safe => 1,
        rebuild => 1,
    },
    pandoc_numsect => {
        type => "boolean",
        example => 0,
        description => "Number sections",
        safe => 1,
        rebuild => 1,
    },
    pandoc_sectdiv => {
        type => "boolean",
        example => 0,
        description => "Attach IDs to section DIVs instead of Headers",
        safe => 1,
        rebuild => 1,
    },
    pandoc_codeclasses => {
        type => "string",
        example => "",
        description => "Classes to use for indented code blocks",
        safe => 1,
        rebuild => 1,
    },
    pandoc_math => {
        type => "string",
        example => "mathjax",
        description => "Process TeX math using",
        safe => 0,
        rebuild => 1,
    },
    pandoc_bibliography => {
        type => "string",
        example => "",
        description => "Path to bibliography file",
        safe => 0,
        rebuild => 1,
    },
    pandoc_csl => {
        type => "string",
        example => "",
        description => "Path to CSL file (for references and bibliography)",
        safe => 0,
        rebuild => 1,
    },
}


sub htmlize ($@) {
    my $format = shift;
    my %params = @_;
    my $page = $params{page};

    local(*PANDOC_IN, *JSON_IN, *JSON_OUT, *PANDOC_OUT);
    my @args;

    my $command = $config{pandoc_command} || "/usr/local/bin/pandoc";

    if ($config{pandoc_smart}) {
        push @args, '--smart';
    };

    if ($config{pandoc_obfuscate}) {
        push @args, '--email-obfuscation=references';
    } else {
        push @args, '--email-obfuscation=none';
    };

    if ($config{pandoc_html5}) {
        push @args, '--html5';
    };

    if ($config{pandoc_ascii}) {
        push @args, '--ascii';
    };

    if ($config{pandoc_numsect}) {
        push @args, '--number-sections';
    };

    if ($config{pandoc_sectdiv}) {
        push @args, '--section-divs';
    };

    if ($config{pandoc_codeclasses} && ($config{pandoc_codeclasses} ne "")) {
        push @args, '--indented-code-classes=' . $config{pandoc_codeclasses};
    };

    if ($config{pandoc_bibliography}) {
        push @args, '--bibliography='.$config{pandoc_bibliography};
    }

    if ($config{pandoc_csl}) {
        push @args, '--csl='.$config{pandoc_csl};
    }

    for ($config{pandoc_math}) {
        if (/^mathjax$/) {
            push @args, '--mathjax=/dev/null';
        }
        elsif (/^jsmath$/) {
            push @args, '--jsmath';
        }
        elsif (/^latexmathml$/) {
            push @args, '--latexmathml';
        }
        elsif (/^mimetex$/) {
            push @args, '--mimetex';
        }
        elsif (/^mathtex$/) {
            push @args, '--mimetex=/cgi-bin/mathtex.cgi';
        }
        elsif (/^google$/) {
            push @args, '--webtex';
        }
        elsif (/^mathml$/) {
            push @args, '--mathml';
        }
        else { }
    }

    # Convert to intermediate JSON format so that the title block
    # can be parsed out
    my $to_json_pid = open2(*JSON_OUT, *PANDOC_OUT, $command,
                    '-f', $format,
                    '-t', 'json',
                    @args);

    error("Unable to open $command") unless $to_json_pid;

    # $ENV{"LC_ALL"} = "en_US.UTF-8";
    my $to_html_pid = open2(*PANDOC_IN, *JSON_IN, $command,
                    '-f', 'json',
                    '-t', 'html',
                    @args);

    error("Unable to open $command") unless $to_html_pid;

    # Workaround for perl bug (#376329)
    require Encode;
    my $content = Encode::encode_utf8($params{content});

    print PANDOC_OUT $content;
    close PANDOC_OUT;

    my $json_content = <JSON_OUT>;
    close JSON_OUT;

    waitpid $to_json_pid, 0;

    print JSON_IN $json_content;
    close JSON_IN;

    my @html = <PANDOC_IN>;
    close PANDOC_IN;

    waitpid $to_html_pid, 0;

    $content = Encode::decode_utf8(join('', @html));

    # Parse the title block out of the JSON and set the meta values
    my @perl_content = @{decode_json($json_content)};
    my %header_section = %{$perl_content[0]};
    my @doc_title = @{$header_section{'docTitle'}};
    my @doc_authors = @{$header_section{'docAuthors'}};
    my $num_authors = @doc_authors;
    my @primary_author = ();
    if ($num_authors gt 0) {
        @primary_author = @{$doc_authors[0]};
    }
    my @doc_date = @{$header_section{'docDate'}};

    sub compile_string {
        # The uncompiled string is an array of hashes containing words and 
        # string with the word "Space".
        my (@uncompiled_string) = @_;
        my $compiled_string = '';
        foreach my $word_or_space(@uncompiled_string) {
            if (ref($word_or_space) eq "HASH") {
                if ($word_or_space->{"Str"}) {
                    $compiled_string .= $word_or_space->{"Str"};
                }
            }
            else {
                $compiled_string .= ' ';
            }
        }
        return $compiled_string;
    }

    my $title = compile_string @doc_title;
    my $author = compile_string @primary_author;
    my $date = compile_string @doc_date;

    if ($title) {
        $pagestate{$page}{meta}{title} = $title;
    }
    if ($author) {
        $pagestate{$page}{meta}{author} = $author;
    }
    if ($date) {
        $pagestate{$page}{meta}{date} = $date;
    }

    return $content;
}

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