# ====================================================================
#   Licensed under the Apache License, Version 2.0 (the "License");
#   you may not use this file except in compliance with the License.
#   You may obtain a copy of the License at
#
#       http://www.apache.org/licenses/LICENSE-2.0
#
#   Unless required by applicable law or agreed to in writing, software
#   distributed under the License is distributed on an "AS IS" BASIS,
#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#   See the License for the specific language governing permissions and
#   limitations under the License.
# ====================================================================
#
# Author: Erik Hatcher
#
# to index all man pages on $MANPATH or /usr/share/man:
#   python manindex.py pages
# ====================================================================

import os, re, sys
from subprocess import *
from lucene import IndexWriter, StandardAnalyzer, Document, Field
from lucene import SimpleFSDirectory, File, initVM, Version

def indexDirectory(dir):

    for name in os.listdir(dir):
        path = os.path.join(dir, name)
        if os.path.isfile(path):
            indexFile(dir, name)


def indexFile(dir,filename):

    path = os.path.join(dir, filename)
    print "  File: ", filename

    if filename.endswith('.gz'):
        child = Popen('gunzip -c ' + path + ' | groff -t -e -E -mandoc -Tascii | col -bx', shell=True, stdout=PIPE, cwd=os.path.dirname(dir)).stdout
        command, section = re.search('^(.*)\.(.*)\.gz$', filename).groups()
    else:
        child = Popen('groff -t -e -E -mandoc -Tascii ' + path + ' | col -bx',
                      shell=True, stdout=PIPE, cwd=os.path.dirname(dir)).stdout
        command, section = re.search('^(.*)\.(.*)$', filename).groups()

    data = child.read()
    err = child.close()
    if err:
        raise RuntimeError, '%s failed with exit code %d' %(command, err)

    matches = re.search('^NAME$(.*?)^\S', data,
                        re.MULTILINE | re.DOTALL)
    name = matches and matches.group(1) or ''

    matches = re.search('^(?:SYNOPSIS|SYNOPSYS)$(.*?)^\S', data,
                        re.MULTILINE | re.DOTALL)
    synopsis = matches and matches.group(1) or ''

    matches = re.search('^(?:DESCRIPTION|OVERVIEW)$(.*?)', data,
                        re.MULTILINE | re.DOTALL)
    description = matches and matches.group(1) or ''

    doc = Document()
    doc.add(Field("command", command,
                  Field.Store.YES, Field.Index.NOT_ANALYZED))
    doc.add(Field("section", section,
                  Field.Store.YES, Field.Index.NOT_ANALYZED))
    doc.add(Field("name", name.strip(),
                  Field.Store.YES, Field.Index.ANALYZED))
    doc.add(Field("synopsis", synopsis.strip(),
                  Field.Store.YES, Field.Index.ANALYZED))
    doc.add(Field("keywords", ' '.join((command, name, synopsis, description)),
                  Field.Store.NO, Field.Index.ANALYZED))
    doc.add(Field("filename", os.path.abspath(path),
                  Field.Store.YES, Field.Index.NOT_ANALYZED))

    writer.addDocument(doc)


if __name__ == '__main__':

    if len(sys.argv) != 2:
        print "Usage: python manindex.py <index dir>"

    else:
        initVM()
        indexDir = sys.argv[1]
        writer = IndexWriter(SimpleFSDirectory(File(indexDir)),
                             StandardAnalyzer(Version.LUCENE_CURRENT), True,
                             IndexWriter.MaxFieldLength.LIMITED)
        manpath = os.environ.get('MANPATH', '/usr/share/man').split(os.pathsep)
        for dir in manpath:
            print "Crawling", dir
            for name in os.listdir(dir):
                path = os.path.join(dir, name)
                if os.path.isdir(path):
                    indexDirectory(path)
        writer.optimize()
        writer.close()