#!/usr/bin/env python3

#  This file is part of Elixir, a source code cross-referencer.
#
#  Copyright (C) 2017--2020 Mikaël Bouillot <mikael.bouillot@bootlin.com>
#  and contributors.
#
#  Elixir is free software: you can redistribute it and/or modify
#  it under the terms of the GNU Affero General Public License as published by
#  the Free Software Foundation, either version 3 of the License, or
#  (at your option) any later version.
#
#  Elixir is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU Affero General Public License for more details.
#
#  You should have received a copy of the GNU Affero General Public License
#  along with Elixir.  If not, see <http://www.gnu.org/licenses/>.

from io import StringIO
from urllib import parse

realprint = print
outputBuffer = StringIO()

def print(arg, end='\n'):
    global outputBuffer
    outputBuffer.write(arg + end)

import cgitb
import cgi
import os
import re
from re import search, sub

# Create /tmp/elixir-errors if not existing yet (could happen after a reboot)
errdir = '/tmp/elixir-errors'

if not(os.path.isdir(errdir)):
    os.makedirs(errdir, exist_ok=True)

# Enable CGI Trackback Manager for debugging (https://docs.python.org/fr/3/library/cgitb.html)
cgitb.enable(display=0, logdir=errdir, format='text')

ident = ''
status = 200

url = os.environ.get('REQUEST_URI') or os.environ.get('SCRIPT_URL')
# Split the URL into its components (project, version, cmd, arg)
m = search('^/([^/]*)/([^/]*)(?:/([^/]))?/([^/]*)(.*)$', url)

if m:
    project = m.group(1)
    version = m.group(2)
    version_decoded = parse.unquote(version)
    family = m.group(3)
    cmd = m.group(4)
    arg = m.group(5)

    if family == None:
        family = 'C'

    basedir = os.environ['LXR_PROJ_DIR']
    datadir = basedir + '/' + project + '/data'
    repodir = basedir + '/' + project + '/repo'

    if not(os.path.exists(datadir)) or not(os.path.exists(repodir)):
        status = 400

    elif cmd == 'source':
        path = arg
        if len(path) > 0 and path[-1] == '/':
            path = path[:-1]
            status = 301
            location = '/'+project+'/'+version+'/source'+path
        else:
            mode = 'source'
            if not search('^[A-Za-z0-9_/.,+-]*$', path):
                status = 400
            url = 'source'+path

    elif cmd == 'ident':
        ident = arg[1:]
        form = cgi.FieldStorage()
        ident2 = form.getvalue('i')
        family2 = form.getvalue('f')
        if ident == '' and ident2:
            status = 302
            ident2 = parse.quote(ident2.strip())
            location = '/'+project+'/'+version+'/'+family2+'/ident/'+ident2
        else:
            mode = 'ident'
            if not(ident and search('^[A-Za-z0-9_-]*$', ident)):
                ident = ''
            url = family + '/ident/' + ident
    else:
        status = 400
else:
    status = 400

if status == 301:
    realprint('Status: 301 Moved Permanently')
    realprint('Location: '+location+'\n')
    exit()
elif status == 302:
    realprint('Status: 302 Found')
    realprint('Location: '+location+'\n')
    exit()
elif status == 400:
    realprint('Status: 400 Bad Request\n')
    exit()

os.environ['LXR_DATA_DIR'] = datadir
os.environ['LXR_REPO_DIR'] = repodir

projects = []
for (dirpath, dirnames, filenames) in os.walk(basedir):
    projects.extend(dirnames)
    break
projects.sort()

import sys
sys.path = [ sys.path[0] + '/..' ] + sys.path
from query import query

if version_decoded == 'latest':
    tag = query('latest')
else:
    tag = version_decoded

data = {
    'baseurl': '/' + project + '/',
    'tag': tag,
    'version': version,
    'url': url,
    'project': project,
    'projects': projects,
    'ident': ident,
    'family': family,
    'breadcrumb': '<a class="project" href="'+version+'/source">/</a>'
}

versions = query('versions')

v = ''
b = 1
for topmenu in versions:
    submenus = versions[topmenu]
    v += '<li>\n'
    v += '\t<span>'+topmenu+'</span>\n'
    v += '\t<ul>\n'
    b += 1
    for submenu in submenus:
        tags = submenus[submenu]
        if submenu == tags[0] and len(tags) == 1:
            if submenu == tag: v += '\t\t<li class="li-link active"><a href="'+submenu+'/'+url+'">'+submenu+'</a></li>\n'
            else: v += '\t\t<li class="li-link"><a href="'+submenu+'/'+url+'">'+submenu+'</a></li>\n'
        else:
            v += '\t\t<li>\n'
            v += '\t\t\t<span>'+submenu+'</span>\n'
            v += '\t\t\t<ul>\n'
            for _tag in tags:
                _tag_encoded = parse.quote(_tag, safe='')
                if _tag == tag: v += '\t\t\t\t<li class="li-link active"><a href="'+_tag_encoded+'/'+url+'">'+_tag+'</a></li>\n'
                else: v += '\t\t\t\t<li class="li-link"><a href="'+_tag_encoded+'/'+url+'">'+_tag+'</a></li>\n'
            v += '\t\t\t</ul></li>\n'
    v += '\t</ul></li>\n'

data['versions'] = v

title_suffix = project.capitalize()+' source code ('+tag+') - Bootlin'

if mode == 'source':
    path_split = path.split('/')[1:]
    path_temp = ''
    links = []
    for p in path_split:
        path_temp += '/'+p
        links.append('<a href="'+version+'/source'+path_temp+'">'+p+'</a>')

    if links:
        data['breadcrumb'] += '/'.join(links)

    data['ident'] = ident
    # Create titles like this:
    # root path: "Linux source code (v5.5.6) - Bootlin"
    # first level path: "arch - Linux source code (v5.5.6) - Bootlin"
    # deeper paths: "Makefile - arch/um/Makefile - Linux source code (v5.5.6) - Bootlin"
    data['title'] = ('' if path == ''
                     else path_split[0]+' - ' if len(path_split) == 1
                     else path_split[-1]+' - '+'/'.join(path_split)+' - ') \
            +title_suffix

    lines = ['null - - -']

    type = query('type', tag, path)
    if len(type) > 0:
        if type == 'tree':
            lines += query('dir', tag, path)
        elif type == 'blob':
            code = query('file', tag, path)
    else:
        print('<div class="lxrerror"><h2>This file does not exist.</h2></div>')
        status = 404

    if type == 'tree':
        if path != '':
            lines[0] = 'back - - -'

        print('<div class="lxrtree">')
        print('<table><tbody>\n')
        for l in lines:
            type, name, size, perm = l.split(' ')

            if type == 'null':
                continue
            elif type == 'tree':
                size = ''
                path2 = path+'/'+name
                name = name
            elif type == 'blob':
                size = size+' bytes'
                path2 = path+'/'+name

                if perm == '120000':
                    # 120000 permission means it's a symlink
                    # So we need to handle that correctly
                    dir_name = os.path.dirname(path)
                    rel_path = query('file', tag, path2)

                    if dir_name != '/':
                        dir_name += '/'

                    path2 = os.path.abspath(dir_name + rel_path)

                    name = name + ' -> ' + path2
            elif type == 'back':
                size = ''
                path2 = os.path.dirname(path[:-1])
                if path2 == '/': path2 = ''
                name = 'Parent directory'

            print('  <tr>\n')
            print('    <td><a class="tree-icon icon-'+type+'" href="'+version+'/source'+path2+'">'+name+'</a></td>\n')
            print('    <td><a tabindex="-1" class="size" href="'+version+'/source'+path2+'">'+size+'</a></td>\n')
            print('  </tr>\n')

        print('</tbody></table>', end='')
        print('</div>')

    elif type == 'blob':

        import pygments
        import pygments.lexers
        import pygments.formatters

        fname = os.path.basename(path)
        filename, extension = os.path.splitext(fname)
        extension = extension[1:].lower()
        family = query('family', fname)
        data['family'] = family

        # Source common filter definitions
        os.chdir('filters')
        exec(open("common.py").read())

        # Source project specific filters
        f = project + '.py'
        if os.path.isfile(f):
            exec(open(f).read())
        os.chdir('..')

        # Apply filters
        for f in filters:
            c = f['case']
            if (c == 'any' or (c == 'filename' and filename in f['match']) or (c == 'extension' and extension in f['match'])):

                apply_filter = True

                if 'path_exceptions' in f:
                    for p in f['path_exceptions']:
                        if re.match(p, path):
                            apply_filter = False
                            break

                if apply_filter:
                    code = sub(f ['prerex'], f ['prefunc'], code, flags=re.MULTILINE)

        try:
            lexer = pygments.lexers.guess_lexer_for_filename(path, code)
        except:
            lexer = pygments.lexers.get_lexer_by_name('text')

        lexer.stripnl = False
        formatter = pygments.formatters.HtmlFormatter(linenos=True, anchorlinenos=True)
        result = pygments.highlight(code, lexer, formatter)

        # Replace line numbers by links to the corresponding line in the current file
        result = sub('href="#-(\d+)', 'name="L\\1" id="L\\1" href="'+version+'/source'+path+'#L\\1', result)

        for f in filters:
            c = f['case']
            if (c == 'any' or (c == 'filename' and filename in f['match']) or (c == 'extension' and extension in f['match'])):
                result = sub(f ['postrex'], f ['postfunc'], result)

        print('<div class="lxrcode">' + result + '</div>')


elif mode == 'ident':
    data['title'] = ident+' identifier - '+title_suffix

    symbol_definitions, symbol_references, symbol_doccomments = query('ident', tag, ident, family)

    print('<div class="lxrident">')
    if len(symbol_definitions):
        print('<h2>Defined in '+str(len(symbol_definitions))+' files:</h2>')
        print('<ul>')
        for symbol_definition in symbol_definitions:
            print('<li><a href="{v}/source/{f}#L{n}"><strong>{f}</strong>, line {n} <em>(as a {t})</em></a>'.format(
                v=version, f=symbol_definition.path, n=symbol_definition.line, t=symbol_definition.type
            ))
        print('</ul>')

        if len(symbol_doccomments):
            print('<h2>Documented in '+str(len(symbol_doccomments))+' files:</h2>')
            print('<ul>')
            for symbol_doccomment in symbol_doccomments:
                print('<li><a href="{v}/source/{f}#L{n}"><strong>{f}</strong>, line {n}</a></li>'.format(
                    v=version, f=symbol_doccomment.path, n=symbol_doccomment.line
                ))
            print('</ul>')


        print('<h2>Referenced in '+str(len(symbol_references))+' files:</h2>')
        print('<ul>')
        for symbol_reference in symbol_references:
            ln = symbol_reference.line.split(',')
            if len(ln) == 1:
                n = ln[0]
                print('<li><a href="{v}/source/{f}#L{n}"><strong>{f}</strong>, line {n}</a>'.format(
                    v=version, f=symbol_reference.path, n=n
                ))
            else:
                if len(symbol_references) > 100:    # Concise display
                    n = len(ln)
                    print('<li><a href="{v}/source/{f}"><strong>{f}</strong>, <em>{n} times</em></a>'.format(
                        v=version, f=symbol_reference.path, n=n
                    ))
                else:    # Verbose display
                    print('<li><a href="{v}/source/{f}#L{n}"><strong>{f}</strong></a>'.format(
                        v=version, f=symbol_reference.path, n=ln[0]
                    ))
                    print('<ul>')
                    for n in ln:
                        print('<li><a href="{v}/source/{f}#L{n}">line {n}</a>'.format(
                            v=version, f=symbol_reference.path, n=n
                        ))
                    print('</ul>')
        print('</ul>')
    else:
        if ident != '':
            print('<h2>Identifier not used</h2>')
            status = 404
    print('</div>')

else:
    print('Invalid request')

if status == 404:
    realprint('Status: 404 Not Found')

import jinja2
loader = jinja2.FileSystemLoader(os.path.join(os.path.dirname(os.path.realpath(__file__)), '../templates/'))
environment = jinja2.Environment(loader=loader)
template = environment.get_template('layout.html')

realprint('Content-Type: text/html;charset=utf-8\n')
data['main'] = outputBuffer.getvalue()
realprint(template.render(data), end='')