#!/usr/bin/python
# Copyright (C) 2011  Codethink Limited
# 
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; version 2 of the License.
# 
# This program 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 General Public License for more details.
# 
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.


import cliapp
import json
import logging
import os


__version__ = '0.0'


class Lorry(cliapp.Application):

    def add_settings(self):
        self.settings.string(['working-area', 'w'],
                             'use DIR as the working area (for holding '
                                'intermediate git repositories, etc)',
                             metavar='DIR')
        self.settings.string(['gitorious-base-url'],
                             'prefix project names with URL when constructing '
                                'the git URL on Gitorious (default: %default)',
                             metavar='URL',
                             default='git@gitorious.org:baserock-morphs')
        self.settings.boolean(['pull-only'], 
                              'only pull from upstreams, do not push to '
                                'gitorious')
        self.settings.boolean(['verbose', 'v'], 
                              'report what is going on to stdout')

    def process_args(self, args):
        for arg in args:
            self.progress('Processing spec file %s' % arg)
            with open(arg) as f:
                specs = json.load(f)
            for name in sorted(specs.keys()):
                self.gitify(name, specs[name])
        self.progress('Done')
    
    def gitify(self, name, spec):
        self.progress('Getting %s from %s' % (name, spec['url']))
        table = {
            'bzr': self.gitify_bzr,
            'cvs': self.gitify_cvs,
            'git': self.mirror_git,
            'svn': self.gitify_svn,
        }
        vcstype = spec['type']
        if vcstype not in table:
            raise cliapp.AppException('Unknown VCS type %s' % vcstype)
        dirname = self.dirname(name)
        if not os.path.exists(dirname):
            os.mkdir(dirname)
        gitdir = os.path.join(dirname, 'git')
        table[vcstype](dirname, gitdir, spec)
        if not self.settings['pull-only']:
            self.push_to_gitorious(name, gitdir)
        
    def mirror_git(self, dirname, gitdir, spec):
        if not os.path.exists(gitdir):
            self.progress('.. doing initial clone')
            self.run_program(['git', 'clone', spec['url'], gitdir])
        else:
            self.progress('.. updating existing clone')
            self.run_program(['git', 'pull'], cwd=gitdir)

    def gitify_bzr(self, dirname, gitdir, spec):
        self.progress('.. fast-exporting from bzr')
        export = os.path.join(dirname, 'fast-export')
        self.run_program(['bzr', 'fast-export', '--quiet', 
                          spec['url'], export])
        if not os.path.exists(gitdir):
            self.progress('.. creating git repo')
            os.mkdir(gitdir)
            self.run_program(['git', 'init', '.'], cwd=gitdir)
        self.progress('.. reading fast-export data')
        with open(export) as f:
            data = f.read()
        self.progress('.. fast-importing into git')
        self.run_program(['git', 'fast-import'], stdin=data, cwd=gitdir)

    def gitify_svn(self, dirname, gitdir, spec):
        if not os.path.exists(gitdir):
            self.progress('.. doing initial clone')
            os.mkdir(gitdir)
            self.run_program(['git', 'svn', 'clone', spec['url'], gitdir])
        else:
            self.progress('.. updating existing clone')
            self.run_program(['git', 'svn', 'rebase'], cwd=gitdir)

    def gitify_cvs(self, dirname, gitdir, spec):
        self.run_program(['git', 'cvsimport', '-d', spec['url'],
                          '-C', gitdir, spec['module']])

    def push_to_gitorious(self, project_name, gitdir):
        out = self.run_program(['git', 'remote', 'show'], cwd=gitdir)
        if 'gitorious' not in out.splitlines():
            self.progress('.. adding gitorious as a remote')
            url = ('%s/%s.git' % 
                   (self.settings['gitorious-base-url'], project_name))
            self.run_program(['git', 'remote', 'add', 'gitorious', url],
                             cwd=gitdir)

        self.progress('.. pushing to gitorious')
        self.run_program(['git', 'push', 'gitorious', 'master'], cwd=gitdir)

    def run_program(self, argv, **kwargs):
        exit, out, err = self.runcmd_unchecked(argv, **kwargs)
        logging.debug('Command: %s\nExit: %s\nStdout:\n%sStderr:\n%s' % 
                      (argv, exit, self.indent(out), self.indent(err)))
        if exit != 0:
            raise Exception('%s failed (exit code %s):\n%s' % 
                                (' '.join(argv), exit, self.indent(err)))
        return out

    def indent(self, string):
        return ''.join('    %s\n' % line for line in string.splitlines())
    
    def dirname(self, project_name):
        assert '/' not in project_name
        assert '\0' not in project_name
        return os.path.join(self.settings['working-area'], project_name)

    def progress(self, msg):
        logging.debug(msg)
        if self.settings['verbose']:
            self.output.write('%s\n' % msg)


if __name__ == '__main__':
    Lorry(version=__version__).run()