#!/usr/bin/env python3
import os

import click
from git import Repo
from setuptools_scm import get_version
import shutil

from . import settings

__all__ = ['Library', 'main']

class Library():
    """A Clean library"""
    def __init__(self, path):
        self.path = Library.get_path(path)

    def upgrade(self):
        repo = Repo(self.path)
        old_sha = repo.head.commit.hexsha
        repo.remotes.origin.pull()
        new_sha = repo.head.commit.hexsha
        return old_sha != new_sha

    def remove(self):
        shutil.rmtree(self.path)

    @staticmethod
    def get_path(lib):
        """Get the path of a library in the installation dir"""
        install_dir = settings.read()['General']['install_dir']
        for path in settings.get_search_paths():
            if os.path.isdir(path + '/' + lib):
                return path + '/' + lib
        raise ValueError('\'%s\': no such library' % lib)

    @staticmethod
    def clone(repo, local_dir):
        """New library by cloning a repo to the installation dir"""
        install_dir = settings.read()['General']['install_dir']
        settings.make_install_dir(install_dir)
        Repo.clone_from(repo, install_dir + '/' + local_dir)
        return Library(local_dir)

@click.group()
def cli():
    pass

@cli.command('version')
def cli_version():
    """Print clmgr's version."""
    print(get_version())

@cli.command('init')
@click.argument('install_dir', type=click.Path(),
        metavar='install_dir', default='~/.clmgr')
def cli_init(install_dir):
    """Initialise the installation directory."""
    settings.init(install_dir)

@cli.command('install')
@click.option('--abs/--github',
        help='Use an absolute path (default: use GitHub)')
@click.argument('repo', metavar='repo')
@click.argument('local_dir', metavar='local_dir', required=False)
def cli_install(abs, repo, local_dir):
    """Clone a repository.

    If local_dir is empty, the last part of repo will be used.
    
    Examples:
    
    \b
        clmgr install username/MyLibrary (local_dir will be MyLibrary)
        clmgr install --abs /var/git/my-library LocalName"""
    if local_dir == None:
        local_dir = list(filter(lambda x: len(x)>0, repo.split('/')))[-1]
        click.secho('No local_dir given, using \'%s\'' % local_dir, 
                err=True, fg='yellow')
    
    if abs:
        Library.clone(repo, local_dir)
    else:
        Library.clone('https://github.com/' + repo, local_dir)

    click.secho('%s installed as %s.' % (repo, local_dir), fg='green')

@cli.command('upgrade')
@click.argument('library')
def cli_upgrade(library):
    """Upgrade an installed library."""
    if Library(library).upgrade():
        click.secho('%s upgraded.' % library, fg='green')
    else:
        click.secho('%s is already the newest version.' % library, fg='yellow')

@cli.command('remove')
@click.argument('library')
def cli_remove(library):
    """Remove an installed library."""
    Library(library).remove()
    click.secho('%s removed.' % library, fg='green')

@cli.command('echo')
@click.option('--indent/--no-indent', help='Indent hierarchically')
@click.argument('what', metavar='what', default='')
def cli_echo(indent, what):
    """Give information about settings.
    
    Examples:
    
    \b
        clmgr echo
        clmgr echo --indent
        clmgr echo General.install_dir

    Magic examples:

    \b
        clmgr echo search_path"""
    if what == 'search_path':
        click.echo('\n'.join(settings.get_search_paths()))
    else:
        settings_path = what.split('.')
        config = dict(settings.read())
        for name in [p for p in settings_path if p != '']:
            try:
                config = dict(config[name])
            except KeyError:
                click.echo('No setting \'%s\'' % name, err=True)
                return
        settings.print_config(config, indent_step=2 if indent else 0)

def main():
    cli()

if __name__ == '__main__':
    main()