import os, shutil

from django.conf import settings
from django.core.management import call_command
from django.core.management.base import BaseCommand, CommandError
from django.core.urlresolvers import reverse
from django.test.client import Client

def get_pages():
    for name in os.listdir(settings.SITE_PAGES_DIR):
        if name.endswith('.html'):
            yield name[:-5]

class Command(BaseCommand):

    def handle(self, *args, **options):
        """Request pages and build output."""

        if args:
            pages = args
            available = list(get_pages())
            invalid  = []

            for page in pages:
                if page not in available:
                    invalid.append(page)
            if invalid:
                msg = "Invalid Pages: {}".format(', '.join(invalid))
                raise CommandError(msg)
        else:
            pages = get_pages()
            if os.path.exists(settings.SITE_OUTPUT_DIR):
                shutil.rmtree(settings.SITE_OUTPUT_DIR)
            os.mkdir(settings.SITE_OUTPUT_DIR)
            os.makedirs(settings.STATIC_ROOT)
        call_command('collectstatic', interactive=False, clear=True, verbosity=0)
        client = Client()

        for page in get_pages():
            url = reverse('page', kwargs={'slug' : page})
            response = client.get(url)
            if page == 'index':
                output_dir = settings.SITE_OUTPUT_DIR
            else:
                output_dir = os.path.join(settings.SITE_OUTPUT_DIR, page)
                os.makedirs(output_dir)
            with open(os.path.join(output_dir, 'index.html'), 'wb') as f:
                f.write(response.content)