# -*- coding: utf-8 -*-
# from __future__ import unicode_literals

import hashlib
import locale
import os
from codecs import open
from tempfile import mkdtemp
from shutil import rmtree
import unittest
import subprocess

from pelican import Pelican
from pelican.settings import read_settings

CUR_DIR = os.path.dirname(__file__)
THEME_DIR = os.path.join(CUR_DIR, 'test_data')
CSS_REF = open(os.path.join(THEME_DIR, 'static', 'css',
                            'style.min.css')).read()
CSS_HASH = hashlib.md5(CSS_REF).hexdigest()[0:8]


def skipIfNoExecutable(executable):
    """Skip test if `executable` is not found

    Tries to run `executable` with subprocess to make sure it's in the path,
    and skips the tests if not found (if subprocess raises a `OSError`).
    """

    with open(os.devnull, 'w') as fnull:
        try:
            res = subprocess.call(executable, stdout=fnull, stderr=fnull)
        except OSError:
            res = None

    if res is None:
        return unittest.skip('{0} executable not found'.format(executable))

    return lambda func: func


def module_exists(module_name):
    """Test if a module is importable."""

    try:
        __import__(module_name)
    except ImportError:
        return False
    else:
        return True



@unittest.skipUnless(module_exists('webassets'), "webassets isn't installed")
@skipIfNoExecutable(['scss', '-v'])
@skipIfNoExecutable(['cssmin', '--version'])
class TestWebAssets(unittest.TestCase):
    """Base class for testing webassets."""

    def setUp(self, override=None):
        import assets
        self.temp_path = mkdtemp(prefix='pelicantests.')
        settings = {
            'PATH': os.path.join(os.path.dirname(CUR_DIR), 'test_data', 'content'),
            'OUTPUT_PATH': self.temp_path,
            'PLUGINS': [assets],
            'THEME': THEME_DIR,
            'LOCALE': locale.normalize('en_US'),
        }
        if override:
            settings.update(override)

        self.settings = read_settings(override=settings)
        pelican = Pelican(settings=self.settings)
        pelican.run()

    def tearDown(self):
        rmtree(self.temp_path)

    def check_link_tag(self, css_file, html_file):
        """Check the presence of `css_file` in `html_file`."""

        link_tag = ('<link rel="stylesheet" href="{css_file}">'
                    .format(css_file=css_file))
        html = open(html_file).read()
        self.assertRegexpMatches(html, link_tag)


class TestWebAssetsRelativeURLS(TestWebAssets):
    """Test pelican with relative urls."""


    def setUp(self):
        TestWebAssets.setUp(self, override={'RELATIVE_URLS': True})

    def test_jinja2_ext(self):
        # Test that the Jinja2 extension was correctly added.

        from webassets.ext.jinja2 import AssetsExtension
        self.assertIn(AssetsExtension, self.settings['JINJA_EXTENSIONS'])

    def test_compilation(self):
        # Compare the compiled css with the reference.

        gen_file = os.path.join(self.temp_path, 'theme', 'gen',
                                'style.{0}.min.css'.format(CSS_HASH))
        self.assertTrue(os.path.isfile(gen_file))

        css_new = open(gen_file).read()
        self.assertEqual(css_new, CSS_REF)

    def test_template(self):
        # Look in the output files for the link tag.

        css_file = './theme/gen/style.{0}.min.css'.format(CSS_HASH)
        html_files = ['index.html', 'archives.html',
                      'this-is-a-super-article.html']
        for f in html_files:
            self.check_link_tag(css_file, os.path.join(self.temp_path, f))

        self.check_link_tag(
            '../theme/gen/style.{0}.min.css'.format(CSS_HASH),
            os.path.join(self.temp_path, 'category/yeah.html'))


class TestWebAssetsAbsoluteURLS(TestWebAssets):
    """Test pelican with absolute urls."""

    def setUp(self):
        TestWebAssets.setUp(self, override={'RELATIVE_URLS': False,
                                            'SITEURL': 'http://localhost'})

    def test_absolute_url(self):
        # Look in the output files for the link tag with absolute url.

        css_file = ('http://localhost/theme/gen/style.{0}.min.css'
                    .format(CSS_HASH))
        html_files = ['index.html', 'archives.html',
                      'this-is-a-super-article.html']
        for f in html_files:
            self.check_link_tag(css_file, os.path.join(self.temp_path, f))