import io
from difflib import unified_diff

from django.conf import settings
from django.core.checks import Error, Warning, register
from django.core.management import call_command


@register()
def check_inspected_databases(app_configs, **kwargs):
    r = []
    r += check_inspected_db('drupal')
    r += check_inspected_db('spip', tables_prefix=settings.SPIP_TABLES_PREFIX)
    return r


def check_inspected_db(dbname, **kwargs):
    buf = io.StringIO()
    rc = call_command('inspectdb', '--database', dbname, stdout=buf, **kwargs)
    if rc is not None:
        return [
            Error(
                "Command inspectdb failed.",
                hint='Try to launch "./manage.py inspectdb --database={}" '
                'and report an issue.'.format(dbname),
                obj='drupal2spip_lal.base',
                id='drupal2spip_lal.E001',
            )
        ]

    buf.seek(0)
    inspected_db = buf.read()
    buf.close()
    try:
        with open('drupal2spip_lal/{}/models.py'.format(dbname), 'r') as f:
            if f.read() != inspected_db:
                f.seek(0)
                for line in unified_diff(
                    f.read().split('\n'), inspected_db.split('\n')
                ):
                    print(line)
                return [
                    Warning(
                        "Outdated drupal2spip_lal/{}/models.py".format(dbname),
                        hint='Refresh it using "make inspectdb".',
                        obj='drupal2spip_lal.base',
                        id='drupal2spip_lal.W002',
                    )
                ]
    except Exception:
        return [
            Warning(
                "Missing drupal2spip_lal/{}/models.py".format(dbname),
                hint='Create it using "make inspectdb".',
                obj='drupal2spip_lal.base',
                id='drupal2spip_lal.W001',
            )
        ]
    return []