import textwrap

from django.contrib import messages
from django.core.mail import mail_admins
from django.core.urlresolvers import reverse
from django.utils.html import escape
from django.utils.safestring import mark_safe
from django.utils.translation import ungettext, ugettext_lazy as _


def get_backends_help_text(backends):
    help_texts = {}
    for backend in backends:
        help_text = backend.__doc__ or ''
        context = {
            'model': backend.model,
            'related_models': str(backend.related_models),
            'script_executable': backend.script_executable,
            'script_method': '.'.join((backend.script_method.__module__, backend.script_method.__name__)),
            'function_method': '.'.join((backend.function_method.__module__, backend.function_method.__name__)),
            'actions': str(backend.actions),
        }
        help_text += textwrap.dedent("""
            - Model: <tt>'%(model)s'</tt>
            - Related models: <tt>%(related_models)s</tt>
            - Script executable: <tt>%(script_executable)s</tt>
            - Script method: <tt>%(script_method)s</tt>
            - Function method: <tt>%(function_method)s</tt>
            - Actions: <tt>%(actions)s</tt>
            """
        ) % context
        help_text = help_text.lstrip().splitlines()
        help_settings = ['']
        if backend.doc_settings:
            module, names = backend.doc_settings
            for name in names:
                value = getattr(module, name)
                if isinstance(value, str):
                    help_settings.append("<tt>%s = '%s'</tt>" % (name, value))
                else:
                    help_settings.append("<tt>%s = %s</tt>" % (name, str(value)))
        help_text += help_settings
        help_texts[backend.get_name()] = '<br>'.join(help_text)
    return help_texts


def send_report(method, args, log):
    server = args[0]
    backend = method.__self__.__class__.__name__
    subject = '[Orchestra] %s execution %s on %s'  % (backend, log.state, server)
    separator = "\n%s\n\n" % ('~ '*40,)
    message = separator.join([
        "[EXIT CODE] %s" % log.exit_code,
        "[STDERR]\n%s" % log.stderr,
        "[STDOUT]\n%s" % log.stdout,
        "[SCRIPT]\n%s" % log.script,
        "[TRACEBACK]\n%s" % log.traceback,
    ])
    html_message = '\n\n'.join([
        '<h4 style="color:#505050;">Exit code %s</h4>' % log.exit_code,
        '<h4 style="color:#505050;">Stderr</h4>'
            '<pre style="margin-left:20px;font-size:11px">%s</pre>' % escape(log.stderr),
        '<h4 style="color:#505050;">Stdout</h4>'
            '<pre style="margin-left:20px;font-size:11px">%s</pre>' % escape(log.stdout),
        '<h4 style="color:#505050;">Script</h4>'
            '<pre style="margin-left:20px;font-size:11px">%s</pre>' % escape(log.script),
        '<h4 style="color:#505050;">Traceback</h4>'
            '<pre style="margin-left:20px;font-size:11px">%s</pre>' % escape(log.traceback),
    ])
    mail_admins(subject, message, html_message=html_message)


def message_user(request, logs):
    total, successes = 0, 0
    ids = []
    for log in logs:
        total += 1
        if log.state != log.EXCEPTION:
            # EXCEPTION logs are not stored on the database
            ids.append(log.pk)
        if log.state in (log.SUCCESS, log.NOTHING):
            successes += 1
    errors = total-successes
    if len(ids) == 1:
        url = reverse('admin:orchestration_backendlog_change', args=ids)
        href = '<a href="{}">backends</a>'.format(url)
    elif len(ids) > 1:
        url = reverse('admin:orchestration_backendlog_changelist')
        url += '?id__in=%s' % ','.join(map(str, ids))
        href = '<a href="{}">backends</a>'.format(url)
    else:
        href = ''
    if errors:
        msg = ungettext(
            _('{errors} out of {total} {href} has fail to execute.'),
            _('{errors} out of {total} {href} have fail to execute.'),
            errors)
        messages.error(request, mark_safe(msg.format(errors=errors, total=total, href=href)))
    else:
        msg = ungettext(
            _('{total} {href} has been executed.'),
            _('{total} {href} have been executed.'),
            total)
        messages.success(request, mark_safe(msg.format(total=total, href=href)))