import creole
from django.conf import settings
from django.urls.base import reverse
from .help import MYCREOLE_HELP
import importlib
import os
import shutil


def get_full_path(rel_path):
    try:
        return os.path.join(settings.MYCREOLE_ROOT, *rel_path.split('/'))
    except AttributeError:
        raise AttributeError("You need to define a root directory for mycreole in settings.py: MYCREOLE_ROOT")


def delete_attachment_target_path(attachment_target_path):
    shutil.rmtree(get_full_path(attachment_target_path), True)


def mycreole_help_pagecontent():
    return creole.creole2html(MYCREOLE_HELP)


def render_simple(text):
    return creole.creole2html(text)


def render(request, text, attachment_target_path, next_anchor=''):
    def get_attachment_name(text, state):
        end_idx = text.index(']]' if state == '[' else '}}')
        try:
            split_idx = text.index('|')
        except ValueError:
            split_idx = len(text)
        return text[:min(end_idx, split_idx)]

    # Call the additional filters before rendering
    try:
        ext_filters = settings.MYCREOLE_EXT_FILTERS
    except AttributeError:
        pass    # No filters defined
    else:
        for function_string in ext_filters:
            m_name, f_name = function_string.rsplit('.', 1)
            try:
                mod = importlib.import_module(m_name)
            except ModuleNotFoundError:
                pass
            else:
                try:
                    func = getattr(mod, f_name)
                except AttributeError:
                    pass
                else:
                    text = func(text)

    if not attachment_target_path.endswith('/'):
        attachment_target_path += '/'
    try:
        render_txt = ''
        while len(text) > 0:
            try:
                link_pos = text.index('[[attachment:')
            except ValueError:
                link_pos = len(text)
            try:
                embed_pos = text.index('{{attachment:')
            except ValueError:
                embed_pos = len(text)
            pos = min(link_pos, embed_pos)
            render_txt += text[:pos]
            text = text[pos + 13:]
            if link_pos != embed_pos:
                if link_pos < embed_pos:
                    state = '['
                else:
                    state = '{'
                attachment_name = get_attachment_name(text, state)
                text = text[len(attachment_name):]
                rel_path = attachment_target_path + attachment_name
                if os.path.isfile(get_full_path(rel_path)):
                    render_txt += 2 * state + url_attachment(rel_path)
                else:
                    render_txt += '[[%s|Upload]]' % url_upload(request, rel_path, next_anchor)
                    text = text[text.index(']]' if state == '[' else '}}') + 2:]
        return creole.creole2html(render_txt)
    except:
        return creole.creole2html(text)


def url_upload(request, rel_path, next_anchor=''):
    nxt = request.GET.get('next', request.get_full_path())
    return reverse('mycreole-upload', kwargs={'rel_path': rel_path}) + '?next=%s' % nxt + ('' if not next_anchor else '#%s' % next_anchor)


def url_attachment(rel_path):
    return reverse('mycreole-attachment', kwargs={'rel_path': rel_path})


def url_manage_uploads(request, rel_path):
    nxt = request.GET.get('next', request.get_full_path())
    return reverse('mycreole-manageuploads', kwargs={'rel_path': rel_path}) + '?next=%s' % nxt