from flask import current_app, request, url_for

from .const import PERMISSION_PREFIX


def app_template_filter(filter_name=""):
    def wrap(f):
        if not hasattr(f, "_filter"):
            f._filter = filter_name
        return f

    return wrap


class TemplateFilters(object):

    security_manager = None

    def __init__(self, app, security_manager):

        self.security_manager = security_manager
        for attr_name in dir(self):
            if hasattr(getattr(self, attr_name), "_filter"):
                attr = getattr(self, attr_name)
                app.jinja_env.filters[attr._filter] = attr

    @app_template_filter("get_actions_on_list")
    def get_actions_on_list(self, actions, modelview_name):
        res_actions = dict()
        for action_key in actions:
            action = actions[action_key]
            if self.is_item_visible(action.name, modelview_name) and action.multiple:
                res_actions[action_key] = action
        return res_actions

    @app_template_filter("get_actions_on_show")
    def get_actions_on_show(self, actions, modelview_name):
        res_actions = dict()
        for action_key in actions:
            action = actions[action_key]
            if self.is_item_visible(action.name, modelview_name) and action.single:
                res_actions[action_key] = action
        return res_actions

    @app_template_filter("safe_url_for")
    def safe_url_for(self, endpoint, **values):
        try:
            return url_for(endpoint, **values)
        except Exception:
            return None

    @app_template_filter("link_order")
    def link_order_filter(self, column, modelview_name):
        """
            Arguments are passed like:
                _oc_<VIEW_NAME>=<COL_NAME>&_od_<VIEW_NAME>='asc'|'desc'
        """
        new_args = request.view_args.copy()
        args = request.args.copy()
        if ("_oc_" + modelview_name) in args:
            args["_oc_" + modelview_name] = column
            if args.get("_od_" + modelview_name) == "asc":
                args["_od_" + modelview_name] = "desc"
            else:
                args["_od_" + modelview_name] = "asc"
        else:
            args["_oc_" + modelview_name] = column
            args["_od_" + modelview_name] = "asc"
        return url_for(
            request.endpoint,
            **dict(list(new_args.items()) + list(args.to_dict().items()))
        )

    @app_template_filter("link_page")
    def link_page_filter(self, page, modelview_name):
        """
            Arguments are passed like: page_<VIEW_NAME>=<PAGE_NUMBER>
        """
        new_args = request.view_args.copy()
        args = request.args.copy()
        args["page_" + modelview_name] = page
        return url_for(
            request.endpoint,
            **dict(list(new_args.items()) + list(args.to_dict().items()))
        )

    @app_template_filter("link_page_size")
    def link_page_size_filter(self, page_size, modelview_name):
        """
        Arguments are passed like: psize_<VIEW_NAME>=<PAGE_NUMBER>
        """
        new_args = request.view_args.copy()
        args = request.args.copy()
        args["psize_" + modelview_name] = page_size
        return url_for(
            request.endpoint,
            **dict(list(new_args.items()) + list(args.to_dict().items()))
        )

    @app_template_filter("get_link_next")
    def get_link_next_filter(self, s):
        return request.args.get("next")

    @app_template_filter("get_link_back")
    def get_link_back_filter(self, request):
        return request.args.get("next") or request.referrer

    # TODO improve this
    @app_template_filter("set_link_filters")
    def set_link_filters_filter(self, path, filters):
        lnkstr = path
        for flt, value in filters.get_filters_values():
            if flt.is_related_view:
                if "?" in lnkstr:
                    lnkstr = lnkstr + "&_flt_0_" + flt.column_name + "=" + str(value)
                else:
                    lnkstr = lnkstr + "?_flt_0_" + flt.column_name + "=" + str(value)
        return lnkstr

    @app_template_filter("get_link_order")
    def get_link_order_filter(self, column, modelview_name):
        if request.args.get("_oc_" + modelview_name) == column:
            if request.args.get("_od_" + modelview_name) == "asc":
                return 2
            else:
                return 1
        else:
            return 0

    @app_template_filter("get_attr")
    def get_attr_filter(self, obj, item):
        return getattr(obj, item)

    @app_template_filter("is_menu_visible")
    def is_menu_visible(self, item):
        return self.security_manager.has_access("menu_access", item.name)

    @staticmethod
    def find_views_by_name(view_name):
        for view in current_app.appbuilder.baseviews:
            if view.__class__.__name__ == view_name:
                return view

    @app_template_filter("is_item_visible")
    def is_item_visible(self, permission: str, item: str) -> bool:
        """
            Check if an item is visible on the template
            this changed with permission mapping feature.
            This is a best effort to deliver the feature
            and not break compatibility

            permission is:
             - 'can_' + <METHOD_NAME>: On normal routes
             - <METHOD_NAME>: when it's an action

        """
        _view = self.find_views_by_name(item)
        item = _view.class_permission_name

        if PERMISSION_PREFIX in permission:
            method = permission.split(PERMISSION_PREFIX)[1]
        else:
            if hasattr(_view, "actions") and _view.actions.get(permission):
                permission_name = _view.get_action_permission_name(permission)
                if permission_name not in _view.base_permissions:
                    return False
                return self.security_manager.has_access(permission_name, item)
            else:
                method = permission
        permission_name = PERMISSION_PREFIX + _view.get_method_permission(method)
        if permission_name not in _view.base_permissions:
            return False
        return self.security_manager.has_access(permission_name, item)
