import os, json, inspect
import mimetypes
from html2text import html2text
from RestrictedPython import compile_restricted, safe_globals
import frappe
import frappe.utils
import frappe.utils.data
from frappe.website.utils import (get_shade, get_toc, get_next_link)
from frappe.modules import scrub
from frappe.www.printview import get_visible_columns
import frappe.exceptions

class ServerScriptNotEnabled(frappe.PermissionError): pass

def safe_exec(script, _globals=None, _locals=None):
	# script reports must be enabled via site_config.json
	if not frappe.conf.server_script_enabled:
		frappe.msgprint('Please Enable Server Scripts')
		raise ServerScriptNotEnabled

	# build globals
	exec_globals = get_safe_globals()
	if _globals:
		exec_globals.update(_globals)

	# execute script compiled by RestrictedPython
	exec(compile_restricted(script), exec_globals, _locals) # pylint: disable=exec-used

def get_safe_globals():
	datautils = {}
	if frappe.db:
		date_format = frappe.db.get_default("date_format") or "yyyy-mm-dd"
	else:
		date_format = 'yyyy-mm-dd'

	add_module_properties(frappe.utils.data, datautils, lambda obj: hasattr(obj, "__call__"))

	if "_" in getattr(frappe.local, 'form_dict', {}):
		del frappe.local.form_dict["_"]

	user = getattr(frappe.local, "session", None) and frappe.local.session.user or "Guest"

	out = frappe._dict(
		# make available limited methods of frappe
		json = json,
		dict = dict,
		frappe =  frappe._dict(
			_ = frappe._,
			_dict = frappe._dict,
			flags = frappe.flags,

			format = frappe.format_value,
			format_value = frappe.format_value,
			date_format = date_format,
			format_date = frappe.utils.data.global_date_format,
			form_dict = getattr(frappe.local, 'form_dict', {}),

			get_meta = frappe.get_meta,
			get_doc = frappe.get_doc,
			get_cached_doc = frappe.get_cached_doc,
			get_list = frappe.get_list,
			get_all = frappe.get_all,
			get_system_settings = frappe.get_system_settings,

			utils = datautils,
			get_url = frappe.utils.get_url,
			render_template = frappe.render_template,
			msgprint = frappe.msgprint,

			user = user,
			get_fullname = frappe.utils.get_fullname,
			get_gravatar = frappe.utils.get_gravatar_url,
			full_name = frappe.local.session.data.full_name if getattr(frappe.local, "session", None) else "Guest",
			request = getattr(frappe.local, 'request', {}),
			session = frappe._dict(
				user = user,
				csrf_token = frappe.local.session.data.csrf_token if getattr(frappe.local, "session", None) else ''
			),
			socketio_port = frappe.conf.socketio_port,
			get_hooks = frappe.get_hooks,
		),
		style = frappe._dict(
			border_color = '#d1d8dd'
		),
		get_toc =  get_toc,
		get_next_link = get_next_link,
		_ =  frappe._,
		get_shade = get_shade,
		scrub =  scrub,
		guess_mimetype = mimetypes.guess_type,
		html2text = html2text,
		dev_server =  1 if os.environ.get('DEV_SERVER', False) else 0
	)

	add_module_properties(frappe.exceptions, out.frappe, lambda obj: inspect.isclass(obj) and issubclass(obj, Exception))

	if not frappe.flags.in_setup_help:
		out.get_visible_columns = get_visible_columns
		out.frappe.date_format = date_format
		out.frappe.db = frappe._dict(
			get_list = frappe.get_list,
			get_all = frappe.get_all,
			get_value = frappe.db.get_value,
			get_single_value = frappe.db.get_single_value,
			get_default = frappe.db.get_default,
			escape = frappe.db.escape,
		)

	if frappe.response:
		out.frappe.response = frappe.response

	out.update(safe_globals)

	# default writer allows write access
	out._write_ = _write
	out._getitem_ = _getitem

	return out

def _getitem(obj, key):
	# guard function for RestrictedPython
	# allow any key to be accessed as long as it does not start with underscore
	if isinstance(key, str) and key.startswith('_'):
		raise SyntaxError('Key starts with _')
	return obj[key]

def _write(obj):
	# guard function for RestrictedPython
	# allow writing to any object
	return obj

def add_module_properties(module, data, filter_method):
	for key, obj in module.__dict__.items():
		if key.startswith("_"):
			# ignore
			continue

		if filter_method(obj):
			# only allow functions
			data[key] = obj