# Copyright (c) 2015, Frappe Technologies Pvt. Ltd. and Contributors
# License: MIT. See LICENSE

# Search
import frappe, json
from frappe.utils import cstr, unique, cint
from frappe.permissions import has_permission
from frappe import _, is_whitelisted
import re
import wrapt

UNTRANSLATED_DOCTYPES = ["DocType", "Role"]

def sanitize_searchfield(searchfield):
	blacklisted_keywords = ['select', 'delete', 'drop', 'update', 'case', 'and', 'or', 'like']

	def _raise_exception(searchfield):
		frappe.throw(_('Invalid Search Field {0}').format(searchfield), frappe.DataError)

	if len(searchfield) == 1:
		# do not allow special characters to pass as searchfields
		regex = re.compile(r'^.*[=;*,\'"$\-+%#@()_].*')
		if regex.match(searchfield):
			_raise_exception(searchfield)

	if len(searchfield) >= 3:

		# to avoid 1=1
		if '=' in searchfield:
			_raise_exception(searchfield)

		# in mysql -- is used for commenting the query
		elif ' --' in searchfield:
			_raise_exception(searchfield)

		# to avoid and, or and like
		elif any(' {0} '.format(keyword) in searchfield.split() for keyword in blacklisted_keywords):
			_raise_exception(searchfield)

		# to avoid select, delete, drop, update and case
		elif any(keyword in searchfield.split() for keyword in blacklisted_keywords):
			_raise_exception(searchfield)

		else:
			regex = re.compile(r'^.*[=;*,\'"$\-+%#@()].*')
			if any(regex.match(f) for f in searchfield.split()):
				_raise_exception(searchfield)

# this is called by the Link Field
@frappe.whitelist()
def search_link(doctype, txt, query=None, filters=None, page_length=20, searchfield=None, reference_doctype=None, ignore_user_permissions=False):
	search_widget(doctype, txt.strip(), query, searchfield=searchfield, page_length=page_length, filters=filters, reference_doctype=reference_doctype, ignore_user_permissions=ignore_user_permissions)
	frappe.response['results'] = build_for_autosuggest(frappe.response["values"])
	del frappe.response["values"]

# this is called by the search box
@frappe.whitelist()
def search_widget(doctype, txt, query=None, searchfield=None, start=0,
	page_length=20, filters=None, filter_fields=None, as_dict=False, reference_doctype=None, ignore_user_permissions=False):

	start = cint(start)

	if isinstance(filters, str):
		filters = json.loads(filters)

	if searchfield:
		sanitize_searchfield(searchfield)

	if not searchfield:
		searchfield = "name"

	standard_queries = frappe.get_hooks().standard_queries or {}

	if query and query.split()[0].lower()!="select":
		# by method
		try:
			is_whitelisted(frappe.get_attr(query))
			frappe.response["values"] = frappe.call(query, doctype, txt,
				searchfield, start, page_length, filters, as_dict=as_dict)
		except frappe.exceptions.PermissionError as e:
			if frappe.local.conf.developer_mode:
				raise e
			else:
				frappe.respond_as_web_page(title='Invalid Method', html='Method not found',
				indicator_color='red', http_status_code=404)
			return
		except Exception as e:
			raise e
	elif not query and doctype in standard_queries:
		# from standard queries
		search_widget(doctype, txt, standard_queries[doctype][0],
			searchfield, start, page_length, filters)
	else:
		meta = frappe.get_meta(doctype)

		if query:
			frappe.throw(_("This query style is discontinued"))
			# custom query
			# frappe.response["values"] = frappe.db.sql(scrub_custom_query(query, searchfield, txt))
		else:
			if isinstance(filters, dict):
				filters_items = filters.items()
				filters = []
				for f in filters_items:
					if isinstance(f[1], (list, tuple)):
						filters.append([doctype, f[0], f[1][0], f[1][1]])
					else:
						filters.append([doctype, f[0], "=", f[1]])

			if filters==None:
				filters = []
			or_filters = []


			# build from doctype
			if txt:
				search_fields = ["name"]
				if meta.title_field:
					search_fields.append(meta.title_field)

				if meta.search_fields:
					search_fields.extend(meta.get_search_fields())

				for f in search_fields:
					fmeta = meta.get_field(f.strip())
					if (doctype not in UNTRANSLATED_DOCTYPES) and (f == "name" or (fmeta and fmeta.fieldtype in ["Data", "Text", "Small Text", "Long Text",
						"Link", "Select", "Read Only", "Text Editor"])):
							or_filters.append([doctype, f.strip(), "like", "%{0}%".format(txt)])

			if meta.get("fields", {"fieldname":"enabled", "fieldtype":"Check"}):
				filters.append([doctype, "enabled", "=", 1])
			if meta.get("fields", {"fieldname":"disabled", "fieldtype":"Check"}):
				filters.append([doctype, "disabled", "!=", 1])

			# format a list of fields combining search fields and filter fields
			fields = get_std_fields_list(meta, searchfield or "name")
			if filter_fields:
				fields = list(set(fields + json.loads(filter_fields)))
			formatted_fields = ['`tab%s`.`%s`' % (meta.name, f.strip()) for f in fields]

			# find relevance as location of search term from the beginning of string `name`. used for sorting results.
			formatted_fields.append("""locate({_txt}, `tab{doctype}`.`name`) as `_relevance`""".format(
				_txt=frappe.db.escape((txt or "").replace("%", "").replace("@", "")), doctype=doctype))


			# In order_by, `idx` gets second priority, because it stores link count
			from frappe.model.db_query import get_order_by
			order_by_based_on_meta = get_order_by(doctype, meta)
			# 2 is the index of _relevance column
			order_by = "_relevance, {0}, `tab{1}`.idx desc".format(order_by_based_on_meta, doctype)

			ptype = 'select' if frappe.only_has_select_perm(doctype) else 'read'
			ignore_permissions = True if doctype == "DocType" else (cint(ignore_user_permissions) and has_permission(doctype, ptype=ptype))

			if doctype in UNTRANSLATED_DOCTYPES:
				page_length = None

			values = frappe.get_list(doctype,
				filters=filters,
				fields=formatted_fields,
				or_filters=or_filters,
				limit_start=start,
				limit_page_length=page_length,
				order_by=order_by,
				ignore_permissions=ignore_permissions,
				reference_doctype=reference_doctype,
				as_list=not as_dict,
				strict=False)

			if doctype in UNTRANSLATED_DOCTYPES:
				# Filtering the values array so that query is included in very element
				values = (
					v for v in values
					if re.search(
						f"{re.escape(txt)}.*", _(v.name if as_dict else v[0]), re.IGNORECASE
					)
				)

			# Sorting the values array so that relevant results always come first
			# This will first bring elements on top in which query is a prefix of element
			# Then it will bring the rest of the elements and sort them in lexicographical order
			values = sorted(values, key=lambda x: relevance_sorter(x, txt, as_dict))

			# remove _relevance from results
			if as_dict:
				for r in values:
					r.pop("_relevance")
				frappe.response["values"] = values
			else:
				frappe.response["values"] = [r[:-1] for r in values]

def get_std_fields_list(meta, key):
	# get additional search fields
	sflist = ["name"]
	if meta.search_fields:
		for d in meta.search_fields.split(","):
			if d.strip() not in sflist:
				sflist.append(d.strip())

	if meta.title_field and meta.title_field not in sflist:
		sflist.append(meta.title_field)

	if key not in sflist:
		sflist.append(key)

	return sflist

def build_for_autosuggest(res):
	results = []
	for r in res:
		out = {"value": r[0], "description": ", ".join(unique(cstr(d) for d in r if d)[1:])}
		results.append(out)
	return results

def scrub_custom_query(query, key, txt):
	if '%(key)s' in query:
		query = query.replace('%(key)s', key)
	if '%s' in query:
		query = query.replace('%s', ((txt or '') + '%'))
	return query

def relevance_sorter(key, query, as_dict):
	value = _(key.name if as_dict else key[0])
	return (
		value.lower().startswith(query.lower()) is not True,
		value
	)

@wrapt.decorator
def validate_and_sanitize_search_inputs(fn, instance, args, kwargs):
	kwargs.update(dict(zip(fn.__code__.co_varnames, args)))
	sanitize_searchfield(kwargs['searchfield'])
	kwargs['start'] = cint(kwargs['start'])
	kwargs['page_len'] = cint(kwargs['page_len'])

	if kwargs['doctype'] and not frappe.db.exists('DocType', kwargs['doctype']):
		return []

	return fn(**kwargs)


@frappe.whitelist()
def get_names_for_mentions(search_term):
	users_for_mentions = frappe.cache().get_value('users_for_mentions', get_users_for_mentions)
	user_groups = frappe.cache().get_value('user_groups', get_user_groups)

	filtered_mentions = []
	for mention_data in users_for_mentions + user_groups:
		if search_term.lower() not in mention_data.value.lower():
			continue

		mention_data['link'] = frappe.utils.get_url_to_form(
			'User Group' if mention_data.get('is_group') else 'User Profile',
			mention_data['id']
		)

		filtered_mentions.append(mention_data)

	return sorted(filtered_mentions, key=lambda d: d['value'])

def get_users_for_mentions():
	return frappe.get_all('User',
		fields=['name as id', 'full_name as value'],
		filters={
			'name': ['not in', ('Administrator', 'Guest')],
			'allowed_in_mentions': True,
			'user_type': 'System User',
			'enabled': True,
		})

def get_user_groups():
	return frappe.get_all('User Group', fields=['name as id', 'name as value'], update={
		'is_group': True
	})