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

from __future__ import unicode_literals
import frappe
from frappe.desk.notifications import clear_notifications

# Note: DefaultValue records are identified by parenttype
# __default, __global or 'User Permission'

common_keys = ["__default", "__global"]

def set_user_default(key, value, user=None, parenttype=None):
	set_default(key, value, user or frappe.session.user, parenttype)

def add_user_default(key, value, user=None, parenttype=None):
	add_default(key, value, user or frappe.session.user, parenttype)

def get_user_default(key, user=None):
	d = get_defaults(user or frappe.session.user).get(key, None)
	return isinstance(d, list) and d[0] or d

def get_user_default_as_list(key, user=None):
	d = get_defaults(user or frappe.session.user).get(key, None)
	return (not isinstance(d, list)) and [d] or d

def get_user_permissions(user=None):
	if not user:
		user = frappe.session.user

	return build_user_permissions(user)

def build_user_permissions(user):
	out = frappe.cache().hget("user_permissions", user)
	if out==None:
		out = {}
		for key, value in frappe.db.sql("""select defkey, ifnull(defvalue, '') as defvalue
			from tabDefaultValue where parent=%s and parenttype='User Permission'""", (user,)):
			out.setdefault(key, []).append(value)

		# add profile match
		if user not in out.get("User", []):
			out.setdefault("User", []).append(user)

		frappe.cache().hset("user_permissions", user, out)
	return out

def get_defaults(user=None):
	globald = get_defaults_for()

	if not user:
		user = frappe.session.user if frappe.session else "Guest"

	if user:
		userd = get_defaults_for(user)
		userd.update({"user": user, "owner": user})
		globald.update(userd)

	return globald

def clear_user_default(key, user=None):
	clear_default(key, parent=user or frappe.session.user)

# Global

def set_global_default(key, value):
	set_default(key, value, "__default")

def add_global_default(key, value):
	add_default(key, value, "__default")

def get_global_default(key):
	d = get_defaults().get(key, None)
	return isinstance(d, list) and d[0] or d

# Common

def set_default(key, value, parent, parenttype="__default"):
	"""Override or add a default value.
	Adds default value in table `tabDefaultValue`.

	:param key: Default key.
	:param value: Default value.
	:param parent: Usually, **User** to whom the default belongs.
	:param parenttype: [optional] default is `__default`."""
	frappe.db.sql("""delete from `tabDefaultValue` where defkey=%s and parent=%s""", (key, parent))
	add_default(key, value, parent)

def add_default(key, value, parent, parenttype=None):
	d = frappe.get_doc({
		"doctype": "DefaultValue",
		"parent": parent,
		"parenttype": parenttype or "__default",
		"parentfield": "system_defaults",
		"defkey": key,
		"defvalue": value
	})
	d.insert(ignore_permissions=True)
	_clear_cache(parent)

def clear_default(key=None, value=None, parent=None, name=None, parenttype=None):
	"""Clear a default value by any of the given parameters and delete caches.

	:param key: Default key.
	:param value: Default value.
	:param parent: User name, or `__global`, `__default`.
	:param name: Default ID.
	:param parenttype: Clear defaults table for a particular type e.g. **User**.
	"""
	conditions = []
	values = []

	if name:
		conditions.append("name=%s")
		values.append(name)

	else:
		if key:
			conditions.append("defkey=%s")
			values.append(key)

		if value:
			conditions.append("defvalue=%s")
			values.append(value)

		if parent:
			conditions.append("parent=%s")
			values.append(parent)

		if parenttype:
			conditions.append("parenttype=%s")
			values.append(parenttype)

	if parent:
		clear_cache(parent)
	else:
		clear_cache("__default")
		clear_cache("__global")

	if not conditions:
		raise Exception, "[clear_default] No key specified."

	frappe.db.sql("""delete from tabDefaultValue where {0}""".format(" and ".join(conditions)),
		tuple(values))

	_clear_cache(parent)

def get_defaults_for(parent="__default"):
	"""get all defaults"""
	defaults = frappe.cache().hget("defaults", parent)
	if defaults==None:
		# sort descending because first default must get preceedence
		res = frappe.db.sql("""select defkey, defvalue from `tabDefaultValue`
			where parent = %s order by creation""", (parent,), as_dict=1)

		defaults = frappe._dict({})
		for d in res:
			if d.defkey in defaults:
				# listify
				if not isinstance(defaults[d.defkey], list) and defaults[d.defkey] != d.defvalue:
					defaults[d.defkey] = [defaults[d.defkey]]

				if d.defvalue not in defaults[d.defkey]:
					defaults[d.defkey].append(d.defvalue)

			elif d.defvalue is not None:
				defaults[d.defkey] = d.defvalue

		frappe.cache().hset("defaults", parent, defaults)

	return defaults

def _clear_cache(parent):
	if parent in common_keys:
		frappe.clear_cache()
	else:
		clear_notifications(user=parent)
		frappe.clear_cache(user=parent)

def clear_cache(user=None):
	if user:
		for p in ([user] + common_keys):
			frappe.cache().hdel("defaults", p)
	elif frappe.flags.in_install!="frappe":
		frappe.cache().delete_key("defaults")