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

import frappe
from frappe import _
from frappe.utils import now_datetime, cint, cstr
import re
from frappe.model import log_types
from frappe.query_builder import DocType


def set_new_name(doc):
	"""
	Sets the `name` property for the document based on various rules.

	1. If amended doc, set suffix.
	2. If `autoname` method is declared, then call it.
	3. If `autoname` property is set in the DocType (`meta`), then build it using the `autoname` property.
	4. If no rule defined, use hash.

	:param doc: Document to be named.
	"""

	doc.run_method("before_naming")

	autoname = frappe.get_meta(doc.doctype).autoname or ""

	if autoname.lower() != "prompt" and not frappe.flags.in_import:
		doc.name = None

	if getattr(doc, "amended_from", None):
		_set_amended_name(doc)
		return

	elif getattr(doc.meta, "issingle", False):
		doc.name = doc.doctype

	elif getattr(doc.meta, "istable", False):
		doc.name = make_autoname("hash", doc.doctype)

	if not doc.name:
		set_naming_from_document_naming_rule(doc)

	if not doc.name:
		doc.run_method("autoname")

	if not doc.name and autoname:
		set_name_from_naming_options(autoname, doc)

	# if the autoname option is 'field:' and no name was derived, we need to
	# notify
	if not doc.name and autoname.startswith("field:"):
		fieldname = autoname[6:]
		frappe.throw(_("{0} is required").format(doc.meta.get_label(fieldname)))

	# at this point, we fall back to name generation with the hash option
	if not doc.name and autoname == "hash":
		doc.name = make_autoname("hash", doc.doctype)

	if not doc.name:
		doc.name = make_autoname("hash", doc.doctype)

	doc.name = validate_name(
		doc.doctype,
		doc.name,
		frappe.get_meta(doc.doctype).get_field("name_case")
	)

def set_name_from_naming_options(autoname, doc):
	"""
	Get a name based on the autoname field option
	"""

	_autoname = autoname.lower()

	if _autoname.startswith("field:"):
		doc.name = _field_autoname(autoname, doc)
	elif _autoname.startswith("naming_series:"):
		set_name_by_naming_series(doc)
	elif _autoname.startswith("prompt"):
		_prompt_autoname(autoname, doc)
	elif _autoname.startswith("format:"):
		doc.name = _format_autoname(autoname, doc)
	elif "#" in autoname:
		doc.name = make_autoname(autoname, doc=doc)

def set_naming_from_document_naming_rule(doc):
	'''
	Evaluate rules based on "Document Naming Series" doctype
	'''
	if doc.doctype in log_types:
		return

	# ignore_ddl if naming is not yet bootstrapped
	for d in frappe.get_all('Document Naming Rule',
		dict(document_type=doc.doctype, disabled=0), order_by='priority desc', ignore_ddl=True):
		frappe.get_cached_doc('Document Naming Rule', d.name).apply(doc)
		if doc.name:
			break

def set_name_by_naming_series(doc):
	"""Sets name by the `naming_series` property"""
	if not doc.naming_series:
		doc.naming_series = get_default_naming_series(doc.doctype)

	if not doc.naming_series:
		frappe.throw(frappe._("Naming Series mandatory"))

	doc.name = make_autoname(doc.naming_series+".#####", "", doc)

def make_autoname(key="", doctype="", doc=""):
	"""
	Creates an autoname from the given key:

	**Autoname rules:**

		 * The key is separated by '.'
		 * '####' represents a series. The string before this part becomes the prefix:
			Example: ABC.#### creates a series ABC0001, ABC0002 etc
		 * 'MM' represents the current month
		 * 'YY' and 'YYYY' represent the current year


   *Example:*

		 * DE/./.YY./.MM./.##### will create a series like
		   DE/09/01/0001 where 09 is the year, 01 is the month and 0001 is the series
	"""
	if key == "hash":
		return frappe.generate_hash(doctype, 10)

	if "#" not in key:
		key = key + ".#####"
	elif "." not in key:
		error_message = _("Invalid naming series (. missing)")
		if doctype:
			error_message = _("Invalid naming series (. missing) for {0}").format(doctype)

		frappe.throw(error_message)

	parts = key.split('.')
	n = parse_naming_series(parts, doctype, doc)
	return n


def parse_naming_series(parts, doctype='', doc=''):
	n = ''
	if isinstance(parts, str):
		parts = parts.split('.')
	series_set = False
	today = now_datetime()
	for e in parts:
		part = ''
		if e.startswith('#'):
			if not series_set:
				digits = len(e)
				part = getseries(n, digits)
				series_set = True
		elif e == 'YY':
			part = today.strftime('%y')
		elif e == 'MM':
			part = today.strftime('%m')
		elif e == 'DD':
			part = today.strftime("%d")
		elif e == 'YYYY':
			part = today.strftime('%Y')
		elif e == 'WW':
			part = determine_consecutive_week_number(today)
		elif e == 'timestamp':
			part = str(today)
		elif e == 'FY':
			part = frappe.defaults.get_user_default("fiscal_year")
		elif e.startswith('{') and doc:
			e = e.replace('{', '').replace('}', '')
			part = doc.get(e)
		elif doc and doc.get(e):
			part = doc.get(e)
		else:
			part = e

		if isinstance(part, str):
			n += part

	return n


def determine_consecutive_week_number(datetime):
	"""Determines the consecutive calendar week"""
	m = datetime.month
	# ISO 8601 calandar week
	w = datetime.strftime('%V')
	# Ensure consecutiveness for the first and last days of a year
	if m == 1 and int(w) >= 52:
		w = '00'
	elif m == 12 and int(w) <= 1:
		w = '53'
	return w


def getseries(key, digits):
	# series created ?
	# Using frappe.qb as frappe.get_values does not allow order_by=None
	series = DocType("Series")
	current = (
		frappe.qb.from_(series)
		.where(series.name == key)
		.for_update()
		.select("current")
	).run()

	if current and current[0][0] is not None:
		current = current[0][0]
		# yes, update it
		frappe.db.sql("UPDATE `tabSeries` SET `current` = `current` + 1 WHERE `name`=%s", (key,))
		current = cint(current) + 1
	else:
		# no, create it
		frappe.db.sql("INSERT INTO `tabSeries` (`name`, `current`) VALUES (%s, 1)", (key,))
		current = 1
	return ('%0'+str(digits)+'d') % current


def revert_series_if_last(key, name, doc=None):
	"""
	Reverts the series for particular naming series:
	* key is naming series		- SINV-.YYYY-.####
	* name is actual name		- SINV-2021-0001

	1. This function split the key into two parts prefix (SINV-YYYY) & hashes (####).
	2. Use prefix to get the current index of that naming series from Series table
	3. Then revert the current index.

	*For custom naming series:*
	1. hash can exist anywhere, if it exist in hashes then it take normal flow.
	2. If hash doesn't exit in hashes, we get the hash from prefix, then update name and prefix accordingly.

	*Example:*
		1. key = SINV-.YYYY.-
			* If key doesn't have hash it will add hash at the end
			* prefix will be SINV-YYYY based on this will get current index from Series table.
		2. key = SINV-.####.-2021
			* now prefix = SINV-#### and hashes = 2021 (hash doesn't exist)
			* will search hash in key then accordingly get prefix = SINV-
		3. key = ####.-2021
			* prefix = #### and hashes = 2021 (hash doesn't exist)
			* will search hash in key then accordingly get prefix = ""
	"""
	if ".#" in key:
		prefix, hashes = key.rsplit(".", 1)
		if "#" not in hashes:
			# get the hash part from the key
			hash = re.search("#+", key)
			if not hash:
				return
			name = name.replace(hashes, "")
			prefix = prefix.replace(hash.group(), "")
	else:
		prefix = key

	if '.' in prefix:
		prefix = parse_naming_series(prefix.split('.'), doc=doc)

	count = cint(name.replace(prefix, ""))
	series = DocType("Series")
	current = (
		frappe.qb.from_(series)
		.where(series.name == prefix)
		.for_update()
		.select("current")
	).run()

	if current and current[0][0]==count:
		frappe.db.sql("UPDATE `tabSeries` SET `current` = `current` - 1 WHERE `name`=%s", prefix)


def get_default_naming_series(doctype):
	"""get default value for `naming_series` property"""
	naming_series = frappe.get_meta(doctype).get_field("naming_series").options or ""
	if naming_series:
		naming_series = naming_series.split("\n")
		return naming_series[0] or naming_series[1]
	else:
		return None


def validate_name(doctype, name, case=None, merge=False):
	if not name:
		frappe.throw(_("No Name Specified for {0}").format(doctype))
	if name.startswith("New "+doctype):
		frappe.throw(_("There were some errors setting the name, please contact the administrator"), frappe.NameError)
	if case == "Title Case":
		name = name.title()
	if case == "UPPER CASE":
		name = name.upper()
	name = name.strip()

	if not frappe.get_meta(doctype).get("issingle") and (doctype == name) and (name != "DocType"):
		frappe.throw(_("Name of {0} cannot be {1}").format(doctype, name), frappe.NameError)

	special_characters = "<>"
	if re.findall("[{0}]+".format(special_characters), name):
		message = ", ".join("'{0}'".format(c) for c in special_characters)
		frappe.throw(_("Name cannot contain special characters like {0}").format(message), frappe.NameError)

	return name


def append_number_if_name_exists(doctype, value, fieldname="name", separator="-", filters=None):
	if not filters:
		filters = dict()
	filters.update({fieldname: value})
	exists = frappe.db.exists(doctype, filters)

	regex = "^{value}{separator}\\d+$".format(value=re.escape(value), separator=separator)

	if exists:
		last = frappe.db.sql("""SELECT `{fieldname}` FROM `tab{doctype}`
			WHERE `{fieldname}` {regex_character} %s
			ORDER BY length({fieldname}) DESC,
			`{fieldname}` DESC LIMIT 1""".format(
				doctype=doctype,
				fieldname=fieldname,
				regex_character=frappe.db.REGEX_CHARACTER),
			regex)

		if last:
			count = str(cint(last[0][0].rsplit(separator, 1)[1]) + 1)
		else:
			count = "1"

		value = "{0}{1}{2}".format(value, separator, count)

	return value


def _set_amended_name(doc):
	am_id = 1
	am_prefix = doc.amended_from
	if frappe.db.get_value(doc.doctype, doc.amended_from, "amended_from"):
		am_id = cint(doc.amended_from.split("-")[-1]) + 1
		am_prefix = "-".join(doc.amended_from.split("-")[:-1])  # except the last hyphen

	doc.name = am_prefix + "-" + str(am_id)
	return doc.name


def _field_autoname(autoname, doc, skip_slicing=None):
	"""
	Generate a name using `DocType` field. This is called when the doctype's
	`autoname` field starts with 'field:'
	"""
	fieldname = autoname if skip_slicing else autoname[6:]
	name = (cstr(doc.get(fieldname)) or "").strip()
	return name

def _prompt_autoname(autoname, doc):
	"""
	Generate a name using Prompt option. This simply means the user will have to set the name manually.
	This is called when the doctype's `autoname` field starts with 'prompt'.
	"""
	# set from __newname in save.py
	if not doc.name:
		frappe.throw(_("Please set the document name"))

def _format_autoname(autoname, doc):
	"""
	Generate autoname by replacing all instances of braced params (fields, date params ('DD', 'MM', 'YY'), series)
	Independent of remaining string or separators.

	Example pattern: 'format:LOG-{MM}-{fieldname1}-{fieldname2}-{#####}'
	"""

	first_colon_index = autoname.find(":")
	autoname_value = autoname[first_colon_index + 1:]

	def get_param_value_for_match(match):
		param = match.group()
		# trim braces
		trimmed_param = param[1:-1]
		return parse_naming_series([trimmed_param], doc=doc)

	# Replace braced params with their parsed value
	name = re.sub(r"(\{[\w | #]+\})", get_param_value_for_match, autoname_value)

	return name