# Copyright (c) 2013, Web Notes Technologies Pvt. Ltd. and Contributors
# MIT License. See license.txt 

from __future__ import unicode_literals
import webnotes, json
from webnotes import _
from webnotes.utils import cstr
from webnotes.model import default_fields

def get_mapped_doclist(from_doctype, from_docname, table_maps, target_doclist=None, 
		postprocess=None, ignore_permissions=False):
	if target_doclist is None:
		target_doclist = []
		
	if isinstance(target_doclist, basestring):
		target_doclist = json.loads(target_doclist)
	
	source = webnotes.bean(from_doctype, from_docname)

	if not ignore_permissions and not webnotes.has_permission(from_doctype, "read", source.doc):
		webnotes.msgprint("No Permission", raise_exception=webnotes.PermissionError)

	source_meta = webnotes.get_doctype(from_doctype)
	target_meta = webnotes.get_doctype(table_maps[from_doctype]["doctype"])
	
	# main
	if target_doclist:
		if isinstance(target_doclist[0], dict):
			target_doc = webnotes.doc(fielddata=target_doclist[0])
		else:
			target_doc = target_doclist[0]
	else:
		target_doc = webnotes.new_doc(table_maps[from_doctype]["doctype"])
	
	map_doc(source.doc, target_doc, table_maps[source.doc.doctype], source_meta, target_meta)
	if target_doclist:
		target_doclist[0] = target_doc
	else:
		target_doclist = [target_doc]
	
	target_doclist = webnotes.doclist(target_doclist)
	
	row_exists_for_parentfield = {}
	
	# children
	for source_d in source.doclist[1:]:
		table_map = table_maps.get(source_d.doctype)
		if table_map:
			if "condition" in table_map:
				if not table_map["condition"](source_d):
					continue
			target_doctype = table_map["doctype"]
			parentfield = target_meta.get({
					"parent": target_doc.doctype, 
					"doctype": "DocField",
					"fieldtype": "Table", 
					"options": target_doctype
				})[0].fieldname
			
			# does row exist for a parentfield?
			if parentfield not in row_exists_for_parentfield:
				row_exists_for_parentfield[parentfield] = True if \
					webnotes.doclist(target_doclist).get({"parentfield": parentfield}) else False
			
			if table_map.get("add_if_empty") and row_exists_for_parentfield.get(parentfield):
				continue
		
			target_d = webnotes.new_doc(target_doctype, target_doc, parentfield)
			map_doc(source_d, target_d, table_map, source_meta, target_meta, source.doclist[0])
			target_d.idx = None
			target_doclist.append(target_d)

	target_doclist = webnotes.doclist(target_doclist)
	
	if postprocess:
		new_target_doclist = postprocess(source, target_doclist)
		if new_target_doclist:
			target_doclist = new_target_doclist
	
	return target_doclist

def map_doc(source_doc, target_doc, table_map, source_meta, target_meta, source_parent=None):
	no_copy_fields = set(\
		  [d.fieldname for d in source_meta.get({"no_copy": 1, 
			"parent": source_doc.doctype})] \
		+ [d.fieldname for d in target_meta.get({"no_copy": 1, 
			"parent": target_doc.doctype})] \
		+ default_fields
		+ table_map.get("field_no_map", []))

	if table_map.get("validation"):
		for key, condition in table_map["validation"].items():
			if condition[0]=="=":
				if source_doc.fields.get(key) != condition[1]:
					webnotes.msgprint(_("Cannot map because following condition fails: ")
						+ key + "=" + cstr(condition[1]), raise_exception=webnotes.ValidationError)

	# map same fields
	target_fields = target_meta.get({"doctype": "DocField", "parent": target_doc.doctype})
	for key in [d.fieldname for d in target_fields]:
		if key not in no_copy_fields:
			val = source_doc.fields.get(key)
			if val not in (None, ""):
				target_doc.fields[key] = val
				

	# map other fields
	field_map = table_map.get("field_map")
	
	if field_map:
		if isinstance(field_map, dict):
			for source_key, target_key in field_map.items():
				val = source_doc.fields.get(source_key)
				if val not in (None, ""):
					target_doc.fields[target_key] = val
		else:
			for fmap in field_map:
				val = source_doc.fields.get(fmap[0])
				if val not in (None, ""):
					target_doc.fields[fmap[1]] = val

	# map idx
	if source_doc.idx:
		target_doc.idx = source_doc.idx
		
	if "postprocess" in table_map:
		table_map["postprocess"](source_doc, target_doc, source_parent)