# Copyright 2013 Google, Inc. All Rights Reserved.
#
# Google Author(s): Behdad Esfahbod, Roozbeh Pournader

from fontTools import ttLib
from fontTools.ttLib.tables.DefaultTable import DefaultTable
from fontTools.ttLib.tables import otTables
from fontTools.merge.base import add_method, mergeObjects
from fontTools.merge.util import *
import logging


log = logging.getLogger("fontTools.merge")


def mergeLookupLists(lst):
	# TODO Do smarter merge.
	return sumLists(lst)

def mergeFeatures(lst):
	assert lst
	self = otTables.Feature()
	self.FeatureParams = None
	self.LookupListIndex = mergeLookupLists([l.LookupListIndex for l in lst if l.LookupListIndex])
	self.LookupCount = len(self.LookupListIndex)
	return self

def mergeFeatureLists(lst):
	d = {}
	for l in lst:
		for f in l:
			tag = f.FeatureTag
			if tag not in d:
				d[tag] = []
			d[tag].append(f.Feature)
	ret = []
	for tag in sorted(d.keys()):
		rec = otTables.FeatureRecord()
		rec.FeatureTag = tag
		rec.Feature = mergeFeatures(d[tag])
		ret.append(rec)
	return ret

def mergeLangSyses(lst):
	assert lst

	# TODO Support merging ReqFeatureIndex
	assert all(l.ReqFeatureIndex == 0xFFFF for l in lst)

	self = otTables.LangSys()
	self.LookupOrder = None
	self.ReqFeatureIndex = 0xFFFF
	self.FeatureIndex = mergeFeatureLists([l.FeatureIndex for l in lst if l.FeatureIndex])
	self.FeatureCount = len(self.FeatureIndex)
	return self

def mergeScripts(lst):
	assert lst

	if len(lst) == 1:
		return lst[0]
	langSyses = {}
	for sr in lst:
		for lsr in sr.LangSysRecord:
			if lsr.LangSysTag not in langSyses:
				langSyses[lsr.LangSysTag] = []
			langSyses[lsr.LangSysTag].append(lsr.LangSys)
	lsrecords = []
	for tag, langSys_list in sorted(langSyses.items()):
		lsr = otTables.LangSysRecord()
		lsr.LangSys = mergeLangSyses(langSys_list)
		lsr.LangSysTag = tag
		lsrecords.append(lsr)

	self = otTables.Script()
	self.LangSysRecord = lsrecords
	self.LangSysCount = len(lsrecords)
	dfltLangSyses = [s.DefaultLangSys for s in lst if s.DefaultLangSys]
	if dfltLangSyses:
		self.DefaultLangSys = mergeLangSyses(dfltLangSyses)
	else:
		self.DefaultLangSys = None
	return self

def mergeScriptRecords(lst):
	d = {}
	for l in lst:
		for s in l:
			tag = s.ScriptTag
			if tag not in d:
				d[tag] = []
			d[tag].append(s.Script)
	ret = []
	for tag in sorted(d.keys()):
		rec = otTables.ScriptRecord()
		rec.ScriptTag = tag
		rec.Script = mergeScripts(d[tag])
		ret.append(rec)
	return ret

otTables.ScriptList.mergeMap = {
	'ScriptCount': lambda lst: None, # TODO
	'ScriptRecord': mergeScriptRecords,
}
otTables.BaseScriptList.mergeMap = {
	'BaseScriptCount': lambda lst: None, # TODO
	# TODO: Merge duplicate entries
	'BaseScriptRecord': lambda lst: sorted(sumLists(lst), key=lambda s: s.BaseScriptTag),
}

otTables.FeatureList.mergeMap = {
	'FeatureCount': sum,
	'FeatureRecord': lambda lst: sorted(sumLists(lst), key=lambda s: s.FeatureTag),
}

otTables.LookupList.mergeMap = {
	'LookupCount': sum,
	'Lookup': sumLists,
}

otTables.Coverage.mergeMap = {
	'Format': min,
	'glyphs': sumLists,
}

otTables.ClassDef.mergeMap = {
	'Format': min,
	'classDefs': sumDicts,
}

otTables.LigCaretList.mergeMap = {
	'Coverage': mergeObjects,
	'LigGlyphCount': sum,
	'LigGlyph': sumLists,
}

otTables.AttachList.mergeMap = {
	'Coverage': mergeObjects,
	'GlyphCount': sum,
	'AttachPoint': sumLists,
}

# XXX Renumber MarkFilterSets of lookups
otTables.MarkGlyphSetsDef.mergeMap = {
	'MarkSetTableFormat': equal,
	'MarkSetCount': sum,
	'Coverage': sumLists,
}

otTables.Axis.mergeMap = {
	'*': mergeObjects,
}

# XXX Fix BASE table merging
otTables.BaseTagList.mergeMap = {
	'BaseTagCount': sum,
	'BaselineTag': sumLists,
}

otTables.GDEF.mergeMap = \
otTables.GSUB.mergeMap = \
otTables.GPOS.mergeMap = \
otTables.BASE.mergeMap = \
otTables.JSTF.mergeMap = \
otTables.MATH.mergeMap = \
{
	'*': mergeObjects,
	'Version': max,
}

ttLib.getTableClass('GDEF').mergeMap = \
ttLib.getTableClass('GSUB').mergeMap = \
ttLib.getTableClass('GPOS').mergeMap = \
ttLib.getTableClass('BASE').mergeMap = \
ttLib.getTableClass('JSTF').mergeMap = \
ttLib.getTableClass('MATH').mergeMap = \
{
	'tableTag': onlyExisting(equal), # XXX clean me up
	'table': mergeObjects,
}

@add_method(ttLib.getTableClass('GSUB'))
def merge(self, m, tables):

	assert len(tables) == len(m.duplicateGlyphsPerFont)
	for i,(table,dups) in enumerate(zip(tables, m.duplicateGlyphsPerFont)):
		if not dups: continue
		if table is None or table is NotImplemented:
			log.warning("Have non-identical duplicates to resolve for '%s' but no GSUB. Are duplicates intended?: %s", m.fonts[i]._merger__name, dups)
			continue

		synthFeature = None
		synthLookup = None
		for script in table.table.ScriptList.ScriptRecord:
			if script.ScriptTag == 'DFLT': continue # XXX
			for langsys in [script.Script.DefaultLangSys] + [l.LangSys for l in script.Script.LangSysRecord]:
				if langsys is None: continue # XXX Create!
				feature = [v for v in langsys.FeatureIndex if v.FeatureTag == 'locl']
				assert len(feature) <= 1
				if feature:
					feature = feature[0]
				else:
					if not synthFeature:
						synthFeature = otTables.FeatureRecord()
						synthFeature.FeatureTag = 'locl'
						f = synthFeature.Feature = otTables.Feature()
						f.FeatureParams = None
						f.LookupCount = 0
						f.LookupListIndex = []
						table.table.FeatureList.FeatureRecord.append(synthFeature)
						table.table.FeatureList.FeatureCount += 1
					feature = synthFeature
					langsys.FeatureIndex.append(feature)
					langsys.FeatureIndex.sort(key=lambda v: v.FeatureTag)

				if not synthLookup:
					subtable = otTables.SingleSubst()
					subtable.mapping = dups
					synthLookup = otTables.Lookup()
					synthLookup.LookupFlag = 0
					synthLookup.LookupType = 1
					synthLookup.SubTableCount = 1
					synthLookup.SubTable = [subtable]
					if table.table.LookupList is None:
						# mtiLib uses None as default value for LookupList,
						# while feaLib points to an empty array with count 0
						# TODO: make them do the same
						table.table.LookupList = otTables.LookupList()
						table.table.LookupList.Lookup = []
						table.table.LookupList.LookupCount = 0
					table.table.LookupList.Lookup.append(synthLookup)
					table.table.LookupList.LookupCount += 1

				if feature.Feature.LookupListIndex[:1] != [synthLookup]:
					feature.Feature.LookupListIndex[:0] = [synthLookup]
					feature.Feature.LookupCount += 1

	DefaultTable.merge(self, m, tables)
	return self

@add_method(otTables.SingleSubst,
		otTables.MultipleSubst,
		otTables.AlternateSubst,
		otTables.LigatureSubst,
		otTables.ReverseChainSingleSubst,
		otTables.SinglePos,
		otTables.PairPos,
		otTables.CursivePos,
		otTables.MarkBasePos,
		otTables.MarkLigPos,
		otTables.MarkMarkPos)
def mapLookups(self, lookupMap):
	pass

# Copied and trimmed down from subset.py
@add_method(otTables.ContextSubst,
		otTables.ChainContextSubst,
		otTables.ContextPos,
		otTables.ChainContextPos)
def __merge_classify_context(self):

	class ContextHelper(object):
		def __init__(self, klass, Format):
			if klass.__name__.endswith('Subst'):
				Typ = 'Sub'
				Type = 'Subst'
			else:
				Typ = 'Pos'
				Type = 'Pos'
			if klass.__name__.startswith('Chain'):
				Chain = 'Chain'
			else:
				Chain = ''
			ChainTyp = Chain+Typ

			self.Typ = Typ
			self.Type = Type
			self.Chain = Chain
			self.ChainTyp = ChainTyp

			self.LookupRecord = Type+'LookupRecord'

			if Format == 1:
				self.Rule = ChainTyp+'Rule'
				self.RuleSet = ChainTyp+'RuleSet'
			elif Format == 2:
				self.Rule = ChainTyp+'ClassRule'
				self.RuleSet = ChainTyp+'ClassSet'

	if self.Format not in [1, 2, 3]:
		return None  # Don't shoot the messenger; let it go
	if not hasattr(self.__class__, "_merge__ContextHelpers"):
		self.__class__._merge__ContextHelpers = {}
	if self.Format not in self.__class__._merge__ContextHelpers:
		helper = ContextHelper(self.__class__, self.Format)
		self.__class__._merge__ContextHelpers[self.Format] = helper
	return self.__class__._merge__ContextHelpers[self.Format]


@add_method(otTables.ContextSubst,
		otTables.ChainContextSubst,
		otTables.ContextPos,
		otTables.ChainContextPos)
def mapLookups(self, lookupMap):
	c = self.__merge_classify_context()

	if self.Format in [1, 2]:
		for rs in getattr(self, c.RuleSet):
			if not rs: continue
			for r in getattr(rs, c.Rule):
				if not r: continue
				for ll in getattr(r, c.LookupRecord):
					if not ll: continue
					ll.LookupListIndex = lookupMap[ll.LookupListIndex]
	elif self.Format == 3:
		for ll in getattr(self, c.LookupRecord):
			if not ll: continue
			ll.LookupListIndex = lookupMap[ll.LookupListIndex]
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(otTables.ExtensionSubst,
		otTables.ExtensionPos)
def mapLookups(self, lookupMap):
	if self.Format == 1:
		self.ExtSubTable.mapLookups(lookupMap)
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(otTables.Lookup)
def mapLookups(self, lookupMap):
	for st in self.SubTable:
		if not st: continue
		st.mapLookups(lookupMap)

@add_method(otTables.LookupList)
def mapLookups(self, lookupMap):
	for l in self.Lookup:
		if not l: continue
		l.mapLookups(lookupMap)

@add_method(otTables.Lookup)
def mapMarkFilteringSets(self, markFilteringSetMap):
	if self.LookupFlag & 0x0010:
		self.MarkFilteringSet = markFilteringSetMap[self.MarkFilteringSet]

@add_method(otTables.LookupList)
def mapMarkFilteringSets(self, markFilteringSetMap):
	for l in self.Lookup:
		if not l: continue
		l.mapMarkFilteringSets(markFilteringSetMap)

@add_method(otTables.Feature)
def mapLookups(self, lookupMap):
	self.LookupListIndex = [lookupMap[i] for i in self.LookupListIndex]

@add_method(otTables.FeatureList)
def mapLookups(self, lookupMap):
	for f in self.FeatureRecord:
		if not f or not f.Feature: continue
		f.Feature.mapLookups(lookupMap)

@add_method(otTables.DefaultLangSys,
		otTables.LangSys)
def mapFeatures(self, featureMap):
	self.FeatureIndex = [featureMap[i] for i in self.FeatureIndex]
	if self.ReqFeatureIndex != 65535:
		self.ReqFeatureIndex = featureMap[self.ReqFeatureIndex]

@add_method(otTables.Script)
def mapFeatures(self, featureMap):
	if self.DefaultLangSys:
		self.DefaultLangSys.mapFeatures(featureMap)
	for l in self.LangSysRecord:
		if not l or not l.LangSys: continue
		l.LangSys.mapFeatures(featureMap)

@add_method(otTables.ScriptList)
def mapFeatures(self, featureMap):
	for s in self.ScriptRecord:
		if not s or not s.Script: continue
		s.Script.mapFeatures(featureMap)

def layoutPreMerge(font):
		# Map indices to references

		GDEF = font.get('GDEF')
		GSUB = font.get('GSUB')
		GPOS = font.get('GPOS')

		for t in [GSUB, GPOS]:
			if not t: continue

			if t.table.LookupList:
				lookupMap = {i:v for i,v in enumerate(t.table.LookupList.Lookup)}
				t.table.LookupList.mapLookups(lookupMap)
				t.table.FeatureList.mapLookups(lookupMap)

				if GDEF and GDEF.table.Version >= 0x00010002:
					markFilteringSetMap = {i:v for i,v in enumerate(GDEF.table.MarkGlyphSetsDef.Coverage)}
					t.table.LookupList.mapMarkFilteringSets(markFilteringSetMap)

			if t.table.FeatureList and t.table.ScriptList:
				featureMap = {i:v for i,v in enumerate(t.table.FeatureList.FeatureRecord)}
				t.table.ScriptList.mapFeatures(featureMap)

		# TODO FeatureParams nameIDs

def layoutPostMerge(font):
		# Map references back to indices

		GDEF = font.get('GDEF')
		GSUB = font.get('GSUB')
		GPOS = font.get('GPOS')

		for t in [GSUB, GPOS]:
			if not t: continue

			if t.table.FeatureList and t.table.ScriptList:

				# Collect unregistered (new) features.
				featureMap = GregariousIdentityDict(t.table.FeatureList.FeatureRecord)
				t.table.ScriptList.mapFeatures(featureMap)

				# Record used features.
				featureMap = AttendanceRecordingIdentityDict(t.table.FeatureList.FeatureRecord)
				t.table.ScriptList.mapFeatures(featureMap)
				usedIndices = featureMap.s

				# Remove unused features
				t.table.FeatureList.FeatureRecord = [f for i,f in enumerate(t.table.FeatureList.FeatureRecord) if i in usedIndices]

				# Map back to indices.
				featureMap = NonhashableDict(t.table.FeatureList.FeatureRecord)
				t.table.ScriptList.mapFeatures(featureMap)

				t.table.FeatureList.FeatureCount = len(t.table.FeatureList.FeatureRecord)

			if t.table.LookupList:

				# Collect unregistered (new) lookups.
				lookupMap = GregariousIdentityDict(t.table.LookupList.Lookup)
				t.table.FeatureList.mapLookups(lookupMap)
				t.table.LookupList.mapLookups(lookupMap)

				# Record used lookups.
				lookupMap = AttendanceRecordingIdentityDict(t.table.LookupList.Lookup)
				t.table.FeatureList.mapLookups(lookupMap)
				t.table.LookupList.mapLookups(lookupMap)
				usedIndices = lookupMap.s

				# Remove unused lookups
				t.table.LookupList.Lookup = [l for i,l in enumerate(t.table.LookupList.Lookup) if i in usedIndices]

				# Map back to indices.
				lookupMap = NonhashableDict(t.table.LookupList.Lookup)
				t.table.FeatureList.mapLookups(lookupMap)
				t.table.LookupList.mapLookups(lookupMap)

				t.table.LookupList.LookupCount = len(t.table.LookupList.Lookup)

				if GDEF and GDEF.table.Version >= 0x00010002:
					markFilteringSetMap = NonhashableDict(GDEF.table.MarkGlyphSetsDef.Coverage)
					t.table.LookupList.mapMarkFilteringSets(markFilteringSetMap)

		# TODO FeatureParams nameIDs