import os
import textwrap
from xml.etree import ElementTree
from fontTools.ttLib import TTFont, newTable
from fontTools.misc.psCharStrings import T2CharString
from fontTools.ttLib.tables.otTables import (
    GSUB,
    ScriptList,
    ScriptRecord,
    Script,
    DefaultLangSys,
    FeatureList,
    FeatureRecord,
    Feature,
    LookupList,
    Lookup,
    AlternateSubst,
    SingleSubst,
)

# paths
directory = os.path.dirname(__file__)
shellSourcePath = os.path.join(directory, "gsubtest-shell.ttx")
shellTempPath = os.path.join(directory, "gsubtest-shell.otf")
featureList = os.path.join(directory, "gsubtest-features.txt")
javascriptData = os.path.join(directory, "gsubtest-features.js")
outputPath = os.path.join(os.path.dirname(directory), "gsubtest-lookup%d")

baseCodepoint = 0xE000

# -------
# Features
# -------

f = open(featureList, "rb")
text = f.read()
f.close()
mapping = []
for line in text.splitlines():
    line = line.strip()
    if not line:
        continue
    if line.startswith("#"):
        continue
    # parse
    values = line.split("\t")
    tag = values.pop(0)
    mapping.append(tag)

# --------
# Outlines
# --------


def addGlyphToCFF(
    glyphName=None,
    program=None,
    private=None,
    globalSubrs=None,
    charStringsIndex=None,
    topDict=None,
    charStrings=None,
):
    charString = T2CharString(program=program, private=private, globalSubrs=globalSubrs)
    charStringsIndex.append(charString)
    glyphID = len(topDict.charset)
    charStrings.charStrings[glyphName] = glyphID
    topDict.charset.append(glyphName)


def makeLookup1():
    # make a variation of the shell TTX data
    f = open(shellSourcePath)
    ttxData = f.read()
    f.close()
    ttxData = ttxData.replace("__familyName__", "gsubtest-lookup1")
    tempShellSourcePath = shellSourcePath + ".temp"
    f = open(tempShellSourcePath, "wb")
    f.write(ttxData)
    f.close()

    # compile the shell
    shell = TTFont(sfntVersion="OTTO")
    shell.importXML(tempShellSourcePath)
    shell.save(shellTempPath)
    os.remove(tempShellSourcePath)

    # load the shell
    shell = TTFont(shellTempPath)

    # grab the PASS and FAIL data
    hmtx = shell["hmtx"]
    glyphSet = shell.getGlyphSet()

    failGlyph = glyphSet["F"]
    failGlyph.decompile()
    failGlyphProgram = list(failGlyph.program)
    failGlyphMetrics = hmtx["F"]

    passGlyph = glyphSet["P"]
    passGlyph.decompile()
    passGlyphProgram = list(passGlyph.program)
    passGlyphMetrics = hmtx["P"]

    # grab some tables
    hmtx = shell["hmtx"]
    cmap = shell["cmap"]

    # start the glyph order
    existingGlyphs = [".notdef", "space", "F", "P"]
    glyphOrder = list(existingGlyphs)

    # start the CFF
    cff = shell["CFF "].cff
    globalSubrs = cff.GlobalSubrs
    topDict = cff.topDictIndex[0]
    topDict.charset = existingGlyphs
    private = topDict.Private
    charStrings = topDict.CharStrings
    charStringsIndex = charStrings.charStringsIndex

    features = sorted(mapping)

    # build the outline, hmtx and cmap data
    cp = baseCodepoint
    for index, tag in enumerate(features):
        # tag.pass
        glyphName = "%s.pass" % tag
        glyphOrder.append(glyphName)
        addGlyphToCFF(
            glyphName=glyphName,
            program=passGlyphProgram,
            private=private,
            globalSubrs=globalSubrs,
            charStringsIndex=charStringsIndex,
            topDict=topDict,
            charStrings=charStrings,
        )
        hmtx[glyphName] = passGlyphMetrics

        for table in cmap.tables:
            if table.format == 4:
                table.cmap[cp] = glyphName
            else:
                raise NotImplementedError(
                    "Unsupported cmap table format: %d" % table.format
                )
        cp += 1

        # tag.fail
        glyphName = "%s.fail" % tag
        glyphOrder.append(glyphName)
        addGlyphToCFF(
            glyphName=glyphName,
            program=failGlyphProgram,
            private=private,
            globalSubrs=globalSubrs,
            charStringsIndex=charStringsIndex,
            topDict=topDict,
            charStrings=charStrings,
        )
        hmtx[glyphName] = failGlyphMetrics

        for table in cmap.tables:
            if table.format == 4:
                table.cmap[cp] = glyphName
            else:
                raise NotImplementedError(
                    "Unsupported cmap table format: %d" % table.format
                )

                # bump this up so that the sequence is the same as the lookup 3 font
        cp += 3

    # set the glyph order
    shell.setGlyphOrder(glyphOrder)

    # start the GSUB
    shell["GSUB"] = newTable("GSUB")
    gsub = shell["GSUB"].table = GSUB()
    gsub.Version = 1.0

    # make a list of all the features we will make
    featureCount = len(features)

    # set up the script list
    scriptList = gsub.ScriptList = ScriptList()
    scriptList.ScriptCount = 1
    scriptList.ScriptRecord = []
    scriptRecord = ScriptRecord()
    scriptList.ScriptRecord.append(scriptRecord)
    scriptRecord.ScriptTag = "DFLT"
    script = scriptRecord.Script = Script()
    defaultLangSys = script.DefaultLangSys = DefaultLangSys()
    defaultLangSys.FeatureCount = featureCount
    defaultLangSys.FeatureIndex = range(defaultLangSys.FeatureCount)
    defaultLangSys.ReqFeatureIndex = 65535
    defaultLangSys.LookupOrder = None
    script.LangSysCount = 0
    script.LangSysRecord = []

    # set up the feature list
    featureList = gsub.FeatureList = FeatureList()
    featureList.FeatureCount = featureCount
    featureList.FeatureRecord = []
    for index, tag in enumerate(features):
        # feature record
        featureRecord = FeatureRecord()
        featureRecord.FeatureTag = tag
        feature = featureRecord.Feature = Feature()
        featureList.FeatureRecord.append(featureRecord)
        # feature
        feature.FeatureParams = None
        feature.LookupCount = 1
        feature.LookupListIndex = [index]

    # write the lookups
    lookupList = gsub.LookupList = LookupList()
    lookupList.LookupCount = featureCount
    lookupList.Lookup = []
    for tag in features:
        # lookup
        lookup = Lookup()
        lookup.LookupType = 1
        lookup.LookupFlag = 0
        lookup.SubTableCount = 1
        lookup.SubTable = []
        lookupList.Lookup.append(lookup)
        # subtable
        subtable = SingleSubst()
        subtable.Format = 2
        subtable.LookupType = 1
        subtable.mapping = {
            "%s.pass" % tag: "%s.fail" % tag,
            "%s.fail" % tag: "%s.pass" % tag,
        }
        lookup.SubTable.append(subtable)

    path = outputPath % 1 + ".otf"
    if os.path.exists(path):
        os.remove(path)
    shell.save(path)

    # get rid of the shell
    if os.path.exists(shellTempPath):
        os.remove(shellTempPath)


def makeLookup3():
    # make a variation of the shell TTX data
    f = open(shellSourcePath)
    ttxData = f.read()
    f.close()
    ttxData = ttxData.replace("__familyName__", "gsubtest-lookup3")
    tempShellSourcePath = shellSourcePath + ".temp"
    f = open(tempShellSourcePath, "wb")
    f.write(ttxData)
    f.close()

    # compile the shell
    shell = TTFont(sfntVersion="OTTO")
    shell.importXML(tempShellSourcePath)
    shell.save(shellTempPath)
    os.remove(tempShellSourcePath)

    # load the shell
    shell = TTFont(shellTempPath)

    # grab the PASS and FAIL data
    hmtx = shell["hmtx"]
    glyphSet = shell.getGlyphSet()

    failGlyph = glyphSet["F"]
    failGlyph.decompile()
    failGlyphProgram = list(failGlyph.program)
    failGlyphMetrics = hmtx["F"]

    passGlyph = glyphSet["P"]
    passGlyph.decompile()
    passGlyphProgram = list(passGlyph.program)
    passGlyphMetrics = hmtx["P"]

    # grab some tables
    hmtx = shell["hmtx"]
    cmap = shell["cmap"]

    # start the glyph order
    existingGlyphs = [".notdef", "space", "F", "P"]
    glyphOrder = list(existingGlyphs)

    # start the CFF
    cff = shell["CFF "].cff
    globalSubrs = cff.GlobalSubrs
    topDict = cff.topDictIndex[0]
    topDict.charset = existingGlyphs
    private = topDict.Private
    charStrings = topDict.CharStrings
    charStringsIndex = charStrings.charStringsIndex

    features = sorted(mapping)

    # build the outline, hmtx and cmap data
    cp = baseCodepoint
    for index, tag in enumerate(features):
        # tag.pass
        glyphName = "%s.pass" % tag
        glyphOrder.append(glyphName)
        addGlyphToCFF(
            glyphName=glyphName,
            program=passGlyphProgram,
            private=private,
            globalSubrs=globalSubrs,
            charStringsIndex=charStringsIndex,
            topDict=topDict,
            charStrings=charStrings,
        )
        hmtx[glyphName] = passGlyphMetrics

        # tag.fail
        glyphName = "%s.fail" % tag
        glyphOrder.append(glyphName)
        addGlyphToCFF(
            glyphName=glyphName,
            program=failGlyphProgram,
            private=private,
            globalSubrs=globalSubrs,
            charStringsIndex=charStringsIndex,
            topDict=topDict,
            charStrings=charStrings,
        )
        hmtx[glyphName] = failGlyphMetrics

        # tag.default
        glyphName = "%s.default" % tag
        glyphOrder.append(glyphName)
        addGlyphToCFF(
            glyphName=glyphName,
            program=passGlyphProgram,
            private=private,
            globalSubrs=globalSubrs,
            charStringsIndex=charStringsIndex,
            topDict=topDict,
            charStrings=charStrings,
        )
        hmtx[glyphName] = passGlyphMetrics

        for table in cmap.tables:
            if table.format == 4:
                table.cmap[cp] = glyphName
            else:
                raise NotImplementedError(
                    "Unsupported cmap table format: %d" % table.format
                )
        cp += 1

        # tag.alt1,2,3
        for i in range(1, 4):
            glyphName = "%s.alt%d" % (tag, i)
            glyphOrder.append(glyphName)
            addGlyphToCFF(
                glyphName=glyphName,
                program=failGlyphProgram,
                private=private,
                globalSubrs=globalSubrs,
                charStringsIndex=charStringsIndex,
                topDict=topDict,
                charStrings=charStrings,
            )
            hmtx[glyphName] = failGlyphMetrics
            for table in cmap.tables:
                if table.format == 4:
                    table.cmap[cp] = glyphName
                else:
                    raise NotImplementedError(
                        "Unsupported cmap table format: %d" % table.format
                    )
            cp += 1

    # set the glyph order
    shell.setGlyphOrder(glyphOrder)

    # start the GSUB
    shell["GSUB"] = newTable("GSUB")
    gsub = shell["GSUB"].table = GSUB()
    gsub.Version = 1.0

    # make a list of all the features we will make
    featureCount = len(features)

    # set up the script list
    scriptList = gsub.ScriptList = ScriptList()
    scriptList.ScriptCount = 1
    scriptList.ScriptRecord = []
    scriptRecord = ScriptRecord()
    scriptList.ScriptRecord.append(scriptRecord)
    scriptRecord.ScriptTag = "DFLT"
    script = scriptRecord.Script = Script()
    defaultLangSys = script.DefaultLangSys = DefaultLangSys()
    defaultLangSys.FeatureCount = featureCount
    defaultLangSys.FeatureIndex = range(defaultLangSys.FeatureCount)
    defaultLangSys.ReqFeatureIndex = 65535
    defaultLangSys.LookupOrder = None
    script.LangSysCount = 0
    script.LangSysRecord = []

    # set up the feature list
    featureList = gsub.FeatureList = FeatureList()
    featureList.FeatureCount = featureCount
    featureList.FeatureRecord = []
    for index, tag in enumerate(features):
        # feature record
        featureRecord = FeatureRecord()
        featureRecord.FeatureTag = tag
        feature = featureRecord.Feature = Feature()
        featureList.FeatureRecord.append(featureRecord)
        # feature
        feature.FeatureParams = None
        feature.LookupCount = 1
        feature.LookupListIndex = [index]

    # write the lookups
    lookupList = gsub.LookupList = LookupList()
    lookupList.LookupCount = featureCount
    lookupList.Lookup = []
    for tag in features:
        # lookup
        lookup = Lookup()
        lookup.LookupType = 3
        lookup.LookupFlag = 0
        lookup.SubTableCount = 1
        lookup.SubTable = []
        lookupList.Lookup.append(lookup)
        # subtable
        subtable = AlternateSubst()
        subtable.Format = 1
        subtable.LookupType = 3
        subtable.alternates = {
            "%s.default" % tag: ["%s.fail" % tag, "%s.fail" % tag, "%s.fail" % tag],
            "%s.alt1" % tag: ["%s.pass" % tag, "%s.fail" % tag, "%s.fail" % tag],
            "%s.alt2" % tag: ["%s.fail" % tag, "%s.pass" % tag, "%s.fail" % tag],
            "%s.alt3" % tag: ["%s.fail" % tag, "%s.fail" % tag, "%s.pass" % tag],
        }
        lookup.SubTable.append(subtable)

    path = outputPath % 3 + ".otf"
    if os.path.exists(path):
        os.remove(path)
    shell.save(path)

    # get rid of the shell
    if os.path.exists(shellTempPath):
        os.remove(shellTempPath)


def makeJavascriptData():
    features = sorted(mapping)
    outStr = []

    outStr.append("")
    outStr.append("/* This file is autogenerated by makegsubfonts.py */")
    outStr.append("")
    outStr.append("/* ")
    outStr.append("  Features defined in gsubtest fonts with associated base")
    outStr.append("  codepoints for each feature:")
    outStr.append("")
    outStr.append("    cp = codepoint for feature featX")
    outStr.append("")
    outStr.append("    cp   default   PASS")
    outStr.append("    cp   featX=1   FAIL")
    outStr.append("    cp   featX=2   FAIL")
    outStr.append("")
    outStr.append("    cp+1 default   FAIL")
    outStr.append("    cp+1 featX=1   PASS")
    outStr.append("    cp+1 featX=2   FAIL")
    outStr.append("")
    outStr.append("    cp+2 default   FAIL")
    outStr.append("    cp+2 featX=1   FAIL")
    outStr.append("    cp+2 featX=2   PASS")
    outStr.append("")
    outStr.append("*/")
    outStr.append("")
    outStr.append("var gFeatures = {")
    cp = baseCodepoint

    taglist = []
    for tag in features:
        taglist.append('"%s": 0x%x' % (tag, cp))
        cp += 4

    outStr.append(
        textwrap.fill(", ".join(taglist), initial_indent="  ", subsequent_indent="  ")
    )
    outStr.append("};")
    outStr.append("")

    if os.path.exists(javascriptData):
        os.remove(javascriptData)

    f = open(javascriptData, "wb")
    f.write("\n".join(outStr))
    f.close()


# build fonts

print("Making lookup type 1 font...")
makeLookup1()

print("Making lookup type 3 font...")
makeLookup3()

# output javascript data

print("Making javascript data file...")
makeJavascriptData()