#!/usr/bin/python3 -i
#
# Copyright (c) 2013-2017 The Khronos Group Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import os,re,sys
from generator import *

# CGeneratorOptions - subclass of GeneratorOptions.
#
# Adds options used by COutputGenerator objects during C language header
# generation.
#
# Additional members
#   prefixText - list of strings to prefix generated header with
#     (usually a copyright statement + calling convention macros).
#   protectFile - True if multiple inclusion protection should be
#     generated (based on the filename) around the entire header.
#   protectFeature - True if #ifndef..#endif protection should be
#     generated around a feature interface in the header file.
#   genFuncPointers - True if function pointer typedefs should be
#     generated
#   protectProto - If conditional protection should be generated
#     around prototype declarations, set to either '#ifdef'
#     to require opt-in (#ifdef protectProtoStr) or '#ifndef'
#     to require opt-out (#ifndef protectProtoStr). Otherwise
#     set to None.
#   protectProtoStr - #ifdef/#ifndef symbol to use around prototype
#     declarations, if protectProto is set
#   apicall - string to use for the function declaration prefix,
#     such as APICALL on Windows.
#   apientry - string to use for the calling convention macro,
#     in typedefs, such as APIENTRY.
#   apientryp - string to use for the calling convention macro
#     in function pointer typedefs, such as APIENTRYP.
#   indentFuncProto - True if prototype declarations should put each
#     parameter on a separate line
#   indentFuncPointer - True if typedefed function pointers should put each
#     parameter on a separate line
#   alignFuncParam - if nonzero and parameters are being put on a
#     separate line, align parameter names at the specified column
class CGeneratorOptions(GeneratorOptions):
    """Represents options during C interface generation for headers"""
    def __init__(self,
                 filename = None,
                 directory = '.',
                 apiname = None,
                 profile = None,
                 versions = '.*',
                 emitversions = '.*',
                 defaultExtensions = None,
                 addExtensions = None,
                 removeExtensions = None,
                 sortProcedure = regSortFeatures,
                 prefixText = "",
                 genFuncPointers = True,
                 protectFile = True,
                 protectFeature = True,
                 protectProto = None,
                 protectProtoStr = None,
                 apicall = '',
                 apientry = '',
                 apientryp = '',
                 indentFuncProto = True,
                 indentFuncPointer = False,
                 alignFuncParam = 0):
        GeneratorOptions.__init__(self, filename, directory, apiname, profile,
                                  versions, emitversions, defaultExtensions,
                                  addExtensions, removeExtensions, sortProcedure)
        self.prefixText      = prefixText
        self.genFuncPointers = genFuncPointers
        self.protectFile     = protectFile
        self.protectFeature  = protectFeature
        self.protectProto    = protectProto
        self.protectProtoStr = protectProtoStr
        self.apicall         = apicall
        self.apientry        = apientry
        self.apientryp       = apientryp
        self.indentFuncProto = indentFuncProto
        self.indentFuncPointer = indentFuncPointer
        self.alignFuncParam  = alignFuncParam

# COutputGenerator - subclass of OutputGenerator.
# Generates C-language API interfaces.
#
# ---- methods ----
# COutputGenerator(errFile, warnFile, diagFile) - args as for
#   OutputGenerator. Defines additional internal state.
# ---- methods overriding base class ----
# beginFile(genOpts)
# endFile()
# beginFeature(interface, emit)
# endFeature()
# genType(typeinfo,name)
# genStruct(typeinfo,name)
# genGroup(groupinfo,name)
# genEnum(enuminfo, name)
# genCmd(cmdinfo)
class COutputGenerator(OutputGenerator):
    """Generate specified API interfaces in a specific style, such as a C header"""
    # This is an ordered list of sections in the header file.
    TYPE_SECTIONS = ['include', 'define', 'basetype', 'handle', 'enum',
                     'group', 'bitmask', 'funcpointer', 'struct']
    ALL_SECTIONS = TYPE_SECTIONS + ['commandPointer', 'command']
    def __init__(self,
                 errFile = sys.stderr,
                 warnFile = sys.stderr,
                 diagFile = sys.stdout):
        OutputGenerator.__init__(self, errFile, warnFile, diagFile)
        # Internal state - accumulators for different inner block text
        self.sections = dict([(section, []) for section in self.ALL_SECTIONS])
    #
    def beginFile(self, genOpts):
        OutputGenerator.beginFile(self, genOpts)
        # C-specific
        #
        # Multiple inclusion protection & C++ wrappers.
        if (genOpts.protectFile and self.genOpts.filename):
            headerSym = re.sub('\.h', '_h_',
                               os.path.basename(self.genOpts.filename)).upper()
            write('#ifndef', headerSym, file=self.outFile)
            write('#define', headerSym, '1', file=self.outFile)
            self.newline()
        write('#ifdef __cplusplus', file=self.outFile)
        write('extern "C" {', file=self.outFile)
        write('#endif', file=self.outFile)
        self.newline()
        #
        # User-supplied prefix text, if any (list of strings)
        if (genOpts.prefixText):
            for s in genOpts.prefixText:
                write(s, file=self.outFile)
        #
        # Some boilerplate describing what was generated - this
        # will probably be removed later since the extensions
        # pattern may be very long.
        # write('/* Generated C header for:', file=self.outFile)
        # write(' * API:', genOpts.apiname, file=self.outFile)
        # if (genOpts.profile):
        #     write(' * Profile:', genOpts.profile, file=self.outFile)
        # write(' * Versions considered:', genOpts.versions, file=self.outFile)
        # write(' * Versions emitted:', genOpts.emitversions, file=self.outFile)
        # write(' * Default extensions included:', genOpts.defaultExtensions, file=self.outFile)
        # write(' * Additional extensions included:', genOpts.addExtensions, file=self.outFile)
        # write(' * Extensions removed:', genOpts.removeExtensions, file=self.outFile)
        # write(' */', file=self.outFile)
    def endFile(self):
        # C-specific
        # Finish C++ wrapper and multiple inclusion protection
        self.newline()
        write('#ifdef __cplusplus', file=self.outFile)
        write('}', file=self.outFile)
        write('#endif', file=self.outFile)
        if (self.genOpts.protectFile and self.genOpts.filename):
            self.newline()
            write('#endif', file=self.outFile)
        # Finish processing in superclass
        OutputGenerator.endFile(self)
    def beginFeature(self, interface, emit):
        # Start processing in superclass
        OutputGenerator.beginFeature(self, interface, emit)
        # C-specific
        # Accumulate includes, defines, types, enums, function pointer typedefs,
        # end function prototypes separately for this feature. They're only
        # printed in endFeature().
        self.sections = dict([(section, []) for section in self.ALL_SECTIONS])
    def endFeature(self):
        # C-specific
        # Actually write the interface to the output file.
        if (self.emit):
            self.newline()
            if (self.genOpts.protectFeature):
                write('#ifndef', self.featureName, file=self.outFile)
            # If type declarations are needed by other features based on
            # this one, it may be necessary to suppress the ExtraProtect,
            # or move it below the 'for section...' loop.
            if (self.featureExtraProtect != None):
                write('#ifdef', self.featureExtraProtect, file=self.outFile)
            write('#define', self.featureName, '1', file=self.outFile)
            for section in self.TYPE_SECTIONS:
                contents = self.sections[section]
                if contents:
                    write('\n'.join(contents), file=self.outFile)
                    self.newline()
            if (self.genOpts.genFuncPointers and self.sections['commandPointer']):
                write('\n'.join(self.sections['commandPointer']), file=self.outFile)
                self.newline()
            if (self.sections['command']):
                if (self.genOpts.protectProto):
                    write(self.genOpts.protectProto,
                          self.genOpts.protectProtoStr, file=self.outFile)
                write('\n'.join(self.sections['command']), end='', file=self.outFile)
                if (self.genOpts.protectProto):
                    write('#endif', file=self.outFile)
                else:
                    self.newline()
            if (self.featureExtraProtect != None):
                write('#endif /*', self.featureExtraProtect, '*/', file=self.outFile)
            if (self.genOpts.protectFeature):
                write('#endif /*', self.featureName, '*/', file=self.outFile)
        # Finish processing in superclass
        OutputGenerator.endFeature(self)
    #
    # Append a definition to the specified section
    def appendSection(self, section, text):
        # self.sections[section].append('SECTION: ' + section + '\n')
        self.sections[section].append(text)
    #
    # Type generation
    def genType(self, typeinfo, name):
        OutputGenerator.genType(self, typeinfo, name)
        typeElem = typeinfo.elem
        # If the type is a struct type, traverse the imbedded <member> tags
        # generating a structure. Otherwise, emit the tag text.
        category = typeElem.get('category')
        if (category == 'struct' or category == 'union'):
            self.genStruct(typeinfo, name)
        else:
            # Replace <apientry /> tags with an APIENTRY-style string
            # (from self.genOpts). Copy other text through unchanged.
            # If the resulting text is an empty string, don't emit it.
            s = noneStr(typeElem.text)
            for elem in typeElem:
                if (elem.tag == 'apientry'):
                    s += self.genOpts.apientry + noneStr(elem.tail)
                else:
                    s += noneStr(elem.text) + noneStr(elem.tail)
            if s:
                # Add extra newline after multi-line entries.
                if '\n' in s:
                    s += '\n'
                # This is a temporary workaround for internal issue #877,
                # while we consider other approaches. The problem is that
                # function pointer types can have dependencies on structures
                # and vice-versa, so they can't be strictly separated into
                # sections. The workaround is to define those types in the
                # same section, in dependency order.
                if (category == 'funcpointer'):
                    self.appendSection('struct', s)
                else:
                    self.appendSection(category, s)
    #
    # Struct (e.g. C "struct" type) generation.
    # This is a special case of the <type> tag where the contents are
    # interpreted as a set of <member> tags instead of freeform C
    # C type declarations. The <member> tags are just like <param>
    # tags - they are a declaration of a struct or union member.
    # Only simple member declarations are supported (no nested
    # structs etc.)
    def genStruct(self, typeinfo, typeName):
        OutputGenerator.genStruct(self, typeinfo, typeName)
        body = 'typedef ' + typeinfo.elem.get('category') + ' ' + typeName + ' {\n'
        # paramdecl = self.makeCParamDecl(typeinfo.elem, self.genOpts.alignFuncParam)
        targetLen = 0;
        for member in typeinfo.elem.findall('.//member'):
            targetLen = max(targetLen, self.getCParamTypeLength(member))
        for member in typeinfo.elem.findall('.//member'):
            body += self.makeCParamDecl(member, targetLen + 4)
            body += ';\n'
        body += '} ' + typeName + ';\n'
        self.appendSection('struct', body)
    #
    # Group (e.g. C "enum" type) generation.
    # These are concatenated together with other types.
    def genGroup(self, groupinfo, groupName):
        OutputGenerator.genGroup(self, groupinfo, groupName)
        groupElem = groupinfo.elem

        expandName = re.sub(r'([0-9a-z_])([A-Z0-9])',r'\1_\2',groupName).upper()

        expandPrefix = expandName
        expandSuffix = ''
        expandSuffixMatch = re.search(r'[A-Z][A-Z]+$',groupName)
        if expandSuffixMatch:
            expandSuffix = '_' + expandSuffixMatch.group()
            # Strip off the suffix from the prefix
            expandPrefix = expandName.rsplit(expandSuffix, 1)[0]

        # Prefix
        body = "\ntypedef enum " + groupName + " {\n"

        # @@ Should use the type="bitmask" attribute instead
        isEnum = ('FLAG_BITS' not in expandPrefix)

        # Loop over the nested 'enum' tags. Keep track of the minimum and
        # maximum numeric values, if they can be determined; but only for
        # core API enumerants, not extension enumerants. This is inferred
        # by looking for 'extends' attributes.
        minName = None
        for elem in groupElem.findall('enum'):
            # Convert the value to an integer and use that to track min/max.
            # Values of form -(number) are accepted but nothing more complex.
            # Should catch exceptions here for more complex constructs. Not yet.
            (numVal,strVal) = self.enumToValue(elem, True)
            name = elem.get('name')

            # Check for duplicate enum values and raise an error if found.
            for elem2 in groupElem.findall('enum'):
                if (elem != elem2):
                    (numVal2,strVal2) = self.enumToValue(elem2, True)
                    if (numVal2 == numVal):
                        raise UserWarning('Duplicate enum ' + name + ' = ' + elem2.get('name') + ' = ' + strVal)

            # Extension enumerants are only included if they are required
            if (self.isEnumRequired(elem)):
                body += "    " + name + " = " + strVal + ",\n"

            if (isEnum and elem.get('extends') is None):
                if (minName == None):
                    minName = maxName = name
                    minValue = maxValue = numVal
                elif (numVal < minValue):
                    minName = name
                    minValue = numVal
                elif (numVal > maxValue):
                    maxName = name
                    maxValue = numVal
        # Generate min/max value tokens and a range-padding enum. Need some
        # additional padding to generate correct names...
        if isEnum:
            body += "    " + expandPrefix + "_BEGIN_RANGE" + expandSuffix + " = " + minName + ",\n"
            body += "    " + expandPrefix + "_END_RANGE" + expandSuffix + " = " + maxName + ",\n"
            body += "    " + expandPrefix + "_RANGE_SIZE" + expandSuffix + " = (" + maxName + " - " + minName + " + 1),\n"

        body += "    " + expandPrefix + "_MAX_ENUM" + expandSuffix + " = 0x7FFFFFFF\n"

        # Postfix
        body += "} " + groupName + ";"
        if groupElem.get('type') == 'bitmask':
            section = 'bitmask'
        else:
            section = 'group'
        self.appendSection(section, body)
    # Enumerant generation
    # <enum> tags may specify their values in several ways, but are usually
    # just integers.
    def genEnum(self, enuminfo, name):
        OutputGenerator.genEnum(self, enuminfo, name)
        (numVal,strVal) = self.enumToValue(enuminfo.elem, False)
        body = '#define ' + name.ljust(33) + ' ' + strVal
        self.appendSection('enum', body)
    #
    # Command generation
    def genCmd(self, cmdinfo, name):
        OutputGenerator.genCmd(self, cmdinfo, name)
        #
        decls = self.makeCDecls(cmdinfo.elem)
        self.appendSection('command', decls[0] + '\n')
        if (self.genOpts.genFuncPointers):
            self.appendSection('commandPointer', decls[1])
