#!/usr/bin/python
# Copyright 2017 The ANGLE Project Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
#
# generate_gl_dispatch_table.py:
#  Generation script for OpenGL bindings with ANGLE.

import sys
import os
import re
import xml.etree.ElementTree as etree
from datetime import date

# Set the CWD to the script directory.
os.chdir(os.path.dirname(os.path.abspath(sys.argv[0])))

sys.path.append('..')
import angle_format

def safe_append(the_dict, key, element):
    if key not in the_dict:
        the_dict[key] = []
    the_dict[key].append(element)

gl_xml_path = os.path.join('..', '..', '..', '..', 'scripts', 'gl.xml')
dispatch_header_path = 'DispatchTableGL_autogen.h'
dispatch_source_path = 'DispatchTableGL_autogen.cpp'
null_functions_header_path = 'null_functions.h'
null_functions_source_path = 'null_functions.cpp'

# Load the JSON and XML data.
data_source_name = 'gl_bindings_data.json'
json_data = angle_format.load_json(data_source_name)
xml_root = etree.parse(gl_xml_path).getroot()

api_feature_info = {}

core_removed_eps = []
for core_removed_ep in xml_root.findall('feature/remove'):
    assert(core_removed_ep.attrib['profile'] == 'core')
    for command in core_removed_ep.findall('./command'):
        core_removed_eps.append(command.attrib['name'])

for feature in xml_root.findall('feature'):
    api = feature.attrib['api']
    name = feature.attrib['name']
    number = feature.attrib['number']

    # OpenGL ES 3.x versions are listed as api 'gles2'
    if api != 'gl' and api != 'gles2':
        continue

    for command in feature.findall('./require/command'):
        command_name = command.attrib['name']
        safe_append(api_feature_info, command_name, (api, name, number))

gl_extension_commands = {}
gles2_extension_commands = {}
both_extension_commands = {}

for extension in xml_root.findall('extensions/extension'):
    extension_name = extension.attrib['name']
    support = extension.attrib['supported'].split('|')
    for command in extension.findall('./require/command'):
        command_name = command.attrib['name']
        if 'gl' in support and 'gles2' in support:
            # Special case for KHR extensions, since in GLES they are suffixed.
            if '_KHR_' in extension_name:
                safe_append(gl_extension_commands, command_name, extension_name)
                safe_append(gles2_extension_commands, command_name, extension_name)
            else:
                safe_append(both_extension_commands, command_name, extension_name)
        elif 'gl' in support:
            safe_append(gl_extension_commands, command_name, extension_name)
        elif 'gles2' in support:
            safe_append(gles2_extension_commands, command_name, extension_name)

gl_requirements = {}
gles2_requirements = {}
gl_extension_requirements = {}
gles2_extension_requirements = {}
both_extension_requirements = {}

# Used later in the NULL bindings.
all_entry_points = []

for comment, entry_points in json_data.iteritems():
    for entry_point_no_prefix in entry_points:
        entry_point = "gl" + entry_point_no_prefix

        all_entry_points.append(entry_point)

        gl_required = None
        gles2_required = None

        if entry_point in api_feature_info:
            for api, name, number in api_feature_info[entry_point]:
                major, minor = number.split(".")
                reqs = (major, minor)
                if api == 'gl':
                    if not gl_required:
                        gl_required = reqs
                    elif entry_point in core_removed_eps:
                        print('Upgrade ' + entry_point + ' to ' + str(reqs) + ' instead of ' + str(gl_required))
                        gl_required = reqs
                    else:
                        print('Keep ' + entry_point + ' at ' + str(gl_required) + ' instead of ' + str(reqs))
                elif api == 'gles2':
                    if not gles2_required:
                        gles2_required = reqs
                    else:
                        print("Duplicate for " + entry_point + ": " + str(reqs) + " and " + str(gles2_required))
                else:
                    raise Exception('Bad api type: ' + api)

        if gl_required:
            safe_append(gl_requirements, gl_required, entry_point)

        if gles2_required:
            safe_append(gles2_requirements, gles2_required, entry_point)

        # Special case for finding extensions that overlap with core functions.

        extension = False

        for ep in [entry_point, entry_point + "EXT", entry_point + "ARB", entry_point + "OES"]:
            if ep in both_extension_commands:
                extension = True
                for extension in both_extension_commands[ep]:
                    safe_append(both_extension_requirements, extension, (entry_point, ep))

            else:
                if ep in gl_extension_commands:
                    extension = True
                    for extension in gl_extension_commands[ep]:
                        safe_append(gl_extension_requirements, extension, (entry_point, ep))

                if ep in gles2_extension_commands:
                    extension = True
                    for extension in gles2_extension_commands[ep]:
                        full_ep = ep
                        if '_KHR_' in extension:
                            full_ep += 'KHR'
                        safe_append(gles2_extension_requirements, extension, (entry_point, full_ep))

        if not (gl_required or gles2_required or extension):
            raise Exception('Entry point ' + entry_point + ' not found in the xml.')

# Template for the header declaration of the dispatch table.
dispatch_table_header_template = """// GENERATED FILE - DO NOT EDIT.
// Generated by {script_name} using data from {data_source_name} and gl.xml.
//
// Copyright {year} The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// {file_name}:
//   Defines the native binding interface for ANGLE's OpenGL back-end.

#ifndef LIBGLESV2_RENDERER_GL_DISPATCH_TABLE_GL_AUTOGEN_H_
#define LIBGLESV2_RENDERER_GL_DISPATCH_TABLE_GL_AUTOGEN_H_

#include "common/angleutils.h"
#include "libANGLE/renderer/gl/functionsgl_typedefs.h"

#include <set>

namespace gl
{{
struct Version;
}}  // namespace gl

namespace rx
{{
class DispatchTableGL : angle::NonCopyable
{{
  public:
{table_data}

  virtual ~DispatchTableGL() = default;

  protected:
    virtual void *loadProcAddress(const std::string &function) const = 0;

    void initProcsDesktopGL(const gl::Version &version, const std::set<std::string> &extensions);
    void initProcsGLES(const gl::Version &version, const std::set<std::string> &extensions);
    void initProcsSharedExtensions(const std::set<std::string> &extensions);

#if defined(ANGLE_ENABLE_OPENGL_NULL)
    void initProcsDesktopGLNULL(const gl::Version &version, const std::set<std::string> &extensions);
    void initProcsGLESNULL(const gl::Version &version, const std::set<std::string> &extensions);
    void initProcsSharedExtensionsNULL(const std::set<std::string> &extensions);
#endif  // defined(ANGLE_ENABLE_OPENGL_NULL)
}};

}}  // namespace rx

#endif  // LIBGLESV2_RENDERER_GL_DISPATCH_TABLE_GL_AUTOGEN_H_
"""

def first_lower(str):
    return str[:1].lower() + str[1:]

def format_ep_decl(entry_point):
    return "    PFNGL" + entry_point.upper() + "PROC " + first_lower(entry_point) + " = nullptr;"

table_data = []
for comment, entry_points in sorted(json_data.iteritems()):
    formatted = ["    // " + comment]
    formatted += [format_ep_decl(entry_point) for entry_point in sorted(entry_points)]

    table_data.append("\n".join(formatted))

dispatch_table_header = dispatch_table_header_template.format(
    script_name = os.path.basename(sys.argv[0]),
    data_source_name = data_source_name,
    year = date.today().year,
    file_name = dispatch_header_path,
    table_data = "\n\n".join(table_data))

with open(dispatch_header_path, "w") as out:
    out.write(dispatch_table_header)

# Template for the initialization file of the dispatch table.
dispatch_table_source_template = """// GENERATED FILE - DO NOT EDIT.
// Generated by {script_name} using data from {data_source_name} and gl.xml.
//
// Copyright {year} The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// {file_name}:
//   Initialize the native bindings for ANGLE's OpenGL back-end.

#include "libANGLE/renderer/gl/DispatchTableGL_autogen.h"

#include "libANGLE/Version.h"
#include "libANGLE/renderer/gl/FunctionsGL.h"

#if defined(ANGLE_ENABLE_OPENGL_NULL)
#include "libANGLE/renderer/gl/null_functions.h"
#endif  // defined(ANGLE_ENABLE_OPENGL_NULL)

// Check for nullptr so extensions do not overwrite core imports.
#define ASSIGN(NAME, FP) if (!FP) *reinterpret_cast<void **>(&FP) = loadProcAddress(NAME)

namespace rx
{{

void DispatchTableGL::initProcsDesktopGL(const gl::Version &version, const std::set<std::string> &extensions)
{{
{gl_data}

{gl_extensions_data}
}}

void DispatchTableGL::initProcsGLES(const gl::Version &version, const std::set<std::string> &extensions)
{{
{gles2_data}

{gles2_extensions_data}
}}

void DispatchTableGL::initProcsSharedExtensions(const std::set<std::string> &extensions)
{{
{both_extensions_data}
}}

#if defined(ANGLE_ENABLE_OPENGL_NULL)
void DispatchTableGL::initProcsDesktopGLNULL(const gl::Version &version, const std::set<std::string> &extensions)
{{
{gl_null_data}

{gl_null_extensions_data}
}}

void DispatchTableGL::initProcsGLESNULL(const gl::Version &version, const std::set<std::string> &extensions)
{{
{gles2_null_data}

{gles2_null_extensions_data}
}}

void DispatchTableGL::initProcsSharedExtensionsNULL(const std::set<std::string> &extensions)
{{
{both_null_extensions_data}
}}
#endif  // defined(ANGLE_ENABLE_OPENGL_NULL)

}}  // namespace rx
"""

def format_assign_ep(entry_point, ep):
    return '        ASSIGN("' + ep + '", ' + first_lower(entry_point[2:]) + ');'

def format_requirements_lines(required, entry_points):
    major, minor = required
    lines = ['    if (version >= gl::Version(' + major + ', ' + minor + '))', '    {']
    lines += [format_assign_ep(entry_point, entry_point) for entry_point in sorted(entry_points)]
    lines += ['    }']
    return '\n'.join(lines)

def format_extension_requirements_lines(extension, entry_points, api):
    lines = ['    if (extensions.count("' + extension + '") != 0)', '    {']
    lines += [format_assign_ep(entry_point, ep) for entry_point, ep in sorted(entry_points)]
    lines += ['    }']
    return '\n'.join(lines)

gl_data = []
for gl_required, entry_points in sorted(gl_requirements.iteritems()):
    gl_data.append(format_requirements_lines(gl_required, entry_points))

gl_extensions_data = []
for extension, entry_points in sorted(gl_extension_requirements.iteritems()):
    gl_extensions_data.append(format_extension_requirements_lines(extension, entry_points, "gl"))

gles2_data = []
for gles2_required, entry_points in sorted(gles2_requirements.iteritems()):
    gles2_data.append(format_requirements_lines(gles2_required, entry_points))

gles2_extensions_data = []
for extension, entry_points in sorted(gles2_extension_requirements.iteritems()):
    gles2_extensions_data.append(format_extension_requirements_lines(extension, entry_points, "gles2"))

both_extensions_data = []
for extension, entry_points in sorted(both_extension_requirements.iteritems()):
    both_extensions_data.append(format_extension_requirements_lines(extension, entry_points, "gles2|gl"))

def assign_null_line(line):
    m = re.match(r'        ASSIGN\("gl.*", (.+)\);', line)
    if m:
        name = m.group(1)
        return '        ' + name + ' = &gl' + name[0].upper() + name[1:] + 'NULL;'
    else:
        return line

def assign_null(entry):
    return '\n'.join([assign_null_line(line) for line in entry.split('\n')])

def nullify(data):
    return [assign_null(entry) for entry in data]

dispatch_table_source = dispatch_table_source_template.format(
    script_name = os.path.basename(sys.argv[0]),
    data_source_name = data_source_name,
    year = date.today().year,
    file_name = dispatch_source_path,
    gl_data = "\n\n".join(gl_data),
    gl_extensions_data = "\n\n".join(gl_extensions_data),
    gles2_data = "\n\n".join(gles2_data),
    gles2_extensions_data = "\n\n".join(gles2_extensions_data),
    both_extensions_data = "\n\n".join(both_extensions_data),
    gl_null_data = "\n\n".join(nullify(gl_data)),
    gl_null_extensions_data = "\n\n".join(nullify(gl_extensions_data)),
    gles2_null_data = "\n\n".join(nullify(gles2_data)),
    gles2_null_extensions_data = "\n\n".join(nullify(gles2_extensions_data)),
    both_null_extensions_data = "\n\n".join(nullify(both_extensions_data)))

with open(dispatch_source_path, "w") as out:
    out.write(dispatch_table_source)

# Generate the NULL/stub entry points.
# Process the whole set of commands

def format_param(param):
    return "".join(param.itertext())

command_defs = {}
command_decls = {}

for command in xml_root.findall('commands/command'):
    proto = command.find('proto')
    command_name = proto.find('name').text
    entry = ''.join(proto.itertext())
    return_type = entry[:-len(command_name)]
    entry = return_type + ' INTERNAL_GL_APIENTRY ' + entry[len(return_type):] + 'NULL('

    param_text = [format_param(param) for param in command.findall('param')]
    entry += ', '.join(param_text) + ')'

    command_decls[command_name] = entry + ';'

    entry += '\n{\n'
    if return_type != 'void ':
        entry += '    return static_cast<' + return_type + '>(0);\n'
    entry += '}'

    command_defs[command_name] = entry

null_decls = [command_decls[entry_point] for entry_point in sorted(all_entry_points)]
null_stubs = [command_defs[entry_point] for entry_point in sorted(all_entry_points)]

null_functions_header_template = """// GENERATED FILE - DO NOT EDIT.
// Generated by {script_name} using data from {data_source_name} and gl.xml.
//
// Copyright {year} The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// {file_name}:
//   Declares the NULL/Stub bindings for the OpenGL back-end.

#ifndef LIBGLESV2_RENDERER_GL_NULL_GL_FUNCTIONS_AUTOGEN_H_
#define LIBGLESV2_RENDERER_GL_NULL_GL_FUNCTIONS_AUTOGEN_H_

#include "libANGLE/renderer/gl/functionsgl_typedefs.h"

namespace rx
{{
{table_data}
}}  // namespace rx

#endif  // LIBGLESV2_RENDERER_GL_NULL_GL_FUNCTIONS_AUTOGEN_H_
"""

null_functions_header = null_functions_header_template.format(
    script_name = os.path.basename(sys.argv[0]),
    data_source_name = data_source_name,
    year = date.today().year,
    file_name = null_functions_header_path,
    table_data = "\n".join(null_decls))

with open(null_functions_header_path, "w") as out:
    out.write(null_functions_header)

null_functions_source_template = """// GENERATED FILE - DO NOT EDIT.
// Generated by {script_name} using data from {data_source_name} and gl.xml.
//
// Copyright {year} The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// {file_name}:
//   Defines the NULL/Stub bindings for the OpenGL back-end.

#include "libANGLE/renderer/gl/null_functions.h"

namespace rx
{{
{table_data}
}}  // namespace rx
"""

null_functions_source = null_functions_source_template.format(
    script_name = os.path.basename(sys.argv[0]),
    data_source_name = data_source_name,
    year = date.today().year,
    file_name = null_functions_source_path,
    table_data = "\n\n".join(null_stubs))

with open(null_functions_source_path, "w") as out:
    out.write(null_functions_source)
