#!/usr/bin/env python

# Copyright (C) 2009 Chia-I Wu <olv@0xlab.org>
# All Rights Reserved.
#
# This is based on extension_helper.py by Ian Romanick.
#
# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and associated documentation files (the "Software"),
# to deal in the Software without restriction, including without limitation
# on the rights to use, copy, modify, merge, publish, distribute, sub
# license, and/or sell copies of the Software, and to permit persons to whom
# the Software is furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice (including the next
# paragraph) shall be included in all copies or substantial portions of the
# Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.  IN NO EVENT SHALL
# IBM AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
# IN THE SOFTWARE.

import argparse

import license
import gl_XML


def get_function_spec(func):
    sig = ""
    # derive parameter signature
    for p in func.parameterIterator():
        if p.is_padding:
            continue
        # FIXME: This is a *really* ugly hack. :(
        tn = p.type_expr.get_base_type_node()
        if p.is_pointer():
            sig += 'p'
        elif tn.integer:
            sig += 'i'
        elif tn.size == 4:
            sig += 'f'
        else:
            sig += 'd'

    spec = [sig]
    for ent in func.entry_points:
        spec.append("gl" + ent)

    # spec is terminated by an empty string
    spec.append('')

    return spec


class PrintGlRemap(gl_XML.gl_print_base):
    def __init__(self):
        gl_XML.gl_print_base.__init__(self)

        self.name = "remap_helper.py (from Mesa)"
        self.license = license.bsd_license_template % ("Copyright (C) 2009 Chia-I Wu <olv@0xlab.org>", "Chia-I Wu")
        return


    def printRealHeader(self):
        print '#include "main/dispatch.h"'
        print '#include "main/remap.h"'
        print ''
        return


    def printBody(self, api):
        pool_indices = {}

        print '/* this is internal to remap.c */'
        print '#ifndef need_MESA_remap_table'
        print '#error Only remap.c should include this file!'
        print '#endif /* need_MESA_remap_table */'
        print ''

        print ''
        print 'static const char _mesa_function_pool[] ='

        # output string pool
        index = 0;
        for f in api.functionIterateAll():
            pool_indices[f] = index

            spec = get_function_spec(f)

            # a function has either assigned offset, fixed offset,
            # or no offset
            if f.assign_offset:
                comments = "will be remapped"
            elif f.offset > 0:
                comments = "offset %d" % f.offset
            else:
                comments = "dynamic"

            print '   /* _mesa_function_pool[%d]: %s (%s) */' \
                            % (index, f.name, comments)
            for line in spec:
                print '   "%s\\0"' % line
                index += len(line) + 1
        print '   ;'
        print ''

        print '/* these functions need to be remapped */'
        print 'static const struct gl_function_pool_remap MESA_remap_table_functions[] = {'
        # output all functions that need to be remapped
        # iterate by offsets so that they are sorted by remap indices
        for f in api.functionIterateByOffset():
            if not f.assign_offset:
                continue
            print '   { %5d, %s_remap_index },' \
                            % (pool_indices[f], f.name)
        print '   {    -1, -1 }'
        print '};'
        print ''

        # collect functions by versions/extensions
        extension_functions = {}
        abi_extensions = []
        for f in api.functionIterateAll():
            for n in f.entry_points:
                category, num = api.get_category_for_name(n)
                # consider only GL_VERSION_X_Y or extensions
                c = gl_XML.real_category_name(category)
                if c.startswith("GL_"):
                    if not extension_functions.has_key(c):
                        extension_functions[c] = []
                    extension_functions[c].append(f)
                    # remember the ext names of the ABI
                    if (f.is_abi() and n == f.name and
                            c not in abi_extensions):
                        abi_extensions.append(c)
        # ignore the ABI itself
        for ext in abi_extensions:
            extension_functions.pop(ext)

        extensions = extension_functions.keys()
        extensions.sort()

        # output ABI functions that have alternative names (with ext suffix)
        print '/* these functions are in the ABI, but have alternative names */'
        print 'static const struct gl_function_remap MESA_alt_functions[] = {'
        for ext in extensions:
            funcs = []
            for f in extension_functions[ext]:
                # test if the function is in the ABI and has alt names
                if f.is_abi() and len(f.entry_points) > 1:
                    funcs.append(f)
            if not funcs:
                continue
            print '   /* from %s */' % ext
            for f in funcs:
                print '   { %5d, _gloffset_%s },' \
                                % (pool_indices[f], f.name)
        print '   {    -1, -1 }'
        print '};'
        print ''
        return


def _parser():
    """Parse input options and return a namsepace."""
    parser = argparse.ArgumentParser()
    parser.add_argument('-f', '--filename',
                        default="gl_API.xml",
                        metavar="input_file_name",
                        dest='file_name',
                        help="An xml description file.")
    parser.add_argument('-c', '--es-version',
                        choices=[None, 'es1', 'es2'],
                        default=None,
                        metavar='ver',
                        dest='es',
                        help='A GLES version to support')
    return parser.parse_args()


def main():
    """Main function."""
    args = _parser()

    api = gl_XML.parse_GL_API(args.file_name)
    if args.es is not None:
        api.filter_functions_by_api(args.es)

    printer = PrintGlRemap()
    printer.Print(api)


if __name__ == '__main__':
    main()