#!/usr/bin/python3
#
# 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.
#
# run_code_generation.py:
#   Runs ANGLE format table and other script code generation scripts.

import argparse
from concurrent import futures
import hashlib
import json
import os
import subprocess
import sys
import platform

script_dir = sys.path[0]
root_dir = os.path.abspath(os.path.join(script_dir, '..'))

hash_dir = os.path.join(script_dir, 'code_generation_hashes')


def get_child_script_dirname(script):
    # All script names are relative to ANGLE's root
    return os.path.dirname(os.path.abspath(os.path.join(root_dir, script)))


def get_executable_name():
    binary = 'vpython3'
    if platform.system() == 'Windows':
        return binary + '.bat'
    else:
        return binary


def paths_from_auto_script(script, param):
    script_dir = get_child_script_dirname(script)
    exe = get_executable_name()
    try:
        res = subprocess.check_output([exe, os.path.basename(script), param],
                                      cwd=script_dir).decode().strip()
    except Exception:
        print('Error with auto_script %s: %s, executable %s' % (param, script, exe))
        raise
    if res == '':
        return []
    return [
        os.path.relpath(os.path.join(script_dir, path), root_dir).replace("\\", "/")
        for path in res.split(',')
    ]


# auto_script is a standard way for scripts to return their inputs and outputs.
def auto_script(script):
    info = {
        'inputs': paths_from_auto_script(script, 'inputs'),
        'outputs': paths_from_auto_script(script, 'outputs')
    }
    return info


generators = {
    'ANGLE format':
        'src/libANGLE/renderer/gen_angle_format_table.py',
    'ANGLE load functions table':
        'src/libANGLE/renderer/gen_load_functions_table.py',
    'ANGLE shader preprocessor':
        'src/compiler/preprocessor/generate_parser.py',
    'ANGLE shader translator':
        'src/compiler/translator/generate_parser.py',
    'D3D11 blit shader selection':
        'src/libANGLE/renderer/d3d/d3d11/gen_blit11helper.py',
    'D3D11 format':
        'src/libANGLE/renderer/d3d/d3d11/gen_texture_format_table.py',
    'DXGI format':
        'src/libANGLE/renderer/gen_dxgi_format_table.py',
    'DXGI format support':
        'src/libANGLE/renderer/gen_dxgi_support_tables.py',
    'Emulated HLSL functions':
        'src/compiler/translator/hlsl/gen_emulated_builtin_function_tables.py',
    'Extension files':
        'src/libANGLE/gen_extensions.py',
    'GL copy conversion table':
        'src/libANGLE/gen_copy_conversion_table.py',
    'GL CTS (dEQP) build files':
        'scripts/gen_vk_gl_cts_build.py',
    'GL/EGL/WGL loader':
        'scripts/generate_loader.py',
    'GL/EGL entry points':
        'scripts/generate_entry_points.py',
    'GLenum value to string map':
        'scripts/gen_gl_enum_utils.py',
    'GL format map':
        'src/libANGLE/gen_format_map.py',
    'interpreter utils':
        'scripts/gen_interpreter_utils.py',
    'Metal format table':
        'src/libANGLE/renderer/metal/gen_mtl_format_table.py',
    'Metal default shaders':
        'src/libANGLE/renderer/metal/shaders/gen_mtl_internal_shaders.py',
    'OpenGL dispatch table':
        'src/libANGLE/renderer/gl/generate_gl_dispatch_table.py',
    'packed enum':
        'src/common/gen_packed_gl_enums.py',
    'proc table':
        'scripts/gen_proc_table.py',
    'restricted traces':
        'src/tests/restricted_traces/gen_restricted_traces.py',
    'SPIR-V helpers':
        'src/common/spirv/gen_spirv_builder_and_parser.py',
    'Static builtins':
        'src/compiler/translator/gen_builtin_symbols.py',
    'uniform type':
        'src/common/gen_uniform_type_table.py',
    'Vulkan format':
        'src/libANGLE/renderer/vulkan/gen_vk_format_table.py',
    'Vulkan internal shader programs':
        'src/libANGLE/renderer/vulkan/gen_vk_internal_shaders.py',
    'Vulkan mandatory format support table':
        'src/libANGLE/renderer/vulkan/gen_vk_mandatory_format_support_table.py',
    'WebGPU format':
        'src/libANGLE/renderer/wgpu/gen_wgpu_format_table.py',
}


# Fast and supports --verify-only without hashes.
hashless_generators = {
    'ANGLE features': 'include/platform/gen_features.py',
}


def md5(fname):
    hash_md5 = hashlib.md5()
    with open(fname, 'rb') as f:
        if sys.platform.startswith('win') or sys.platform == 'cygwin':
            # Beware: Windows crlf + git behavior + unicode in some files
            hash_md5.update(f.read().replace(b'\r\n', b'\n'))
        else:
            for chunk in iter(lambda: f.read(4096), b''):
                hash_md5.update(chunk)
    return hash_md5.hexdigest()


def get_hash_file_name(name):
    return name.replace(' ', '_').replace('/', '_') + '.json'


def any_hash_dirty(name, filenames, new_hashes, old_hashes):
    found_dirty_hash = False

    for fname in filenames:
        if not os.path.isfile(os.path.join(root_dir, fname)):
            print('File not found: "%s". Code gen dirty for %s' % (fname, name))
            found_dirty_hash = True
        else:
            new_hashes[fname] = md5(fname)
            if (not fname in old_hashes) or (old_hashes[fname] != new_hashes[fname]):
                print('Hash for "%s" dirty for %s generator.' % (fname, name))
                found_dirty_hash = True
    return found_dirty_hash


def any_old_hash_missing(all_new_hashes, all_old_hashes):
    result = False
    for file, old_hashes in all_old_hashes.items():
        if file not in all_new_hashes:
            print('"%s" does not exist. Code gen dirty.' % file)
            result = True
        else:
            for name, _ in old_hashes.items():
                if name not in all_new_hashes[file]:
                    print('Hash for %s is missing from "%s". Code gen is dirty.' % (name, file))
                    result = True
    return result


def update_output_hashes(script, outputs, new_hashes):
    for output in outputs:
        if not os.path.isfile(output):
            print('Output is missing from %s: %s' % (script, output))
            sys.exit(1)
        new_hashes[output] = md5(output)


def load_hashes():
    hashes = {}
    for file in os.listdir(hash_dir):
        hash_fname = os.path.join(hash_dir, file)
        with open(hash_fname) as hash_file:
            try:
                hashes[file] = json.load(hash_file)
            except ValueError:
                raise Exception("Could not decode JSON from %s" % file)
    return hashes


def main():
    all_old_hashes = load_hashes()
    all_new_hashes = {}
    any_dirty = False
    dirty_generator_outputs = []

    parser = argparse.ArgumentParser(description='Generate ANGLE internal code.')
    parser.add_argument(
        '-v',
        '--verify-no-dirty',
        dest='verify_only',
        action='store_true',
        help='verify hashes are not dirty')
    parser.add_argument(
        '-g', '--generator', action='append', nargs='*', type=str, dest='specified_generators'),

    args = parser.parse_args()

    ranGenerators = generators
    runningSingleGenerator = False
    if (args.specified_generators):
        ranGenerators = {k: v for k, v in generators.items() if k in args.specified_generators[0]}
        runningSingleGenerator = True

    if len(ranGenerators) == 0:
        print("No valid generators specified.")
        return 1

    # Just get 'inputs' and 'outputs' from scripts but this runs the scripts so it's a bit slow
    infos = {}
    with futures.ThreadPoolExecutor(max_workers=8) as executor:
        for _, script in sorted(ranGenerators.items()):
            infos[script] = executor.submit(auto_script, script)

    for name, script in sorted(ranGenerators.items()):
        info = infos[script].result()
        fname = get_hash_file_name(name)
        filenames = info['inputs'] + info['outputs'] + [script]
        new_hashes = {}
        if fname not in all_old_hashes:
            all_old_hashes[fname] = {}
        if any_hash_dirty(name, filenames, new_hashes, all_old_hashes[fname]):
            any_dirty = True
            dirty_generator_outputs += info['outputs']


            if not args.verify_only:
                print('Running ' + name + ' code generator')

                exe = get_executable_name()
                subprocess.check_call([exe, os.path.basename(script)],
                                      cwd=get_child_script_dirname(script))

        # Update the hash dictionary.
        all_new_hashes[fname] = new_hashes

    if not runningSingleGenerator and any_old_hash_missing(all_new_hashes, all_old_hashes):
        any_dirty = True

    # Handle hashless_generators separately as these don't have hash maps.
    hashless_generators_dirty = False
    for name, script in sorted(hashless_generators.items()):
        cmd = [get_executable_name(), os.path.basename(script)]
        rc = subprocess.call(cmd + ['--verify-only'], cwd=get_child_script_dirname(script))
        if rc != 0:
            print(name + ' generator dirty')
            # Don't set any_dirty as we don't need git cl format in this case.
            hashless_generators_dirty = True

            if not args.verify_only:
                print('Running ' + name + ' code generator')
                subprocess.check_call(cmd, cwd=get_child_script_dirname(script))

    if args.verify_only:
        return int(any_dirty or hashless_generators_dirty)

    if any_dirty:
        git = 'git.bat' if os.name == 'nt' else 'git'

        # Format dirty generator outputs in `--full` mode so the resulting files
        # are identical regardless of platform. This also avoids a Windows
        # failure mode where diff-based `git cl format` invokes clang-format
        # with one --lines argument per diff hunk; large auto-generated files
        # can produce enough hunks to exceed the OS command-line length limit
        # (~32K), failing with "The filename or extension is too long" and
        # leaving generated files unformatted.
        if dirty_generator_outputs:
            full_format_files = sorted(dirty_generator_outputs)
            print('Calling git cl format --full on %d generated file(s)' % len(full_format_files))
            subprocess.check_call([git, 'cl', 'format', '--full'] + full_format_files)


        # Update the output hashes again since they can be formatted.
        for name, script in sorted(ranGenerators.items()):
            info = auto_script(script)
            fname = get_hash_file_name(name)
            update_output_hashes(name, info['outputs'], all_new_hashes[fname])

        for fname, new_hashes in all_new_hashes.items():
            hash_fname = os.path.join(hash_dir, fname)
            with open(hash_fname, "w") as f:
                json.dump(new_hashes, f, indent=2, sort_keys=True, separators=(',', ':\n    '))
                f.write('\n')  # json.dump doesn't end with newline

    return 0


if __name__ == '__main__':
    sys.exit(main())