#!/usr/bin/env python
#
# Copyright 2021 Espressif Systems (Shanghai) CO LTD
#
# 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 argparse
import errno
import json
import os
import subprocess
import sys
import tempfile
from io import StringIO

from entity import EntityDB
from fragments import FragmentFile
from generation import Generation
from ldgen_common import LdGenFailure
from linker_script import LinkerScript
from pyparsing import ParseException, ParseFatalException
from sdkconfig import SDKConfig

try:
    import confgen
except Exception:
    parent_dir_name = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))
    kconfig_new_dir = os.path.abspath(parent_dir_name + '/kconfig_new')
    sys.path.insert(0, kconfig_new_dir)
    import confgen


def _update_environment(args):
    env = [(name, value) for (name,value) in (e.split('=',1) for e in args.env)]
    for name, value in env:
        value = ' '.join(value.split())
        os.environ[name] = value

    if args.env_file is not None:
        env = json.load(args.env_file)
        os.environ.update(confgen.dict_enc_for_env(env))


def main():

    argparser = argparse.ArgumentParser(description='ESP-IDF linker script generator')

    argparser.add_argument(
        '--input', '-i',
        help='Linker template file',
        type=argparse.FileType('r'))

    argparser.add_argument(
        '--fragments', '-f',
        type=argparse.FileType('r'),
        help='Input fragment files',
        nargs='+')

    argparser.add_argument(
        '--libraries-file',
        type=argparse.FileType('r'),
        help='File that contains the list of libraries in the build')

    argparser.add_argument(
        '--output', '-o',
        help='Output linker script',
        type=str)

    argparser.add_argument(
        '--config', '-c',
        help='Project configuration')

    argparser.add_argument(
        '--kconfig', '-k',
        help='IDF Kconfig file')

    argparser.add_argument(
        '--check-mapping',
        help='Perform a check if a mapping (archive, obj, symbol) exists',
        action='store_true'
    )

    argparser.add_argument(
        '--check-mapping-exceptions',
        help='Mappings exempted from check',
        type=argparse.FileType('r')
    )

    argparser.add_argument(
        '--env', '-e',
        action='append', default=[],
        help='Environment to set when evaluating the config file', metavar='NAME=VAL')

    argparser.add_argument('--env-file', type=argparse.FileType('r'),
                           help='Optional file to load environment variables from. Contents '
                           'should be a JSON object where each key/value pair is a variable.')

    argparser.add_argument(
        '--objdump',
        help='Path to toolchain objdump')

    args = argparser.parse_args()

    input_file = args.input
    fragment_files = [] if not args.fragments else args.fragments
    libraries_file = args.libraries_file
    config_file = args.config
    output_path = args.output
    kconfig_file = args.kconfig
    objdump = args.objdump

    check_mapping = args.check_mapping
    if args.check_mapping_exceptions:
        check_mapping_exceptions = [line.strip() for line in args.check_mapping_exceptions]
    else:
        check_mapping_exceptions = None

    try:
        sections_infos = EntityDB()
        for library in libraries_file:
            library = library.strip()
            if library:
                dump = StringIO(subprocess.check_output([objdump, '-h', library]).decode())
                dump.name = library
                sections_infos.add_sections_info(dump)

        generation_model = Generation(check_mapping, check_mapping_exceptions)

        _update_environment(args)  # assign args.env and args.env_file to os.environ

        sdkconfig = SDKConfig(kconfig_file, config_file)

        for fragment_file in fragment_files:
            try:
                fragment_file = FragmentFile(fragment_file, sdkconfig)
            except (ParseException, ParseFatalException) as e:
                # ParseException is raised on incorrect grammar
                # ParseFatalException is raised on correct grammar, but inconsistent contents (ex. duplicate
                # keys, key unsupported by fragment, unexpected number of values, etc.)
                raise LdGenFailure('failed to parse %s\n%s' % (fragment_file.name, str(e)))
            generation_model.add_fragments_from_file(fragment_file)

        mapping_rules = generation_model.generate(sections_infos)

        script_model = LinkerScript(input_file)
        script_model.fill(mapping_rules)

        with tempfile.TemporaryFile('w+') as output:
            script_model.write(output)
            output.seek(0)

            if not os.path.exists(os.path.dirname(output_path)):
                try:
                    os.makedirs(os.path.dirname(output_path))
                except OSError as exc:
                    if exc.errno != errno.EEXIST:
                        raise

            with open(output_path, 'w') as f:  # only create output file after generation has suceeded
                f.write(output.read())
    except LdGenFailure as e:
        print('linker script generation failed for %s\nERROR: %s' % (input_file.name, e))
        sys.exit(1)


if __name__ == '__main__':
    main()