#!/usr/bin/env python3
#############################################################################
#
#   Copyright (C) 2013-2018 PX4 Pro Development Team. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in
#    the documentation and/or other materials provided with the
#    distribution.
# 3. Neither the name PX4 nor the names of its contributors may be
#    used to endorse or promote products derived from this software
#    without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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#############################################################################

"""
px_generate_uorb_topic_files.py
Generates c/cpp header/source files for uorb topics from .msg (ROS syntax)
message files
"""

import os
import shutil
import filecmp
import argparse
import sys
import errno

try:
    import em
except ImportError as e:
    print("Python import error: ", e)
    print('''
Required python package empy not installed.

Please run:
    pip3 install --user empy
''')
    exit(1)

try:
    import genmsg.template_tools
except ImportError as e:
    print("Python import error: ", e)
    print('''
Required python package pyros-genmsg not installed.

Please run:
    pip3 install --user pyros-genmsg
''')
    exit(1)


__author__ = "Sergey Belash, Thomas Gubler, Beat Kueng"
__copyright__ = "Copyright (C) 2013-2016 PX4 Development Team."
__license__ = "BSD"
__email__ = "thomasgubler@gmail.com"


TEMPLATE_FILE = ['msg.h.em', 'msg.cpp.em']
TOPICS_LIST_TEMPLATE_FILE = 'uORBTopics.cpp.em'
OUTPUT_FILE_EXT = ['.h', '.cpp']
INCL_DEFAULT = ['std_msgs:./msg/std_msgs']
PACKAGE = 'px4'
TOPICS_TOKEN = '# TOPICS '
IDL_TEMPLATE_FILE = 'msg.idl.em'

CONSTRAINED_FLASH = False


class MsgScope:
    NONE = 0
    SEND = 1
    RECEIVE = 2


def get_multi_topics(filename):
    """
    Get TOPICS names from a "# TOPICS" line
    """
    ofile = open(filename, 'r')
    text = ofile.read()
    result = []
    for each_line in text.split('\n'):
        if each_line.startswith(TOPICS_TOKEN):
            topic_names_str = each_line.strip()
            topic_names_str = topic_names_str.replace(TOPICS_TOKEN, "")
            result.extend(topic_names_str.split(" "))
    ofile.close()
    return result


def get_msgs_list(msgdir):
    """
    Makes list of msg files in the given directory
    """
    return [fn for fn in os.listdir(msgdir) if fn.endswith(".msg")]


def generate_output_from_file(format_idx, filename, outputdir, package, templatedir, includepath):
    """
    Converts a single .msg file to an uorb header/source file
    """
    msg_context = genmsg.msg_loader.MsgContext.create_default()
    full_type_name = genmsg.gentools.compute_full_type_name(
        package, os.path.basename(filename))
    spec = genmsg.msg_loader.load_msg_from_file(
        msg_context, filename, full_type_name)
    field_name_and_type = {}
    for field in spec.parsed_fields():
        field_name_and_type.update({field.name: field.type})
    # assert if the timestamp field exists
    try:
        assert 'timestamp' in field_name_and_type
    except AssertionError:
        print("[ERROR] uORB topic files generator:\n\tgenerate_output_from_file:\tNo 'timestamp' field found in " +
              spec.short_name + " msg definition!")
        exit(1)
    # assert if the timestamp field is of type uint64
    try:
        assert field_name_and_type.get('timestamp') == 'uint64'
    except AssertionError:
        print("[ERROR] uORB topic files generator:\n\tgenerate_output_from_file:\t'timestamp' field in " + spec.short_name +
              " msg definition is not of type uint64 but rather of type " + field_name_and_type.get('timestamp') + "!")
        exit(1)
    topics = get_multi_topics(filename)
    if includepath:
        search_path = genmsg.command_line.includepath_to_dict(includepath)
    else:
        search_path = {}
    genmsg.msg_loader.load_depends(msg_context, spec, search_path)
    md5sum = genmsg.gentools.compute_md5(msg_context, spec)
    if len(topics) == 0:
        topics.append(spec.short_name)
    em_globals = {
        "file_name_in": filename,
        "md5sum": md5sum,
        "search_path": search_path,
        "msg_context": msg_context,
        "spec": spec,
        "topics": topics,
        "constrained_flash": CONSTRAINED_FLASH
    }

    # Make sure output directory exists:
    if not os.path.isdir(outputdir):
        os.makedirs(outputdir)

    template_file = os.path.join(templatedir, TEMPLATE_FILE[format_idx])
    output_file = os.path.join(outputdir, spec.short_name +
                               OUTPUT_FILE_EXT[format_idx])

    return generate_by_template(output_file, template_file, em_globals)


def generate_idl_file(filename_msg, msg_dir, alias, outputdir, templatedir, package, includepath, fastrtpsgen_version, ros2_distro, ids):
    """
    Generates an .idl from .msg file
    """
    msg = os.path.join(msg_dir, filename_msg + ".msg")

    if (alias != ""):
        em_globals = get_em_globals(
            msg, alias, package, includepath, ids, fastrtpsgen_version, ros2_distro, MsgScope.NONE)
        spec_short_name = alias
    else:
        em_globals = get_em_globals(
            msg, "", package, includepath, ids, fastrtpsgen_version, ros2_distro, MsgScope.NONE)
        spec_short_name = em_globals["spec"].short_name

    # Make sure output directory exists:
    if not os.path.isdir(outputdir):
        os.makedirs(outputdir)

    template_file = os.path.join(templatedir, IDL_TEMPLATE_FILE)
    if 1.5 <= fastrtpsgen_version <= 1.7:
        output_file = os.path.join(outputdir, IDL_TEMPLATE_FILE.replace(
            "msg.idl.em", str(spec_short_name + "_.idl")))
    else:
        output_file = os.path.join(outputdir, IDL_TEMPLATE_FILE.replace(
            "msg.idl.em", str(spec_short_name + ".idl")))

    return generate_by_template(output_file, template_file, em_globals)


def generate_uRTPS_general(filename_send_msgs, filename_alias_send_msgs, filename_receive_msgs, filename_alias_receive_msgs,
                           msg_dir, outputdir, templatedir, package, includepath, ids, fastrtpsgen_version, ros2_distro, template_name):
    """
    Generates source file by msg content
    """
    send_msgs = list(os.path.join(msg_dir, msg + ".msg")
                     for msg in filename_send_msgs)
    receive_msgs = list(os.path.join(msg_dir, msg + ".msg")
                        for msg in filename_receive_msgs)

    alias_send_msgs = list([os.path.join(
        msg_dir, msg[1] + ".msg"), list(msg[0].keys())[0]] for msg in filename_alias_send_msgs)

    alias_receive_msgs = list([os.path.join(
        msg_dir, msg[1] + ".msg"), list(msg[0].keys())[0]] for msg in filename_alias_receive_msgs)

    em_globals_list = []
    if send_msgs:
        em_globals_list.extend([get_em_globals(
            f, "", package, includepath, ids, fastrtpsgen_version, ros2_distro, MsgScope.SEND) for f in send_msgs])

    if alias_send_msgs:
        em_globals_list.extend([get_em_globals(
            f[0], f[1], package, includepath, ids, fastrtpsgen_version, ros2_distro, MsgScope.SEND) for f in alias_send_msgs])

    if receive_msgs:
        em_globals_list.extend([get_em_globals(
            f, "", package, includepath, ids, fastrtpsgen_version, ros2_distro, MsgScope.RECEIVE) for f in receive_msgs])

    if alias_receive_msgs:
        em_globals_list.extend([get_em_globals(
            f[0], f[1], package, includepath, ids, fastrtpsgen_version, ros2_distro, MsgScope.RECEIVE) for f in alias_receive_msgs])

    merged_em_globals = merge_em_globals_list(em_globals_list)

    # Make sure output directory exists:
    if not os.path.isdir(outputdir):
        os.makedirs(outputdir)

    template_file = os.path.join(templatedir, template_name)
    output_file = os.path.join(
        outputdir, template_name.replace(".em", ""))

    return generate_by_template(output_file, template_file, merged_em_globals)


def generate_topic_file(filename_msg, msg_dir, alias, outputdir, templatedir, package, includepath, ids, fastrtpsgen_version, ros2_distro, template_name):
    """
    Generates a sources and headers from .msg file
    """
    msg = os.path.join(msg_dir, filename_msg + ".msg")

    if (alias):
        em_globals = get_em_globals(
            msg, alias, package, includepath, ids, fastrtpsgen_version, ros2_distro, MsgScope.NONE)
        spec_short_name = alias
    else:
        em_globals = get_em_globals(
            msg, "", package, includepath, ids, fastrtpsgen_version, ros2_distro, MsgScope.NONE)
        spec_short_name = em_globals["spec"].short_name

    # Make sure output directory exists:
    if not os.path.isdir(outputdir):
        os.makedirs(outputdir)

    template_file = os.path.join(templatedir, template_name)
    output_file = os.path.join(
        outputdir, spec_short_name + "_" + template_name.replace(".em", ""))

    return generate_by_template(output_file, template_file, em_globals)


def get_em_globals(filename_msg, alias, package, includepath, ids, fastrtpsgen_version, ros2_distro, scope):
    """
    Generates em globals dictionary
    """
    msg_context = genmsg.msg_loader.MsgContext.create_default()
    full_type_name = genmsg.gentools.compute_full_type_name(
        package, os.path.basename(filename_msg))
    spec = genmsg.msg_loader.load_msg_from_file(
        msg_context, filename_msg, full_type_name)
    topics = get_multi_topics(filename_msg)
    if includepath:
        search_path = genmsg.command_line.includepath_to_dict(includepath)
    else:
        search_path = {}
    genmsg.msg_loader.load_depends(msg_context, spec, search_path)
    md5sum = genmsg.gentools.compute_md5(msg_context, spec)
    if len(topics) == 0:
        topics.append(spec.short_name)
    em_globals = {
        "file_name_in": filename_msg,
        "md5sum": md5sum,
        "search_path": search_path,
        "msg_context": msg_context,
        "spec": spec,
        "topics": topics,
        "ids": ids,
        "scope": scope,
        "package": package,
        "alias": alias,
        "fastrtpsgen_version": fastrtpsgen_version,
        "ros2_distro": ros2_distro
    }

    return em_globals


def merge_em_globals_list(em_globals_list):
    """
        Merges a list of em_globals to a single dictionary where each attribute is a list
    """
    if len(em_globals_list) < 1:
        return {}

    merged_em_globals = {}
    for name in em_globals_list[0]:
        merged_em_globals[name] = [em_globals[name]
                                   for em_globals in em_globals_list]

    return merged_em_globals


def generate_by_template(output_file, template_file, em_globals):
    """
    Invokes empy intepreter to geneate output_file by the
    given template_file and predefined em_globals dict
    """
    # check if folder exists:
    folder_name = os.path.dirname(output_file)
    if not os.path.exists(folder_name):
        os.makedirs(folder_name)

    ofile = open(output_file, 'w')
    # todo, reuse interpreter
    interpreter = em.Interpreter(output=ofile, globals=em_globals, options={
                                 em.RAW_OPT: True, em.BUFFERED_OPT: True})
    try:
        interpreter.file(open(template_file))
    except OSError as e:
        ofile.close()
        os.remove(output_file)
        raise
    interpreter.shutdown()
    ofile.close()
    return True


def convert_dir(format_idx, inputdir, outputdir, package, templatedir):
    """
    Converts all .msg files in inputdir to uORB header/source files
    """

    # Find the most recent modification time in input dir
    maxinputtime = 0
    for f in os.listdir(inputdir):
        fni = os.path.join(inputdir, f)
        if os.path.isfile(fni):
            it = os.path.getmtime(fni)
            if it > maxinputtime:
                maxinputtime = it

    # Find the most recent modification time in output dir
    maxouttime = 0
    if os.path.isdir(outputdir):
        for f in os.listdir(outputdir):
            fni = os.path.join(outputdir, f)
            if os.path.isfile(fni):
                it = os.path.getmtime(fni)
                if it > maxouttime:
                    maxouttime = it

    # Do not generate if nothing changed on the input
    if (maxinputtime != 0 and maxouttime != 0 and maxinputtime < maxouttime):
        return False

    includepath = INCL_DEFAULT + [':'.join([package, inputdir])]
    for f in os.listdir(inputdir):
        # Ignore hidden files
        if f.startswith("."):
            continue

        fn = os.path.join(inputdir, f)
        # Only look at actual files
        if not os.path.isfile(fn):
            continue

        if fn[-4:].lower() != '.msg':
            continue

        generate_output_from_file(
            format_idx, fn, outputdir, package, templatedir, includepath)
    return True


def copy_changed(inputdir, outputdir, prefix='', quiet=False):
    """
    Copies files from inputdir to outputdir if they don't exist in
    ouputdir or if their content changed
    """

    # Make sure output directory exists:
    if not os.path.isdir(outputdir):
        os.makedirs(outputdir)

    for input_file in os.listdir(inputdir):
        fni = os.path.join(inputdir, input_file)
        if os.path.isfile(fni):
            # Check if input_file exists in outpoutdir, copy the file if not
            fno = os.path.join(outputdir, prefix + input_file)
            if not os.path.isfile(fno):
                shutil.copy(fni, fno)
                if not quiet:
                    print("{0}: new header file".format(fno))
                continue

            if os.path.getmtime(fni) > os.path.getmtime(fno):
                # The file exists in inputdir and outputdir
                # only copy if contents do not match
                if not filecmp.cmp(fni, fno):
                    shutil.copy(fni, fno)
                    if not quiet:
                        print("{0}: updated".format(input_file))
                    continue

            if not quiet:
                print("{0}: unchanged".format(input_file))


def convert_dir_save(format_idx, inputdir, outputdir, package, templatedir, temporarydir, prefix, quiet=False):
    """
    Converts all .msg files in inputdir to uORB header files
    Unchanged existing files are not overwritten.
    """
    # Create new headers in temporary output directory
    convert_dir(format_idx, inputdir, temporarydir, package, templatedir)
    if generate_idx == 1:
        generate_topics_list_file(inputdir, temporarydir, templatedir)
    # Copy changed headers from temporary dir to output dir
    copy_changed(temporarydir, outputdir, prefix, quiet)


def generate_topics_list_file(msgdir, outputdir, templatedir):
    # generate cpp file with topics list
    msgs = get_msgs_list(msgdir)
    multi_topics = []
    for msg in msgs:
        msg_filename = os.path.join(msgdir, msg)
        multi_topics.extend(get_multi_topics(msg_filename))
    tl_globals = {"msgs": msgs, "multi_topics": multi_topics}
    tl_template_file = os.path.join(templatedir, TOPICS_LIST_TEMPLATE_FILE)
    tl_out_file = os.path.join(
        outputdir, TOPICS_LIST_TEMPLATE_FILE.replace(".em", ""))
    generate_by_template(tl_out_file, tl_template_file, tl_globals)


def generate_topics_list_file_from_files(files, outputdir, templatedir):
    # generate cpp file with topics list
    filenames = [os.path.basename(
        p) for p in files if os.path.basename(p).endswith(".msg")]
    multi_topics = []
    for msg_filename in files:
        multi_topics.extend(get_multi_topics(msg_filename))
    tl_globals = {"msgs": filenames, "multi_topics": multi_topics}
    tl_template_file = os.path.join(templatedir, TOPICS_LIST_TEMPLATE_FILE)
    tl_out_file = os.path.join(
        outputdir, TOPICS_LIST_TEMPLATE_FILE.replace(".em", ""))
    generate_by_template(tl_out_file, tl_template_file, tl_globals)


def append_to_include_path(path_to_append, curr_include, package):
    for p in path_to_append:
        curr_include.append('%s:%s' % (package, p))


if __name__ == "__main__":
    parser = argparse.ArgumentParser(
        description='Convert msg files to uorb headers/sources')
    parser.add_argument('--headers', help='Generate header files',
                        action='store_true')
    parser.add_argument('--sources', help='Generate source files',
                        action='store_true')
    parser.add_argument('-d', dest='dir', help='directory with msg files')
    parser.add_argument('-f', dest='file',
                        help="files to convert (use only without -d)",
                        nargs="+")
    parser.add_argument('-i', dest="include_paths",
                        help='Additional Include Paths', nargs="*",
                        default=None)
    parser.add_argument('-e', dest='templatedir',
                        help='directory with template files',)
    parser.add_argument('-k', dest='package', default=PACKAGE,
                        help='package name')
    parser.add_argument('-o', dest='outputdir',
                        help='output directory for header files')
    parser.add_argument('-t', dest='temporarydir',
                        help='temporary directory')
    parser.add_argument('-p', dest='prefix', default='',
                        help='string added as prefix to the output file '
                        ' name when converting directories')
    parser.add_argument('-q', dest='quiet', default=False, action='store_true',
                        help='string added as prefix to the output file '
                        ' name when converting directories')
    parser.add_argument('--constrained-flash', dest='constrained_flash', default=False, action='store_true',
                        help='set to save flash space')
    args = parser.parse_args()

    if args.include_paths:
        append_to_include_path(args.include_paths, INCL_DEFAULT, args.package)

    CONSTRAINED_FLASH = args.constrained_flash

    if args.headers:
        generate_idx = 0
    elif args.sources:
        generate_idx = 1
    else:
        print('Error: either --headers or --sources must be specified')
        exit(-1)
    if args.file is not None:
        for f in args.file:
            generate_output_from_file(
                generate_idx, f, args.temporarydir, args.package, args.templatedir, INCL_DEFAULT)
        if generate_idx == 1:
            generate_topics_list_file_from_files(
                args.file, args.outputdir, args.templatedir)
        copy_changed(args.temporarydir, args.outputdir,
                     args.prefix, args.quiet)
    elif args.dir is not None:
        convert_dir_save(
            generate_idx,
            args.dir,
            args.outputdir,
            args.package,
            args.templatedir,
            args.temporarydir,
            args.prefix,
            args.quiet)