#! /usr/bin/env python3

# Copyright (c) 2015 Sanderd17
#
# Licensed under the MIT License:
#
# 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 the rights
# to use, copy, modify, merge, publish, distribute, sublicense, 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 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 NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS 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 os
import struct
import sys


parser = argparse.ArgumentParser(
    description="Convert maps compatible with 0 A.D. version Alpha XVIII (A18) to maps compatible "
    "with version Alpha XIX (A19), or the other way around."
)

parser.add_argument(
    "--reverse",
    action="store_true",
    help="Make an A19 map compatible with A18 (note that conversion will fail "
    "if mountains are too high)",
)
parser.add_argument(
    "--no-version-bump", action="store_true", help="Don't change the version number of the map"
)
parser.add_argument(
    "--no-color-spelling",
    action="store_true",
    help="Don't change the spelling of color and colour",
)
parser.add_argument("--no-height-change", action="store_true", help="Don't change the heightmap")

parser.add_argument(
    "files", nargs="+", help="XML file to process (use wildcards '*' to select multiple files)"
)
args = parser.parse_args()

HEIGHTMAP_BIT_SHIFT = 3

for xml_file in args.files:
    pmp_file = xml_file[:-3] + "pmp"

    print("Processing " + xml_file + " ...")

    if os.path.isfile(pmp_file):
        with open(pmp_file, "rb") as f1, open(pmp_file + "~", "wb") as f2:
            # 4 bytes PSMP to start the file
            f2.write(f1.read(4))

            # 4 bytes to encode the version of the file format
            version = struct.unpack("<I", f1.read(4))[0]
            if args.no_version_bump:
                f2.write(struct.pack("<I", version))
            elif args.reverse:
                if version != 6:
                    print(
                        f"Warning: File {pmp_file} was not at version 6, while a negative version "
                        f"bump was requested.\nABORTING ..."
                    )
                    continue
                f2.write(struct.pack("<I", version - 1))
            else:
                if version != 5:
                    print(
                        f"Warning: File {pmp_file} was not at version 5, while a version bump was "
                        f"requested.\nABORTING ..."
                    )
                    continue
                f2.write(struct.pack("<I", version + 1))

            # 4 bytes a for file size (which shouldn't change)
            f2.write(f1.read(4))

            # 4 bytes to encode the map size
            map_size = struct.unpack("<I", f1.read(4))[0]
            f2.write(struct.pack("<I", map_size))

            # half all heights using the shift '>>' operator
            if args.no_height_change:

                def height_transform(h):
                    return h
            elif args.reverse:

                def height_transform(h):
                    return h << HEIGHTMAP_BIT_SHIFT
            else:

                def height_transform(h):
                    return h >> HEIGHTMAP_BIT_SHIFT

            for _i in range((map_size * 16 + 1) * (map_size * 16 + 1)):
                height = struct.unpack("<H", f1.read(2))[0]
                f2.write(struct.pack("<H", height_transform(height)))

            # copy the rest of the file
            byte = f1.read(1)
            while byte != b"":
                f2.write(byte)
                byte = f1.read(1)

            f2.close()
            f1.close()

        # replace the old file, comment to see both files
        os.remove(pmp_file)
        os.rename(pmp_file + "~", pmp_file)

    if os.path.isfile(xml_file):
        with (
            open(xml_file, encoding="utf-8") as f1,
            open(xml_file + "~", "w", encoding="utf-8") as f2,
        ):
            data = f1.read()

            # bump version number (rely on how Atlas formats the XML)
            if not args.no_version_bump:
                if args.reverse:
                    if data.find('<Scenario version="6">') == -1:
                        print(
                            f"Warning: File {xml_file} was not at version 6, while a negative "
                            f"version bump was requested.\nABORTING ..."
                        )
                        sys.exit()
                    else:
                        data = data.replace('<Scenario version="6">', '<Scenario version="5">')
                elif data.find('<Scenario version="5">') == -1:
                    print(
                        f"Warning: File {xml_file} was not at version 5, while a version bump "
                        f"was requested.\nABORTING ..."
                    )
                    sys.exit()
                else:
                    data = data.replace('<Scenario version="5">', '<Scenario version="6">')

            # transform the color keys
            if not args.no_color_spelling:
                if args.reverse:
                    data = data.replace("color", "colour").replace("Color", "Colour")
                else:
                    data = data.replace("colour", "color").replace("Colour", "Color")

            f2.write(data)
            f1.close()
            f2.close()

        # replace the old file, comment to see both files
        os.remove(xml_file)
        os.rename(xml_file + "~", xml_file)