#! /usr/bin/env python3
import argparse
import os
import os.path
import struct
import sys
from PIL import Image, ImageOps  # type: ignore
from typing import Any, List

from bemani.format.dxt import DXTBuffer
from bemani.protocol.binary import BinaryEncoding
from bemani.protocol.lz77 import Lz77


# Coverage tracker to help find missing chunks.
coverage: List[bool]


def add_coverage(offset: int, length: int, unique: bool = True) -> None:
    global coverage
    for i in range(offset, offset + length):
        if coverage[i] and unique:
            raise Exception(f"Already covered {hex(offset)}!")
        coverage[i] = True


def print_coverage() -> None:
    global coverage

    # First offset that is not coverd in a run.
    start = None

    for offset, covered in enumerate(coverage):
        if covered:
            if start is not None:
                print(f"Uncovered: {hex(start)} - {hex(offset)} ({offset-start} bytes)")
                start = None
        else:
            if start is None:
                start = offset
    if start is not None:
        # Print final range
        offset = len(coverage)
        print(f"Uncovered: {hex(start)} - {hex(offset)} ({offset-start} bytes)")


def get_until_null(data: bytes, offset: int) -> bytes:
    out = b""
    while data[offset] != 0:
        out += data[offset:(offset + 1)]
        offset += 1
    return out


def descramble_text(text: bytes, obfuscated: bool) -> str:
    if len(text):
        if obfuscated and (text[0] - 0x20) > 0x7F:
            # Gotta do a weird demangling where we swap the
            # top bit.
            return bytes(((x + 0x80) & 0xFF) for x in text).decode('ascii')
        else:
            return text.decode('ascii')
    else:
        return ""


def descramble_pman(package_data: bytes, offset: int, obfuscated: bool) -> List[str]:
    # Unclear what the first three unknowns are, but the fourth
    # looks like it could possibly be two int16s indicating unknown?
    magic, _, _, _, numentries, _, data_offset = struct.unpack(
        "<4sIIIIII",
        package_data[offset:(offset + 28)],
    )
    add_coverage(offset, 28)

    if magic != b"PMAN":
        raise Exception("Invalid magic value in PMAN structure!")

    names = []
    if numentries > 0:
        # Jump to the offset, parse it out
        for i in range(numentries):
            file_offset = data_offset + (i * 12)
            # Really not sure on the first entry here, it looks
            # completely random, so it might be a CRC?
            _, entry_no, nameoffset = struct.unpack(
                "<III",
                package_data[file_offset:(file_offset + 12)],
            )
            add_coverage(file_offset, 12)
            if nameoffset == 0:
                raise Exception("Expected name offset in PMAN data!")

            bytedata = get_until_null(package_data, nameoffset)
            add_coverage(nameoffset, len(bytedata) + 1, unique=False)
            name = descramble_text(bytedata, obfuscated)
            names.append(name)

    return names


def swap32(i: int) -> int:
    return struct.unpack("<I", struct.pack(">I", i))[0]


def extract(filename: str, output_dir: str, *, write: bool, verbose: bool = False) -> None:
    with open(filename, "rb") as fp:
        data = fp.read()

    # Initialize coverage. This is used to help find missed/hidden file
    # sections that we aren't parsing correctly.
    global coverage
    coverage = [False] * len(data)

    # Suppress debug text unless asked
    if verbose:
        vprint = print
    else:
        def vprint(*args: Any, **kwargs: Any) -> None:  # type: ignore
            pass

    # First, check the signature
    add_coverage(0, 4)
    if data[0:4] != b"2PXT":
        raise Exception("Invalid graphic file format!")

    # Not sure what words 2 and 3 are, they seem to be some sort of
    # version or date?
    add_coverage(4, 8)

    # Now, grab the file length, verify that we have the right amount
    # of data.
    length = struct.unpack("<I", data[12:16])[0]
    add_coverage(12, 4)
    if length != len(data):
        raise Exception(f"Invalid graphic file length, expecting {length} bytes!")

    # I think that offset 16-20 are the file data offset, but I'm not sure?
    header_length = struct.unpack("<I", data[16:20])[0]
    add_coverage(16, 4)

    # Now, the meat of the file format. Bytes 20-24 are a bitfield for
    # what parts of the header exist in the file. We need to understand
    # each bit so we know how to skip past each section.
    feature_mask = struct.unpack("<I", data[20:24])[0]
    add_coverage(20, 4)
    header_offset = 24

    # Lots of magic happens if this bit is set.
    text_obfuscated = bool(feature_mask & 0x20)
    legacy_lz = bool(feature_mask & 0x04)
    modern_lz = bool(feature_mask & 0x40000)

    # Get raw directory where we want to put files
    path = os.path.abspath(output_dir)

    if feature_mask & 0x01:
        # List of textures that exist in the file, with pointers to their data.
        length, offset = struct.unpack("<II", data[header_offset:(header_offset + 8)])
        add_coverage(header_offset, 8)
        header_offset += 8

        names = []
        for x in range(length):
            interesting_offset = offset + (x * 12)
            if interesting_offset != 0:
                name_offset, texture_length, texture_offset = struct.unpack(
                    "<III",
                    data[interesting_offset:(interesting_offset + 12)],
                )
                add_coverage(interesting_offset, 12)

                if name_offset != 0:
                    # Let's decode this until the first null.
                    bytedata = get_until_null(data, name_offset)
                    add_coverage(name_offset, len(bytedata) + 1, unique=False)
                    name = descramble_text(bytedata, text_obfuscated)
                    names.append(name)

                if texture_offset != 0:
                    filename = os.path.join(path, name)

                    if legacy_lz:
                        raise Exception("We don't support legacy lz mode!")
                    elif modern_lz:
                        # Get size, round up to nearest power of 4
                        inflated_size, deflated_size = struct.unpack(
                            ">II",
                            data[texture_offset:(texture_offset + 8)],
                        )
                        add_coverage(texture_offset, 8)
                        if deflated_size != (texture_length - 8):
                            raise Exception("We got an incorrect length for lz texture!")
                        inflated_size = (inflated_size + 3) & (~3)

                        # Get the data offset
                        lz_data_offset = texture_offset + 8
                        lz_data = data[lz_data_offset:(lz_data_offset + deflated_size)]
                        add_coverage(lz_data_offset, deflated_size)

                        # This takes forever, so skip it if we're pretending.
                        if write:
                            print(f"Inflating {filename}...")
                            lz77 = Lz77()
                            raw_data = lz77.decompress(lz_data)
                        else:
                            raw_data = None
                    else:
                        inflated_size, deflated_size = struct.unpack(
                            ">II",
                            data[texture_offset:(texture_offset + 8)],
                        )

                        # I'm guessing how raw textures work because I haven't seen them.
                        # I assume they're like the above, so lets put in some asertions.
                        if deflated_size != (texture_length - 8):
                            raise Exception("We got an incorrect length for raw texture!")
                        raw_data = data[(texture_offset + 8):(texture_offset + 8 + deflated_size)]
                        add_coverage(texture_offset, deflated_size + 8)

                    if not write:
                        print(f"Would extract {filename}...")
                    else:
                        # Now, see if we can extract this data.
                        print(f"Extracting {filename}...")
                        magic, _, _, _, width, height, fmt, _, flags2, flags1 = struct.unpack(
                            "<4sIIIHHBBBB",
                            raw_data[0:24],
                        )

                        if magic != b"TDXT":
                            raise Exception("Unexpected texture format!")

                        img = None
                        if fmt == 0x0E:
                            # RGB image, no alpha.
                            img = Image.frombytes(
                                'RGB', (width, height), raw_data[64:], 'raw', 'RGB',
                            )
                        # 0x10 = Seems to be some sort of RGB with color swapping.
                        # 0x15 = Looks like RGB but reversed (end and beginning bytes swapped).
                        # 0x16 = DTX1 format, when I encounter this I'll hook it up.
                        elif fmt == 0x1A:
                            # DXT5 format.
                            dxt = DXTBuffer(width, height)
                            img = Image.frombuffer(
                                'RGBA',
                                (width, height),
                                dxt.DXT5Decompress(raw_data[64:]),
                                'raw',
                                'RGBA',
                                0,
                                1,
                            )
                            img = ImageOps.flip(img).rotate(-90, expand=True)
                        # 0x1E = I have no idea what format this is.
                        # 0x1F = 16bpp, possibly grayscale? Maybe 555A or 565 color?
                        elif fmt == 0x20:
                            # RGBA format.
                            img = Image.frombytes(
                                'RGBA', (width, height), raw_data[64:], 'raw', 'BGRA',
                            )
                        else:
                            raise Exception(f"Unsupported format {hex(fmt)} for texture {name}")

                        # Actually place the file down.
                        os.makedirs(path, exist_ok=True)
                        with open(f"{filename}.raw", "wb") as bfp:
                            bfp.write(raw_data)
                        if img:
                            with open(f"{filename}.png", "wb") as bfp:
                                img.save(bfp, format='PNG')

        vprint(f"Bit 0x000001 - count: {length}, offset: {hex(offset)}")
        for name in names:
            vprint(f"    {name}")
    else:
        vprint("Bit 0x000001 - NOT PRESENT")

    if feature_mask & 0x02:
        # Seems to be a structure that duplicates texture names? Maybe this is
        # used elsewhere to map sections to textures? The structure includes
        # the entry number that seems to correspond with the above table.
        offset = struct.unpack("<I", data[header_offset:(header_offset + 4)])[0]
        add_coverage(header_offset, 4)
        header_offset += 4

        vprint(f"Bit 0x000002 - offset: {hex(offset)}")

        if offset != 0:
            names = descramble_pman(data, offset, text_obfuscated)
            for name in names:
                vprint(f"    {name}")
    else:
        vprint("Bit 0x000002 - NOT PRESENT")

    if feature_mask & 0x04:
        vprint("Bit 0x000004 - legacy lz mode on")
    else:
        vprint("Bit 0x000004 - legacy lz mode off")

    if feature_mask & 0x08:
        # I *THINK* that this is the mapping between sections and their
        # respective textures, but I haven't dug in yet.
        length, offset = struct.unpack("<II", data[header_offset:(header_offset + 8)])
        add_coverage(header_offset, 8)
        header_offset += 8

        vprint(f"Bit 0x000008 - count: {length}, offset: {hex(offset)}")
    else:
        vprint("Bit 0x000008 - NOT PRESENT")

    if feature_mask & 0x10:
        # Seems to be a strucure that duplicates the above section?
        offset = struct.unpack("<I", data[header_offset:(header_offset + 4)])[0]
        add_coverage(header_offset, 4)
        header_offset += 4

        vprint(f"Bit 0x000010 - offset: {hex(offset)}")

        if offset != 0:
            names = descramble_pman(data, offset, text_obfuscated)
            for name in names:
                vprint(f"    {name}")
    else:
        vprint("Bit 0x000010 - NOT PRESENT")

    if feature_mask & 0x20:
        vprint(f"Bit 0x000020 - text obfuscation on")
    else:
        vprint(f"Bit 0x000020 - text obfuscation off")

    if feature_mask & 0x40:
        # Two unknown bytes, first is a length or a count. Secound is
        # an optional offset to grab another set of bytes from.
        length, offset = struct.unpack("<II", data[header_offset:(header_offset + 8)])
        add_coverage(header_offset, 8)
        header_offset += 8

        # TODO: 0x40 has some weird offset calculations, gotta look into
        # this further.

        names = []
        for x in range(length):
            interesting_offset = offset + (x * 12)
            if interesting_offset != 0:
                interesting_offset = struct.unpack(
                    "<I",
                    data[interesting_offset:(interesting_offset + 4)],
                )[0]
            if interesting_offset != 0:
                # Let's decode this until the first null.
                bytedata = get_until_null(data, interesting_offset)
                add_coverage(interesting_offset, len(bytedata) + 1, unique=False)
                name = descramble_text(bytedata, text_obfuscated)
                names.append(name)

        vprint(f"Bit 0x000040 - count: {length}, offset: {hex(offset)}")
        for name in names:
            vprint(f"    {name}")
    else:
        vprint("Bit 0x000040 - NOT PRESENT")

    if feature_mask & 0x80:
        # One unknown byte, treated as an offset.
        offset = struct.unpack("<I", data[header_offset:(header_offset + 4)])[0]
        add_coverage(header_offset, 4)
        header_offset += 4

        vprint(f"Bit 0x000080 - offset: {hex(offset)}")

        if offset != 0:
            names = descramble_pman(data, offset, text_obfuscated)
            for name in names:
                vprint(f"    {name}")
    else:
        vprint("Bit 0x000080 - NOT PRESENT")

    if feature_mask & 0x100:
        # Two unknown bytes, first is a length or a count. Secound is
        # an optional offset to grab another set of bytes from.
        length, offset = struct.unpack("<II", data[header_offset:(header_offset + 8)])
        add_coverage(header_offset, 8)
        header_offset += 8

        vprint(f"Bit 0x000100 - count: {length}, offset: {hex(offset)}")

        # TODO: We do something if length is > 0, we use the magic flag
        # from above in this case to optionally transform each thing we
        # extract.
    else:
        vprint("Bit 0x000100 - NOT PRESENT")

    if feature_mask & 0x200:
        # One unknown byte, treated as an offset.
        offset = struct.unpack("<I", data[header_offset:(header_offset + 4)])[0]
        add_coverage(header_offset, 4)
        header_offset += 4

        vprint(f"Bit 0x000200 - offset: {hex(offset)}")

        if offset != 0:
            names = descramble_pman(data, offset, text_obfuscated)
            for name in names:
                vprint(f"    {name}")
    else:
        vprint("Bit 0x000200 - NOT PRESENT")

    if feature_mask & 0x400:
        # One unknown byte, treated as an offset.
        offset = struct.unpack("<I", data[header_offset:(header_offset + 4)])[0]
        add_coverage(header_offset, 4)
        header_offset += 4

        vprint(f"Bit 0x000400 - offset: {hex(offset)}")
    else:
        vprint("Bit 0x000400 - NOT PRESENT")

    if feature_mask & 0x800:
        # This is the names of the animations as far as I can tell.
        length, offset = struct.unpack("<II", data[header_offset:(header_offset + 8)])
        add_coverage(header_offset, 8)
        header_offset += 8

        pp_19 = length
        pp_20 = offset

        vprint(f"Bit 0x000800 - count: {length}, offset: {hex(offset)}")

        names = []
        for x in range(length):
            interesting_offset = offset + (x * 12)
            if interesting_offset != 0:
                name_offset, anim_length, anim_offset = struct.unpack(
                    "<III",
                    data[interesting_offset:(interesting_offset + 12)],
                )
                add_coverage(interesting_offset, 12)
                if name_offset != 0:
                    # Let's decode this until the first null.
                    bytedata = get_until_null(data, name_offset)
                    add_coverage(name_offset, len(bytedata) + 1, unique=False)
                    name = descramble_text(bytedata, text_obfuscated)
                    names.append(name)

        for name in names:
            vprint(f"    {name}")
    else:
        vprint("Bit 0x000800 - NOT PRESENT")
        pp_19 = 0
        pp_20 = 0

    if feature_mask & 0x1000:
        # Seems to be a secondary structure mirroring the above.
        offset = struct.unpack("<I", data[header_offset:(header_offset + 4)])[0]
        add_coverage(header_offset, 4)
        header_offset += 4

        vprint(f"Bit 0x001000 - offset: {hex(offset)}")

        if offset != 0:
            names = descramble_pman(data, offset, text_obfuscated)
            for name in names:
                vprint(f"    {name}")
    else:
        vprint("Bit 0x001000 - NOT PRESENT")

    if feature_mask & 0x2000:
        # I am making a very preliminary guess that these are shapes used along
        # with animations specified below. The names in these sections tend to
        # have the word "shape" in them.
        length, offset = struct.unpack("<II", data[header_offset:(header_offset + 8)])
        add_coverage(header_offset, 8)
        header_offset += 8

        vprint(f"Bit 0x002000 - count: {length}, offset: {hex(offset)}")

        # TODO: We do a LOT of extra stuff with this one, if count > 0...

        names = []
        for x in range(length):
            interesting_offset = offset + (x * 12)
            if interesting_offset != 0:
                interesting_offset = struct.unpack(
                    "<I",
                    data[interesting_offset:(interesting_offset + 4)],
                )[0]
            if interesting_offset != 0:
                # Let's decode this until the first null.
                bytedata = get_until_null(data, interesting_offset)
                add_coverage(interesting_offset, len(bytedata) + 1, unique=False)
                name = descramble_text(bytedata, text_obfuscated)
                names.append(name)

        for name in names:
            vprint(f"    {name}")
    else:
        vprint("Bit 0x002000 - NOT PRESENT")

    if feature_mask & 0x4000:
        # Seems to be a secondary section mirroring the names from above.
        offset = struct.unpack("<I", data[header_offset:(header_offset + 4)])[0]
        add_coverage(header_offset, 4)
        header_offset += 4

        vprint(f"Bit 0x004000 - offset: {hex(offset)}")

        if offset != 0:
            names = descramble_pman(data, offset, text_obfuscated)
            for name in names:
                vprint(f"    {name}")
    else:
        vprint("Bit 0x004000 - NOT PRESENT")

    if feature_mask & 0x8000:
        # One unknown byte, treated as an offset.
        offset = struct.unpack("<I", data[header_offset:(header_offset + 4)])[0]
        add_coverage(header_offset, 4)
        header_offset += 4

        vprint(f"Bit 0x008000 - offset: {hex(offset)}")
    else:
        vprint("Bit 0x008000 - NOT PRESENT")

    if feature_mask & 0x10000:
        # Included font package, BINXRPC encoded.
        offset = struct.unpack("<I", data[header_offset:(header_offset + 4)])[0]
        add_coverage(header_offset, 4)
        header_offset += 4

        # I am not sure what the unknown byte is for. It always appears as
        # all zeros in all files I've looked at.
        _, length, binxrpc_offset = struct.unpack("<III", data[offset:(offset + 12)])
        add_coverage(offset, 12)

        if binxrpc_offset != 0:
            benc = BinaryEncoding()
            fontdata = benc.decode(data[binxrpc_offset:(binxrpc_offset + length)])
            add_coverage(binxrpc_offset, length)
        else:
            fontdata = None

        vprint(f"Bit 0x010000 - offset: {hex(offset)}, binxrpc offset: {hex(binxrpc_offset)}")
        if fontdata is not None:
            filename = os.path.join(path, "fontinfo.xml")

            if write:
                os.makedirs(path, exist_ok=True)
                print(f"Writing {filename} font information...")
                with open(filename, "w") as sfp:
                    sfp.write(str(fontdata))
            else:
                print(f"Would write {filename} font information...")
    else:
        vprint("Bit 0x010000 - NOT PRESENT")

    if feature_mask & 0x20000:
        # I am beginning to suspect that this is animation/level data. I have
        # no idea what "afp" is.
        offset = struct.unpack("<I", data[header_offset:(header_offset + 4)])[0]
        add_coverage(header_offset, 4)
        header_offset += 4

        vprint(f"Bit 0x020000 - offset: {hex(offset)}")

        if offset > 0 and pp_19 > 0 and pp_20 > 0:
            for x in range(pp_19):
                structure_offset = offset + (x * 12)
                anim_info_ptr = pp_20 + (x * 12)

                # First word is always zero, as observed. I am not ENTIRELY sure that
                # the second field is length, but it lines up with everything else
                # I've observed and seems to make sense.
                _, afp_header_length, afp_header = struct.unpack(
                    "<III",
                    data[structure_offset:(structure_offset + 12)]
                )
                add_coverage(structure_offset, 12)
                add_coverage(afp_header, afp_header_length)

                # This chunk of data is referred to by name, and then a chunk.
                anim_name_offset, anim_afp_data_length, anim_afp_data_offset = struct.unpack(
                    "<III",
                    data[anim_info_ptr:(anim_info_ptr + 12)],
                )
                add_coverage(anim_info_ptr, 12, unique=False)
                add_coverage(anim_afp_data_offset, anim_afp_data_length)

                # Grab some debugging info to print, I am really not sure what to do with
                # some of this data.
                bytedata = get_until_null(data, anim_name_offset)
                add_coverage(anim_name_offset, len(bytedata) + 1, unique=False)
                name = descramble_text(bytedata, text_obfuscated)

                vprint("    ", end="")
                vprint(f"afp_header_length: {hex(afp_header_length)}, ", end="")
                vprint(f"afp_header: {hex(afp_header)}, ", end="")
                vprint(f"name: {name}, ", end="")
                vprint(f"data: {hex(anim_afp_data_offset)}, ", end="")
                vprint(f"length: {hex(anim_afp_data_length)}")
    else:
        vprint("Bit 0x020000 - NOT PRESENT")

    if feature_mask & 0x40000:
        vprint("Bit 0x040000 - modern lz mode on")
    else:
        vprint("Bit 0x040000 - modern lz mode off")

    if header_offset != header_length:
        raise Exception("Failed to parse bitfield of header correctly!")

    if verbose:
        print_coverage()


def main() -> int:
    parser = argparse.ArgumentParser(description="BishiBashi graphic file unpacker.")
    parser.add_argument(
        "file",
        metavar="FILE",
        help="The file to extract",
    )
    parser.add_argument(
        "dir",
        metavar="DIR",
        help="Directory to extract to",
    )
    parser.add_argument(
        "-p",
        "--pretend",
        action="store_true",
        help="Pretend to extract instead of extracting.",
    )
    parser.add_argument(
        "-v",
        "--verbose",
        action="store_true",
        help="Display verbuse debugging output.",
    )
    args = parser.parse_args()

    extract(args.file, args.dir, write=not args.pretend, verbose=args.verbose)

    return 0


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