# This file was contributed to the Volatility Framework Version 3.
# Copyright (C) 2018 Volatility Foundation.
#
# THE LICENSED WORK IS PROVIDED UNDER THE TERMS OF THE Volatility Contributors
# Public License V1.0("LICENSE") AS FIRST COMPLETED BY: Volatility Foundation,
# Inc. ANY USE, PUBLIC DISPLAY, PUBLIC PERFORMANCE, REPRODUCTION OR DISTRIBUTION
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# ON, THE LICENSED WORK CONSTITUTES RECIPIENT'S ACCEPTANCE OF THIS LICENSE AND ITS
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# LICENSE IS LOCATED IN THE TEXT FILE ENTITLED "LICENSE.txt" ACCOMPANYING THE
# CONTENTS OF THIS FILE. IF A COPY OF THE LICENSE DOES NOT ACCOMPANY THIS FILE, A
# COPY OF THE LICENSE MAY ALSO BE OBTAINED AT THE FOLLOWING WEB SITE:
# https://www.volatilityfoundation.org/license/vcpl_v1.0
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# Software distributed under the License is distributed on an "AS IS" basis,
# WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for the
# specific language governing rights and limitations under the License.
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import datetime
import logging
import sys
from typing import Callable, Any

from volatility.framework.renderers import format_hints

vollog = logging.getLogger(__name__)

try:
    CAPSTONE_PRESENT = True
    import capstone
except ImportError:
    CAPSTONE_PRESENT = False
    vollog.debug("Disassembly library capstone not found")

from volatility.framework import interfaces, renderers


def hex_bytes_as_text(value: bytes) -> str:
    """Renders HexBytes as text

    Args:
        value: A series of bytes to convert to text

    Returns:
        A text representation of the hexadecimal bytes plus their ascii equivalents, separated by newline characters
    """
    if not isinstance(value, bytes):
        raise TypeError("hex_bytes_as_text takes bytes not: {}".format(type(value)))
    ascii = []
    hex = []
    count = 0
    output = ""
    for byte in value:
        hex.append("{:02x}".format(byte))
        ascii.append(chr(byte) if 0x20 < byte <= 0x7E else ".")
        if (count % 8) == 7:
            output += "\n"
            output += " ".join(hex[count - 7:count + 1])
            output += "\t"
            output += "".join(ascii[count - 7:count + 1])
        count += 1
    return output


class Optional(object):

    def __init__(self, func: Callable[[Any], str]) -> None:
        self._func = func

    def __call__(self, x: Any) -> str:
        if isinstance(x, interfaces.renderers.BaseAbsentValue):
            if isinstance(x, renderers.NotApplicableValue):
                return "N/A"
            else:
                return "-"
        return self._func(x)


def display_disassembly(disasm: interfaces.renderers.Disassembly) -> str:
    """Renders a disassembly renderer type into string format

    Args:
        disasm: Input disassembly objects

    Returns:
        A string as rendererd by capstone where available, otherwise output as if it were just bytes

    """

    if CAPSTONE_PRESENT:
        disasm_types = {
            'intel': capstone.Cs(capstone.CS_ARCH_X86, capstone.CS_MODE_32),
            'intel64': capstone.Cs(capstone.CS_ARCH_X86, capstone.CS_MODE_64),
            'arm': capstone.Cs(capstone.CS_ARCH_ARM, capstone.CS_MODE_ARM),
            'arm64': capstone.Cs(capstone.CS_ARCH_ARM64, capstone.CS_MODE_ARM)
        }
        output = ""
        if disasm.architecture is not None:
            for i in disasm_types[disasm.architecture].disasm(disasm.data, disasm.offset):
                output += "\n0x%x:\t%s\t%s" % (i.address, i.mnemonic, i.op_str)
        return output
    return QuickTextRenderer.type_renderers[bytes](disasm.data)


class QuickTextRenderer(interfaces.renderers.Renderer):
    type_renderers = {
        format_hints.Bin: Optional(lambda x: "0b{:b}".format(x)),
        format_hints.Hex: Optional(lambda x: "0x{:x}".format(x)),
        format_hints.HexBytes: Optional(hex_bytes_as_text),
        interfaces.renderers.Disassembly: Optional(display_disassembly),
        bytes: Optional(lambda x: " ".join(["{0:2x}".format(b) for b in x])),
        datetime.datetime: Optional(lambda x: x.strftime("%Y-%m-%d %H:%M:%S.%f %Z")),
        'default': Optional(lambda x: "{}".format(x))
    }

    def __init__(self, options = None) -> None:
        super().__init__(options)

    def get_render_options(self):
        pass

    def render(self, grid: interfaces.renderers.TreeGrid) -> None:
        """
        Renders each column immediately to stdout.

        This does not format each line's width appropriately, it merely tab separates each field

        Args:
            grid: The TreeGrid object to render

        """
        # TODO: Docstrings
        # TODO: Improve text output
        outfd = sys.stdout

        line = []
        for column in grid.columns:
            # Ignore the type because namedtuples don't realize they have accessible attributes
            line.append("{}".format(column.name))
        outfd.write("\n{}\n".format("\t".join(line)))

        def visitor(node, accumulator):
            accumulator.write("\n")
            # Nodes always have a path value, giving them a path_depth of at least 1, we use max just in case
            accumulator.write("*" * max(0, node.path_depth - 1))
            line = []
            for column in grid.columns:
                renderer = self.type_renderers.get(column.type, self.type_renderers['default'])
                line.append(renderer(node.values[column.index]))
            accumulator.write("{}".format("\t".join(line)))
            return accumulator

        grid.populate(visitor, outfd)

        outfd.write("\n")