import binascii
import errno
import hashlib
import os
import sys
import tempfile
import zlib

import serial.tools.list_ports

from .transport import TransportError, TransportExecError, stdout_write_bytes
from .transport_serial import SerialTransport
from .romfs import make_romfs, VfsRomWriter


class CommandError(Exception):
    pass


def do_connect(state, args=None):
    dev = args.device[0] if args else "auto"
    do_disconnect(state)

    try:
        if dev == "list":
            # List attached devices.
            for p in sorted(serial.tools.list_ports.comports()):
                print(
                    "{} {} {:04x}:{:04x} {} {}".format(
                        p.device,
                        p.serial_number,
                        p.vid if isinstance(p.vid, int) else 0,
                        p.pid if isinstance(p.pid, int) else 0,
                        p.manufacturer,
                        p.product,
                    )
                )
            # Don't do implicit REPL command.
            state.did_action()
        elif dev == "auto":
            # Auto-detect and auto-connect to the first available USB serial port.
            for p in sorted(serial.tools.list_ports.comports()):
                if p.vid is not None and p.pid is not None:
                    try:
                        state.transport = SerialTransport(p.device, baudrate=115200)
                        return
                    except TransportError as er:
                        if not er.args[0].startswith("failed to access"):
                            raise er
            raise TransportError("no device found")
        elif dev.startswith("id:"):
            # Search for a device with the given serial number.
            serial_number = dev[len("id:") :]
            dev = None
            for p in serial.tools.list_ports.comports():
                if p.serial_number == serial_number:
                    state.transport = SerialTransport(p.device, baudrate=115200)
                    return
            raise TransportError("no device with serial number {}".format(serial_number))
        else:
            # Connect to the given device.
            if dev.startswith("port:"):
                dev = dev[len("port:") :]
            state.transport = SerialTransport(dev, baudrate=115200)
            return
    except TransportError as er:
        msg = er.args[0]
        if msg.startswith("failed to access"):
            msg += " (it may be in use by another program)"
        raise CommandError(msg)


def do_disconnect(state, _args=None):
    if not state.transport:
        return

    try:
        if state.transport.mounted:
            if not state.transport.in_raw_repl:
                state.transport.enter_raw_repl(soft_reset=False)
            state.transport.umount_local()
        if state.transport.in_raw_repl:
            state.transport.exit_raw_repl()
    except OSError:
        # Ignore any OSError exceptions when shutting down, eg:
        # - filesystem_command will close the connection if it had an error
        # - umounting will fail if serial port disappeared
        pass
    state.transport.close()
    state.transport = None
    state._auto_soft_reset = True


def show_progress_bar(size, total_size, op="copying"):
    if not sys.stdout.isatty():
        return
    verbose_size = 2048
    bar_length = 20
    if total_size < verbose_size:
        return
    elif size >= total_size:
        # Clear progress bar when copy completes
        print("\r" + " " * (13 + len(op) + bar_length) + "\r", end="")
    else:
        bar = size * bar_length // total_size
        progress = size * 100 // total_size
        print(
            "\r ... {} {:3d}% [{}{}]".format(op, progress, "#" * bar, "-" * (bar_length - bar)),
            end="",
        )


def _remote_path_join(a, *b):
    if not a:
        a = "./"
    result = a.rstrip("/")
    for x in b:
        result += "/" + x.strip("/")
    return result


def _remote_path_dirname(a):
    a = a.rsplit("/", 1)
    if len(a) == 1:
        return ""
    else:
        return a[0]


def _remote_path_basename(a):
    return a.rsplit("/", 1)[-1]


def do_filesystem_cp(state, src, dest, multiple, check_hash=False):
    if dest.startswith(":"):
        dest_no_slash = dest.rstrip("/" + os.path.sep + (os.path.altsep or ""))
        dest_exists = state.transport.fs_exists(dest_no_slash[1:])
        dest_isdir = dest_exists and state.transport.fs_isdir(dest_no_slash[1:])

        # A trailing / on dest forces it to be a directory.
        if dest != dest_no_slash:
            if not dest_isdir:
                raise CommandError("cp: destination is not a directory")
            dest = dest_no_slash
    else:
        dest_exists = os.path.exists(dest)
        dest_isdir = dest_exists and os.path.isdir(dest)

    if multiple:
        if not dest_exists:
            raise CommandError("cp: destination does not exist")
        if not dest_isdir:
            raise CommandError("cp: destination is not a directory")

    # Download the contents of source.
    try:
        if src.startswith(":"):
            data = state.transport.fs_readfile(src[1:], progress_callback=show_progress_bar)
            filename = _remote_path_basename(src[1:])
        else:
            with open(src, "rb") as f:
                data = f.read()
            filename = os.path.basename(src)
    except IsADirectoryError:
        raise CommandError("cp: -r not specified; omitting directory")

    # Write back to dest.
    if dest.startswith(":"):
        # If the destination path is just the directory, then add the source filename.
        if dest_isdir:
            dest = ":" + _remote_path_join(dest[1:], filename)

        # Skip copy if the destination file is identical.
        if check_hash:
            try:
                remote_hash = state.transport.fs_hashfile(dest[1:], "sha256")
                source_hash = hashlib.sha256(data).digest()
                # remote_hash will be None if the device doesn't support
                # hashlib.sha256 (and therefore won't match).
                if remote_hash == source_hash:
                    print("Up to date:", dest[1:])
                    return
            except OSError:
                pass

        # Write to remote.
        state.transport.fs_writefile(dest[1:], data, progress_callback=show_progress_bar)
    else:
        # If the destination path is just the directory, then add the source filename.
        if dest_isdir:
            dest = os.path.join(dest, filename)

        # Write to local file.
        with open(dest, "wb") as f:
            f.write(data)


def do_filesystem_recursive_cp(state, src, dest, multiple, check_hash):
    # Ignore trailing / on both src and dest. (Unix cp ignores them too)
    src = src.rstrip("/" + os.path.sep + (os.path.altsep if os.path.altsep else ""))
    dest = dest.rstrip("/" + os.path.sep + (os.path.altsep if os.path.altsep else ""))

    # If the destination directory exists, then we copy into it. Otherwise we
    # use the destination as the target.
    if dest.startswith(":"):
        dest_exists = state.transport.fs_exists(dest[1:])
    else:
        dest_exists = os.path.exists(dest)

    # Recursively find all files to copy from a directory.
    # `dirs` will be a list of dest split paths.
    # `files` will be a list of `(dest split path, src joined path)`.
    dirs = []
    files = []

    # For example, if src=/tmp/foo, with /tmp/foo/x.py and /tmp/foo/a/b/c.py,
    # and if the destination directory exists, then we will have:
    #   dirs = [['foo'], ['foo', 'a'], ['foo', 'a', 'b']]
    #   files = [(['foo', 'x.py'], '/tmp/foo/x.py'), (['foo', 'a', 'b', 'c.py'], '/tmp/foo/a/b/c.py')]
    # If the destination doesn't exist, then we will have:
    #   dirs = [['a'], ['a', 'b']]
    #   files = [(['x.py'], '/tmp/foo/x.py'), (['a', 'b', 'c.py'], '/tmp/foo/a/b/c.py')]

    def _list_recursive(base, src_path, dest_path, src_join_fun, src_isdir_fun, src_listdir_fun):
        src_path_joined = src_join_fun(base, *src_path)
        if src_isdir_fun(src_path_joined):
            if dest_path:
                dirs.append(dest_path)
            for entry in src_listdir_fun(src_path_joined):
                _list_recursive(
                    base,
                    src_path + [entry],
                    dest_path + [entry],
                    src_join_fun,
                    src_isdir_fun,
                    src_listdir_fun,
                )
        else:
            files.append(
                (
                    dest_path,
                    src_path_joined,
                )
            )

    if src.startswith(":"):
        src_dirname = [_remote_path_basename(src[1:])]
        dest_dirname = src_dirname if dest_exists else []
        _list_recursive(
            _remote_path_dirname(src[1:]),
            src_dirname,
            dest_dirname,
            src_join_fun=_remote_path_join,
            src_isdir_fun=state.transport.fs_isdir,
            src_listdir_fun=lambda p: [x.name for x in state.transport.fs_listdir(p)],
        )
    else:
        src_dirname = [os.path.basename(src)]
        dest_dirname = src_dirname if dest_exists else []
        _list_recursive(
            os.path.dirname(src),
            src_dirname,
            dest_dirname,
            src_join_fun=os.path.join,
            src_isdir_fun=os.path.isdir,
            src_listdir_fun=os.listdir,
        )

    # If no directories were encountered then we must have just had a file.
    if not dirs:
        return do_filesystem_cp(state, src, dest, multiple, check_hash)

    def _mkdir(a, *b):
        try:
            if a.startswith(":"):
                state.transport.fs_mkdir(_remote_path_join(a[1:], *b))
            else:
                os.mkdir(os.path.join(a, *b))
        except FileExistsError:
            pass

    # Create the destination if necessary.
    if not dest_exists:
        _mkdir(dest)

    # Create all sub-directories relative to the destination.
    for d in dirs:
        _mkdir(dest, *d)

    # Copy all files, in sorted order to help it be deterministic.
    files.sort()
    for dest_path_split, src_path_joined in files:
        if src.startswith(":"):
            src_path_joined = ":" + src_path_joined

        if dest.startswith(":"):
            dest_path_joined = ":" + _remote_path_join(dest[1:], *dest_path_split)
        else:
            dest_path_joined = os.path.join(dest, *dest_path_split)

        do_filesystem_cp(state, src_path_joined, dest_path_joined, False, check_hash)


def do_filesystem_recursive_rm(state, path, args):
    if state.transport.fs_isdir(path):
        if state.transport.mounted:
            r_cwd = state.transport.eval("os.getcwd()")
            abs_path = os.path.normpath(
                os.path.join(r_cwd, path) if not os.path.isabs(path) else path
            )
            if isinstance(state.transport, SerialTransport) and abs_path.startswith(
                f"{SerialTransport.fs_hook_mount}/"
            ):
                raise CommandError(
                    f"rm -r not permitted on {SerialTransport.fs_hook_mount} directory"
                )
        for entry in state.transport.fs_listdir(path):
            do_filesystem_recursive_rm(state, _remote_path_join(path, entry.name), args)
        if path:
            try:
                state.transport.fs_rmdir(path)
                if args.verbose:
                    print(f"removed directory: '{path}'")
            except OSError as e:
                if e.errno != errno.EINVAL:  # not vfs mountpoint
                    raise CommandError(
                        f"rm -r: cannot remove :{path} {os.strerror(e.errno) if e.errno else ''}"
                    ) from e
                if args.verbose:
                    print(f"skipped: '{path}' (vfs mountpoint)")
    else:
        state.transport.fs_rmfile(path)
        if args.verbose:
            print(f"removed: '{path}'")


def human_size(size, decimals=1):
    for unit in ["B", "K", "M", "G", "T"]:
        if size < 1024.0 or unit == "T":
            break
        size /= 1024.0
    return f"{size:.{decimals}f}{unit}" if unit != "B" else f"{int(size)}"


def do_filesystem_tree(state, path, args):
    """Print a tree of the device's filesystem starting at path."""
    connectors = ("├── ", "└── ")

    def _tree_recursive(path, prefix=""):
        entries = state.transport.fs_listdir(path)
        entries.sort(key=lambda e: e.name)
        for i, entry in enumerate(entries):
            connector = connectors[1] if i == len(entries) - 1 else connectors[0]
            is_dir = entry.st_mode & 0x4000  # Directory
            size_str = ""
            # most MicroPython filesystems don't support st_size on directories, reduce clutter
            if entry.st_size > 0 or not is_dir:
                if args.size:
                    size_str = f"[{entry.st_size:>9}]  "
                elif args.human:
                    size_str = f"[{human_size(entry.st_size):>6}]  "
            print(f"{prefix}{connector}{size_str}{entry.name}")
            if is_dir:
                _tree_recursive(
                    _remote_path_join(path, entry.name),
                    prefix + ("    " if i == len(entries) - 1 else "│   "),
                )

    if not path or path == ".":
        path = state.transport.exec("import os;print(os.getcwd())").strip().decode("utf-8")
    if not (path == "." or state.transport.fs_isdir(path)):
        raise CommandError(f"tree: '{path}' is not a directory")
    if args.verbose:
        print(f":{path} on {state.transport.device_name}")
    else:
        print(f":{path}")
    _tree_recursive(path)


def do_filesystem(state, args):
    state.ensure_raw_repl()
    state.did_action()

    command = args.command[0]
    paths = args.path

    if command == "cat":
        # Don't do verbose output for `cat` unless explicitly requested.
        verbose = args.verbose is True
    else:
        verbose = args.verbose is not False

    if command == "cp":
        # Note: cp requires the user to specify local/remote explicitly via
        # leading ':'.

        # The last argument must be the destination.
        if len(paths) <= 1:
            raise CommandError("cp: missing destination path")
        cp_dest = paths[-1]
        paths = paths[:-1]
    else:
        # All other commands implicitly use remote paths. Strip the
        # leading ':' if the user included them.
        paths = [path[1:] if path.startswith(":") else path for path in paths]

    # ls and tree implicitly lists the cwd.
    if command in ("ls", "tree") and not paths:
        paths = [""]

    try:
        # Handle each path sequentially.
        for path in paths:
            if verbose:
                if command == "cp":
                    print("{} {} {}".format(command, path, cp_dest))
                else:
                    print("{} :{}".format(command, path))

            if command == "cat":
                state.transport.fs_printfile(path)
            elif command == "ls":
                for result in state.transport.fs_listdir(path):
                    print(
                        "{:12} {}{}".format(
                            result.st_size, result.name, "/" if result.st_mode & 0x4000 else ""
                        )
                    )
            elif command == "mkdir":
                state.transport.fs_mkdir(path)
            elif command == "rm":
                if args.recursive:
                    do_filesystem_recursive_rm(state, path, args)
                else:
                    state.transport.fs_rmfile(path)
            elif command == "rmdir":
                state.transport.fs_rmdir(path)
            elif command == "touch":
                state.transport.fs_touchfile(path)
            elif command.endswith("sum") and command[-4].isdigit():
                digest = state.transport.fs_hashfile(path, command[:-3])
                print(digest.hex())
            elif command == "cp":
                if args.recursive:
                    do_filesystem_recursive_cp(
                        state, path, cp_dest, len(paths) > 1, not args.force
                    )
                else:
                    do_filesystem_cp(state, path, cp_dest, len(paths) > 1, not args.force)
            elif command == "tree":
                do_filesystem_tree(state, path, args)
    except OSError as er:
        raise CommandError("{}: {}: {}.".format(command, er.strerror, os.strerror(er.errno)))
    except TransportError as er:
        raise CommandError("Error with transport:\n{}".format(er.args[0]))


def do_edit(state, args):
    state.ensure_raw_repl()
    state.did_action()

    if not os.getenv("EDITOR"):
        raise CommandError("edit: $EDITOR not set")
    for src in args.files:
        src = src.lstrip(":")
        dest_fd, dest = tempfile.mkstemp(suffix=os.path.basename(src))
        try:
            print("edit :%s" % (src,))
            state.transport.fs_touchfile(src)
            data = state.transport.fs_readfile(src, progress_callback=show_progress_bar)
            with open(dest_fd, "wb") as f:
                f.write(data)
            if os.system('%s "%s"' % (os.getenv("EDITOR"), dest)) == 0:
                with open(dest, "rb") as f:
                    state.transport.fs_writefile(
                        src, f.read(), progress_callback=show_progress_bar
                    )
        finally:
            os.unlink(dest)


def _do_execbuffer(state, buf, follow):
    state.ensure_raw_repl()
    state.did_action()

    try:
        state.transport.exec_raw_no_follow(buf)
        if follow:
            ret, ret_err = state.transport.follow(timeout=None, data_consumer=stdout_write_bytes)
            if ret_err:
                stdout_write_bytes(ret_err)
                sys.exit(1)
    except TransportError as er:
        raise CommandError(er.args[0])
    except KeyboardInterrupt:
        sys.exit(1)


def do_exec(state, args):
    _do_execbuffer(state, args.expr[0], args.follow)


def do_eval(state, args):
    buf = "print(" + args.expr[0] + ")"
    _do_execbuffer(state, buf, True)


def do_run(state, args):
    filename = args.path[0]
    try:
        with open(filename, "rb") as f:
            buf = f.read()
    except OSError:
        raise CommandError(f"could not read file '{filename}'")
    _do_execbuffer(state, buf, args.follow)


def do_mount(state, args):
    state.ensure_raw_repl()
    path = args.path[0]
    state.transport.mount_local(path, unsafe_links=args.unsafe_links)
    print(f"Local directory {path} is mounted at /remote")


def do_umount(state, path):
    state.ensure_raw_repl()
    state.transport.umount_local()


def do_resume(state, _args=None):
    state._auto_soft_reset = False


def do_soft_reset(state, _args=None):
    state.ensure_raw_repl(soft_reset=True)
    state.did_action()


def do_rtc(state, args):
    state.ensure_raw_repl()
    state.did_action()

    state.transport.exec("import machine")

    if args.set:
        import datetime

        now = datetime.datetime.now()
        timetuple = "({}, {}, {}, {}, {}, {}, {}, {})".format(
            now.year,
            now.month,
            now.day,
            now.weekday(),
            now.hour,
            now.minute,
            now.second,
            now.microsecond,
        )
        state.transport.exec("machine.RTC().datetime({})".format(timetuple))
    else:
        print(state.transport.eval("machine.RTC().datetime()"))


def _do_romfs_query(state, args):
    state.ensure_raw_repl()
    state.did_action()

    # Detect the romfs and get its associated device.
    state.transport.exec("import vfs")
    if not state.transport.eval("hasattr(vfs,'rom_ioctl')"):
        print("ROMFS is not enabled on this device")
        return
    num_rom_partitions = state.transport.eval("vfs.rom_ioctl(1)")
    if num_rom_partitions <= 0:
        print("No ROMFS partitions available")
        return

    for rom_id in range(num_rom_partitions):
        state.transport.exec(f"dev=vfs.rom_ioctl(2,{rom_id})")
        has_object = state.transport.eval("hasattr(dev,'ioctl')")
        if has_object:
            rom_block_count = state.transport.eval("dev.ioctl(4,0)")
            rom_block_size = state.transport.eval("dev.ioctl(5,0)")
            rom_size = rom_block_count * rom_block_size
            print(
                f"ROMFS{rom_id} partition has size {rom_size} bytes ({rom_block_count} blocks of {rom_block_size} bytes each)"
            )
        else:
            rom_size = state.transport.eval("len(dev)")
            print(f"ROMFS{rom_id} partition has size {rom_size} bytes")
        romfs = state.transport.eval("bytes(memoryview(dev)[:12])")
        print(f"  Raw contents: {romfs.hex(':')} ...")
        if not romfs.startswith(b"\xd2\xcd\x31"):
            print("  Not a valid ROMFS")
        else:
            size = 0
            for value in romfs[3:]:
                size = (size << 7) | (value & 0x7F)
                if not value & 0x80:
                    break
            print(f"  ROMFS image size: {size}")


def _do_romfs_build(state, args):
    state.did_action()

    if args.path is None:
        raise CommandError("romfs build: source path not given")

    input_directory = args.path

    if args.output is None:
        output_file = input_directory + ".romfs"
    else:
        output_file = args.output

    romfs = make_romfs(input_directory, mpy_cross=args.mpy)

    print(f"Writing {len(romfs)} bytes to output file {output_file}")
    with open(output_file, "wb") as f:
        f.write(romfs)


def _do_romfs_deploy(state, args):
    state.ensure_raw_repl()
    state.did_action()
    transport = state.transport

    if args.path is None:
        raise CommandError("romfs deploy: source path not given")

    rom_id = args.partition
    romfs_filename = args.path

    # Read in or create the ROMFS filesystem image.
    if os.path.isfile(romfs_filename) and romfs_filename.endswith((".img", ".romfs")):
        with open(romfs_filename, "rb") as f:
            romfs = f.read()
    else:
        romfs = make_romfs(romfs_filename, mpy_cross=args.mpy)
    print(f"Image size is {len(romfs)} bytes")

    # Detect the ROMFS partition and get its associated device.
    state.transport.exec("import vfs")
    if not state.transport.eval("hasattr(vfs,'rom_ioctl')"):
        raise CommandError("ROMFS is not enabled on this device")
    transport.exec(f"dev=vfs.rom_ioctl(2,{rom_id})")
    if transport.eval("isinstance(dev,int) and dev<0"):
        raise CommandError(f"ROMFS{rom_id} partition not found on device")
    has_object = transport.eval("hasattr(dev,'ioctl')")
    if has_object:
        rom_block_count = transport.eval("dev.ioctl(4,0)")
        rom_block_size = transport.eval("dev.ioctl(5,0)")
        rom_size = rom_block_count * rom_block_size
        print(
            f"ROMFS{rom_id} partition has size {rom_size} bytes ({rom_block_count} blocks of {rom_block_size} bytes each)"
        )
    else:
        rom_size = transport.eval("len(dev)")
        print(f"ROMFS{rom_id} partition has size {rom_size} bytes")

    # Check if ROMFS image is valid
    if not romfs.startswith(VfsRomWriter.ROMFS_HEADER):
        print("Invalid ROMFS image")
        sys.exit(1)

    # Check if ROMFS filesystem image will fit in the target partition.
    if len(romfs) > rom_size:
        print("ROMFS image is too big for the target partition")
        sys.exit(1)

    # Prepare ROMFS partition for writing.
    print(f"Preparing ROMFS{rom_id} partition for writing")
    transport.exec("import vfs\ntry:\n vfs.umount('/rom')\nexcept:\n pass")
    chunk_size = 4096
    if has_object:
        for offset in range(0, len(romfs), rom_block_size):
            transport.exec(f"dev.ioctl(6,{offset // rom_block_size})")
        chunk_size = min(chunk_size, rom_block_size)
    else:
        rom_min_write = transport.eval(f"vfs.rom_ioctl(3,{rom_id},{len(romfs)})")
        chunk_size = max(chunk_size, rom_min_write)

    # Detect capabilities of the device to use the fastest method of transfer.
    has_bytes_fromhex = transport.eval("hasattr(bytes,'fromhex')")
    try:
        transport.exec("from binascii import a2b_base64")
        has_a2b_base64 = True
    except TransportExecError:
        has_a2b_base64 = False
    try:
        transport.exec("from io import BytesIO")
        transport.exec("from deflate import DeflateIO,RAW")
        has_deflate_io = True
    except TransportExecError:
        has_deflate_io = False

    # Deploy the ROMFS filesystem image to the device.
    for offset in range(0, len(romfs), chunk_size):
        romfs_chunk = romfs[offset : offset + chunk_size]
        romfs_chunk += bytes(chunk_size - len(romfs_chunk))
        if has_deflate_io:
            # Needs: binascii.a2b_base64, io.BytesIO, deflate.DeflateIO.
            compressor = zlib.compressobj(wbits=-9)
            romfs_chunk_compressed = compressor.compress(romfs_chunk)
            romfs_chunk_compressed += compressor.flush()
            buf = binascii.b2a_base64(romfs_chunk_compressed).strip()
            transport.exec(f"buf=DeflateIO(BytesIO(a2b_base64({buf})),RAW,9).read()")
        elif has_a2b_base64:
            # Needs: binascii.a2b_base64.
            buf = binascii.b2a_base64(romfs_chunk)
            transport.exec(f"buf=a2b_base64({buf})")
        elif has_bytes_fromhex:
            # Needs: bytes.fromhex.
            buf = romfs_chunk.hex()
            transport.exec(f"buf=bytes.fromhex('{buf}')")
        else:
            # Needs nothing special.
            transport.exec("buf=" + repr(romfs_chunk))
        print(f"\rWriting at offset {offset}", end="")
        if has_object:
            transport.exec(
                f"dev.writeblocks({offset // rom_block_size},buf,{offset % rom_block_size})"
            )
        else:
            transport.exec(f"vfs.rom_ioctl(4,{rom_id},{offset},buf)")

    # Complete writing.
    if not has_object:
        transport.eval(f"vfs.rom_ioctl(5,{rom_id})")

    print()
    print("ROMFS image deployed")


def do_romfs(state, args):
    if args.command[0] == "query":
        _do_romfs_query(state, args)
    elif args.command[0] == "build":
        _do_romfs_build(state, args)
    elif args.command[0] == "deploy":
        _do_romfs_deploy(state, args)
    else:
        raise CommandError(
            f"romfs: '{args.command[0]}' is not a command; pass romfs --help for a list"
        )