from . import (

    constants,

)

INDEX_ENTRY_DEBUG_COLUMN = []

NODE_SIZE = object()

class _column_base:

    """constains the definition of a revlog column

    name:       the column header,

    value_func: the function called to get a value,

    size:       the width of the column.

    """

    def __init__(self, name, value_func, size=None):

        self.name = name

        self.value_func = value_func

        if size is not NODE_SIZE:

            if size is None:

                size = 8  # arbitrary default

            size = max(len(name), size)

        self._size = size

    def get_size(self, node_size):

        if self._size is NODE_SIZE:

            return node_size

        else:

            return self._size

def debug_column(name, size=None):

    """decorated function is registered as a column

    name: the name of the column,

    size: the expected size of the column.

    """

    def register(func):

        entry = _column_base(

            name=name,

            value_func=func,

            size=size,

        )

        INDEX_ENTRY_DEBUG_COLUMN.append(entry)

        return entry

    return register

@debug_column(b"rev", size=6)

def _rev(index, rev, entry, hexfn):

    return b"%d" % rev

@debug_column(b"linkrev", size=6)

def _linkrev(index, rev, entry, hexfn):

    return b"%d" % entry[constants.ENTRY_LINK_REV]

@debug_column(b"nodeid", size=NODE_SIZE)

def _nodeid(index, rev, entry, hexfn):

    return hexfn(entry[constants.ENTRY_NODE_ID])

@debug_column(b"p1-nodeid", size=NODE_SIZE)

def _p1_node(index, rev, entry, hexfn):

    parent = entry[constants.ENTRY_PARENT_1]

    p_entry = index[parent]

    return hexfn(p_entry[constants.ENTRY_NODE_ID])

@debug_column(b"p2-nodeid", size=NODE_SIZE)

def _p2_node(index, rev, entry, hexfn):

    parent = entry[constants.ENTRY_PARENT_2]

    p_entry = index[parent]

    return hexfn(p_entry[constants.ENTRY_NODE_ID])

    header_pieces = []

    for column in INDEX_ENTRY_DEBUG_COLUMN:

        size = column.get_size(idlen)

        name = column.name

        header_pieces.append(name.rjust(size))

    fm.plain(b' '.join(header_pieces) + b'\n')

    index = revlog.index

        fm.startitem()

        entry = index[rev]

        first = True

        for column in INDEX_ENTRY_DEBUG_COLUMN:

            if not first:

                fm.plain(b' ')

            first = False

            size = column.get_size(idlen)

            value = column.value_func(index, rev, entry, hexfn)

            display = b"%%%ds" % size

            fm.write(column.name, display, value)