# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.

# Generates tables of background images which correspond with border images for
# creating reftests. Input is the filename containing input defined below (a subset
# of the allowed CSS border properties). An html representation of a table is
# output to stdout.
#
# Usage: python gen-refs.py input_filename
#
# Input must take the form (order is not important, nothing is optional, distance in order top, right, bottom, left):
# width: p;
# height: p;
# border-width: p;
# border-image-source: ...;
# border-image-slice: p p p p;
# note that actually border-image-slice takes numbers without px, which represent pixels anyway (or at least coords)
# border-image-width: np np np np;
# border-image-repeat: stretch | repeat | round;
# border-image-outset: np np np np;
#
# where:
# p ::= n'px'
# np ::= n | p
#
# Assumes there is no intrinsic size for the border-image-source, so uses
# the size of the border image area.

import sys


class Point:
    def __init__(self, w=0, h=0):
        self.x = w
        self.y = h


class Size:
    def __init__(self, w=0, h=0):
        self.width = w
        self.height = h


class Rect:
    def __init__(self, x=0, y=0, x2=0, y2=0):
        self.x = x
        self.y = y
        self.x2 = x2
        self.y2 = y2

    def width(self):
        return self.x2 - self.x

    def height(self):
        return self.y2 - self.y


class Props:
    def __init__(self):
        self.size = Size()


class np:
    def __init__(self, n, p):
        self.n = n
        self.p = p

    def get_absolute(self, ref):
        if not self.p == 0:
            return self.p
        return self.n * ref


def parse_p(tok):
    if tok[-2:] == "px":
        return float(tok[:-2])
    print("Whoops, not a pixel value", tok)


def parse_np(tok):
    if tok[-2:] == "px":
        return np(0, float(tok[:-2]))
    return np(float(tok), 0)


def parse(filename):
    f = open(filename, "r")
    props = Props()
    for l in f:
        l = l.strip()
        if not l[-1] == ";":
            continue
        toks = l[:-1].split()
        if toks[0] == "border-width:":
            props.width = parse_p(toks[1])
        if toks[0] == "height:":
            props.size.height = parse_p(toks[1])
        if toks[0] == "width:":
            props.size.width = parse_p(toks[1])
        if toks[0] == "border-image-source:":
            props.source = l[l.find(":") + 1 : l.rfind(";")].strip()
        if toks[0] == "border-image-repeat:":
            props.repeat = toks[1]
        if toks[0] == "border-image-slice:":
            props.slice = map(parse_p, toks[1:5])
        if toks[0] == "border-image-width:":
            props.image_width = map(parse_np, toks[1:5])
        if toks[0] == "border-image-outset:":
            props.outset = map(parse_np, toks[1:5])
    f.close()
    return props


# the result of normalisation is that all sizes are in pixels and the size,
# widths, and outset have been normalised to a size and width - the former is
# the element's interior, the latter is the width of the drawn border.
def normalise(props):
    result = Props()
    result.source = props.source
    result.repeat = props.repeat
    result.width = map(lambda x: x.get_absolute(props.width), props.image_width)
    outsets = map(lambda x: x.get_absolute(props.width), props.outset)
    result.size.width = props.size.width + 2 * props.width + outsets[1] + outsets[3]
    result.size.height = props.size.height + 2 * props.width + outsets[0] + outsets[2]
    result.slice = props.slice
    for i in [0, 2]:
        if result.slice[i] > result.size.height:
            result.slice[i] = result.size.height
        if result.slice[i + 1] > result.size.width:
            result.slice[i + 1] = result.size.width

    return result


def check_parse(props):
    if not hasattr(props, "source"):
        print("missing border-image-source")
        return False
    if not hasattr(props.size, "width"):
        print("missing width")
        return False
    if not hasattr(props.size, "height"):
        print("missing height")
        return False
    if not hasattr(props, "width"):
        print("missing border-width")
        return False
    if not hasattr(props, "image_width"):
        print("missing border-image-width")
        return False
    if not hasattr(props, "slice"):
        print("missing border-image-slice")
        return False
    if not hasattr(props, "repeat") or (
        props.repeat not in ["stretch", "repeat", "round"]
    ):
        print("missing or incorrect border-image-repeat '" + props.repeat + "'")
        return False
    if not hasattr(props, "outset"):
        print("missing border-image-outset")
        return False

    return True


def check_normalise(props):
    if not hasattr(props, "source"):
        print("missing border-image-source")
        return False
    if not hasattr(props.size, "width"):
        print("missing width")
        return False
    if not hasattr(props.size, "height"):
        print("missing height")
        return False
    if not hasattr(props, "slice"):
        print("missing border-image-slice")
        return False
    if not hasattr(props, "repeat") or (
        props.repeat not in ["stretch", "repeat", "round"]
    ):
        print("missing or incorrect border-image-repeat '" + props.repeat + "'")
        return False

    return True


class Tile:
    def __init__(self):
        self.slice = Rect()
        self.border_width = Rect()


# throughout, we will use arrays for nine-patches, the indices correspond thusly:
# 0 1 2
# 3 4 5
# 6 7 8


# Compute the source tiles' slice and border-width sizes
def make_src_tiles():
    tiles = [Tile() for i in range(9)]

    rows = [range(3 * i, 3 * (i + 1)) for i in range(3)]
    cols = [[i, i + 3, i + 6] for i in range(3)]

    row_limits_slice = [
        0,
        props.slice[3],
        props.size.width - props.slice[1],
        props.size.width,
    ]
    row_limits_width = [
        0,
        props.width[3],
        props.size.width - props.width[1],
        props.size.width,
    ]
    for r in range(3):
        for t in [tiles[i] for i in cols[r]]:
            t.slice.x = row_limits_slice[r]
            t.slice.x2 = row_limits_slice[r + 1]
            t.border_width.x = row_limits_width[r]
            t.border_width.x2 = row_limits_width[r + 1]

    col_limits_slice = [
        0,
        props.slice[0],
        props.size.height - props.slice[2],
        props.size.height,
    ]
    col_limits_width = [
        0,
        props.width[0],
        props.size.height - props.width[2],
        props.size.height,
    ]
    for c in range(3):
        for t in [tiles[i] for i in rows[c]]:
            t.slice.y = col_limits_slice[c]
            t.slice.y2 = col_limits_slice[c + 1]
            t.border_width.y = col_limits_width[c]
            t.border_width.y2 = col_limits_width[c + 1]

    return tiles


def compute(props):
    tiles = make_src_tiles()

    # corners scale easy
    for t in [tiles[i] for i in [0, 2, 6, 8]]:
        t.scale = Point(
            t.border_width.width() / t.slice.width(),
            t.border_width.height() / t.slice.height(),
        )
    # edges are by their secondary dimension
    for t in [tiles[i] for i in [1, 7]]:
        t.scale = Point(
            t.border_width.height() / t.slice.height(),
            t.border_width.height() / t.slice.height(),
        )
    for t in [tiles[i] for i in [3, 5]]:
        t.scale = Point(
            t.border_width.width() / t.slice.width(),
            t.border_width.width() / t.slice.width(),
        )
    # the middle is scaled by the factors for the top and left edges
    tiles[4].scale = Point(tiles[1].scale.x, tiles[3].scale.y)

    # the size of a source tile for the middle section
    src_tile_size = Size(
        tiles[4].slice.width() * tiles[4].scale.x,
        tiles[4].slice.height() * tiles[4].scale.y,
    )

    # the size of a single destination tile in the central part
    dest_tile_size = Size()
    if props.repeat == "stretch":
        dest_tile_size.width = tiles[4].border_width.width()
        dest_tile_size.height = tiles[4].border_width.height()
        for t in [tiles[i] for i in [1, 7]]:
            t.scale.x = t.border_width.width() / t.slice.width()
        for t in [tiles[i] for i in [3, 5]]:
            t.scale.y = t.border_width.height() / t.slice.height()
    elif props.repeat == "repeat":
        dest_tile_size = src_tile_size
    elif props.repeat == "round":
        dest_tile_size.width = tiles[4].border_width.width() / math.ceil(
            tiles[4].border_width.width() / src_tile_size.width
        )
        dest_tile_size.height = tiles[4].border_width.height() / math.ceil(
            tiles[4].border_width.height() / src_tile_size.height
        )
        for t in [tiles[i] for i in [1, 4, 7]]:
            t.scale.x = dest_tile_size.width / t.slice.width()
        for t in [tiles[i] for i in [3, 4, 5]]:
            t.scale.y = dest_tile_size.height / t.slice.height()
    else:
        print("Whoops, invalid border-image-repeat value")

    # catch overlapping slices. Its easier to deal with it here than to catch
    # earlier and have to avoid all the divide by zeroes above
    for t in tiles:
        if t.slice.width() < 0:
            t.scale.x = 0
        if t.slice.height() < 0:
            t.scale.y = 0

    tiles_h = int(math.ceil(tiles[4].border_width.width() / dest_tile_size.width) + 2)
    tiles_v = int(math.ceil(tiles[4].border_width.height() / dest_tile_size.height) + 2)

    # if border-image-repeat: repeat, then we will later center the tiles, that
    # means we need an extra tile for the two 'half' tiles at either end
    if props.repeat == "repeat":
        if tiles_h % 2 == 0:
            tiles_h += 1
        if tiles_v % 2 == 0:
            tiles_v += 1
    dest_tiles = [Tile() for i in range(tiles_h * tiles_v)]

    # corners
    corners = [
        (0, 0),
        (tiles_h - 1, 2),
        (tiles_v * (tiles_h - 1), 6),
        (tiles_v * tiles_h - 1, 8),
    ]
    for d, s in corners:
        dest_tiles[d].size = Size(
            tiles[s].scale.x * props.size.width, tiles[s].scale.y * props.size.height
        )
        dest_tiles[d].dest_size = Size(
            tiles[s].border_width.width(), tiles[s].border_width.height()
        )
    dest_tiles[0].offset = Point(0, 0)
    dest_tiles[tiles_h - 1].offset = Point(
        tiles[2].border_width.width() - dest_tiles[tiles_h - 1].size.width, 0
    )
    dest_tiles[tiles_v * (tiles_h - 1)].offset = Point(
        0,
        tiles[6].border_width.height()
        - dest_tiles[tiles_v * (tiles_h - 1)].size.height,
    )
    dest_tiles[tiles_v * tiles_h - 1].offset = Point(
        tiles[8].border_width.width() - dest_tiles[tiles_h * tiles_v - 1].size.width,
        tiles[8].border_width.height() - dest_tiles[tiles_h * tiles_v - 1].size.height,
    )

    # horizontal edges
    for i in range(1, tiles_h - 1):
        dest_tiles[i].size = Size(
            tiles[1].scale.x * props.size.width, tiles[1].scale.y * props.size.height
        )
        dest_tiles[(tiles_v - 1) * tiles_h + i].size = Size(
            tiles[7].scale.x * props.size.width, tiles[7].scale.y * props.size.height
        )
        dest_tiles[i].dest_size = Size(
            dest_tile_size.width, tiles[1].border_width.height()
        )
        dest_tiles[(tiles_v - 1) * tiles_h + i].dest_size = Size(
            dest_tile_size.width, tiles[7].border_width.height()
        )
        dest_tiles[i].offset = Point(
            -tiles[1].scale.x * tiles[1].slice.x, -tiles[1].scale.y * tiles[1].slice.y
        )
        dest_tiles[(tiles_v - 1) * tiles_h + i].offset = Point(
            -tiles[7].scale.x * tiles[7].slice.x, -tiles[7].scale.y * tiles[7].slice.y
        )

    # vertical edges
    for i in range(1, tiles_v - 1):
        dest_tiles[i * tiles_h].size = Size(
            tiles[3].scale.x * props.size.width, tiles[3].scale.y * props.size.height
        )
        dest_tiles[(i + 1) * tiles_h - 1].size = Size(
            tiles[5].scale.x * props.size.width, tiles[5].scale.y * props.size.height
        )
        dest_tiles[i * tiles_h].dest_size = Size(
            tiles[3].border_width.width(), dest_tile_size.height
        )
        dest_tiles[(i + 1) * tiles_h - 1].dest_size = Size(
            tiles[5].border_width.width(), dest_tile_size.height
        )
        dest_tiles[i * tiles_h].offset = Point(
            -tiles[3].scale.x * tiles[3].slice.x, -tiles[3].scale.y * tiles[3].slice.y
        )
        dest_tiles[(i + 1) * tiles_h - 1].offset = Point(
            -tiles[5].scale.x * tiles[5].slice.x, -tiles[5].scale.y * tiles[5].slice.y
        )

    # middle
    for i in range(1, tiles_v - 1):
        for j in range(1, tiles_h - 1):
            dest_tiles[i * tiles_h + j].size = Size(
                tiles[4].scale.x * props.size.width,
                tiles[4].scale.y * props.size.height,
            )
            dest_tiles[i * tiles_h + j].offset = Point(
                -tiles[4].scale.x * tiles[4].slice.x,
                -tiles[4].scale.y * tiles[4].slice.y,
            )
            dest_tiles[i * tiles_h + j].dest_size = dest_tile_size

    # edge and middle tiles are centered with border-image-repeat: repeat
    # we need to change the offset to take account of this and change the dest_size
    # of the tiles at the sides of the edges if they are clipped
    if props.repeat == "repeat":
        diff_h = (
            (tiles_h - 2) * dest_tile_size.width - tiles[4].border_width.width()
        ) / 2
        diff_v = (
            (tiles_v - 2) * dest_tile_size.height - tiles[4].border_width.height()
        ) / 2
        for i in range(0, tiles_h):
            dest_tiles[tiles_h + i].dest_size.height -= diff_v
            dest_tiles[tiles_h + i].offset.y -= diff_v  # * tiles[4].scale.y
            dest_tiles[(tiles_v - 2) * tiles_h + i].dest_size.height -= diff_v
        for i in range(0, tiles_v):
            dest_tiles[i * tiles_h + 1].dest_size.width -= diff_h
            dest_tiles[i * tiles_h + 1].offset.x -= diff_h  # * tiles[4].scale.x
            dest_tiles[(i + 1) * tiles_h - 2].dest_size.width -= diff_h

    # output the table to simulate the border
    print("<table>")
    for i in range(tiles_h):
        print('<col style="width: ' + str(dest_tiles[i].dest_size.width) + 'px;">')
    for i in range(tiles_v):
        print(
            '<tr style="height: '
            + str(dest_tiles[i * tiles_h].dest_size.height)
            + 'px;">'
        )
        for j in range(tiles_h):
            width = dest_tiles[i * tiles_h + j].size.width
            height = dest_tiles[i * tiles_h + j].size.height
            # catch any tiles with negative widths/heights
            # this happends when the total of the border-image-slices > borde drawing area
            if width <= 0 or height <= 0:
                print('  <td style="background: white;"></td>')
            else:
                print(
                    '  <td style="background-image: '
                    + props.source
                    + "; background-size: "
                    + str(width)
                    + "px "
                    + str(height)
                    + "px; background-position: "
                    + str(dest_tiles[i * tiles_h + j].offset.x)
                    + "px "
                    + str(dest_tiles[i * tiles_h + j].offset.y)
                    + 'px;"></td>'
                )
        print("</tr>")
    print("</table>")


# start here
args = sys.argv[1:]
if len(args) == 0:
    print("whoops: no source file")
    exit(1)


props = parse(args[0])
if not check_parse(props):
    print(dir(props))
    exit(1)
props = normalise(props)
if not check_normalise(props):
    exit(1)
compute(props)