# Copyright 2003-2008 by Leighton Pritchard.  All rights reserved.
# Revisions copyright 2008-2017 by Peter Cock.
#
# This file is part of the Biopython distribution and governed by your
# choice of the "Biopython License Agreement" or the "BSD 3-Clause License".
# Please see the LICENSE file that should have been included as part of this
# package.
#
# Contact:       Leighton Pritchard, The James Hutton Institute,
#                Invergowrie, Dundee, Scotland, DD2 5DA, UK
#                Leighton.Pritchard@hutton.ac.uk
################################################################################

"""AbstractDrawer module (considered to be a private module, the API may change!).

Provides:
 - AbstractDrawer - Superclass for methods common to the Drawer objects
 - page_sizes - Method that returns a ReportLab pagesize when passed
   a valid ISO size
 - draw_box - Method that returns a closed path object when passed
   the proper coordinates.  For HORIZONTAL boxes only.
 - angle2trig - Method that returns a tuple of values that are the
   vector for rotating a point through a passed angle,
   about an origin
 - intermediate_points - Method that returns a list of values intermediate
   between the points in a passed dataset

For drawing capabilities, this module uses reportlab to draw and write
the diagram: http://www.reportlab.com

For dealing with biological information, the package expects Biopython objects
like SeqFeatures.
"""

from itertools import islice
from math import cos
from math import pi
from math import sin

from reportlab.graphics.shapes import Polygon
from reportlab.lib import colors
from reportlab.lib import pagesizes

################################################################################
# METHODS
################################################################################


# Utility method to translate strings to ISO page sizes
def page_sizes(size):
    """Convert size string into a Reportlab pagesize.

    Arguments:
     - size - A string representing a standard page size, eg 'A4' or 'LETTER'

    """
    sizes = {  # ReportLab pagesizes, keyed by ISO string
        "A0": pagesizes.A0,
        "A1": pagesizes.A1,
        "A2": pagesizes.A2,
        "A3": pagesizes.A3,
        "A4": pagesizes.A4,
        "A5": pagesizes.A5,
        "A6": pagesizes.A6,
        "B0": pagesizes.B0,
        "B1": pagesizes.B1,
        "B2": pagesizes.B2,
        "B3": pagesizes.B3,
        "B4": pagesizes.B4,
        "B5": pagesizes.B5,
        "B6": pagesizes.B6,
        "ELEVENSEVENTEEN": pagesizes.ELEVENSEVENTEEN,
        "LEGAL": pagesizes.LEGAL,
        "LETTER": pagesizes.LETTER,
    }
    try:
        return sizes[size]
    except KeyError:
        raise ValueError(f"{size} not in list of page sizes") from None


def _stroke_and_fill_colors(color, border):
    """Deal with  border and fill colors (PRIVATE)."""
    if not isinstance(color, colors.Color):
        raise ValueError(f"Invalid color {color!r}")

    if color == colors.white and border is None:
        # Force black border on white boxes with undefined border
        strokecolor = colors.black
    elif border is None:
        strokecolor = color  # use fill color
    elif border:
        if not isinstance(border, colors.Color):
            raise ValueError(f"Invalid border color {border!r}")
        strokecolor = border
    else:
        # e.g. False
        strokecolor = None

    return strokecolor, color


def draw_box(
    point1, point2, color=colors.lightgreen, border=None, colour=None, **kwargs
):
    """Draw a box.

    Arguments:
     - point1, point2 - coordinates for opposite corners of the box
       (x,y tuples)
     - color /colour - The color for the box (colour takes priority
       over color)
     - border - Border color for the box

    Returns a closed path object, beginning at (x1,y1) going round
    the four points in order, and filling with the passed color.
    """
    x1, y1 = point1
    x2, y2 = point2

    # Let the UK spelling (colour) override the USA spelling (color)
    if colour is not None:
        color = colour
        del colour

    strokecolor, color = _stroke_and_fill_colors(color, border)

    x1, y1, x2, y2 = min(x1, x2), min(y1, y2), max(x1, x2), max(y1, y2)
    return Polygon(
        [x1, y1, x2, y1, x2, y2, x1, y2],
        strokeColor=strokecolor,
        fillColor=color,
        strokewidth=0,
        **kwargs,
    )


def draw_cut_corner_box(
    point1, point2, corner=0.5, color=colors.lightgreen, border=None, **kwargs
):
    """Draw a box with the corners cut off."""
    x1, y1 = point1
    x2, y2 = point2

    if not corner:
        return draw_box(point1, point2, color, border)
    elif corner < 0:
        raise ValueError("Arrow head length ratio should be positive")

    strokecolor, color = _stroke_and_fill_colors(color, border)

    boxheight = y2 - y1
    boxwidth = x2 - x1
    x_corner = min(boxheight * 0.5 * corner, boxwidth * 0.5)
    y_corner = min(boxheight * 0.5 * corner, boxheight * 0.5)

    points = [
        x1,
        y1 + y_corner,
        x1,
        y2 - y_corner,
        x1 + x_corner,
        y2,
        x2 - x_corner,
        y2,
        x2,
        y2 - y_corner,
        x2,
        y1 + y_corner,
        x2 - x_corner,
        y1,
        x1 + x_corner,
        y1,
    ]
    return Polygon(
        deduplicate(points),
        strokeColor=strokecolor,
        strokeWidth=1,
        strokeLineJoin=1,  # 1=round
        fillColor=color,
        **kwargs,
    )


def draw_polygon(
    list_of_points, color=colors.lightgreen, border=None, colour=None, **kwargs
):
    """Draw polygon.

    Arguments:
     - list_of_point - list of (x,y) tuples for the corner coordinates
     - color / colour - The color for the box

    Returns a closed path object, beginning at (x1,y1) going round
    the four points in order, and filling with the passed colour.

    """
    # Let the UK spelling (colour) override the USA spelling (color)
    if colour is not None:
        color = colour
        del colour

    strokecolor, color = _stroke_and_fill_colors(color, border)

    xy_list = []
    for x, y in list_of_points:
        xy_list.append(x)
        xy_list.append(y)

    return Polygon(
        deduplicate(xy_list),
        strokeColor=strokecolor,
        fillColor=color,
        strokewidth=0,
        **kwargs,
    )


def draw_arrow(
    point1,
    point2,
    color=colors.lightgreen,
    border=None,
    shaft_height_ratio=0.4,
    head_length_ratio=0.5,
    orientation="right",
    colour=None,
    **kwargs,
):
    """Draw an arrow.

    Returns a closed path object representing an arrow enclosed by the
    box with corners at {point1=(x1,y1), point2=(x2,y2)}, a shaft height
    given by shaft_height_ratio (relative to box height), a head length
    given by head_length_ratio (also relative to box height), and
    an orientation that may be 'left' or 'right'.
    """
    x1, y1 = point1
    x2, y2 = point2

    if shaft_height_ratio < 0 or 1 < shaft_height_ratio:
        raise ValueError("Arrow shaft height ratio should be in range 0 to 1")
    if head_length_ratio < 0:
        raise ValueError("Arrow head length ratio should be positive")

    # Let the UK spelling (colour) override the USA spelling (color)
    if colour is not None:
        color = colour
        del colour

    strokecolor, color = _stroke_and_fill_colors(color, border)

    # Depending on the orientation, we define the bottom left (x1, y1) and
    # top right (x2, y2) coordinates differently, but still draw the box
    # using the same relative coordinates:
    xmin, ymin = min(x1, x2), min(y1, y2)
    xmax, ymax = max(x1, x2), max(y1, y2)
    if orientation == "right":
        x1, x2, y1, y2 = xmin, xmax, ymin, ymax
    elif orientation == "left":
        x1, x2, y1, y2 = xmax, xmin, ymin, ymax
    else:
        raise ValueError(
            f"Invalid orientation {orientation!r}, should be 'left' or 'right'"
        )

    # We define boxheight and boxwidth accordingly, and calculate the shaft
    # height from these.  We also ensure that the maximum head length is
    # the width of the box enclosure
    boxheight = y2 - y1
    boxwidth = x2 - x1
    shaftheight = boxheight * shaft_height_ratio
    headlength = min(abs(boxheight) * head_length_ratio, abs(boxwidth))
    if boxwidth < 0:
        headlength *= -1  # reverse it

    shafttop = 0.5 * (boxheight + shaftheight)
    shaftbase = boxheight - shafttop
    headbase = boxwidth - headlength
    midheight = 0.5 * boxheight

    points = [
        x1,
        y1 + shafttop,
        x1 + headbase,
        y1 + shafttop,
        x1 + headbase,
        y2,
        x2,
        y1 + midheight,
        x1 + headbase,
        y1,
        x1 + headbase,
        y1 + shaftbase,
        x1,
        y1 + shaftbase,
    ]

    return Polygon(
        deduplicate(points),
        strokeColor=strokecolor,
        # strokeWidth=max(1, int(boxheight/40.)),
        strokeWidth=1,
        # default is mitre/miter which can stick out too much:
        strokeLineJoin=1,  # 1=round
        fillColor=color,
        **kwargs,
    )


def deduplicate(points):
    """Remove adjacent duplicate points.

    This is important for use with the Polygon class since reportlab has a
    bug with duplicate points.

    Arguments:
     - points - list of points [x1, y1, x2, y2,...]

    Returns a list in the same format with consecutive duplicates removed
    """
    assert len(points) % 2 == 0
    if len(points) < 2:
        return points
    newpoints = points[0:2]
    for x, y in zip(islice(points, 2, None, 2), islice(points, 3, None, 2)):
        if x != newpoints[-2] or y != newpoints[-1]:
            newpoints.append(x)
            newpoints.append(y)
    return newpoints


def angle2trig(theta):
    """Convert angle to a reportlab ready tuple.

    Arguments:
     - theta -  Angle in degrees, counter clockwise from horizontal

    Returns a representation of the passed angle in a format suitable
    for ReportLab rotations (i.e. cos(theta), sin(theta), -sin(theta),
    cos(theta) tuple)
    """
    c = cos(theta * pi / 180)
    s = sin(theta * pi / 180)
    return (c, s, -s, c)  # Vector for rotating point around an origin


def intermediate_points(start, end, graph_data):
    """Generate intermediate points describing provided graph data..

    Returns a list of (start, end, value) tuples describing the passed
    graph data as 'bins' between position midpoints.
    """
    newdata = []  # data in form (X0, X1, val)
    # add first block
    newdata.append(
        (
            start,
            graph_data[0][0] + (graph_data[1][0] - graph_data[0][0]) / 2.0,
            graph_data[0][1],
        )
    )
    # add middle set
    for index in range(1, len(graph_data) - 1):
        lastxval, lastyval = graph_data[index - 1]
        xval, yval = graph_data[index]
        nextxval, nextyval = graph_data[index + 1]
        newdata.append(
            (lastxval + (xval - lastxval) / 2.0, xval + (nextxval - xval) / 2.0, yval)
        )
    # add last block
    newdata.append((xval + (nextxval - xval) / 2.0, end, graph_data[-1][1]))
    return newdata


################################################################################
# CLASSES
################################################################################


class AbstractDrawer:
    """Abstract Drawer.

    Attributes:
     - tracklines    Boolean for whether to draw lines delineating tracks
     - pagesize      Tuple describing the size of the page in pixels
     - x0            Float X co-ord for leftmost point of drawable area
     - xlim          Float X co-ord for rightmost point of drawable area
     - y0            Float Y co-ord for lowest point of drawable area
     - ylim          Float Y co-ord for topmost point of drawable area
     - pagewidth     Float pixel width of drawable area
     - pageheight    Float pixel height of drawable area
     - xcenter       Float X co-ord of center of drawable area
     - ycenter       Float Y co-ord of center of drawable area
     - start         Int, base to start drawing from
     - end           Int, base to stop drawing at
     - length        Size of sequence to be drawn
     - cross_track_links List of tuples each with four entries (track A,
       feature A, track B, feature B) to be linked.

    """

    def __init__(
        self,
        parent,
        pagesize="A3",
        orientation="landscape",
        x=0.05,
        y=0.05,
        xl=None,
        xr=None,
        yt=None,
        yb=None,
        start=None,
        end=None,
        tracklines=0,
        cross_track_links=None,
    ):
        """Create the object.

        Arguments:
         - parent    Diagram object containing the data that the drawer draws
         - pagesize  String describing the ISO size of the image, or a tuple
           of pixels
         - orientation   String describing the required orientation of the
           final drawing ('landscape' or 'portrait')
         - x         Float (0->1) describing the relative size of the X
           margins to the page
         - y         Float (0->1) describing the relative size of the Y
           margins to the page
         - xl        Float (0->1) describing the relative size of the left X
           margin to the page (overrides x)
         - xr        Float (0->1) describing the relative size of the right X
           margin to the page (overrides x)
         - yt        Float (0->1) describing the relative size of the top Y
           margin to the page (overrides y)
         - yb        Float (0->1) describing the relative size of the lower Y
           margin to the page (overrides y)
         - start     Int, the position to begin drawing the diagram at
         - end       Int, the position to stop drawing the diagram at
         - tracklines    Boolean flag to show (or not) lines delineating tracks
           on the diagram
         - cross_track_links List of tuples each with four entries (track A,
           feature A, track B, feature B) to be linked.

        """
        self._parent = parent  # The calling Diagram object

        # Perform 'administrative' tasks of setting up the page
        self.set_page_size(pagesize, orientation)  # Set drawing size
        self.set_margins(x, y, xl, xr, yt, yb)  # Set page margins
        self.set_bounds(start, end)  # Set limits on what will be drawn
        self.tracklines = tracklines  # Set flags
        if cross_track_links is None:
            cross_track_links = []
        else:
            self.cross_track_links = cross_track_links

    def set_page_size(self, pagesize, orientation):
        """Set page size of the drawing..

        Arguments:
         - pagesize      Size of the output image, a tuple of pixels (width,
           height, or a string in the reportlab.lib.pagesizes
           set of ISO sizes.
         - orientation   String: 'landscape' or 'portrait'

        """
        if isinstance(pagesize, str):  # A string, so translate
            pagesize = page_sizes(pagesize)
        elif isinstance(pagesize, tuple):  # A tuple, so don't translate
            pass
        else:
            raise ValueError(f"Page size {pagesize} not recognised")
        shortside, longside = min(pagesize), max(pagesize)

        orientation = orientation.lower()
        if orientation not in ("landscape", "portrait"):
            raise ValueError(f"Orientation {orientation} not recognised")
        if orientation == "landscape":
            self.pagesize = (longside, shortside)
        else:
            self.pagesize = (shortside, longside)

    def set_margins(self, x, y, xl, xr, yt, yb):
        """Set page margins.

        Arguments:
         - x         Float(0->1), Absolute X margin as % of page
         - y         Float(0->1), Absolute Y margin as % of page
         - xl        Float(0->1), Left X margin as % of page
         - xr        Float(0->1), Right X margin as % of page
         - yt        Float(0->1), Top Y margin as % of page
         - yb        Float(0->1), Bottom Y margin as % of page

        Set the page margins as proportions of the page 0->1, and also
        set the page limits x0, y0 and xlim, ylim, and page center
        xorigin, yorigin, as well as overall page width and height
        """
        # Set left, right, top and bottom margins
        xmargin_l = xl or x
        xmargin_r = xr or x
        ymargin_top = yt or y
        ymargin_btm = yb or y

        # Set page limits, center and height/width
        self.x0, self.y0 = self.pagesize[0] * xmargin_l, self.pagesize[1] * ymargin_btm
        self.xlim, self.ylim = (
            self.pagesize[0] * (1 - xmargin_r),
            self.pagesize[1] * (1 - ymargin_top),
        )
        self.pagewidth = self.xlim - self.x0
        self.pageheight = self.ylim - self.y0
        self.xcenter, self.ycenter = (
            self.x0 + self.pagewidth / 2.0,
            self.y0 + self.pageheight / 2.0,
        )

    def set_bounds(self, start, end):
        """Set start and end points for the drawing as a whole.

        Arguments:
         - start - The first base (or feature mark) to draw from
         - end - The last base (or feature mark) to draw to

        """
        low, high = self._parent.range()  # Extent of tracks

        if start is not None and end is not None and start > end:
            start, end = end, start

        if start is None or start < 0:  # Check validity of passed args and
            start = 0  # default to 0
        if end is None or end < 0:
            end = high + 1  # default to track range top limit

        self.start, self.end = int(start), int(end)
        self.length = self.end - self.start + 1

    def is_in_bounds(self, value):
        """Check if given value is within the region selected for drawing.

        Arguments:
         - value - A base position

        """
        if value >= self.start and value <= self.end:
            return 1
        return 0

    def __len__(self):
        """Return the length of the region to be drawn."""
        return self.length

    def _current_track_start_end(self):
        track = self._parent[self.current_track_level]
        if track.start is None:
            start = self.start
        else:
            start = max(self.start, track.start)
        if track.end is None:
            end = self.end
        else:
            end = min(self.end, track.end)
        return start, end