# Copyright 2003-2008 by Leighton Pritchard.  All rights reserved.
# Revisions copyright 2008-2009 by Peter Cock.
# This code is part of the Biopython distribution and governed by its
# license.  Please see the LICENSE file that should have been included
# as part of this package.
#
# Contact:       Leighton Pritchard, Scottish Crop Research Institute,
#                Invergowrie, Dundee, Scotland, DD2 5DA, UK
#                L.Pritchard@scri.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 co-ordinates.  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.
"""

# ReportLab imports
from __future__ import print_function

from Bio._py3k import range

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

from math import pi

__docformat__ = "restructuredtext en"

################################################################################
# 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 = {'A0': pagesizes.A0,    # ReportLab pagesizes, keyed by ISO string
             '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:
        raise ValueError("%s not in list of page sizes" % size)


def _stroke_and_fill_colors(color, border):
    """Helper function handle border and fill colors (PRIVATE)."""
    if not isinstance(color, colors.Color):
        raise ValueError("Invalid color %r" % color)

    if color == colors.white and border is None:   # Force black border on
        strokecolor = colors.black                 # white boxes with
    elif border is None:                           # undefined border, else
        strokecolor = color                        # use fill color
    elif border:
        if not isinstance(border, colors.Color):
            raise ValueError("Invalid border color %r" % border)
        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
    corner = min(boxheight*0.5, boxheight*0.5*corner)

    return Polygon([x1, y1+corner,
                    x1, y2-corner,
                    x1+corner, y2,
                    x2-corner, y2,
                    x2, y2-corner,
                    x2, y1+corner,
                    x2-corner, y1,
                    x1+corner, y1],
                   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(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 co-ordinates:
    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("Invalid orientation %s, should be 'left' or 'right'"
                         % repr(orientation))

    # 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
    return Polygon([x1, y1+shafttop,
                    x1+headbase, y1+shafttop,
                    x1+headbase, y2,
                    x2, y1+midheight,
                    x1+headbase, y1,
                    x1+headbase, y1+shaftbase,
                    x1, y1+shaftbase],
                   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 angle2trig(theta):
    """Convert anngle 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.
    """
    # print start, end, len(graph_data)
    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.,
                    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.,
                        xval+(nextxval-xval)/2., yval))
    # add last block
    newdata.append((xval+(nextxval-xval)/2.,
                         end, graph_data[-1][1]))
    # print newdata[-1]
    # print newdata
    return newdata

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


class AbstractDrawer(object):
    """AbstractDrawer

        Provides:

        Methods:

            - __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) Called on instantiation

            - set_page_size(self, pagesize, orientation)    Set the page size to the
              passed size and orientation

            - set_margins(self, x, y, xl, xr, yt, yb)   Set the drawable area of the
              page

            - set_bounds(self, start, end)  Set the bounds for the elements to be
              drawn

            - is_in_bounds(self, value)     Returns a boolean for whether the position
              is actually to be drawn

            - __len__(self)     Returns the length of sequence that will be drawn

        Attributes:

            - tracklines    Boolean for whether to draw lines dilineating 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)

                - 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
            pagesize = pagesize
        else:
            raise ValueError("Page size %s not recognised" % pagesize)
        shortside, longside = min(pagesize), max(pagesize)

        orientation = orientation.lower()
        if orientation not in ('landscape', 'portrait'):
            raise ValueError("Orientation %s not recognised" % orientation)
        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., self.y0+self.pageheight/2.

    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 withing 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):
        """Returns 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
