# Authors: see git history
#
# Copyright (c) 2010 Authors
# Licensed under the GNU GPL version 3.0 or later.  See the file LICENSE for details.

import math
import sys
import traceback

from shapely import geometry as shgeo

from .element import param
from .fill import Fill
from .validation import ValidationWarning
from ..i18n import _
from ..stitch_plan import StitchGroup
from ..stitches import auto_fill
from ..svg.tags import INKSCAPE_LABEL
from ..utils import cache, version


class SmallShapeWarning(ValidationWarning):
    name = _("Small Fill")
    description = _("This fill object is so small that it would probably look better as running stitch or satin column. "
                    "For very small shapes, fill stitch is not possible, and Ink/Stitch will use running stitch around "
                    "the outline instead.")


class ExpandWarning(ValidationWarning):
    name = _("Expand")
    description = _("The expand parameter for this fill object cannot be applied. "
                    "Ink/Stitch will ignore it and will use original size instead.")


class UnderlayInsetWarning(ValidationWarning):
    name = _("Inset")
    description = _("The underlay inset parameter for this fill object cannot be applied. "
                    "Ink/Stitch will ignore it and will use the original size instead.")


class AutoFill(Fill):
    element_name = _("AutoFill")

    @property
    @param('auto_fill', _('Automatically routed fill stitching'), type='toggle', default=True)
    def auto_fill(self):
        return self.get_boolean_param('auto_fill', True)

    @property
    @cache
    def outline(self):
        return self.shape.boundary[0]

    @property
    @cache
    def outline_length(self):
        return self.outline.length

    @property
    def flip(self):
        return False

    @property
    @param('running_stitch_length_mm',
           _('Running stitch length (traversal between sections)'),
           tooltip=_('Length of stitches around the outline of the fill region used when moving from section to section.'),
           unit='mm',
           type='float',
           default=1.5)
    def running_stitch_length(self):
        return max(self.get_float_param("running_stitch_length_mm", 1.5), 0.01)

    @property
    @param('fill_underlay', _('Underlay'), type='toggle', group=_('AutoFill Underlay'), default=True)
    def fill_underlay(self):
        return self.get_boolean_param("fill_underlay", default=True)

    @property
    @param('fill_underlay_angle',
           _('Fill angle'),
           tooltip=_('Default: fill angle + 90 deg. Insert comma-seperated list for multiple layers.'),
           unit='deg',
           group=_('AutoFill Underlay'),
           type='float')
    @cache
    def fill_underlay_angle(self):
        underlay_angles = self.get_param('fill_underlay_angle', None)
        default_value = [self.angle + math.pi / 2.0]
        if underlay_angles is not None:
            underlay_angles = underlay_angles.strip().split(',')
            try:
                underlay_angles = [math.radians(float(angle)) for angle in underlay_angles]
            except (TypeError, ValueError):
                return default_value
        else:
            underlay_angles = default_value

        return underlay_angles

    @property
    @param('fill_underlay_row_spacing_mm',
           _('Row spacing'),
           tooltip=_('default: 3x fill row spacing'),
           unit='mm',
           group=_('AutoFill Underlay'),
           type='float')
    @cache
    def fill_underlay_row_spacing(self):
        return self.get_float_param("fill_underlay_row_spacing_mm") or self.row_spacing * 3

    @property
    @param('fill_underlay_max_stitch_length_mm',
           _('Max stitch length'),
           tooltip=_('default: equal to fill max stitch length'),
           unit='mm',
           group=_('AutoFill Underlay'), type='float')
    @cache
    def fill_underlay_max_stitch_length(self):
        return self.get_float_param("fill_underlay_max_stitch_length_mm") or self.max_stitch_length

    @property
    @param('fill_underlay_inset_mm',
           _('Inset'),
           tooltip=_('Shrink the shape before doing underlay, to prevent underlay from showing around the outside of the fill.'),
           unit='mm',
           group=_('AutoFill Underlay'),
           type='float',
           default=0)
    def fill_underlay_inset(self):
        return self.get_float_param('fill_underlay_inset_mm', 0)

    @property
    @param(
        'fill_underlay_skip_last',
        _('Skip last stitch in each row'),
        tooltip=_('The last stitch in each row is quite close to the first stitch in the next row.  '
                  'Skipping it decreases stitch count and density.'),
        group=_('AutoFill Underlay'),
        type='boolean',
        default=False)
    def fill_underlay_skip_last(self):
        return self.get_boolean_param("fill_underlay_skip_last", False)

    @property
    @param('expand_mm',
           _('Expand'),
           tooltip=_('Expand the shape before fill stitching, to compensate for gaps between shapes.'),
           unit='mm',
           type='float',
           default=0)
    def expand(self):
        return self.get_float_param('expand_mm', 0)

    @property
    @param('underpath',
           _('Underpath'),
           tooltip=_('Travel inside the shape when moving from section to section.  Underpath '
                     'stitches avoid traveling in the direction of the row angle so that they '
                     'are not visible.  This gives them a jagged appearance.'),
           type='boolean',
           default=True)
    def underpath(self):
        return self.get_boolean_param('underpath', True)

    @property
    @param(
        'underlay_underpath',
        _('Underpath'),
        tooltip=_('Travel inside the shape when moving from section to section.  Underpath '
                  'stitches avoid traveling in the direction of the row angle so that they '
                  'are not visible.  This gives them a jagged appearance.'),
        group=_('AutoFill Underlay'),
        type='boolean',
        default=True)
    def underlay_underpath(self):
        return self.get_boolean_param('underlay_underpath', True)

    def shrink_or_grow_shape(self, amount, validate=False):
        if amount:
            shape = self.shape.buffer(amount)
            # changing the size can empty the shape
            # in this case we want to use the original shape rather than returning an error
            if shape.is_empty and not validate:
                return self.shape
            if not isinstance(shape, shgeo.MultiPolygon):
                shape = shgeo.MultiPolygon([shape])
            return shape
        else:
            return self.shape

    @property
    def underlay_shape(self):
        return self.shrink_or_grow_shape(-self.fill_underlay_inset)

    @property
    def fill_shape(self):
        return self.shrink_or_grow_shape(self.expand)

    def get_starting_point(self, last_patch):
        # If there is a "fill_start" Command, then use that; otherwise pick
        # the point closest to the end of the last patch.

        if self.get_command('fill_start'):
            return self.get_command('fill_start').target_point
        elif last_patch:
            return last_patch.stitches[-1]
        else:
            return None

    def get_ending_point(self):
        if self.get_command('fill_end'):
            return self.get_command('fill_end').target_point
        else:
            return None

    def to_stitch_groups(self, last_patch):
        stitch_groups = []

        starting_point = self.get_starting_point(last_patch)
        ending_point = self.get_ending_point()

        try:
            if self.fill_underlay:
                for i in range(len(self.fill_underlay_angle)):
                    underlay = StitchGroup(
                        color=self.color,
                        tags=("auto_fill", "auto_fill_underlay"),
                        stitches=auto_fill(
                            self.underlay_shape,
                            self.fill_underlay_angle[i],
                            self.fill_underlay_row_spacing,
                            self.fill_underlay_row_spacing,
                            self.fill_underlay_max_stitch_length,
                            self.running_stitch_length,
                            self.staggers,
                            self.fill_underlay_skip_last,
                            starting_point,
                            underpath=self.underlay_underpath))
                    stitch_groups.append(underlay)

                    starting_point = underlay.stitches[-1]

            stitch_group = StitchGroup(
                color=self.color,
                tags=("auto_fill", "auto_fill_top"),
                stitches=auto_fill(
                    self.fill_shape,
                    self.angle,
                    self.row_spacing,
                    self.end_row_spacing,
                    self.max_stitch_length,
                    self.running_stitch_length,
                    self.staggers,
                    self.skip_last,
                    starting_point,
                    ending_point,
                    self.underpath))
            stitch_groups.append(stitch_group)
        except Exception:
            if hasattr(sys, 'gettrace') and sys.gettrace():
                # if we're debugging, let the exception bubble up
                raise

            # for an uncaught exception, give a little more info so that they can create a bug report
            message = ""
            message += _("Error during autofill!  This means that there is a problem with Ink/Stitch.")
            message += "\n\n"
            # L10N this message is followed by a URL: https://github.com/inkstitch/inkstitch/issues/new
            message += _("If you'd like to help us make Ink/Stitch better, please paste this whole message into a new issue at: ")
            message += "https://github.com/inkstitch/inkstitch/issues/new\n\n"
            message += version.get_inkstitch_version() + "\n\n"
            message += traceback.format_exc()

            self.fatal(message)

        return stitch_groups


def validation_warnings(self):
    if self.shape.area < 20:
        label = self.node.get(INKSCAPE_LABEL) or self.node.get("id")
        yield SmallShapeWarning(self.shape.centroid, label)

    if self.shrink_or_grow_shape(self.expand, True).is_empty:
        yield ExpandWarning(self.shape.centroid)

    if self.shrink_or_grow_shape(-self.fill_underlay_inset, True).is_empty:
        yield UnderlayInsetWarning(self.shape.centroid)

    for warning in super(AutoFill, self).validation_warnings():
        yield warning
