from ..svg import PIXELS_PER_MM
from ..threads import ThreadColor
from ..utils.geometry import Point
from .stitch import Stitch
from .ties import add_ties


def patches_to_stitch_plan(patches, collapse_len=3.0 * PIXELS_PER_MM, disable_ties=False):
    """Convert a collection of inkstitch.element.Patch objects to a StitchPlan.

    * applies instructions embedded in the Patch such as trim_after and stop_after
    * adds tie-ins and tie-offs
    * adds jump-stitches between patches if necessary
    """

    stitch_plan = StitchPlan()
    color_block = stitch_plan.new_color_block(color=patches[0].color)

    for patch in patches:
        if not patch.stitches:
            continue

        if color_block.color != patch.color:
            if len(color_block) == 0:
                # We just processed a stop, which created a new color block.
                # We'll just claim this new block as ours:
                color_block.color = patch.color
            else:
                # end the previous block with a color change
                color_block.add_stitch(color_change=True)

                # make a new block of our color
                color_block = stitch_plan.new_color_block(color=patch.color)

                # always start a color with a JUMP to the first stitch position
                color_block.add_stitch(patch.stitches[0], jump=True)
        else:
            if len(color_block) and (patch.stitches[0] - color_block.stitches[-1]).length() > collapse_len:
                color_block.add_stitch(patch.stitches[0], jump=True)

        color_block.add_stitches(patch.stitches, no_ties=patch.stitch_as_is)

        if patch.trim_after:
            color_block.add_stitch(trim=True)

        if patch.stop_after:
            color_block.add_stitch(stop=True)
            color_block = stitch_plan.new_color_block(color_block.color)

    if len(color_block) == 0:
        # last block ended in a stop, so now we have an empty block
        del stitch_plan.color_blocks[-1]

    stitch_plan.filter_duplicate_stitches()

    if not disable_ties:
        stitch_plan.add_ties()

    return stitch_plan


class StitchPlan(object):
    """Holds a set of color blocks, each containing stitches."""

    def __init__(self):
        self.color_blocks = []

    def new_color_block(self, *args, **kwargs):
        color_block = ColorBlock(*args, **kwargs)
        self.color_blocks.append(color_block)
        return color_block

    def delete_empty_color_blocks(self):
        color_blocks = []
        for color_block in self.color_blocks:
            if len(color_block) > 0:
                color_blocks.append(color_block)

        self.color_blocks = color_blocks

    def add_color_block(self, color_block):
        self.color_blocks.append(color_block)

    def filter_duplicate_stitches(self):
        for color_block in self:
            color_block.filter_duplicate_stitches()

    def add_ties(self):
        # see ties.py
        add_ties(self)

    def __iter__(self):
        return iter(self.color_blocks)

    def __len__(self):
        return len(self.color_blocks)

    def __repr__(self):
        return "StitchPlan(%s)" % ", ".join(repr(cb) for cb in self.color_blocks)

    def __json__(self):
        return dict(color_blocks=self.color_blocks,
                    num_stops=self.num_stops,
                    num_trims=self.num_trims,
                    num_stitches=self.num_stitches,
                    bounding_box=self.bounding_box
                    )

    @property
    def num_colors(self):
        """Number of unique colors in the stitch plan."""
        return len({block.color for block in self})

    @property
    def num_color_blocks(self):
        return len(self.color_blocks)

    @property
    def num_stops(self):
        return sum(1 for block in self if block.stop_after)

    @property
    def num_trims(self):
        return sum(block.num_trims for block in self)

    @property
    def num_stitches(self):
        return sum(block.num_stitches for block in self)

    @property
    def bounding_box(self):
        color_block_bounding_boxes = [cb.bounding_box for cb in self]
        minx = min(bb[0] for bb in color_block_bounding_boxes)
        miny = min(bb[1] for bb in color_block_bounding_boxes)
        maxx = max(bb[2] for bb in color_block_bounding_boxes)
        maxy = max(bb[3] for bb in color_block_bounding_boxes)

        return minx, miny, maxx, maxy

    @property
    def dimensions(self):
        minx, miny, maxx, maxy = self.bounding_box
        return (maxx - minx, maxy - miny)

    @property
    def extents(self):
        minx, miny, maxx, maxy = self.bounding_box

        return max(-minx, maxx), max(-miny, maxy)

    @property
    def dimensions_mm(self):
        dimensions = self.dimensions
        return (dimensions[0] / PIXELS_PER_MM, dimensions[1] / PIXELS_PER_MM)

    @property
    def last_color_block(self):
        if self.color_blocks:
            return self.color_blocks[-1]
        else:
            return None


class ColorBlock(object):
    """Holds a set of stitches, all with the same thread color."""

    def __init__(self, color=None, stitches=None):
        self.color = color
        self.stitches = stitches or []

    def __iter__(self):
        return iter(self.stitches)

    def __len__(self):
        return len(self.stitches)

    def __repr__(self):
        return "ColorBlock(%s, %s)" % (self.color, self.stitches)

    def __getitem__(self, item):
        return self.stitches[item]

    def __delitem__(self, item):
        del self.stitches[item]

    def __json__(self):
        return dict(color=self.color, stitches=self.stitches)

    def has_color(self):
        return self._color is not None

    @property
    def color(self):
        return self._color

    @color.setter
    def color(self, value):
        if isinstance(value, ThreadColor):
            self._color = value
        elif value is None:
            self._color = None
        else:
            self._color = ThreadColor(value)

    @property
    def last_stitch(self):
        if self.stitches:
            return self.stitches[-1]
        else:
            return None

    @property
    def num_stitches(self):
        """Number of stitches in this color block."""
        return len(self.stitches)

    @property
    def num_trims(self):
        """Number of trims in this color block."""

        return sum(1 for stitch in self if stitch.trim)

    @property
    def stop_after(self):
        if self.last_stitch is not None:
            return self.last_stitch.stop
        else:
            return False

    @property
    def trim_after(self):
        # If there's a STOP, it will be at the end.  We still want to return
        # True.
        for stitch in reversed(self.stitches):
            if stitch.stop or stitch.jump:
                continue
            elif stitch.trim:
                return True
            else:
                break

        return False

    def filter_duplicate_stitches(self):
        if not self.stitches:
            return

        stitches = [self.stitches[0]]

        for stitch in self.stitches[1:]:
            if stitches[-1].jump or stitch.stop or stitch.trim or stitch.color_change:
                # Don't consider jumps, stops, color changes, or trims as candidates for filtering
                pass
            else:
                length = (stitch - stitches[-1]).length()
                if length <= 0.1 * PIXELS_PER_MM:
                    # duplicate stitch, skip this one
                    continue

            stitches.append(stitch)

        self.stitches = stitches

    def add_stitch(self, *args, **kwargs):
        if not args:
            # They're adding a command, e.g. `color_block.add_stitch(stop=True)``.
            # Use the position from the last stitch.
            if self.last_stitch:
                args = (self.last_stitch.x, self.last_stitch.y)
            else:
                raise ValueError("internal error: can't add a command to an empty stitch block")

        if isinstance(args[0], Stitch):
            self.stitches.append(args[0])
        elif isinstance(args[0], Point):
            self.stitches.append(Stitch(args[0].x, args[0].y, *args[1:], **kwargs))
        else:
            if not args and self.last_stitch:
                args = (self.last_stitch.x, self.last_stitch.y)
            self.stitches.append(Stitch(*args, **kwargs))

    def add_stitches(self, stitches, *args, **kwargs):
        for stitch in stitches:
            if isinstance(stitch, (Stitch, Point)):
                self.add_stitch(stitch, *args, **kwargs)
            else:
                self.add_stitch(*(list(stitch) + args), **kwargs)

    def replace_stitches(self, stitches):
        self.stitches = stitches

    @property
    def bounding_box(self):
        minx = min(stitch.x for stitch in self)
        miny = min(stitch.y for stitch in self)
        maxx = max(stitch.x for stitch in self)
        maxy = max(stitch.y for stitch in self)

        return minx, miny, maxx, maxy