# Copyright (c) 2019-2021, Manfred Moitzi
# License: MIT License
from typing import List, Sequence, TYPE_CHECKING, Iterable
import math
from ezdxf.math import Vec2
from .bbox import BoundingBox2d
from .line import ConstructionLine
from .construct2d import point_to_line_relation

if TYPE_CHECKING:
    from ezdxf.math import Vertex

ABS_TOL = 1e-12

__all__ = ["ConstructionBox"]


class ConstructionBox:
    """
    Helper class to create rectangles.

    Args:
        center: center of rectangle
        width: width of rectangle
        height: height of rectangle
        angle: angle of rectangle in degrees

    """

    def __init__(
        self,
        center: "Vertex" = (0, 0),
        width: float = 1,
        height: float = 1,
        angle: float = 0,
    ):
        self._center = Vec2(center)
        self._width: float = abs(width)
        self._height: float = abs(height)
        self._angle: float = angle  # in degrees
        # corners: lower left, lower right, upper right, upper left:
        self._corners: Sequence[Vec2] = tuple()
        self._tainted: bool = True

    @classmethod
    def from_points(cls, p1: "Vertex", p2: "Vertex") -> "ConstructionBox":
        """Creates a box from two opposite corners, box sides are parallel to x-
        and y-axis.

        Args:
            p1: first corner as :class:`Vec2` compatible object
            p2: second corner as :class:`Vec2` compatible object

        """
        _p1 = Vec2(p1)
        _p2 = Vec2(p2)
        width: float = abs(_p2.x - _p1.x)
        height: float = abs(_p2.y - _p1.y)
        center: Vec2 = _p1.lerp(_p2)
        return cls(center=center, width=width, height=height)

    def update(self) -> None:
        if not self._tainted:
            return
        center = self.center
        w2 = Vec2.from_deg_angle(self._angle, self._width / 2.0)
        h2 = Vec2.from_deg_angle(self._angle + 90, self._height / 2.0)
        self._corners = (
            center - w2 - h2,  # lower left
            center + w2 - h2,  # lower right
            center + w2 + h2,  # upper right
            center - w2 + h2,  # upper left
        )
        self._tainted = False

    @property
    def bounding_box(self) -> BoundingBox2d:
        """:class:`BoundingBox2d`"""
        return BoundingBox2d(self.corners)

    @property
    def center(self) -> Vec2:
        """box center"""
        return self._center

    @center.setter
    def center(self, c: "Vertex") -> None:
        self._center = Vec2(c)
        self._tainted = True

    @property
    def width(self) -> float:
        """box width"""
        return self._width

    @width.setter
    def width(self, w: float) -> None:
        self._width = abs(w)
        self._tainted = True

    @property
    def height(self) -> float:
        """box height"""
        return self._height

    @height.setter
    def height(self, h: float) -> None:
        self._height = abs(h)
        self._tainted = True

    @property
    def incircle_radius(self) -> float:
        """incircle radius"""
        return min(self._width, self._height) * 0.5

    @property
    def circumcircle_radius(self) -> float:
        """circum circle radius"""
        return math.hypot(self._width, self._height) * 0.5

    @property
    def angle(self) -> float:
        """rotation angle in degrees"""
        return self._angle

    @angle.setter
    def angle(self, a: float) -> None:
        self._angle = a
        self._tainted = True

    @property
    def corners(self) -> Sequence[Vec2]:
        """box corners as sequence of :class:`Vec2` objects."""
        self.update()
        return self._corners

    def __iter__(self) -> Iterable[Vec2]:
        """Iterable of box corners as :class:`Vec2` objects."""
        return iter(self.corners)

    def __getitem__(self, corner) -> Vec2:
        """Get corner by index `corner`, ``list`` like slicing is supported."""
        return self.corners[corner]

    def __repr__(self) -> str:
        """Returns string representation of box as
        ``ConstructionBox(center, width, height, angle)``"""
        return "ConstructionBox({0.center}, {0.width}, {0.height}, {0.angle})".format(
            self
        )

    def translate(self, dx: float, dy: float) -> None:
        """
        Move box about `dx` in x-axis and about `dy` in y-axis.

        Args:
            dx: translation in x-axis
            dy: translation in y-axis

        """
        self.center += Vec2((dx, dy))

    def expand(self, dw: float, dh: float) -> None:
        """Expand box: `dw` expand width, `dh` expand height."""
        self.width += dw
        self.height += dh

    def scale(self, sw: float, sh: float) -> None:
        """Scale box: `sw` scales width, `sh` scales height."""
        self.width *= sw
        self.height *= sh

    def rotate(self, angle: float) -> None:
        """Rotate box by `angle` in degrees."""
        self.angle += angle

    def is_inside(self, point: "Vertex") -> bool:
        """Returns ``True`` if `point` is inside of box."""
        point = Vec2(point)
        delta = self.center - point
        if abs(self.angle) < ABS_TOL:  # fast path for horizontal rectangles
            return abs(delta.x) <= (self._width / 2.0) and abs(delta.y) <= (
                self._height / 2.0
            )
        else:
            distance = delta.magnitude
            if distance > self.circumcircle_radius:
                return False
            elif distance <= self.incircle_radius:
                return True
            else:
                # inside if point is "left of line" of all border lines.
                p1, p2, p3, p4 = self.corners
                return all(
                    (
                        point_to_line_relation(point, a, b) < 1
                        for a, b in [(p1, p2), (p2, p3), (p3, p4), (p4, p1)]
                    )
                )

    def is_any_corner_inside(self, other: "ConstructionBox") -> bool:
        """Returns ``True`` if any corner of `other` box is inside this box."""
        return any(self.is_inside(p) for p in other.corners)

    def is_overlapping(self, other: "ConstructionBox") -> bool:
        """Returns ``True`` if this box and `other` box do overlap."""
        distance = (self.center - other.center).magnitude
        max_distance = self.circumcircle_radius + other.circumcircle_radius
        if distance > max_distance:
            return False
        min_distance = self.incircle_radius + other.incircle_radius
        if distance <= min_distance:
            return True

        if self.is_any_corner_inside(other):
            return True
        if other.is_any_corner_inside(self):
            return True
        # no corner inside of any box, maybe crossing boxes?
        # check intersection of diagonals
        c1, c2, c3, c4 = self.corners
        diag1 = ConstructionLine(c1, c3)
        diag2 = ConstructionLine(c2, c4)

        t1, t2, t3, t4 = other.corners
        test_diag = ConstructionLine(t1, t3)
        if test_diag.has_intersection(diag1) or test_diag.has_intersection(diag2):
            return True
        test_diag = ConstructionLine(t2, t4)
        if test_diag.has_intersection(diag1) or test_diag.has_intersection(diag2):
            return True

        return False

    def border_lines(self) -> Sequence[ConstructionLine]:
        """Returns border lines of box as sequence of :class:`ConstructionLine`.
        """
        p1, p2, p3, p4 = self.corners
        return (
            ConstructionLine(p1, p2),
            ConstructionLine(p2, p3),
            ConstructionLine(p3, p4),
            ConstructionLine(p4, p1),
        )

    def intersect(self, line: ConstructionLine) -> List[Vec2]:
        """Returns 0, 1 or 2 intersection points between `line` and box border
        lines.

        Args:
            line: line to intersect with border lines

        Returns:
            list of intersection points

            =========== ==================================
            list size   Description
            =========== ==================================
            0           no intersection
            1           line touches box at one corner
            2           line intersects with box
            =========== ==================================

        """
        result = set()
        for border_line in self.border_lines():
            p = line.intersect(border_line)
            if p is not None:
                result.add(p)
        return sorted(result)
