# -*- coding: utf-8 -*-

# ***************************************************************************
# *                                                                         *
# *   Copyright (c) 2016 sliptonic <shopinthewoods@gmail.com>               *
# *                                                                         *
# *   This program is free software; you can redistribute it and/or modify  *
# *   it under the terms of the GNU Lesser General Public License (LGPL)    *
# *   as published by the Free Software Foundation; either version 2 of     *
# *   the License, or (at your option) any later version.                   *
# *   for detail see the LICENCE text file.                                 *
# *                                                                         *
# *   This program is distributed in the hope that it will be useful,       *
# *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
# *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
# *   GNU Library General Public License for more details.                  *
# *                                                                         *
# *   You should have received a copy of the GNU Library General Public     *
# *   License along with this program; if not, write to the Free Software   *
# *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  *
# *   USA                                                                   *
# *                                                                         *
# ***************************************************************************

import FreeCAD
import math
import Part
import Path
import PathScripts.PathLog as PathLog

from FreeCAD import Vector

PathGeomTolerance = 0.000001

#PathLog.setLevel(PathLog.Level.DEBUG, PathLog.thisModule())

class Side:
    """Class to determine and define the side a Path is on, or Vectors are in relation to each other."""
    Left  = +1
    Right = -1
    Straight = 0
    On = 0

    @classmethod
    def toString(cls, side):
        """(side)
        Returns a string representation of the enum value."""
        if side == cls.Left:
            return 'Left'
        if side == cls.Right:
            return 'Right'
        return 'On'

    @classmethod
    def of(cls, ptRef, pt):
        """(ptRef, pt)
        Determine the side of pt in relation to ptRef.
        If both Points are viewed as vectors with their origin in (0,0,0)
        then the two vectors are either form a straigt line (On) or pt
        lies in the left or right hemishpere in regards to ptRef."""
        d = -ptRef.x*pt.y + ptRef.y*pt.x
        if d < 0:
            return cls.Left
        if d > 0:
            return cls.Right
        return cls.Straight

class PathGeom:
    """Class to transform Path Commands into Edges and Wire and back again.
    The interface might eventuallly become part of Path itself."""
    CmdMoveRapid    = ['G0', 'G00']
    CmdMoveStraight = ['G1', 'G01']
    CmdMoveCW       = ['G2', 'G02']
    CmdMoveCCW      = ['G3', 'G03']
    CmdMoveArc      = CmdMoveCW + CmdMoveCCW
    CmdMove         = CmdMoveStraight + CmdMoveArc

    Tolerance = PathGeomTolerance

    @classmethod
    def isRoughly(cls, float1, float2, error=PathGeomTolerance):
        """(float1, float2, [error=%s])
        Returns true if the two values are the same within a given error.""" % PathGeomTolerance
        return math.fabs(float1 - float2) <= error

    @classmethod
    def pointsCoincide(cls, p1, p2, error=PathGeomTolerance):
        """(p1, p2, [error=%s])
        Return True if two points are roughly identical (see also isRoughly).""" % PathGeomTolerance
        return cls.isRoughly(p1.x, p2.x, error) and cls.isRoughly(p1.y, p2.y, error) and cls.isRoughly(p1.z, p2.z, error)

    @classmethod
    def edgesMatch(cls, e0, e1, error=PathGeomTolerance):
        """(e0, e1, [error=%s]
        Return true if the edges start and end at the same point and have the same type of curve.""" % PathGeomTolerance
        if type(e0.Curve) != type(e1.Curve):
            return False
        if not cls.pointsCoincide(e0.valueAt(e0.FirstParameter), e1.valueAt(e1.FirstParameter)):
            return False
        if not cls.pointsCoincide(e0.valueAt(e0.LastParameter), e1.valueAt(e1.LastParameter)):
            return False
        return True

    @classmethod
    def edgeConnectsTo(cls, edge, vector, error=PathGeomTolerance):
        """(edge, vector, error=%f)
        Returns True if edge connects to given vector.""" % PathGeomTolerance
        return cls.pointsCoincide(edge.valueAt(edge.FirstParameter), vector) or cls.pointsCoincide(edge.valueAt(edge.LastParameter), vector)

    @classmethod
    def getAngle(cls, vector):
        """(vector)
        Returns the angle [-pi,pi] of a vector using the X-axis as the reference.
        Positive angles for vertexes in the upper hemishpere (positive y values)
        and negative angles for the lower hemishpere."""
        a = vector.getAngle(Vector(1,0,0))
        if vector.y < 0:
            return -a
        return a

    @classmethod
    def diffAngle(cls, a1, a2, direction = 'CW'):
        """(a1, a2, [direction='CW'])
        Returns the difference between two angles (a1 -> a2) into a given direction."""
        if direction == 'CW':
            while a1 < a2:
                a1 += 2*math.pi
            a = a1 - a2
        else:
            while a2 < a1:
                a2 += 2*math.pi
            a = a2 - a1
        return a

    @classmethod
    def commandEndPoint(cls, cmd, defaultPoint = Vector(), X='X', Y='Y', Z='Z'):
        """(cmd, [defaultPoint=Vector()], [X='X'], [Y='Y'], [Z='Z'])
        Extracts the end point from a Path Command."""
        x = cmd.Parameters.get(X, defaultPoint.x)
        y = cmd.Parameters.get(Y, defaultPoint.y)
        z = cmd.Parameters.get(Z, defaultPoint.z)
        return Vector(x, y, z)

    @classmethod
    def xy(cls, point):
        """(point)
        Convenience function to return the projection of the Vector in the XY-plane."""
        return Vector(point.x, point.y, 0)

    @classmethod
    def cmdsForEdge(cls, edge, flip = False, useHelixForBSpline = True, segm = 50):
        """(edge, flip=False, useHelixForBSpline=True, segm=50) -> List(Path.Command)
        Returns a list of Path.Command representing the given edge.
        If flip is True the edge is considered to be backwards.
        If useHelixForBSpline is True an Edge based on a BSplineCurve is considered
        to represent a helix and results in G2 or G3 command. Otherwise edge has
        no direct Path.Command mapping and will be approximated by straight segments.
        segm is a factor for the segmentation of arbitrary curves not mapped to G1/2/3
        commands. The higher the value the more segments will be used."""
        pt = edge.valueAt(edge.LastParameter) if not flip else edge.valueAt(edge.FirstParameter)
        params = {'X': pt.x, 'Y': pt.y, 'Z': pt.z}
        if type(edge.Curve) == Part.Line or type(edge.Curve) == Part.LineSegment:
            commands =  [Path.Command('G1', params)]
        else:
            p1 = edge.valueAt(edge.FirstParameter) if not flip else edge.valueAt(edge.LastParameter)
            p2 = edge.valueAt((edge.FirstParameter + edge.LastParameter)/2)
            p3 = pt

            if (type(edge.Curve) == Part.Circle and cls.isRoughly(edge.Curve.Axis.x, 0) and cls.isRoughly(edge.Curve.Axis.y, 0)) or (useHelixForBSpline and type(edge.Curve) == Part.BSplineCurve):
                # This is an arc or a helix and it should be represented by a simple G2/G3 command
                if edge.Curve.Axis.z < 0:
                    cmd = 'G2' if not flip else 'G3'
                else:
                    cmd = 'G3' if not flip else 'G2'
                pd = Part.Circle(PathGeom.xy(p1), PathGeom.xy(p2), PathGeom.xy(p3)).Center
                PathLog.info("**** %s.%d: (%.2f, %.2f, %.2f) - (%.2f, %.2f, %.2f) - (%.2f, %.2f, %.2f) -> center=(%.2f, %.2f)" % (cmd, flip, p1.x, p1.y, p1.z, p2.x, p2.y, p2.z, p3.x, p3.y, p3.z, pd.x, pd.y))

                # Have to calculate the center in the XY plane, using pd leads to an error if this is a helix
                pa = PathGeom.xy(p1)
                pb = PathGeom.xy(p2)
                pc = PathGeom.xy(p3)
                offset = Part.Circle(pa, pb, pc).Center - pa

                PathLog.debug("**** (%.2f, %.2f, %.2f) - (%.2f, %.2f, %.2f)" % (pa.x, pa.y, pa.z, pc.x, pc.y, pc.z))
                PathLog.debug("**** (%.2f, %.2f, %.2f) - (%.2f, %.2f, %.2f)" % (pb.x, pb.y, pb.z, pd.x, pd.y, pd.z))
                PathLog.debug("**** (%.2f, %.2f, %.2f)" % (offset.x, offset.y, offset.z))

                params.update({'I': offset.x, 'J': offset.y, 'K': (p3.z - p1.z)/2})
                commands = [ Path.Command(cmd, params) ]

            else:
                # We're dealing with a helix or a more complex shape and it has to get approximated
                # by a number of straight segments
                eStraight = Part.Edge(Part.LineSegment(p1, p3))
                esP2 = eStraight.valueAt((eStraight.FirstParameter + eStraight.LastParameter)/2)
                deviation = (p2 - esP2).Length
                if cls.isRoughly(deviation, 0):
                    return [ Path.Command('G1', {'X': p3.x, 'Y': p3.y, 'Z': p3.z}) ]
                # at this point pixellation is all we can do
                commands = []
                segments = int(math.ceil((deviation / eStraight.Length) * segm))
                #print("**** pixellation with %d segments" % segments)
                dParameter = (edge.LastParameter - edge.FirstParameter) / segments
                for i in range(0, segments):
                    if flip:
                        p = edge.valueAt(edge.LastParameter - (i + 1) * dParameter)
                    else:
                        p = edge.valueAt(edge.FirstParameter + (i + 1) * dParameter)
                    cmd = Path.Command('G1', {'X': p.x, 'Y': p.y, 'Z': p.z})
                    #print("***** %s" % cmd)
                    commands.append(cmd)
        #print commands
        return commands

    @classmethod
    def edgeForCmd(cls, cmd, startPoint):
        """(cmd, startPoint).
        Returns an Edge representing the given command, assuming a given startPoint."""

        endPoint = cls.commandEndPoint(cmd, startPoint)
        if (cmd.Name in cls.CmdMoveStraight) or (cmd.Name in cls.CmdMoveRapid):
            if cls.pointsCoincide(startPoint, endPoint):
                return None
            return Part.Edge(Part.LineSegment(startPoint, endPoint))

        if cmd.Name in cls.CmdMoveArc:
            center = startPoint + cls.commandEndPoint(cmd, Vector(0,0,0), 'I', 'J', 'K')
            A = cls.xy(startPoint - center)
            B = cls.xy(endPoint - center)
            d = -B.x * A.y + B.y * A.x

            if cls.isRoughly(d, 0, 0.005):
                PathLog.info("Half circle arc at: (%.2f, %.2f, %.2f)" % (center.x, center.y, center.z))
                # we're dealing with half a circle here
                angle = cls.getAngle(A) + math.pi/2
                if cmd.Name in cls.CmdMoveCW:
                    angle -= math.pi
            else:
                C = A + B
                angle = cls.getAngle(C)
                PathLog.info("Arc (%8f) at: (%.2f, %.2f, %.2f) -> angle=%f" % (d, center.x, center.y, center.z, angle / math.pi))

            R = A.Length
            PathLog.debug("arc: p1=(%.2f, %.2f) p2=(%.2f, %.2f) -> center=(%.2f, %.2f)" % (startPoint.x, startPoint.y, endPoint.x, endPoint.y, center.x, center.y))
            PathLog.debug("arc: A=(%.2f, %.2f) B=(%.2f, %.2f) -> d=%.2f" % (A.x, A.y, B.x, B.y, d))
            PathLog.debug("arc: R=%.2f angle=%.2f" % (R, angle/math.pi))
            if cls.isRoughly(startPoint.z, endPoint.z):
                midPoint = center + Vector(math.cos(angle), math.sin(angle), 0) * R
                PathLog.debug("arc: (%.2f, %.2f) -> (%.2f, %.2f) -> (%.2f, %.2f)" % (startPoint.x, startPoint.y, midPoint.x, midPoint.y, endPoint.x, endPoint.y))
                return Part.Edge(Part.Arc(startPoint, midPoint, endPoint))

            # It's a Helix
            #print('angle: A=%.2f B=%.2f' % (cls.getAngle(A)/math.pi, cls.getAngle(B)/math.pi))
            if cmd.Name in cls.CmdMoveCW:
                cw = True
            else:
                cw = False
            angle = cls.diffAngle(cls.getAngle(A), cls.getAngle(B), 'CW' if cw else 'CCW')
            height = endPoint.z - startPoint.z
            pitch = height * math.fabs(2 * math.pi / angle)
            if angle > 0:
                cw = not cw
            #print("Helix: R=%.2f h=%.2f angle=%.2f pitch=%.2f" % (R, height, angle/math.pi, pitch))
            helix = Part.makeHelix(pitch, height, R, 0, not cw)
            helix.rotate(Vector(), Vector(0,0,1), 180 * cls.getAngle(A) / math.pi)
            e = helix.Edges[0]
            helix.translate(startPoint - e.valueAt(e.FirstParameter))
            return helix.Edges[0]
        return None

    @classmethod
    def wireForPath(cls, path, startPoint = Vector(0, 0, 0)):
        """(path, [startPoint=Vector(0,0,0)])
        Returns a wire representing all move commands found in the given path."""
        edges = []
        rapid = []
        if hasattr(path, "Commands"):
            for cmd in path.Commands:
                edge = cls.edgeForCmd(cmd, startPoint)
                if edge:
                    if cmd.Name in cls.CmdMoveRapid:
                        rapid.append(edge)
                    edges.append(edge)
                    startPoint = cls.commandEndPoint(cmd, startPoint)
        return (Part.Wire(edges), rapid)

    @classmethod
    def wiresForPath(cls, path, startPoint = Vector(0, 0, 0)):
        """(path, [startPoint=Vector(0,0,0)])
        Returns a collection of wires, each representing a continuous cutting Path in path."""
        wires = []
        if hasattr(path, "Commands"):
            edges = []
            for cmd in path.Commands:
                if cmd.Name in cls.CmdMove:
                    edges.append(cls.edgeForCmd(cmd, startPoint))
                    startPoint = cls.commandEndPoint(cmd, startPoint)
                elif cmd.Name in cls.CmdMoveRapid:
                    wires.append(Part.Wire(edges))
                    edges = []
                    startPoint = cls.commandEndPoint(cmd, startPoint)
            if edges:
                wires.append(Part.Wire(edges))
        return wires

    @classmethod
    def arcToHelix(cls, edge, z0, z1):
        """(edge, z0, z1)
        Assuming edge is an arc it'll return a helix matching the arc starting at z0 and rising/falling to z1."""


        p1 = edge.valueAt(edge.FirstParameter)
        p2 = edge.valueAt(edge.LastParameter)

        cmd = cls.cmdsForEdge(edge)[0]
        params = cmd.Parameters
        params.update({'Z': z1, 'K': (z1 - z0)/2})
        command = Path.Command(cmd.Name, params)

        #print("- (%.2f, %.2f, %.2f) - (%.2f, %.2f, %.2f): %.2f:%.2f" % (edge.Vertexes[0].X, edge.Vertexes[0].Y, edge.Vertexes[0].Z, edge.Vertexes[1].X, edge.Vertexes[1].Y, edge.Vertexes[1].Z, z0, z1))
        #print("- %s -> %s" % (cmd, command))

        return cls.edgeForCmd(command, Vector(p1.x, p1.y, z0))


    @classmethod
    def helixToArc(cls, edge, z = 0):
        """(edge, z=0)
        Returns the projection of the helix onto the XY-plane with a given offset."""
        p1 = edge.valueAt(edge.FirstParameter)
        p2 = edge.valueAt((edge.FirstParameter + edge.LastParameter)/2)
        p3 = edge.valueAt(edge.LastParameter)
        p01 = Vector(p1.x, p1.y, z)
        p02 = Vector(p2.x, p2.y, z)
        p03 = Vector(p3.x, p3.y, z)
        return Part.Edge(Part.Arc(p01, p02, p03))

    @classmethod
    def splitArcAt(cls, edge, pt):
        """(edge, pt)
        Returns a list of 2 edges which together form the original arc split at the given point.
        The Vector pt has to represnt a point on the given arc."""
        p1 = edge.valueAt(edge.FirstParameter)
        p2 = pt
        p3 = edge.valueAt(edge.LastParameter)
        edges = []

        p = edge.Curve.parameter(p2)
        #print("splitArcAt(%.2f, %.2f, %.2f): %.2f - %.2f - %.2f" % (pt.x, pt.y, pt.z, edge.FirstParameter, p, edge.LastParameter))

        p12 = edge.Curve.value((edge.FirstParameter + p)/2)
        p23 = edge.Curve.value((p + edge.LastParameter)/2)
        #print("splitArcAt: p12=(%.2f, %.2f, %.2f) p23=(%.2f, %.2f, %.2f)" % (p12.x, p12.y, p12.z, p23.x, p23.y, p23.z))

        edges.append(Part.Edge(Part.Arc(p1, p12, p2)))
        edges.append(Part.Edge(Part.Arc(p2, p23, p3)))

        return edges

    @classmethod
    def splitEdgeAt(cls, edge, pt):
        """(edge, pt)
        Returns a list of 2 edges, forming the original edge split at the given point.
        The results are undefined if the Vector representing the point is not part of the edge."""
        # I could not get the OCC parameterAt and split to work ...
        # pt HAS to be on the edge, otherwise the results are undefined
        p1 = edge.valueAt(edge.FirstParameter)
        p2 = pt
        p3 = edge.valueAt(edge.LastParameter)
        edges = []

        if type(edge.Curve) == Part.Line or type(edge.Curve) == Part.LineSegment:
            # it's a line
            return [Part.Edge(Part.LineSegment(p1, p2)), Part.Edge(Part.LineSegment(p2, p3))]
        elif type(edge.Curve) == Part.Circle:
            # it's an arc
            return cls.splitArcAt(edge, pt)
        else:
            # it's a helix
            arc = cls.helixToArc(edge, 0)
            aes = cls.splitArcAt(arc, Vector(pt.x, pt.y, 0))
            return [cls.arcToHelix(aes[0], p1.z, p2.z), cls.arcToHelix(aes[1], p2.z, p3.z)]

