# ***************************************************************************
# *   Copyright (c) 2009, 2010 Yorik van Havre <yorik@uncreated.net>        *
# *   Copyright (c) 2009, 2010 Ken Cline <cline@frii.com>                   *
# *   Copyright (c) 2020 FreeCAD Developers                                 *
# *                                                                         *
# *   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                                                                   *
# *                                                                         *
# ***************************************************************************
"""Provides functions to join wires together into a single wire."""
## @package join
# \ingroup draftfuctions
# \brief Provides functions to join wires together into a single wire.

## \addtogroup draftfuctions
# @{
import FreeCAD as App


def join_wires(wires, joinAttempts = 0):
    """joinWires(objects): merges a set of wires where possible, if any of those
    wires have a coincident start and end point"""
    if joinAttempts > len(wires):
        return
    joinAttempts += 1
    for wire1Index, wire1 in enumerate(wires):
        for wire2Index, wire2 in enumerate(wires):
            if wire2Index <= wire1Index:
                continue
            if joinTwoWires(wire1, wire2):
                wires.pop(wire2Index)
                break
    joinWires(wires, joinAttempts)


joinWires = join_wires


def join_two_wires(wire1, wire2):
    """joinTwoWires(object, object): joins two wires if they share a common
    point as a start or an end.

    BUG: it occasionally fails to join lines even if the lines
    visually share a point.
    This is a rounding error in the comparison of the shared point;
    a small difference will result in the points being considered different
    and thus the lines not joining.
    Test properly using `DraftVecUtils.equals` because then it will consider
    the precision set in the Draft preferences.
    """
    wire1AbsPoints = [wire1.Placement.multVec(point) for point in wire1.Points]
    wire2AbsPoints = [wire2.Placement.multVec(point) for point in wire2.Points]
    if ((wire1AbsPoints[0] == wire2AbsPoints[-1] and 
        wire1AbsPoints[-1] == wire2AbsPoints[0]) or
        (wire1AbsPoints[0] == wire2AbsPoints[0] and 
        wire1AbsPoints[-1] == wire2AbsPoints[-1])):
        wire2AbsPoints.pop()
        wire1.Closed = True
    elif wire1AbsPoints[0] == wire2AbsPoints[0]:
        wire1AbsPoints = list(reversed(wire1AbsPoints))
    elif wire1AbsPoints[0] == wire2AbsPoints[-1]:
        wire1AbsPoints = list(reversed(wire1AbsPoints))
        wire2AbsPoints = list(reversed(wire2AbsPoints))
    elif wire1AbsPoints[-1] == wire2AbsPoints[-1]:
        wire2AbsPoints = list(reversed(wire2AbsPoints))
    elif wire1AbsPoints[-1] == wire2AbsPoints[0]:
        pass
    else:
        return False
    wire2AbsPoints.pop(0)
    wire1.Points = ([wire1.Placement.inverse().multVec(point) 
                     for point in wire1AbsPoints] +
                    [wire1.Placement.inverse().multVec(point)
                     for point in wire2AbsPoints])
    App.ActiveDocument.removeObject(wire2.Name)
    return True


joinTwoWires = join_two_wires

## @}