# SPDX-License-Identifier: GPL-2.0-or-later

from bpy.types import Operator
from mathutils import Vector


def worldspace_bounds_from_object_bounds(bb_world):

    # Initialize the variables with the 8th vertex
    left, right, front, back, down, up = (
        bb_world[7][0],
        bb_world[7][0],
        bb_world[7][1],
        bb_world[7][1],
        bb_world[7][2],
        bb_world[7][2],
    )

    # Test against the other 7 verts
    for i in range(7):

        # X Range
        val = bb_world[i][0]
        if val < left:
            left = val

        if val > right:
            right = val

        # Y Range
        val = bb_world[i][1]
        if val < front:
            front = val

        if val > back:
            back = val

        # Z Range
        val = bb_world[i][2]
        if val < down:
            down = val

        if val > up:
            up = val

    return (Vector((left, front, up)), Vector((right, back, down)))


def worldspace_bounds_from_object_data(depsgraph, obj):

    matrix_world = obj.matrix_world.copy()

    # Initialize the variables with the last vertex
    ob_eval = obj.evaluated_get(depsgraph)
    me = ob_eval.to_mesh()
    verts = me.vertices

    val = matrix_world @ (verts[-1].co if verts else Vector((0.0, 0.0, 0.0)))

    left, right, front, back, down, up = (
        val[0],
        val[0],
        val[1],
        val[1],
        val[2],
        val[2],
    )

    # Test against all other verts
    for v in verts:
        vco = matrix_world @ v.co

        # X Range
        val = vco[0]
        if val < left:
            left = val

        if val > right:
            right = val

        # Y Range
        val = vco[1]
        if val < front:
            front = val

        if val > back:
            back = val

        # Z Range
        val = vco[2]
        if val < down:
            down = val

        if val > up:
            up = val

    ob_eval.to_mesh_clear()

    return Vector((left, front, up)), Vector((right, back, down))


def align_objects(context,
                  align_x,
                  align_y,
                  align_z,
                  align_mode,
                  relative_to,
                  bb_quality):

    depsgraph = context.evaluated_depsgraph_get()
    scene = context.scene

    cursor = scene.cursor.location

    # We are accessing runtime data such as evaluated bounding box, so we need to
    # be sure it is properly updated and valid (bounding box might be lost on operator
    # redo).
    context.view_layer.update()

    Left_Front_Up_SEL = [0.0, 0.0, 0.0]
    Right_Back_Down_SEL = [0.0, 0.0, 0.0]

    flag_first = True

    objects = []

    for obj in context.selected_objects:
        matrix_world = obj.matrix_world.copy()
        bb_world = [matrix_world @ Vector(v) for v in obj.bound_box]
        objects.append((obj, bb_world))

    if not objects:
        return False

    for obj, bb_world in objects:

        if bb_quality and obj.type == 'MESH':
            GBB = worldspace_bounds_from_object_data(depsgraph, obj)
        else:
            GBB = worldspace_bounds_from_object_bounds(bb_world)

        Left_Front_Up = GBB[0]
        Right_Back_Down = GBB[1]

        # Active Center

        if obj == context.active_object:

            center_active_x = (Left_Front_Up[0] + Right_Back_Down[0]) / 2.0
            center_active_y = (Left_Front_Up[1] + Right_Back_Down[1]) / 2.0
            center_active_z = (Left_Front_Up[2] + Right_Back_Down[2]) / 2.0

            size_active_x = (Right_Back_Down[0] - Left_Front_Up[0]) / 2.0
            size_active_y = (Right_Back_Down[1] - Left_Front_Up[1]) / 2.0
            size_active_z = (Left_Front_Up[2] - Right_Back_Down[2]) / 2.0

        # Selection Center

        if flag_first:
            flag_first = False

            Left_Front_Up_SEL[0] = Left_Front_Up[0]
            Left_Front_Up_SEL[1] = Left_Front_Up[1]
            Left_Front_Up_SEL[2] = Left_Front_Up[2]

            Right_Back_Down_SEL[0] = Right_Back_Down[0]
            Right_Back_Down_SEL[1] = Right_Back_Down[1]
            Right_Back_Down_SEL[2] = Right_Back_Down[2]

        else:
            # X axis
            if Left_Front_Up[0] < Left_Front_Up_SEL[0]:
                Left_Front_Up_SEL[0] = Left_Front_Up[0]
            # Y axis
            if Left_Front_Up[1] < Left_Front_Up_SEL[1]:
                Left_Front_Up_SEL[1] = Left_Front_Up[1]
            # Z axis
            if Left_Front_Up[2] > Left_Front_Up_SEL[2]:
                Left_Front_Up_SEL[2] = Left_Front_Up[2]

            # X axis
            if Right_Back_Down[0] > Right_Back_Down_SEL[0]:
                Right_Back_Down_SEL[0] = Right_Back_Down[0]
            # Y axis
            if Right_Back_Down[1] > Right_Back_Down_SEL[1]:
                Right_Back_Down_SEL[1] = Right_Back_Down[1]
            # Z axis
            if Right_Back_Down[2] < Right_Back_Down_SEL[2]:
                Right_Back_Down_SEL[2] = Right_Back_Down[2]

    center_sel_x = (Left_Front_Up_SEL[0] + Right_Back_Down_SEL[0]) / 2.0
    center_sel_y = (Left_Front_Up_SEL[1] + Right_Back_Down_SEL[1]) / 2.0
    center_sel_z = (Left_Front_Up_SEL[2] + Right_Back_Down_SEL[2]) / 2.0

    # Main Loop

    for obj, bb_world in objects:
        matrix_world = obj.matrix_world.copy()
        bb_world = [matrix_world @ Vector(v[:]) for v in obj.bound_box]

        if bb_quality and obj.type == 'MESH':
            GBB = worldspace_bounds_from_object_data(depsgraph, obj)
        else:
            GBB = worldspace_bounds_from_object_bounds(bb_world)

        Left_Front_Up = GBB[0]
        Right_Back_Down = GBB[1]

        center_x = (Left_Front_Up[0] + Right_Back_Down[0]) / 2.0
        center_y = (Left_Front_Up[1] + Right_Back_Down[1]) / 2.0
        center_z = (Left_Front_Up[2] + Right_Back_Down[2]) / 2.0

        positive_x = Right_Back_Down[0]
        positive_y = Right_Back_Down[1]
        positive_z = Left_Front_Up[2]

        negative_x = Left_Front_Up[0]
        negative_y = Left_Front_Up[1]
        negative_z = Right_Back_Down[2]

        obj_loc = obj.location

        if align_x:

            # Align Mode

            if relative_to == 'OPT_4':  # Active relative
                if align_mode == 'OPT_1':
                    obj_x = obj_loc[0] - negative_x - size_active_x

                elif align_mode == 'OPT_3':
                    obj_x = obj_loc[0] - positive_x + size_active_x

            else:  # Everything else relative
                if align_mode == 'OPT_1':
                    obj_x = obj_loc[0] - negative_x

                elif align_mode == 'OPT_3':
                    obj_x = obj_loc[0] - positive_x

            if align_mode == 'OPT_2':  # All relative
                obj_x = obj_loc[0] - center_x

            # Relative To

            if relative_to == 'OPT_1':
                loc_x = obj_x

            elif relative_to == 'OPT_2':
                loc_x = obj_x + cursor[0]

            elif relative_to == 'OPT_3':
                loc_x = obj_x + center_sel_x

            elif relative_to == 'OPT_4':
                loc_x = obj_x + center_active_x

            obj.location[0] = loc_x

        if align_y:
            # Align Mode

            if relative_to == 'OPT_4':  # Active relative
                if align_mode == 'OPT_1':
                    obj_y = obj_loc[1] - negative_y - size_active_y

                elif align_mode == 'OPT_3':
                    obj_y = obj_loc[1] - positive_y + size_active_y

            else:  # Everything else relative
                if align_mode == 'OPT_1':
                    obj_y = obj_loc[1] - negative_y

                elif align_mode == 'OPT_3':
                    obj_y = obj_loc[1] - positive_y

            if align_mode == 'OPT_2':  # All relative
                obj_y = obj_loc[1] - center_y

            # Relative To

            if relative_to == 'OPT_1':
                loc_y = obj_y

            elif relative_to == 'OPT_2':
                loc_y = obj_y + cursor[1]

            elif relative_to == 'OPT_3':
                loc_y = obj_y + center_sel_y

            elif relative_to == 'OPT_4':
                loc_y = obj_y + center_active_y

            obj.location[1] = loc_y

        if align_z:
            # Align Mode
            if relative_to == 'OPT_4':  # Active relative
                if align_mode == 'OPT_1':
                    obj_z = obj_loc[2] - negative_z - size_active_z

                elif align_mode == 'OPT_3':
                    obj_z = obj_loc[2] - positive_z + size_active_z

            else:  # Everything else relative
                if align_mode == 'OPT_1':
                    obj_z = obj_loc[2] - negative_z

                elif align_mode == 'OPT_3':
                    obj_z = obj_loc[2] - positive_z

            if align_mode == 'OPT_2':  # All relative
                obj_z = obj_loc[2] - center_z

            # Relative To

            if relative_to == 'OPT_1':
                loc_z = obj_z

            elif relative_to == 'OPT_2':
                loc_z = obj_z + cursor[2]

            elif relative_to == 'OPT_3':
                loc_z = obj_z + center_sel_z

            elif relative_to == 'OPT_4':
                loc_z = obj_z + center_active_z

            obj.location[2] = loc_z

    return True


from bpy.props import (
    BoolProperty,
    EnumProperty,
)


class AlignObjects(Operator):
    """Align objects"""
    bl_idname = "object.align"
    bl_label = "Align Objects"
    bl_options = {'REGISTER', 'UNDO'}

    bb_quality: BoolProperty(
        name="High Quality",
        description=(
            "Enables high quality but slow calculation of the "
            "bounding box for perfect results on complex "
            "shape meshes with rotation/scale"
        ),
        default=True,
    )
    align_mode: EnumProperty(
        name="Align Mode",
        description="Side of object to use for alignment",
        items=(
            ('OPT_1', "Negative Sides", ""),
            ('OPT_2', "Centers", ""),
            ('OPT_3', "Positive Sides", ""),
        ),
        default='OPT_2',
    )
    relative_to: EnumProperty(
        name="Relative To",
        description="Reference location to align to",
        items=(
            ('OPT_1', "Scene Origin", "Use the scene origin as the position for the selected objects to align to"),
            ('OPT_2', "3D Cursor", "Use the 3D cursor as the position for the selected objects to align to"),
            ('OPT_3', "Selection", "Use the selected objects as the position for the selected objects to align to"),
            ('OPT_4', "Active", "Use the active object as the position for the selected objects to align to"),
        ),
        default='OPT_4',
    )
    align_axis: EnumProperty(
        name="Align",
        description="Align to axis",
        items=(
            ('X', "X", ""),
            ('Y', "Y", ""),
            ('Z', "Z", ""),
        ),
        options={'ENUM_FLAG'},
    )

    @classmethod
    def poll(cls, context):
        return context.mode == 'OBJECT'

    def execute(self, context):
        align_axis = self.align_axis
        ret = align_objects(
            context,
            'X' in align_axis,
            'Y' in align_axis,
            'Z' in align_axis,
            self.align_mode,
            self.relative_to,
            self.bb_quality,
        )

        if not ret:
            self.report({'WARNING'}, "No objects with bound-box selected")
            return {'CANCELLED'}
        else:
            return {'FINISHED'}


classes = (
    AlignObjects,
)