#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU General Public License
#  as published by the Free Software Foundation; either version 2
#  of the License, or (at your option) any later version.
#
#  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 General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software Foundation,
#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
"""
Display Active Image Node on Image Editor

When selecting an Image node, it will show it on the Image editor (if
there is any available). If you don't like this behavior, you can
disable it from the Amaranth Toolset panel on the Scene properties.
Coded by the awesome Sergey Sharybin. This feature only works on Blender
2.68 and newer. Select an Image Node in the Compositor or Cycles nodes
editor, there must be at least one image editor available.
"""

import bpy


KEYMAPS = list()

image_nodes = ("CompositorNodeRLayers",
               "CompositorNodeImage",
               "CompositorNodeViewer",
               "CompositorNodeComposite",
               "ShaderNodeTexImage",
               "ShaderNodeTexEnvironment")


class AMTH_NODE_OT_show_active_node_image(bpy.types.Operator):
    """Show active image node image in the image editor"""
    bl_idname = "node.show_active_node_image"
    bl_label = "Show Active Node Node"
    bl_options = {"UNDO"}

    def execute(self, context):
        return {'FINISHED'}

    def invoke(self, context, event):
        mlocx = event.mouse_region_x
        mlocy = event.mouse_region_y
        select_node = bpy.ops.node.select(mouse_x=mlocx, mouse_y=mlocy, extend=False)

        if 'FINISHED' in select_node:  # Only run if we're clicking on a node
            get_addon = "amaranth" in context.preferences.addons.keys()
            if not get_addon:
                return {"CANCELLED"}

            preferences = context.preferences.addons["amaranth"].preferences
            if preferences.use_image_node_display:
                if context.active_node:
                    active_node = context.active_node

                    if active_node.bl_idname in image_nodes:
                        # Use largest image editor
                        area = None
                        area_size = 0
                        for a in context.screen.areas:
                            if a.type == "IMAGE_EDITOR":
                                size = a.width * a.height
                                if size > area_size:
                                    area_size = size
                                    area = a
                        if area:
                            for space in area.spaces:
                                if space.type == "IMAGE_EDITOR":
                                    if active_node.bl_idname == "CompositorNodeViewer":
                                        space.image = bpy.data.images[
                                            "Viewer Node"]
                                    elif active_node.bl_idname in ["CompositorNodeComposite", "CompositorNodeRLayers"]:
                                        space.image = bpy.data.images[
                                            "Render Result"]
                                    elif active_node.image:
                                        space.image = active_node.image
                                break
                        else:
                            return {'CANCELLED'}

            return {"FINISHED"}
        else:
            return {"PASS_THROUGH"}


def register():
    bpy.utils.register_class(AMTH_NODE_OT_show_active_node_image)
    kc = bpy.context.window_manager.keyconfigs.addon
    km = kc.keymaps.new(name="Node Editor", space_type="NODE_EDITOR")
    kmi = km.keymap_items.new("node.show_active_node_image",
                              "LEFTMOUSE", "DOUBLE_CLICK")
    KEYMAPS.append((km, kmi))


def unregister():
    bpy.utils.unregister_class(AMTH_NODE_OT_show_active_node_image)
    for km, kmi in KEYMAPS:
        km.keymap_items.remove(kmi)
    KEYMAPS.clear()