import bpy
from bpy.types import Operator
from . import utils


def get_layer_list(self, context):
    '''return (identifier, name, description) of enum content'''
    if not context:
        return [('None', 'None','None')]
    if not context.object:
        return [('None', 'None','None')]
    return [(l.name, l.name, '') for l in context.object.data.layers if l != context.object.data.layers.active]
    # try:
    # except:
    #     return [("", "", "")]
    # return [(i, basename(i), "") for i in blends]
    # return [(i.path, basename(i.path), "") for i in self.blends]

class GPTB_OT_duplicate_send_to_layer(Operator) :
    bl_idname = "gp.duplicate_send_to_layer"
    bl_label = 'Duplicate Send To Layer'
    bl_description = 'Duplicate selected keys in active layer and send to chosen layer'
    # important to have the updated enum here as bl_property
    bl_property = "layers_enum"

    layers_enum : bpy.props.EnumProperty(
        name="Duplicate to layers",
        description="Duplicate selected keys in active layer and send them to chosen layer",
        items=get_layer_list,
        options={'HIDDEN'},
        )

    delete_source : bpy.props.BoolProperty(default=False, options={'SKIP_SAVE'})

    @classmethod
    def description(cls, context, properties):
        if properties.delete_source:
            return f"Move selected keys in active layer to chosen layer"
        else:
            return f"Copy selected keys in active layer and send to chosen layer"

    @classmethod
    def poll(cls, context):
        return context.object and context.object.type == 'GREASEPENCIL'\
            and context.space_data.bl_rna.identifier == 'SpaceDopeSheetEditor' and context.space_data.ui_mode == 'GPENCIL'

    # history : bpy.props.StringProperty(default='', options={'SKIP_SAVE'}) # need to have a variable to store (to get it in self)

    def execute(self, context):
        target_layer = self.layers_enum
        if not target_layer:
            self.report({'WARNING'}, 'Target layer not specified')
            return {'CANCELLED'}

        gpl = context.object.data.layers
        target_layer = gpl.get(target_layer)
        
        act_layer = gpl.active
        selected_frames = [f for f in act_layer.frames if f.select]
        
        act_frame_num = [f.frame_number for f in act_layer.frames if f.select]

        to_replace = [f for f in target_layer.frames if f.frame_number in act_frame_num]
        
        replaced = len(to_replace)
        
        ## Remove overlapping frames
        for f in reversed(to_replace):
            target_layer.frames.remove(f.frame_number)

        ## Copy original frames
        for f in selected_frames:
            utils.copy_frame_at(f, target_layer, f.frame_number)
            # target_layer.frames.copy(f) # GPv2
        sent = len(selected_frames)

        ## Delete original frames as an option
        if self.delete_source:
            for f in reversed(selected_frames):
                act_layer.frames.remove(f.frame_number)
            mess = f'{sent} keys moved'
        else:
            mess = f'{sent} keys copied'

        if replaced:
            mess += f' ({replaced} replaced)'
        
        self.report({'INFO'}, mess)
        return {'FINISHED'}

    def invoke(self, context, event):
        gp = context.object.data
        if not len(gp.layers):
            self.report({'WARNING'}, 'No layers on current GP object')
            return {'CANCELLED'}
        
        active = gp.layers.active

        if not active:
            self.report({'WARNING'}, 'No active layer to take keys from')
            return {'CANCELLED'}
        
        self.selected_frames = [f for f in active.frames if f.select]

        if not self.selected_frames:
            self.report({'WARNING'}, 'No selected keys in active layer')
            return {'CANCELLED'}
        
        wm = context.window_manager
        wm.invoke_search_popup(self) # can't specify size... width=500, height=600
        return {'FINISHED'}


addon_keymaps = []
def register_keymaps():
    addon = bpy.context.window_manager.keyconfigs.addon
    km = addon.keymaps.new(name = "Dopesheet", space_type = "DOPESHEET_EDITOR")
    kmi = km.keymap_items.new('gp.duplicate_send_to_layer', type='D', value="PRESS", ctrl=True, shift=True)
    addon_keymaps.append((km,kmi))
    
    # km = addon.keymaps.new(name = "Dopesheet", space_type = "DOPESHEET_EDITOR") # try duplicating km (seem to be error at unregsiter)
    kmi = km.keymap_items.new('gp.duplicate_send_to_layer', type='X', value="PRESS", ctrl=True, shift=True)
    kmi.properties.delete_source = True
    addon_keymaps.append((km,kmi))


def unregister_keymaps():
    for km, kmi in addon_keymaps:
        km.keymap_items.remove(kmi)
    addon_keymaps.clear()


def menu_duplicate_and_send_to_layer(self, context):
    if context.space_data.ui_mode == 'GPENCIL':
        self.layout.operator_context = 'INVOKE_REGION_WIN'
        self.layout.operator('gp.duplicate_send_to_layer', text='Move Keys To Layer').delete_source = True
        self.layout.operator('gp.duplicate_send_to_layer', text='Copy Keys To Layer')

classes = (
GPTB_OT_duplicate_send_to_layer,
)

def register():
    if bpy.app.background:
        return

    for cls in classes:
        bpy.utils.register_class(cls)

    register_keymaps()
    bpy.types.DOPESHEET_MT_key.append(menu_duplicate_and_send_to_layer)
    bpy.types.DOPESHEET_MT_context_menu.append(menu_duplicate_and_send_to_layer)


def unregister():
    if bpy.app.background:
        return

    bpy.types.DOPESHEET_MT_context_menu.remove(menu_duplicate_and_send_to_layer)
    bpy.types.DOPESHEET_MT_key.remove(menu_duplicate_and_send_to_layer)
    unregister_keymaps()

    for cls in reversed(classes):
        bpy.utils.unregister_class(cls)