#  reportpanel.py
#
#  (c) 2017,2021 Michel Anders
#
#  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 3 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.


import bpy
from bpy.props import FloatProperty, StringProperty
from bpy.types import Scene
from time import sleep

bl_info = {
    "name": "Report Panel",
    "author": "Michel Anders (varkenvarken)",
    "version": (0, 0, 202105091029),
    "blender": (2, 92, 0),
    "location": "Info header",
    "description": "Puts a progress indicator the view3d header region",
    "warning": "",
    "wiki_url": "",
    "tracker_url": "",
    "category": "Sample scripts"}

# a regular operator. will NOT work without a hack
# it is better to use a modal operator  when doing
# time consuming things

class TestProgress(bpy.types.Operator):
    bl_idname = 'scene.testprogress'
    bl_label = 'Test Progress'
    bl_options = {'REGISTER'}

    def execute(self, context):
        context.scene.progress_indicator_text = "Heavy job"
        context.scene.progress_indicator = 0
        for tick in range(10):
            sleep(1) # placeholder for heavy work
            context.scene.progress_indicator = tick*10
            # see https://docs.blender.org/api/current/info_gotcha.html
            bpy.ops.wm.redraw_timer(type='DRAW_WIN_SWAP', iterations=1)

        context.scene.progress_indicator = 101 # done
        return {"FINISHED"}

class TestProgressModal(bpy.types.Operator):
    bl_idname = 'scene.testprogressmodal'
    bl_label = 'Test Progress Modal'
    bl_options = {'REGISTER'}

    def modal(self, context, event):
        if event.type == 'TIMER':
            self.ticks += 1
        if self.ticks > 9:
            context.scene.progress_indicator = 101 # done
            context.window_manager.event_timer_remove(self.timer)
            return {'CANCELLED'}

        context.scene.progress_indicator = self.ticks*10

        return {'RUNNING_MODAL'}

    def invoke(self, context, event):
        self.ticks = 0
        context.scene.progress_indicator_text = "Heavy modal job"
        context.scene.progress_indicator = 0
        wm = context.window_manager
        self.timer = wm.event_timer_add(1.0, window=context.window)
        wm.modal_handler_add(self)
        return {'RUNNING_MODAL'}

def menu_func(self, context):
    self.layout.operator(TestProgress.bl_idname)
    self.layout.operator(TestProgressModal.bl_idname)

# update function to tag all info areas for redraw
def update(self, context):
    print('update')
    areas = context.window.screen.areas
    for area in areas:
        if area.type == 'VIEW_3D':
            area.tag_redraw()

# a variable where we can store the original draw funtion
info_header_draw = lambda s,c: None

classes = [TestProgress, TestProgressModal]

register_classes, unregister_classes = bpy.utils.register_classes_factory(classes)

def register():
    # a value between [0,100] will show the slider
    Scene.progress_indicator = FloatProperty(
                                    default=-1,
                                    subtype='PERCENTAGE',
                                    precision=1,
                                    min=-1,
                                    soft_min=0,
                                    soft_max=100,
                                    max=101,
                                    update=update)

    # the label in front of the slider can be configured
    Scene.progress_indicator_text = StringProperty(
                                    default="Progress",
                                    update=update)

    # save the original draw method of the Info header
    global info_header_draw
    info_header_draw = bpy.types.VIEW3D_HT_tool_header.draw

    # create a new draw function
    def newdraw(self, context):
        global info_header_draw
        # first call the original stuff
        info_header_draw(self, context)
        print('newdraw')
        # then add the prop that acts as a progress indicator
        if (context.scene.progress_indicator >= 0 and
            context.scene.progress_indicator <= 100) :
            self.layout.separator()
            text = context.scene.progress_indicator_text
            self.layout.prop(context.scene,
                                "progress_indicator",
                                text=text,
                                slider=True)

    # replace it
    bpy.types.VIEW3D_HT_tool_header.draw = newdraw

    # regular registration stuff
    register_classes()
    bpy.types.VIEW3D_MT_object.append(menu_func)


def unregister():
    bpy.types.VIEW3D_MT_object.remove(menu_func)
    global info_header_draw
    bpy.types.VIEW3D_HT_tool_header.draw = info_header_draw
    unregister_classes()