from . import gds 

import importlib
if "gds" in locals():
    gds = importlib.reload(gds)

import pathlib
import bpy
from bpy_extras.wm_utils.progress_report import ProgressReport

class Progressor:
    def __init__(self, wm, precision = 0.0001):
        self.wm = wm
        self.report = 0
        self.precision = precision
        self.next_update = 0

    @property
    def total(self):
        return self.report
    
    @total.setter
    def total(self, t):
        if self.report >= t:
            return

        if self.report:
            self.wm.progress_end()
            self.next_update = 0

        self.wm.progress_begin(0, t)
        self.report = t

        print ("begin new report , total {}".format(t))

    @property
    def current(self):
        return 0

    @current.setter
    def current(self, c):
        prog = float(c)/self.total
        if prog >= self.next_update:
            self.next_update = prog + self.precision
            self.wm.progress_update(c)

    def end(self):
        if self.report:
            self.report = 0
            self.next_update = 0 

            self.wm.progress_end()

    def __call__(self, update):
        self.total = update.total
        self.current = update.current

class SceneInserter(object):    
    class Layer(object):
        def __init__(self, context, number):
            self.name = "layer{}".format(number)
            
            if self.name not in bpy.data.groups:
                # create new group
                self.group = bpy.data.groups.new(self.name)
                self.name = self.group.name
            else:
                self.group = bpy.data.groups[self.name]

        def link(self, obj):
            self.group.objects.link(obj)

    def __init__(self, context, lib, ignore_structures={}, top_cell=None):
            self.lib = lib
            self.context = context

            self.layers = {}
            self.ignore_structures = {}
            
            self.top_cell = top_cell
            if top_cell == "":
                self.top_cell = None
                
            if self.top_cell:
                self.top_cell = self.top_cell.strip()
                return

            for sname in ignore_structures:
                if sname in lib.structures:
                    self.ignore_structures[sname] = True

        
    def new_empty(self, name):
        obj = bpy.data.objects.new(name, None)
        self.link(obj)
        return obj

    def link(self, obj):
        self.context.scene.objects.link(obj)

    def build_object(self, structure):
        # is the object already existent => return new instance
        if structure.name in bpy.data.objects:
            return self.new_instance(bpy.data.objects[structure.name])

        verts = {} 
        faces = {}

        # create control empty
        root = self.new_empty(structure.name)

        # reset name in case blender 
        # changes the object name
        # (e.g. due to duplicates)
        structure.name = root.name

        #print("structure name: {}".format(structure.name))

        # add all geometry
        for element in structure.elements:
            if isinstance(element, gds.Boundary):
                if element.layer not in faces:
                    verts[element.layer] = []
                    faces[element.layer] = []

                indices = []
                for point in element.points[:-1]:
                    pos = self.lib.normalize_coord(point)
                    verts[element.layer].append((pos[0], pos[1], 0))

                    indices.append(len(verts[element.layer])-1)

                faces[element.layer].append(tuple(indices))
        
        # build structure mesh objects
        # create mesh object for each layer
        for layer in verts.keys():
            if layer not in self.layers:
                self.layers[layer] = SceneInserter.Layer(self.context, layer)

            meshname = "{}[{}]".format(structure.name, layer)

            mesh = bpy.data.meshes.new(meshname)
            mesh.from_pydata(verts[layer], [], faces[layer])
            mesh.update()

            obj = bpy.data.objects.new(meshname, mesh)
            self.link(obj)
            self.layers[layer].link(obj)
            obj.parent = root

        # handle all references
        # build tree depth first
        for reference in structure.references:
            obj = self.build_object(reference.structure)
                
            if hasattr(reference, "size"):
                def add(a,b):
                    return (a[0] + b[0], a[1] + b[1])
                def inv(a):
                    return (-a[0], -a[1])

                def sub(a, b):
                    return add(inv(a), b)
                def scale(a, f):
                    return (a[0] * f, a[1] * f)

                vx = sub(reference.bounds[0], reference.position)
                vy = sub(reference.bounds[1], reference.position)
                
                xspace = 1.0/reference.size[0]
                yspace = 1.0/reference.size[1]

                master = obj
                obj = self.new_empty(reference.structure.name)
                master.parent = obj
                master.location = (0,0,0)

                # this is an aref, create object array
                for i in range(0, reference.size[0]):
                    for j in range(0, reference.size[1]):
                        if i == 0 and j == 0:
                            continue
                        
                        # calc new pos
                        iobj = self.new_instance(master)

                        pos = add(scale(vy, j*yspace), scale(vx, i*xspace))
                        loc = self.lib.normalize_coord(pos)
                        
                        iobj.location = (loc[0], loc[1], 0)
                        iobj.hide = True
            else:
                # this is a single reference
                # just copy the object
                pass

            # use single arrow for references
            obj.empty_draw_type = "SINGLE_ARROW"
            
            # reparent new instance
            obj.parent = root

            pos = self.lib.normalize_coord(reference.position)
            obj.location = (pos[0], pos[1], 0)

            # apply transformations
            trans = reference.transformation
            obj.rotation_euler.z = math.radians(trans.rotation)
            obj.scale = (trans.zoom, trans.zoom, 1)

        return root

    def new_instance(self, obj):
        root = obj.copy()
        self.link(root)

        for child in obj.children:
            childObj = child.copy()
            self.link(childObj)

            childObj.parent = root

            # relink copy to groups
            for group in child.users_group:
                group.objects.link(childObj)

        return root

    
    def __call__(self, progress=None):
        class ProgressTracker:
            def __init__(self, total, callback):
                self.total = total
                self.current = 0
                self.callback = callback
            
            def inc(self):
                if self.callback:
                    self.current += 1
                    self.callback(self)

        
        # build one cell only
        if self.top_cell:
            if self.top_cell not in self.lib.structures:
                return None
            
            self.build_object(self.lib.structures[self.top_cell])
            return True

        # build all structures in object
        progressTracker = ProgressTracker(2*(len(self.lib.structures)-len(self.ignore_structures)), progress)
        # build all structures first
        # since references could reference unknown objects otherwise
        for name, value in self.lib.structures.items():
            progressTracker.inc()
            if name in self.ignore_structures:
                continue

            self.build_object(value)
            progressTracker.total += len(value.references)
            
            
        return True
                
import math

def load(context,
         filepath,
         *,
         top_cell_name=""
         ):

    path = pathlib.Path(filepath)
    lib = None
    print(lib)

    with ProgressReport(context.window_manager) as progress:
        progress.enter_substeps(2, "Importing GDS %r..." % filepath)
        prog = Progressor(context.window_manager)
        with open(filepath, "rb") as f:
            lib = gds.parse_file(f, progress_func=prog)
    
        progress.step("linking references")
        prog.end()

        lib.link_refs(prog)

        progress.step("inserting structures into scene")
        prog.end()

        if not SceneInserter(context=context, lib=lib, top_cell=top_cell_name)(prog):
            return {"CANCELLED"}

        progress.leave_substeps("Done")
        prog.end()    

        context.scene.update()
        

    return {"FINISHED"}