import bpy
from bpy.props import (StringProperty,
                       BoolProperty,
                       EnumProperty,
                       IntProperty,
                       FloatProperty,
                       CollectionProperty)
from bpy.types import Operator
from bpy_extras.io_utils import ImportHelper, ExportHelper
from io_scene_gltf2 import ConvertGLTF2_Base 
from .common import Font

# taken from blender_git/blender/scripts/addons/io_scene_gltf2/__init__.py 

def get_font_faces_in_file(filepath):
    from io_scene_gltf2.io.imp.gltf2_io_gltf import glTFImporter, ImportError
    
    try:
        import_settings = { 'import_user_extensions': [] }
        gltf_importer = glTFImporter(filepath, import_settings)
        gltf_importer.read()
        gltf_importer.checks()
        
        out = []
        for node in gltf_importer.data.nodes:
            if type(node.extras) != type(None) \
                    and "glyph" in node.extras \
                    and not ("type" in node.extras and node.extras["type"] is "metrics"):
                out.append(node.extras)
        return out
    
    except ImportError as e:
        return None

# taken from blender_git/blender/scripts/addons/io_scene_gltf2/__init__.py 

class GetFontFacesInFile(Operator, ImportHelper):
    """Load a glTF 2.0 font and check which faces are in there"""
    bl_idname = f"abc3d.check_font_gltf"
    bl_label = 'Check glTF 2.0 Font'
    bl_options = {'REGISTER', 'UNDO'}

    files: CollectionProperty(
        name="File Path",
        type=bpy.types.OperatorFileListElement,
    )

# bpy.ops.abc3d.check_font_gltf(filepath="/home/jrkb/.config/blender/4.1/datafiles/abc3d/fonts/JRKB_LOL.glb")
    found_fonts = []

    def execute(self, context):
        return self.check_gltf2(context)

    def check_gltf2(self, context):
        import os
        import sys

        if self.files:
            # Multiple file check
            ret = {'CANCELLED'}
            dirname = os.path.dirname(self.filepath)
            for file in self.files:
                path = os.path.join(dirname, file.name)
                if self.unit_check(path) == {'FINISHED'}:
                    ret = {'FINISHED'}
            return ret
        else:
            # Single file check
            return self.unit_check(self.filepath)

    def unit_check(self, filename):
        self.found_fonts.append(["LOL","WHATEVER"])
        return {'FINISHED'}

class ImportGLTF2(Operator, ConvertGLTF2_Base, ImportHelper):
    """Load a glTF 2.0 font"""
    bl_idname = f"abc3d.import_font_gltf"
    bl_label = 'Import glTF 2.0 Font'
    bl_options = {'REGISTER', 'UNDO'}

    filter_glob: StringProperty(default="*.glb;*.gltf", options={'HIDDEN'})

    files: CollectionProperty(
        name="File Path",
        type=bpy.types.OperatorFileListElement,
    )

    loglevel: IntProperty(
        name='Log Level',
        description="Log Level")

    import_pack_images: BoolProperty(
        name='Pack Images',
        description='Pack all images into .blend file',
        default=True
    )

    merge_vertices: BoolProperty(
        name='Merge Vertices',
        description=(
            'The glTF format requires discontinuous normals, UVs, and '
            'other vertex attributes to be stored as separate vertices, '
            'as required for rendering on typical graphics hardware. '
            'This option attempts to combine co-located vertices where possible. '
            'Currently cannot combine verts with different normals'
        ),
        default=False,
    )

    import_shading: EnumProperty(
        name="Shading",
        items=(("NORMALS", "Use Normal Data", ""),
               ("FLAT", "Flat Shading", ""),
               ("SMOOTH", "Smooth Shading", "")),
        description="How normals are computed during import",
        default="NORMALS")

    bone_heuristic: EnumProperty(
        name="Bone Dir",
        items=(
            ("BLENDER", "Blender (best for import/export round trip)",
                "Good for re-importing glTFs exported from Blender, "
                "and re-exporting glTFs to glTFs after Blender editing. "
                "Bone tips are placed on their local +Y axis (in glTF space)"),
            ("TEMPERANCE", "Temperance (average)",
                "Decent all-around strategy. "
                "A bone with one child has its tip placed on the local axis "
                "closest to its child"),
            ("FORTUNE", "Fortune (may look better, less accurate)",
                "Might look better than Temperance, but also might have errors. "
                "A bone with one child has its tip placed at its child's root. "
                "Non-uniform scalings may get messed up though, so beware"),
        ),
        description="Heuristic for placing bones. Tries to make bones pretty",
        default="BLENDER",
    )

    guess_original_bind_pose: BoolProperty(
        name='Guess Original Bind Pose',
        description=(
            'Try to guess the original bind pose for skinned meshes from '
            'the inverse bind matrices. '
            'When off, use default/rest pose as bind pose'
        ),
        default=True,
    )

    import_webp_texture: BoolProperty(
        name='Import WebP textures',
        description=(
            "If a texture exists in WebP format, "
            "loads the WebP texture instead of the fallback PNG/JPEG one"
        ),
        default=False,
    )

    glyphs: StringProperty(
        name='Import only these glyphs',
        description=(
            "Loading glyphs is expensive, if the meshes are huge"
            "So we can filter all glyphs out that we do not want"
        ),
        default="A",
    )

    marker_property: StringProperty(
        name="Mark imported objects with this custom property.",
        default="font_import",
    )

    font_name: StringProperty(
        name="If defined, only import this font",
        default="",
    )

    face_name: StringProperty(
        name="If defined, only import this font face",
        default="",
    )

    def draw(self, context):
        layout = self.layout

        layout.use_property_split = True
        layout.use_property_decorate = False  # No animation.

        layout.prop(self, 'import_pack_images')
        layout.prop(self, 'merge_vertices')
        layout.prop(self, 'import_shading')
        layout.prop(self, 'guess_original_bind_pose')
        layout.prop(self, 'bone_heuristic')
        layout.prop(self, 'export_import_convert_lighting_mode')
        layout.prop(self, 'import_webp_texture')

    def invoke(self, context, event):
        import sys
        preferences = bpy.context.preferences
        for addon_name in preferences.addons.keys():
            try:
                if hasattr(sys.modules[addon_name], 'glTF2ImportUserExtension') or hasattr(sys.modules[addon_name], 'glTF2ImportUserExtensions'):
                    importer_extension_panel_unregister_functors.append(sys.modules[addon_name].register_panel())
            except Exception:
                pass

        self.has_active_importer_extensions = len(importer_extension_panel_unregister_functors) > 0
        return ImportHelper.invoke(self, context, event)

    def execute(self, context):
        return self.import_gltf2(context)

    def import_gltf2(self, context):
        import os

        self.set_debug_log()
        import_settings = self.as_keywords()

        user_extensions = []

        import sys
        preferences = bpy.context.preferences
        for addon_name in preferences.addons.keys():
            try:
                module = sys.modules[addon_name]
            except Exception:
                continue
            if hasattr(module, 'glTF2ImportUserExtension'):
                extension_ctor = module.glTF2ImportUserExtension
                user_extensions.append(extension_ctor())
        import_settings['import_user_extensions'] = user_extensions

        if self.files:
            # Multiple file import
            ret = {'CANCELLED'}
            dirname = os.path.dirname(self.filepath)
            for file in self.files:
                path = os.path.join(dirname, file.name)
                if self.unit_import(path, import_settings) == {'FINISHED'}:
                    ret = {'FINISHED'}
            return ret
        else:
            # Single file import
            return self.unit_import(self.filepath, import_settings)

    def unit_import(self, filename, import_settings):
        import time
        from io_scene_gltf2.io.imp.gltf2_io_gltf import glTFImporter, ImportError
        from io_scene_gltf2.blender.imp.gltf2_blender_gltf import BlenderGlTF
        from io_scene_gltf2.blender.imp.gltf2_blender_vnode import VNode, compute_vnodes
        from io_scene_gltf2.blender.com.gltf2_blender_extras import set_extras
        from io_scene_gltf2.blender.imp.gltf2_blender_node import BlenderNode

        try:
            gltf = glTFImporter(filename, import_settings)
            gltf.read()
            gltf.checks()

            # start filtering glyphs like this:
            # - collect indices of nodes that contain our glyphs
            # - collect indices of their meshes
            # - collect the node's parent tree
            # - use these indices to create new lists of nodes and meshes
            # - update the scene tree to contain only our nodes
            # - replace the node and mesh list with ours

            # indices of meshes to keep
            mesh_indices = []
            # indices of nodes to keep
            node_indices = []

            # convenience function to add a node to the indices
            def add_node(node, recursive=True):
                node_index = gltf.data.nodes.index(node)
                if node_index not in node_indices:
                    node_indices.append(node_index)
                if type(node.mesh) != type(None) and node.mesh >= 0:
                    mesh_index = node.mesh
                    if mesh_index not in mesh_indices:
                        mesh_indices.append(mesh_index)
                if recursive and type(node.children) != type(None):
                    for c in node.children:
                        child = gltf.data.nodes[c]
                        add_node(child)

            # convenience function to add a mesh to the indices
            def add_parent_node(node, recursive=True):
                index = gltf.data.nodes.index(node)
                for parent in gltf.data.nodes:
                    if type(parent.children) != type(None) and index in parent.children:
                        add_node(parent, False)
                        if recursive:
                            add_parent_node(parent)

            # populate our node_indices and mesh_indices
            # by iterating through the nodes and check if they are
            # indeed representing a glyph we want
            for node in gltf.data.nodes:
                # :-O woah
                if type(node.extras) != type(None) \
                        and "glyph" in node.extras \
                        and (node.extras["glyph"] in self.glyphs \
                            or len(self.glyphs) == 0) \
                        and (self.font_name == "" or \
                            ( "font_name" in node.extras \
                            and (node.extras["font_name"] in self.font_name \
                                or len(self.glyphs) == 0))) \
                        and (self.face_name == "" or \
                            ( "face_name" in node.extras \
                            and (node.extras["face_name"] in self.face_name \
                                or len(self.glyphs) == 0))):
                    # if there is a match, add the node incl children ..
                    add_node(node)
                    # .. and their parents recursively
                    add_parent_node(node)

            # in the end we need the objects, not the indices
            # so let's prepare empy lists
            meshes = []
            nodes = []

            # the indices will be off, as we have fewer elements
            # so let's have a lookup table
            mesh_index_table = {}
            node_index_table = {}

            # first, add all meshes and fill in lookup table
            for mesh_index, mesh in enumerate(gltf.data.meshes):
                if mesh_index in mesh_indices:
                    meshes.append(mesh)
                    mesh_index_table[mesh_index] = len(meshes) - 1

            # second, add all nodes and fill in lookup table
            # nodes also refer to their meshes
            for node_index, node in enumerate(gltf.data.nodes):
                if node_index in node_indices:
                    if type(node.mesh) != type(None):
                        node.mesh = mesh_index_table[node.mesh]
                    nodes.append(node)
                    node_index_table[node_index] = len(nodes) - 1

            # the indices to children are messed up.
            # some children are lost :(
            # and some have different indices
            for node in nodes:
                if type(node.children) != type(None):
                    children = [] # brand new children
                    for i, c in enumerate(node.children):
                        # check if children are lost
                        if c in node_indices:
                            children.append(node_index_table[c])
                    # now replace old children with the new, however
                    # if we don't have children, we don't even need a list!
                    node.children = None if len(children) == 0 else children

            # last step, kick nodes out of the scene tree if they're lost
            for s in gltf.data.scenes:
                scene_nodes = []
                for n in s.nodes:
                    if n in node_indices:
                        scene_nodes.append(node_index_table[n])
                s.nodes = scene_nodes

            # very last step, replace nodes and meshes
            gltf.data.nodes = nodes
            gltf.data.meshes = meshes

            # that's fucking it, we're done!
            # hand over back to default blender behaviour :-)
            # or.. not! blender will do some funny scene stuff
            # which we don't want.
            # so let's do it quick

            print("Data are loaded, start creating Blender stuff")

            start_time = time.time()
            # first, convert gltf to blender
            BlenderGlTF.set_convert_functions(gltf)
            # compute things
            BlenderGlTF.pre_compute(gltf)
            compute_vnodes(gltf)

            # apparently we need a scene, because
            # when creating the objects, it will link the objects here
            gltf.blender_scene = bpy.context.scene.name

            def create_blender_object(gltf, vi, nodes):
                vnode = gltf.vnodes[vi]
                if vnode.type == VNode.Object:
                    if vnode.parent is not None:
                        if not hasattr(gltf.vnodes[vnode.parent],
                                       "blender_object"):
                            create_blender_object(gltf,
                                                  vnode.parent,
                                                  nodes)
                    if not hasattr(vnode,
                                   "blender_object"):
                        obj = BlenderNode.create_object(gltf, vi)
                        obj["font_import"] = True
                        n_vars = vars(nodes[vi])
                        if "extras" in n_vars:
                            set_extras(obj, n_vars["extras"])
                            if "glyph" in n_vars["extras"] and \
                                    not ("type" in n_vars["extras"] and \
                                    n_vars["extras"]["type"] == "metrics"):
                                obj["type"] = "glyph"

            for vi, vnode in gltf.vnodes.items():
                create_blender_object(gltf, vi, nodes)

            elapsed_s = "{:.2f}s".format(time.time() - start_time)
            print("font import gltf finished in " + elapsed_s)

            gltf.log.removeHandler(gltf.log_handler)

            return {'FINISHED'}

        except ImportError as e:
            self.report({'ERROR'}, e.args[0])
            return {'CANCELLED'}

    def set_debug_log(self):
        import logging
        if bpy.app.debug_value == 0:
            self.loglevel = logging.CRITICAL
        elif bpy.app.debug_value == 1:
            self.loglevel = logging.ERROR
        elif bpy.app.debug_value == 2:
            self.loglevel = logging.WARNING
        elif bpy.app.debug_value == 3:
            self.loglevel = logging.INFO
        else:
            self.loglevel = logging.NOTSET