import bpy
import os


def silence_puresky():
    removed = 0
    for handler_list in [bpy.app.handlers.depsgraph_update_pre,
                         bpy.app.handlers.depsgraph_update_post]:
        for h in handler_list[:]:
            if "puresky" in str(h).lower() or "PureSky" in str(h):
                try:
                    handler_list.remove(h)
                    removed += 1
                except Exception:
                    pass
    return removed


def _snapshot_fragile_sockets(obj, mod, iface):
    """Snapshot Material/Object sockets before modifying any override."""
    FRAGILE_TYPES = {'NodeSocketMaterial', 'NodeSocketObject'}
    snapshot = {}
    for item in iface.items_tree:
        if item.item_type != 'SOCKET' or item.in_out != 'INPUT':
            continue
        if item.socket_type not in FRAGILE_TYPES:
            continue
        sid = item.identifier
        if sid in mod and mod[sid] is not None:
            snapshot[sid] = mod[sid]
            # Debug output to verify we grab the material
            # print(f"  [SNAPSHOT] {obj.name} -> {item.name}: {mod[sid]}")
    return snapshot


def _restore_fragile_sockets(mod, snapshot):
    """Restore Material/Object sockets that got wiped by override re-eval."""
    restored = 0
    for sid, value in snapshot.items():
        current = mod[sid] if sid in mod else None
        # Force restore if the current value no longer matches our snapshot
        if current != value:
            try:
                mod[sid] = value
                restored += 1
            except Exception as e:
                print(f"  [RESTORE FAILED] {sid}: {e}")
    return restored


def fix_lib_overrides():
    fixed = 0
    for obj in bpy.data.objects:
        if not obj.modifiers:
            continue
        for mod in obj.modifiers:
            if mod.type != 'NODES' or not mod.node_group:
                continue
            if not hasattr(mod.node_group, 'interface'):
                continue

            ng = mod.node_group
            iface = getattr(ng, 'interface', None)
            if not iface or not hasattr(iface, 'items_tree'):
                continue

            # Snapshot fragile sockets BEFORE any writes
            snapshot = _snapshot_fragile_sockets(obj, mod, iface)

            name_to_sid = {}
            for item in iface.items_tree:
                if item.item_type == 'SOCKET' and item.in_out == 'INPUT':
                    name_to_sid[item.name] = (item.identifier, item.socket_type)

            for item in iface.items_tree:
                if item.item_type != 'SOCKET' or item.in_out != 'INPUT':
                    continue
                sid = item.identifier
                if sid not in mod:
                    continue
                stored = mod[sid]
                st = item.socket_type
                tt = type(stored).__name__
                if st == 'NodeSocketBool' and tt == 'int':
                    mod[sid] = bool(stored)
                    fixed += 1
                elif st == 'NodeSocketMenu' and tt == 'int':
                    mod[sid] = int(stored)
                    fixed += 1

            ng_name = ng.name
            if ng_name == "Add Shader v1.0":
                if "Filter by ID" in name_to_sid:
                    sid = name_to_sid["Filter by ID"][0]
                    if mod.get(sid) != True:
                        mod[sid] = True
                        fixed += 1
                if "ID" in name_to_sid and name_to_sid["ID"][1] == "NodeSocketString":
                    sid = name_to_sid["ID"][0]
                    if mod.get(sid) != "Index":
                        mod[sid] = "Index"
                        fixed += 1
            elif ng_name in ["Add Shaders by Index v1.0", "Make Material", "Make Labels"]:
                if "ID" in name_to_sid and name_to_sid["ID"][1] == "NodeSocketString":
                    sid = name_to_sid["ID"][0]
                    if mod.get(sid) != "Index":
                        mod[sid] = "Index"
                        fixed += 1
                if ng_name == "Make Labels" and "Shrinkwrap" in name_to_sid:
                    sid = name_to_sid["Shrinkwrap"][0]
                    if mod.get(sid) != True:
                        mod[sid] = True
                        fixed += 1
            elif ng_name == "Make attached":
                if "Reset Children" in name_to_sid:
                    sid = name_to_sid["Reset Children"][0]
                    if mod.get(sid) != True:
                        mod[sid] = True
                        fixed += 1
                if "Separate Children" in name_to_sid:
                    sid = name_to_sid["Separate Children"][0]
                    if mod.get(sid) != True:
                        mod[sid] = True
                        fixed += 1
            elif ng_name == "Proxy v1.0":
                if "Reset Children" in name_to_sid:
                    sid = name_to_sid["Reset Children"][0]
                    if mod.get(sid) != True:
                        mod[sid] = True
                        fixed += 1

            # Restore any fragile sockets that got wiped
            restored = _restore_fragile_sockets(mod, snapshot)
            if restored:
                print(f"  [RESTORE] {obj.name}/{mod.name}: "
                      f"restored {restored} Material/Object sockets")
            fixed += restored

    return fixed


def fix_missing_images():
    fixed = 0
    for img in bpy.data.images:
        if img.source == 'FILE' and img.filepath:
            if getattr(img, "packed_file", None):
                continue
            abs_path = (bpy.path.abspath(img.filepath, library=img.library)
                        if img.library else bpy.path.abspath(img.filepath))
            if not os.path.exists(abs_path):
                img.source = 'GENERATED'
                img.generated_width = 8
                img.generated_height = 8
                img.generated_type = 'BLANK'
                img.generated_color = (1.0, 0.0, 1.0, 1.0)
                fixed += 1
    return fixed


def init_metal_gpu():
    try:
        prefs = bpy.context.preferences.addons['cycles'].preferences
        prefs.compute_device_type = 'METAL'
        prefs.get_devices()
        for dev in prefs.devices:
            dev.use = True
        return True
    except Exception:
        return False


def get_scenes():
    return [s.name for s in bpy.data.scenes
            if not s.name.startswith("_") and s.name != "_Shots"]