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():
    # Disabled as forcing "True" or "Index" onto generic modifier properties
    # destroys the library overrides and clears all material assignments.
    return 0



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"]