"""Video SequencerサイドバーのSE Palette UI。"""

from __future__ import annotations

import os

import bpy
import bpy.utils.previews as previews
from bpy.types import Panel

from .operators import populate_items


_preview_collection = None


def clear_previews():
    global _preview_collection
    if _preview_collection is not None:
        try:
            previews.remove(_preview_collection)
        except Exception:
            pass
    _preview_collection = None


def _custom_icon_value(item) -> int:
    global _preview_collection
    raw_path = item.icon_path.strip()
    if not raw_path:
        return 0
    filepath = os.path.abspath(bpy.path.abspath(raw_path))
    if not os.path.isfile(filepath):
        return 0
    try:
        if _preview_collection is None:
            _preview_collection = previews.new()
        key = f"{filepath}:{os.path.getmtime(filepath)}"
        if key not in _preview_collection:
            _preview_collection.load(key, filepath, "IMAGE")
        return _preview_collection[key].icon_id
    except Exception:
        return 0


def _draw_insert_button(row, item):
    icon_value = _custom_icon_value(item)
    kwargs = {"text": item.label}
    if icon_value:
        kwargs["icon_value"] = icon_value
    else:
        kwargs["icon"] = item.icon or "PLAY_SOUND"
    operator = row.operator("se_palette.insert", **kwargs)
    operator.filepath = item.filepath


def draw_palette(layout, context):
    """ポップアップなど任意のUILayoutへSE Paletteを描画する。"""
    props = context.scene.se_palette

    folder_box = layout.box()
    row = folder_box.row(align=True)
    row.prop(props, "folder", text="")
    row.operator("se_palette.scan", text="", icon="FILE_REFRESH")

    if not props.items and os.path.isdir(os.path.abspath(bpy.path.abspath(props.folder))):
        try:
            populate_items(props)
        except Exception:
            pass

    settings = layout.box()
    row = settings.row(align=True)
    row.prop(props, "channel")
    row.prop(props, "volume")
    row = settings.row(align=True)
    row.prop(props, "advance_playhead")
    row.prop(props, "compact")
    settings.prop(props, "grid_columns", slider=True)

    row = layout.row(align=True)
    row.prop(props, "search", text="", icon="VIEWZOOM")
    row.operator("se_palette.stop_preview", text="", icon="PAUSE")

    folder = os.path.abspath(bpy.path.abspath(props.folder))
    if not os.path.isdir(folder):
        warning = layout.row()
        warning.alert = True
        warning.label(text="Select an SE folder", icon="ERROR")
        return

    query = props.search.strip().casefold()
    visible_items = [
        item
        for item in props.items
        if not query
        or query in item.label.casefold()
        or query in item.filename.casefold()
    ]

    if not visible_items:
        layout.label(
            text="No matching sound effects" if query else "No sound effects found",
            icon="INFO",
        )
        return

    grid = layout.grid_flow(
        row_major=True,
        columns=props.grid_columns,
        even_columns=True,
        even_rows=True,
        align=True,
    )
    for item in visible_items:
        card = grid.box()
        insert_row = card.row(align=True)
        insert_row.scale_y = 1.0 if props.compact else 1.5
        _draw_insert_button(insert_row, item)

        controls = card.row(align=True)
        preview = controls.operator(
            "se_palette.preview",
            text="" if props.compact else "Preview",
            icon="PLAY",
        )
        preview.filepath = item.filepath
        edit = controls.operator(
            "se_palette.edit_item",
            text="" if props.compact else "Edit",
            icon="PREFERENCES",
        )
        edit.filepath = item.filepath

    layout.label(text=f"{len(visible_items)} / {len(props.items)} sounds", icon="SOUND")


class SEPALETTE_PT_main(Panel):
    """VSEサイドバーに表示するSE Palette。"""

    bl_label = "SE Palette"
    bl_idname = "SEPALETTE_PT_main"
    bl_space_type = "SEQUENCE_EDITOR"
    bl_region_type = "UI"
    bl_category = "SE Palette"

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