# /// script
# requires-python = ">=3.10"
# dependencies = ["numpy"]
# ///
"""
@effect threshold
@version 1.0.0
@author artdag

@description
Threshold effect. Converts to high-contrast black and white.
Creates stark, graphic look by converting grayscale to pure
black/white based on a threshold value.

@param level int
  @range 0 255
  @default 128
  Threshold level. Pixels above = white, below = black.

@param invert bool
  @default false
  Swap black and white.

@param color_mode string
  @enum bw color
  @default bw
  Output mode:
  - bw: pure black and white
  - color: keep original colors where above threshold

@example
  (effect threshold :level 100)

@example
  ;; Beat-reactive threshold
  (effect threshold :level (bind bass :range [80 180]) :invert true)
"""

import numpy as np


def process_frame(frame: np.ndarray, params: dict, state: dict) -> tuple:
    """
    Apply threshold effect to a video frame.

    Args:
        frame: Input frame as numpy array (H, W, 3) RGB uint8
        params: Effect parameters
            - level: threshold 0-255 (default 128)
            - invert: swap black/white (default False)
            - color_mode: bw or color (default bw)
        state: Persistent state dict

    Returns:
        Tuple of (processed_frame, new_state)
    """
    level = int(np.clip(params.get("level", 128), 0, 255))
    invert = params.get("invert", False)
    color_mode = params.get("color_mode", "bw")

    if state is None:
        state = {}

    # Convert to grayscale for threshold comparison
    if len(frame.shape) == 3:
        gray = np.mean(frame, axis=2)
    else:
        gray = frame

    # Apply threshold
    mask = gray > level

    if invert:
        mask = ~mask

    if color_mode == "bw":
        # Pure black and white
        result = np.where(mask[:, :, np.newaxis], 255, 0).astype(np.uint8)
        if len(frame.shape) == 3:
            result = np.repeat(result, frame.shape[2], axis=2)
    else:
        # Keep original colors where above threshold
        result = np.where(mask[:, :, np.newaxis], frame, 0).astype(np.uint8)

    return result, state