"""Visualization helpers: tokenization-grid overlay, foveation outline, prompt I/O."""

import os

import numpy as np
import pandas as pd


def load_prompt_dataset(prompt_dataset_path: str):
    """Load prompts from a CSV with a `prompt` column."""
    df = pd.read_csv(prompt_dataset_path)
    return [row["prompt"] for _, row in df.iterrows()]


def create_tokenization_mask_vis(foveation_mask, height: int, width: int, lr_factor: int = 2):
    """Render the HR/LR token grid implied by a token-grid foveation mask.

    HR region (mask=1) is white with 16x16 token outlines; LR region (mask=0)
    is light gray with (16*lr_factor)x(16*lr_factor) outlines.
    """
    mask_np = foveation_mask.detach().cpu().numpy() if hasattr(foveation_mask, "detach") else np.asarray(foveation_mask)
    upsampled = np.repeat(np.repeat(mask_np, 16, axis=0), 16, axis=1)[:height, :width]

    vis = np.full((height, width, 3), 255, dtype=np.uint8)
    if lr_factor > 1:
        vis[upsampled < 0.5] = [225, 225, 225]

    yy = np.arange(height)
    xx = np.arange(width)
    border_px = 4
    hr_grid = np.zeros((height, width), dtype=bool)
    hr_grid[yy % 16 < border_px, :] = True
    hr_grid[:, xx % 16 < border_px] = True

    lr_grid = np.zeros((height, width), dtype=bool)
    lr_grid[yy % (16 * lr_factor) < border_px, :] = True
    lr_grid[:, xx % (16 * lr_factor) < border_px] = True

    hr_region = upsampled > 0.5
    outline = (hr_grid & hr_region) | (lr_grid & ~hr_region)
    vis[outline] = [0, 0, 0]

    vis[yy < border_px, :] = [0, 0, 0]
    vis[yy > height - border_px, :] = [0, 0, 0]
    vis[:, xx < border_px] = [0, 0, 0]
    vis[:, xx > width - border_px] = [0, 0, 0]
    return vis


def draw_foveation_outline(
    image_np,
    mask_token_grid,
    height: int,
    width: int,
    outline_width_frac: float = 0.01,
    color=(255, 0, 0),
):
    """Draw a white outline (with thin black backing) around the foveation region, in-place."""
    try:
        import cv2
    except ImportError:
        return image_np
    mask_np = mask_token_grid.detach().cpu().numpy() if hasattr(mask_token_grid, "detach") else np.asarray(mask_token_grid)
    mask_uint8 = (mask_np > 0.5).astype(np.uint8) * 255
    mask_high = cv2.resize(mask_uint8, (width, height), interpolation=cv2.INTER_NEAREST)
    contours, _ = cv2.findContours(mask_high, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
    border_width = max(1, int(outline_width_frac * width))
    black_stroke = max(1, int(0.10 * border_width))
    white_stroke = max(1, int(0.80 * border_width))
    cv2.drawContours(image_np, contours, -1, (255, 255, 255), black_stroke + white_stroke)
    cv2.drawContours(image_np, contours, -1, (255, 255, 255), white_stroke)
    return image_np