from pathlib import Path

import cv2 as cv
import numpy as np


input_path = Path("input/scene.png")
output_path = Path("output/scene-perspective.png")

image = cv.imread(str(input_path))
if image is None:
    raise SystemExit(f"Could not read {input_path}")

source_points = np.float32([
    [125, 82],
    [600, 62],
    [670, 398],
    [35, 360],
])
output_size = (640, 360)
target_points = np.float32([
    [0, 0],
    [output_size[0] - 1, 0],
    [output_size[0] - 1, output_size[1] - 1],
    [0, output_size[1] - 1],
])

matrix = cv.getPerspectiveTransform(source_points, target_points)
warped = cv.warpPerspective(
    image,
    matrix,
    output_size,
    flags=cv.INTER_LINEAR,
    borderMode=cv.BORDER_CONSTANT,
    borderValue=(245, 245, 245),
)

output_path.parent.mkdir(parents=True, exist_ok=True)
if not cv.imwrite(str(output_path), warped):
    raise SystemExit(f"Could not write {output_path}")

print(f"source shape: {image.shape}")
print("matrix:")
print(np.array2string(matrix, precision=6, suppress_small=True))
print(f"output size: {output_size[0]}x{output_size[1]}")
print(f"output shape: {warped.shape}")
print(f"wrote: {output_path}")