webshop/build_image_cache.py

from dotenv import load_dotenv

load_dotenv(".env")
import logging
import os
import time
from multiprocessing import Pool
from pathlib import Path

import cv2
import typer

from app.git import git_get_list_of_changed_filepaths_in_last_commit, git_ls_files
from app.read_settings import read_settings

logger = logging.getLogger(__name__)


app = typer.Typer()


# TODO this can be done better!
# we're re-reading the git-repo path instead of assuming
# we're currently in there, though empirical testing shows
# doign Path.cwd() returns git repo path
cwd = Path(__file__).parent
settings = read_settings(f"{cwd}/settings.toml", False)
git_repo = Path(settings.git_repo).expanduser()

IMAGE_CACHE_PATH = f"{cwd}/static/images/cache"

SIZES = {
    ".": [
        (320,),
        (640,),
        (760,),
        (1024,),
        (1366,),
        (1600,),
        (1920,),
        (2400,),
        (2880,),
        (3840,),
    ],
    "products": [
        (120, 120),
        (240, 240),  # -- checkout
        (220, 220),
        (440, 440),
        (320,),
        (640,),  # - product-grid
        (380,),
        (760,),
        (256,),
        (512,),
        (340,),
        (683,),
        (400,),
        (800,),
        (480,),
        (960,),
        (460,),
        (920,),
        (560,),
        (1120,),
        (1024,),  # -- product specific sizes
        (1200,),
        (1366,),
        (1920,),
        (2400,),
    ],
    "pages": [(320,), (640,), (760,), (1024,), (1366,), (1600,), (1920,), (2400,)],
}


def calculate_height_on_width(img, input_width: int) -> int:
    """Calculate thumbnail's height value of given image by using the
    desired width.
    """
    width_percent = input_width / float(img.shape[1])

    return int((float(img.shape[0]) * float(width_percent)))


def make_thumb(size_type: str, img, fp: os.PathLike):
    """Make a thumbnail image for each defined size."""
    try:
        new_filepath = Path(f"{fp.parent.stem}__{fp.stem}_{size_type[0]}{fp.suffix}")

        if Path(f"{IMAGE_CACHE_PATH}/{new_filepath}").exists():
            pass

        else:
            # check if size_type is a full tuple or is missing the
            # height value
            if len(size_type) == 2:
                img = cv2.resize(img, size_type)
            else:
                img_height = calculate_height_on_width(img, size_type[0])
                img = cv2.resize(img, (size_type[0], img_height))

            # save it to disk
            cv2.imwrite(f"{IMAGE_CACHE_PATH}/{new_filepath}", img)

    except OSError as e:
        logging.error(f"image-resize error => {e}")


def image_resize(image: tuple[str, str]):
    """Resize an image at given preset, if it does not exist yet.

    We're saving each thumbnail in static/images/cache/,
    in the format /<pa/th>/<image>_<size>.<ext>
    """
    template, filepath = image
    fp = Path(filepath)
    selected_size = SIZES[template]

    # read image and keep it in memory
    img = cv2.imread(f"{git_repo}/{filepath}")

    # copy also image as is to the cache
    copy_filepath = Path(f"{fp.parent.stem}__{fp.stem}_{img.shape[1]}{fp.suffix}")

    if not Path(f"{IMAGE_CACHE_PATH}/{copy_filepath}").exists():
        cv2.imwrite(f"{IMAGE_CACHE_PATH}/{copy_filepath}", img)

    for size_type in selected_size:
        if img.shape[1] > size_type[0]:
            make_thumb(size_type, img, fp)


@app.command()
def build_all_images(repo: str):
    """Build set of defined thumbnails for each image in the list.

    Ref: <https://stackoverflow.com/a/51822265>
    """
    pool = Pool(int(os.getenv("CPU_CORE")))

    repo = Path(repo).expanduser()

    pattern_matching = ["*.png", "*.jpg"]
    filepaths = git_ls_files(repo, pattern_matching, False)

    images = [
        (str(Path(filepath).parent).split("/")[0], filepath) for filepath in filepaths
    ]

    if len(images) > 0:
        start_time = time.time()
        pool.map(image_resize, images)
        logging.info("--- %s seconds ---" % (time.time() - start_time))

    else:
        logging.info("build-images: no images in the repo.")


@app.command()
def build_images(repo: str, oldrev: str, newrev: str):
    """Build set of defined thumbnails for each image in the list.

    Ref: <https://stackoverflow.com/a/51822265>
    """
    pool = Pool(int(os.getenv("CPU_CORE")))

    repo = Path(repo).expanduser()

    pattern_matching = [".png", ".jpg"]
    filepaths = git_get_list_of_changed_filepaths_in_last_commit(
        repo, oldrev, newrev, pattern_matching
    )

    images = [
        (str(Path(filepath).parent).split("/")[0], filepath) for filepath in filepaths
    ]

    if len(images) > 0:
        start_time = time.time()
        pool.map(image_resize, images)
        logging.info("--- %s seconds ---" % (time.time() - start_time))

    else:
        logging.info("build-images: no image in this commit.")


if __name__ == "__main__":
    app()