feat: generate jpeg thumbnail 128px closes #17

docs: add documentation for `thumbnail` command

README.md

@@ -44,6 +44,7 @@ Avaiable command for this package:
 - `mdsanima webp` convert to webp
 - `mdsanima pixelart` generate pixel art 32px
 - `mdsanima grid` generate grid 2x2
+- `mdsanima thumbnail` generate jpeg thumbnail 128px
 
 The `pixelart` command works in folder that have only `.png` images and convert this images to pixel
 art with creating the new file and appending the suffix `pixelart` to original file name.

src/mdsanima_cli/__init__.py

@@ -13,6 +13,7 @@
 from mdsanima_cli.command.number import cli_number
 from mdsanima_cli.command.pixelart import cli_pixelart
 from mdsanima_cli.command.png import cli_png
+from mdsanima_cli.command.thumbnail import cli_thumbnail
 from mdsanima_cli.command.uuids import cli_uuid
 from mdsanima_cli.command.watermark import cli_watermark
 from mdsanima_cli.command.webp import cli_webp
@@ -51,5 +52,7 @@ def main_cli():
             cli_pixelart()
         if args.command == "grid":
             cli_grid()
+        if args.command == "thumbnail":
+            cli_thumbnail()
     except AttributeError:
         parser.print_help()

src/mdsanima_cli/command/thumbnail.py

@@ -0,0 +1,83 @@
+# Copyright © 2023 Marcin Różewski MDSANIMA
+
+
+"""Generating JPEG thumbnails from all images in the curreny directory. It operates within
+a specified folder and can process all images at once.
+"""
+
+
+from __future__ import annotations
+
+import os
+
+from PIL import Image
+
+from mdsanima_cli.command.check import directory_statistic
+from mdsanima_cli.parser import THUMBNAIL_COMMAND
+from mdsanima_cli.parser import THUMBNAIL_HELP
+from mdsanima_cli.utils.ascii import ascii_title
+from mdsanima_cli.utils.exif import get_exif_bytes
+from mdsanima_cli.utils.print import print_cli_proc
+
+
+def generate_jpeg_thumbnail(image_path: str, new_name: str) -> None:
+    """Generate JPEG thumbnail 128, and then save the result with a new name and exif data."""
+
+    # Open image file.
+    image = Image.open(image_path)
+
+    # Image size.
+    image_width, image_height = image.size
+
+    # Calculating size for thumbnail.
+    size = 128
+    resize_ratio = int(image_width / size)
+    thumbnail_width = int(image_width / resize_ratio)
+    thumbnail_height = int(image_height / resize_ratio)
+    thumbnail_size = (thumbnail_width, thumbnail_height)
+
+    # Add exif data.
+    exif_bytes = get_exif_bytes(THUMBNAIL_HELP)
+
+    # Create JPEG thumbnail and save the result.
+    image.thumbnail(thumbnail_size)
+    image.save(new_name, "JPEG", exif=exif_bytes)
+
+
+def compute_thumbnail() -> None:
+    """Generating JPEG thumbnails 128 from all images in the current directory."""
+
+    # Get directory stats info.
+    directory = os.listdir()
+    count = 1
+
+    # New file name suffix for generated files.
+    suffix = "_thumbnail"
+    png = ".png"
+    jpg = ".jpg"
+    webp = ".webp"
+
+    # Checking extension and compute thumbnail from all images in directory.
+    for file in directory:
+        if file.endswith(png) and not file.endswith(suffix + jpg):
+            new_name = file[:-4] + suffix + jpg
+            generate_jpeg_thumbnail(file, new_name)
+            print_cli_proc("computing", count, file, new_name)
+            count += 1
+        if file.endswith(jpg) and not file.endswith(suffix + jpg):
+            new_name = file[:-4] + suffix + jpg
+            generate_jpeg_thumbnail(file, new_name)
+            print_cli_proc("computing", count, file, new_name)
+            count += 1
+        if file.endswith(webp) and not file.endswith(suffix + jpg):
+            new_name = file[:-5] + suffix + jpg
+            generate_jpeg_thumbnail(file, new_name)
+            print_cli_proc("computing", count, file, new_name)
+            count += 1
+
+
+def cli_thumbnail() -> None:
+    """Main function for `thumbnail` command."""
+    directory_statistic(THUMBNAIL_COMMAND, THUMBNAIL_HELP)
+    ascii_title("processing")
+    compute_thumbnail()

src/mdsanima_cli/parser.py

@@ -58,6 +58,10 @@
 GRID_DESCRIPTION = f"Generate grid 2x2 from {ALL_IMAGES}"
 GRID_HELP = "generate grid 2x2"
 
+THUMBNAIL_COMMAND = "thumbnail"
+THUMBNAIL_DESCRIPTION = f"Generate JPEG thumbnails 128px from {ALL_IMAGES}"
+THUMBNAIL_HELP = "generate jpeg thumbnail 128px"
+
 
 def create_parser() -> None:
     """This function creates an argument parser for all available functions in this package, which
@@ -169,4 +173,13 @@ def create_parser() -> None:
     )
     grid_parser.set_defaults(command=GRID_COMMAND)
 
+    # Create subparser for thumbnail command.
+    thumbnail_parser = subparser.add_parser(
+        name=THUMBNAIL_COMMAND,
+        description=THUMBNAIL_DESCRIPTION,
+        help=THUMBNAIL_HELP,
+        epilog=EPILOG,
+    )
+    thumbnail_parser.set_defaults(command=THUMBNAIL_COMMAND)
+
     return parser