# Generated by Django 1.9.2 on 2016-03-05 00:40

import os
import re
import shutil
import subprocess
import tempfile
from pathlib import Path

import gnupg
from django.conf import settings
from django.db import migrations
from django.utils.termcolors import colorize as colourise  # Spelling hurts me


class GnuPG:
    """
    A handy singleton to use when handling encrypted files.
    """

    gpg = gnupg.GPG(gnupghome=settings.GNUPG_HOME)

    @classmethod
    def decrypted(cls, file_handle):
        return cls.gpg.decrypt_file(file_handle, passphrase=settings.PASSPHRASE).data

    @classmethod
    def encrypted(cls, file_handle):
        return cls.gpg.encrypt_file(
            file_handle,
            recipients=None,
            passphrase=settings.PASSPHRASE,
            symmetric=True,
        ).data


def move_documents_and_create_thumbnails(apps, schema_editor):
    (Path(settings.MEDIA_ROOT) / "documents" / "originals").mkdir(
        parents=True,
        exist_ok=True,
    )
    (Path(settings.MEDIA_ROOT) / "documents" / "thumbnails").mkdir(
        parents=True,
        exist_ok=True,
    )

    documents: list[str] = os.listdir(Path(settings.MEDIA_ROOT) / "documents")  # noqa: PTH208

    if set(documents) == {"originals", "thumbnails"}:
        return

    print(
        colourise(
            "\n\n"
            "  This is a one-time only migration to generate thumbnails for all of your\n"
            "  documents so that future UIs will have something to work with.  If you have\n"
            "  a lot of documents though, this may take a while, so a coffee break may be\n"
            "  in order."
            "\n",
            opts=("bold",),
        ),
    )

    Path(settings.SCRATCH_DIR).mkdir(parents=True, exist_ok=True)

    for f in sorted(documents):
        if not f.endswith("gpg"):
            continue

        print(
            "    {} {} {}".format(
                colourise("*", fg="green"),
                colourise("Generating a thumbnail for", fg="white"),
                colourise(f, fg="cyan"),
            ),
        )

        thumb_temp: str = tempfile.mkdtemp(prefix="paperless", dir=settings.SCRATCH_DIR)
        orig_temp: str = tempfile.mkdtemp(prefix="paperless", dir=settings.SCRATCH_DIR)

        orig_source: Path = Path(settings.MEDIA_ROOT) / "documents" / f
        orig_target: Path = Path(orig_temp) / f.replace(".gpg", "")

        with orig_source.open("rb") as encrypted, orig_target.open("wb") as unencrypted:
            unencrypted.write(GnuPG.decrypted(encrypted))

        subprocess.Popen(
            (
                settings.CONVERT_BINARY,
                "-scale",
                "500x5000",
                "-alpha",
                "remove",
                orig_target,
                Path(thumb_temp) / "convert-%04d.png",
            ),
        ).wait()

        thumb_source: Path = Path(thumb_temp) / "convert-0000.png"
        thumb_target: Path = (
            Path(settings.MEDIA_ROOT)
            / "documents"
            / "thumbnails"
            / re.sub(r"(\d+)\.\w+(\.gpg)", "\\1.png\\2", f)
        )
        with (
            thumb_source.open("rb") as unencrypted,
            thumb_target.open("wb") as encrypted,
        ):
            encrypted.write(GnuPG.encrypted(unencrypted))

        shutil.rmtree(thumb_temp)
        shutil.rmtree(orig_temp)

        shutil.move(
            Path(settings.MEDIA_ROOT) / "documents" / f,
            Path(settings.MEDIA_ROOT) / "documents" / "originals" / f,
        )


class Migration(migrations.Migration):
    dependencies = [
        ("documents", "0011_auto_20160303_1929"),
    ]

    operations = [
        migrations.RunPython(move_documents_and_create_thumbnails),
    ]