import contextlib
import os
import tempfile

from .base import BaseStorage

class Storage(BaseStorage):
    def __init__(self, app):
        super().__init__(app)
        os.makedirs(self.app.config['FILE_DIRECTORY'], exist_ok=True)
        os.makedirs(self.app.config['THUMB_DIRECTORY'], exist_ok=True)

    def _get_legacy_path(self, file_hash, filename):
        return os.path.join(self.app.config['FILE_DIRECTORY'], file_hash + os.path.splitext(filename)[1])

    def _get_path(self, file_hash):
        return os.path.join(self.app.config['FILE_DIRECTORY'], file_hash)

    def _find_path(self, f):
        path = self._get_legacy_path(f.hash, f.filename)
        if path and os.path.exists(path):
            return path
        path = self._get_path(f.hash)
        if path and os.path.exists(path):
            return path
        return None

    def get_thumb_path(self, f):
        return os.path.join(self.app.config['THUMB_DIRECTORY'], f.hash + '.jpg')

    def upload_file(self, uploaded_file, file_hash, user):
        size = uploaded_file.content_length
        if hasattr(uploaded_file.stream, 'file'):
            temp = None
            temp_path = uploaded_file.stream.name
        else:
            temp = tempfile.NamedTemporaryFile(prefix='upload_', dir=self.app.config['FILE_DIRECTORY'], delete=False)
            uploaded_file.save(temp.file)
            temp_path = temp.name
            size = os.path.getsize(temp_path)
        new_path = self._get_path(file_hash)
        os.rename(temp_path, new_path)
        if self.app.config.get('DESTINATION_MODE'):
            os.chmod(new_path, self.app.config.get('DESTINATION_MODE'))
        return new_path, size

    def store_file(self, uploaded_file, file_hash, user, ip):
        file_path, size = self.upload_file(uploaded_file, file_hash, user)
        try:
            return self.add_file(file_hash, uploaded_file.filename, size, user, ip)
        except:
            if os.path.exists(file_path):
                os.unlink(file_path)
            raise

    def file_exists(self, f):
        path = self._find_path(f)
        return path and os.path.exists(path)

    def get_file(self, f):
        path = self._find_path(f)
        if not path or not os.path.exists(path):
            return
        return path

    def delete_file(self, f):
        path = self._find_path(f)
        if path and os.path.exists(path):
            os.unlink(path)
        thumb_path = self.get_thumb_path(f)
        if thumb_path and os.path.exists(thumb_path):
            os.unlink(thumb_path)

    @contextlib.contextmanager
    def temp_file(self, f):
        path = self._find_path(f)
        if not path or not os.path.exists(path):
            raise FileNotFoundError(path)
        with open(path, 'rb') as f:
            yield f

    def get_thumbnail(self, f):
        path = self.get_thumb_path(f)
        if not path or not os.path.exists(path):
            return
        return path

    def store_thumbnail(self, f, stream):
        path = self.get_thumb_path(f)
        with open(path, 'wb') as f:
            buf = stream.read(1024*10)
            while buf:
                f.write(buf)
                buf = stream.read(1024*10)