import os
from pathlib import Path
from typing import Any, Callable, Optional, Tuple, Union

from PIL import Image

from .utils import check_integrity, download_and_extract_archive, download_url
from .vision import VisionDataset


class SBU(VisionDataset):
    """`SBU Captioned Photo <http://www.cs.virginia.edu/~vicente/sbucaptions/>`_ Dataset.

    Args:
        root (str or ``pathlib.Path``): Root directory of dataset where tarball
            ``SBUCaptionedPhotoDataset.tar.gz`` exists.
        transform (callable, optional): A function/transform that takes in a PIL image
            and returns a transformed version. E.g, ``transforms.RandomCrop``
        target_transform (callable, optional): A function/transform that takes in the
            target and transforms it.
        download (bool, optional): If True, downloads the dataset from the internet and
            puts it in root directory. If dataset is already downloaded, it is not
            downloaded again.
    """

    url = "https://www.cs.rice.edu/~vo9/sbucaptions/SBUCaptionedPhotoDataset.tar.gz"
    filename = "SBUCaptionedPhotoDataset.tar.gz"
    md5_checksum = "9aec147b3488753cf758b4d493422285"

    def __init__(
        self,
        root: Union[str, Path],
        transform: Optional[Callable] = None,
        target_transform: Optional[Callable] = None,
        download: bool = True,
    ) -> None:
        super().__init__(root, transform=transform, target_transform=target_transform)

        if download:
            self.download()

        if not self._check_integrity():
            raise RuntimeError("Dataset not found or corrupted. You can use download=True to download it")

        # Read the caption for each photo
        self.photos = []
        self.captions = []

        file1 = os.path.join(self.root, "dataset", "SBU_captioned_photo_dataset_urls.txt")
        file2 = os.path.join(self.root, "dataset", "SBU_captioned_photo_dataset_captions.txt")

        for line1, line2 in zip(open(file1), open(file2)):
            url = line1.rstrip()
            photo = os.path.basename(url)
            filename = os.path.join(self.root, "dataset", photo)
            if os.path.exists(filename):
                caption = line2.rstrip()
                self.photos.append(photo)
                self.captions.append(caption)

    def __getitem__(self, index: int) -> Tuple[Any, Any]:
        """
        Args:
            index (int): Index

        Returns:
            tuple: (image, target) where target is a caption for the photo.
        """
        filename = os.path.join(self.root, "dataset", self.photos[index])
        img = Image.open(filename).convert("RGB")
        if self.transform is not None:
            img = self.transform(img)

        target = self.captions[index]
        if self.target_transform is not None:
            target = self.target_transform(target)

        return img, target

    def __len__(self) -> int:
        """The number of photos in the dataset."""
        return len(self.photos)

    def _check_integrity(self) -> bool:
        """Check the md5 checksum of the downloaded tarball."""
        root = self.root
        fpath = os.path.join(root, self.filename)
        if not check_integrity(fpath, self.md5_checksum):
            return False
        return True

    def download(self) -> None:
        """Download and extract the tarball, and download each individual photo."""

        if self._check_integrity():
            return

        download_and_extract_archive(self.url, self.root, self.root, self.filename, self.md5_checksum)

        # Download individual photos
        with open(os.path.join(self.root, "dataset", "SBU_captioned_photo_dataset_urls.txt")) as fh:
            for line in fh:
                url = line.rstrip()
                try:
                    download_url(url, os.path.join(self.root, "dataset"))
                except OSError:
                    # The images point to public images on Flickr.
                    # Note: Images might be removed by users at anytime.
                    pass

import os
from pathlib import Path
from typing import Any, Callable, Optional, Tuple, Union

from PIL import Image

from .utils import check_integrity, download_and_extract_archive, download_url
from .vision import VisionDataset


class SBU(VisionDataset):
    """`SBU Captioned Photo <http://www.cs.virginia.edu/~vicente/sbucaptions/>`_ Dataset.

    Args:
        root (str or ``pathlib.Path``): Root directory of dataset where tarball
            ``SBUCaptionedPhotoDataset.tar.gz`` exists.
        transform (callable, optional): A function/transform that takes in a PIL image
            and returns a transformed version. E.g, ``transforms.RandomCrop``
        target_transform (callable, optional): A function/transform that takes in the
            target and transforms it.
        download (bool, optional): If True, downloads the dataset from the internet and
            puts it in root directory. If dataset is already downloaded, it is not
            downloaded again.
    """

    url = "https://www.cs.rice.edu/~vo9/sbucaptions/SBUCaptionedPhotoDataset.tar.gz"
    filename = "SBUCaptionedPhotoDataset.tar.gz"
    md5_checksum = "9aec147b3488753cf758b4d493422285"

    def __init__(
        self,
        root: Union[str, Path],
        transform: Optional[Callable] = None,
        target_transform: Optional[Callable] = None,
        download: bool = True,
    ) -> None:
        super().__init__(root, transform=transform, target_transform=target_transform)

        if download:
            self.download()

        if not self._check_integrity():
            raise RuntimeError("Dataset not found or corrupted. You can use download=True to download it")

        # Read the caption for each photo
        self.photos = []
        self.captions = []

        file1 = os.path.join(self.root, "dataset", "SBU_captioned_photo_dataset_urls.txt")
        file2 = os.path.join(self.root, "dataset", "SBU_captioned_photo_dataset_captions.txt")

        for line1, line2 in zip(open(file1), open(file2)):
            url = line1.rstrip()
            photo = os.path.basename(url)
            filename = os.path.join(self.root, "dataset", photo)
            if os.path.exists(filename):
                caption = line2.rstrip()
                self.photos.append(photo)
                self.captions.append(caption)

    def __getitem__(self, index: int) -> Tuple[Any, Any]:
        """
        Args:
            index (int): Index

        Returns:
            tuple: (image, target) where target is a caption for the photo.
        """
        filename = os.path.join(self.root, "dataset", self.photos[index])
        img = Image.open(filename).convert("RGB")
        if self.transform is not None:
            img = self.transform(img)

        target = self.captions[index]
        if self.target_transform is not None:
            target = self.target_transform(target)

        return img, target

    def __len__(self) -> int:
        """The number of photos in the dataset."""
        return len(self.photos)

    def _check_integrity(self) -> bool:
        """Check the md5 checksum of the downloaded tarball."""
        root = self.root
        fpath = os.path.join(root, self.filename)
        if not check_integrity(fpath, self.md5_checksum):
            return False
        return True

    def download(self) -> None:
        """Download and extract the tarball, and download each individual photo."""

        if self._check_integrity():
            print("Files already downloaded and verified")
            return

        download_and_extract_archive(self.url, self.root, self.root, self.filename, self.md5_checksum)

        # Download individual photos
        with open(os.path.join(self.root, "dataset", "SBU_captioned_photo_dataset_urls.txt")) as fh:
            for line in fh:
                url = line.rstrip()
                try:
                    download_url(url, os.path.join(self.root, "dataset"))
                except OSError:
                    # The images point to public images on Flickr.
                    # Note: Images might be removed by users at anytime.
                    pass
