import os
import sys
import tarfile
import zipfile
from datetime import datetime
from io import BytesIO, TextIOWrapper
from pathlib import Path
from typing import Dict, Iterable, Optional, Union

import yaml


class Archiver:
    def __init__(self, file, mode="r"):
        if Path(file).suffix == ".tar":
            self.type = "tar"
        elif Path(file).suffix == ".tgz" or Path(file).suffixes == [".tar", ".gz"]:
            self.type = "tar"
            if mode == "w":
                mode = "w:gz"
        elif Path(file).suffix == ".tbz2" or Path(file).suffixes == [".tar", ".bz2"]:
            self.type = "tar"
            if mode == "w":
                mode = "w:bz2"
        elif Path(file).suffix == ".txz" or Path(file).suffixes == [".tar", ".xz"]:
            self.type = "tar"
            if mode == "w":
                mode = "w:xz"
        elif Path(file).suffix == ".zip":
            self.type = "zip"
        else:
            raise ValueError(f"Cannot detect archive format: type={file}")

        if self.type == "tar":
            self.fopen = tarfile.open(file, mode=mode)
        elif self.type == "zip":
            self.fopen = zipfile.ZipFile(file, mode=mode)
        else:
            raise ValueError(f"Not supported: type={type}")

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        self.fopen.close()

    def close(self):
        self.fopen.close()

    def __iter__(self):
        if self.type == "tar":
            return iter(self.fopen)
        elif self.type == "zip":
            return iter(self.fopen.infolist())
        else:
            raise ValueError(f"Not supported: type={self.type}")

    def add(self, filename, arcname=None, recursive: bool = True):
        if arcname is not None:
            print(f"adding: {arcname}")
        else:
            print(f"adding: {filename}")

        if recursive and Path(filename).is_dir():
            for f in Path(filename).glob("**/*"):
                if f.is_dir():
                    continue

                if arcname is not None:
                    _arcname = Path(arcname) / f
                else:
                    _arcname = None

                self.add(f, _arcname)
            return

        if self.type == "tar":
            return self.fopen.add(filename, arcname)
        elif self.type == "zip":
            return self.fopen.write(filename, arcname)
        else:
            raise ValueError(f"Not supported: type={self.type}")

    def addfile(self, info, fileobj):
        print(f"adding: {self.get_name_from_info(info)}")

        if self.type == "tar":
            return self.fopen.addfile(info, fileobj)
        elif self.type == "zip":
            return self.fopen.writestr(info, fileobj.read())
        else:
            raise ValueError(f"Not supported: type={self.type}")

    def generate_info(self, name, size) -> Union[tarfile.TarInfo, zipfile.ZipInfo]:
        """Generate TarInfo using system information"""
        if self.type == "tar":
            tarinfo = tarfile.TarInfo(str(name))
            if os.name == "posix":
                tarinfo.gid = os.getgid()
                tarinfo.uid = os.getuid()
            tarinfo.mtime = datetime.now().timestamp()
            tarinfo.size = size
            # Keep mode as default
            return tarinfo
        elif self.type == "zip":
            zipinfo = zipfile.ZipInfo(str(name), datetime.now().timetuple()[:6])
            zipinfo.file_size = size
            return zipinfo
        else:
            raise ValueError(f"Not supported: type={self.type}")

    def get_name_from_info(self, info):
        if self.type == "tar":
            assert isinstance(info, tarfile.TarInfo), type(info)
            return info.name
        elif self.type == "zip":
            assert isinstance(info, zipfile.ZipInfo), type(info)
            return info.filename
        else:
            raise ValueError(f"Not supported: type={self.type}")

    def extract(self, info, path=None):
        if self.type == "tar":
            return self.fopen.extract(info, path)
        elif self.type == "zip":
            return self.fopen.extract(info, path)
        else:
            raise ValueError(f"Not supported: type={self.type}")

    def extractfile(self, info, mode="r"):
        if self.type == "tar":
            f = self.fopen.extractfile(info)
            if mode == "r":
                return TextIOWrapper(f)
            else:
                return f
        elif self.type == "zip":
            if mode == "rb":
                mode = "r"
            return self.fopen.open(info, mode)
        else:
            raise ValueError(f"Not supported: type={self.type}")


def find_path_and_change_it_recursive(value, src: str, tgt: str):
    if isinstance(value, dict):
        return {
            k: find_path_and_change_it_recursive(v, src, tgt) for k, v in value.items()
        }
    elif isinstance(value, (list, tuple)):
        return [find_path_and_change_it_recursive(v, src, tgt) for v in value]
    elif isinstance(value, str) and Path(value) == Path(src):
        return tgt
    else:
        return value


def get_dict_from_cache(meta: Union[Path, str]) -> Optional[Dict[str, str]]:
    meta = Path(meta)
    outpath = meta.parent.parent
    if not meta.exists():
        return None

    with meta.open("r", encoding="utf-8") as f:
        d = yaml.safe_load(f)
        assert isinstance(d, dict), type(d)
        yaml_files = d["yaml_files"]
        files = d["files"]
        assert isinstance(yaml_files, dict), type(yaml_files)
        assert isinstance(files, dict), type(files)

        retval = {}
        for key, value in list(yaml_files.items()) + list(files.items()):
            if not (outpath / value).exists():
                return None
            retval[key] = str(outpath / value)
        return retval


def unpack(
    input_archive: Union[Path, str],
    outpath: Union[Path, str],
    use_cache: bool = True,
) -> Dict[str, str]:
    """Scan all files in the archive file and return as a dict of files.

    Examples:
        tarfile:
           model.pth
           some1.file
           some2.file

        >>> unpack("tarfile", "out")
        {'asr_model_file': 'out/model.pth'}
    """
    input_archive = Path(input_archive)
    outpath = Path(outpath)

    with Archiver(input_archive) as archive:
        for info in archive:
            if Path(archive.get_name_from_info(info)).name == "meta.yaml":
                if (
                    use_cache
                    and (outpath / Path(archive.get_name_from_info(info))).exists()
                ):
                    retval = get_dict_from_cache(
                        outpath / Path(archive.get_name_from_info(info))
                    )
                    if retval is not None:
                        return retval
                d = yaml.safe_load(archive.extractfile(info))
                assert isinstance(d, dict), type(d)
                yaml_files = d["yaml_files"]
                files = d["files"]
                assert isinstance(yaml_files, dict), type(yaml_files)
                assert isinstance(files, dict), type(files)
                break
        else:
            raise RuntimeError("Format error: not found meta.yaml")

        for info in archive:
            fname = archive.get_name_from_info(info)
            outname = outpath / fname
            outname.parent.mkdir(parents=True, exist_ok=True)
            if fname in set(yaml_files.values()):
                d = yaml.safe_load(archive.extractfile(info))
                # Rewrite yaml
                for info2 in archive:
                    name = archive.get_name_from_info(info2)
                    d = find_path_and_change_it_recursive(d, name, str(outpath / name))
                with outname.open("w", encoding="utf-8") as f:
                    yaml.safe_dump(d, f)
            else:
                archive.extract(info, path=outpath)

        retval = {}
        for key, value in list(yaml_files.items()) + list(files.items()):
            retval[key] = str(outpath / value)
        return retval


def _to_relative_or_resolve(f):
    # Resolve to avoid symbolic link
    p = Path(f).resolve()
    try:
        # Change to relative if it can
        p = p.relative_to(Path(".").resolve())
    except ValueError:
        pass
    return str(p)


def pack(
    files: Dict[str, Union[str, Path]],
    yaml_files: Dict[str, Union[str, Path]],
    outpath: Union[str, Path],
    option: Iterable[Union[str, Path]] = (),
):
    for v in list(files.values()) + list(yaml_files.values()) + list(option):
        if not Path(v).exists():
            raise FileNotFoundError(f"No such file or directory: {v}")

    files = {k: _to_relative_or_resolve(v) for k, v in files.items()}
    yaml_files = {k: _to_relative_or_resolve(v) for k, v in yaml_files.items()}
    option = [_to_relative_or_resolve(v) for v in option]

    meta_objs = dict(
        files=files,
        yaml_files=yaml_files,
        timestamp=datetime.now().timestamp(),
        python=sys.version,
    )

    try:
        import torch

        meta_objs.update(torch=str(torch.__version__))
    except ImportError:
        pass
    try:
        import espnet

        meta_objs.update(espnet=espnet.__version__)
    except ImportError:
        pass

    Path(outpath).parent.mkdir(parents=True, exist_ok=True)
    with Archiver(outpath, mode="w") as archive:
        # Write packed/meta.yaml
        fileobj = BytesIO(yaml.safe_dump(meta_objs).encode())
        info = archive.generate_info("meta.yaml", fileobj.getbuffer().nbytes)
        archive.addfile(info, fileobj=fileobj)

        for f in list(yaml_files.values()) + list(files.values()) + list(option):
            archive.add(f)

    print(f"Generate: {outpath}")
