#!/usr/bin/env python3

# Copyright (C) 2009-2022 Jérôme Poisson (goffi@goffi.org)

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.

# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

from pathlib import Path
from typing import Self, cast

from pydantic import BaseModel, Field
from twisted.words.xish import domish

from libervia.backend.core import exceptions
from libervia.backend.core.constants import Const as C
from libervia.backend.core.i18n import _
from libervia.backend.core.log import getLogger
from libervia.backend.plugins.plugin_xep_0300 import XEP_0300
from libervia.backend.tools import utils

log = getLogger(__name__)


PLUGIN_INFO = {
    C.PI_NAME: "File Metadata Element",
    C.PI_IMPORT_NAME: "XEP-0446",
    C.PI_TYPE: "XEP",
    C.PI_MODES: C.PLUG_MODE_BOTH,
    C.PI_PROTOCOLS: ["XEP-0446"],
    C.PI_DEPENDENCIES: ["XEP-0300"],
    C.PI_MAIN: "XEP_0446",
    C.PI_HANDLER: "no",
    C.PI_DESCRIPTION: _("""Implementation of XEP-0446 (File Metadata Element)"""),
}

NS_FILE_METADATA = "urn:xmpp:file:metadata:0"


class FileMetadata(BaseModel):
    """
    Model for file metadata.
    """

    name: str | None = Field(None, description="Name of the file.")
    media_type: str | None = Field(None, description="Media type of the file.")
    desc: str | None = Field(None, description="Description of the file.")
    size: int | None = Field(None, description="Size of the file in bytes.")
    file_hash: tuple[str, str] | None = Field(
        None, description="File hash as a tuple of (algo, hash)."
    )
    date: float | int | None = Field(
        None, description="Timestamp of the last modification datetime."
    )
    width: int | None = Field(None, description="Image or video width in pixels.")
    height: int | None = Field(None, description="Image or video height in pixels.")
    length: int | None = Field(None, description="Video or audio length in milliseconds.")
    thumbnail: str | None = Field(None, description="URL to a thumbnail.")

    _hash: XEP_0300 | None = None

    @classmethod
    def from_element(cls, file_metadata_elt: domish.Element) -> Self:
        """Create a FileMetadata instance from a <file> element or its parent.

        @param file_metadata_elt: The <file> element or a parent element.
        @return: FileMetadata instance.
        @raise exceptions.NotFound: If the <file> element is not found.
        """
        assert cls._hash is not None, "_hash attribute is not set"

        if file_metadata_elt.uri != NS_FILE_METADATA or file_metadata_elt.name != "file":
            child_file_metadata_elt = next(
                file_metadata_elt.elements(NS_FILE_METADATA, "file"), None
            )
            if child_file_metadata_elt is None:
                raise exceptions.NotFound("<file> element not found")
            else:
                file_metadata_elt = child_file_metadata_elt

        kwargs = {}
        for key in (
            "name",
            "media_type",
            "desc",
            "size",
            "date",
            "width",
            "height",
            "length",
        ):
            elt = next(file_metadata_elt.elements(NS_FILE_METADATA, key), None)
            if elt is not None:
                if key in ("name", "media_type", "desc"):
                    content = str(elt)
                    if key == "name":
                        content = Path(content).name
                    kwargs[key] = content
                elif key in ("size", "width", "height", "length"):
                    kwargs[key] = int(str(elt))
                elif key == "date":
                    kwargs[key] = utils.parse_xmpp_date(str(elt))

        hash_elt = next(file_metadata_elt.elements(NS_FILE_METADATA, "hash"), None)
        if hash_elt:
            try:
                algo, hash_ = cls._hash.parse_hash_elt(hash_elt)
            except exceptions.NotFound:
                pass
            except exceptions.DataError:
                from libervia.backend.tools.xml_tools import p_fmt_elt

                log.warning(f"invalid <hash/> element:\n{p_fmt_elt(file_metadata_elt)}")
            else:
                kwargs["file_hash"] = (algo, hash_)

        return cls(**kwargs)

    def to_element(self) -> domish.Element:
        """Build the <file> element from this instance's data.

        @return: <file> element.
        """
        assert self._hash is not None, "_hash attribute is not set"

        file_elt = domish.Element((NS_FILE_METADATA, "file"))

        for key, value in (
            ("name", self.name),
            ("media-type", self.media_type),
            ("desc", self.desc),
            ("size", self.size),
            ("width", self.width),
            ("height", self.height),
            ("length", self.length),
        ):
            if value is not None:
                file_elt.addElement(key, content=str(value))

        if self.file_hash is not None:
            hash_algo, hash_ = self.file_hash
            file_elt.addChild(self._hash.build_hash_elt(hash_, hash_algo))

        if self.date is not None:
            file_elt.addElement("date", content=utils.xmpp_date(self.date))

        if self.thumbnail is not None:
            log.warning("thumbnail is not implemented yet")

        return file_elt

    @classmethod
    def from_filedata_dict(cls, file_data: dict) -> Self:
        """Create an instance of FileMetadata from data dict as returned by ``memory``.

        @param data: A filedata dict as returned by ``memory.get_files``
        @return: An instance of FileMetadata.
        """

        # Extracting relevant fields
        name = file_data["name"]
        media_type = f'{file_data["media_type"]}/{file_data["media_subtype"]}'
        desc = None  # TODO
        size = file_data["size"]
        file_hash = (file_data["hash_algo"], file_data["file_hash"])
        date = file_data.get("modified") or file_data["created"]
        width = None  # TODO
        height = None  # TODO
        length = None  # TODO
        thumbnail = None  # TODO

        return cls(
            name=name,
            media_type=media_type,
            desc=desc,
            size=size,
            file_hash=file_hash,
            date=date,
            width=width,
            height=height,
            length=length,
            thumbnail=thumbnail,
        )


class XEP_0446:
    def __init__(self, host):
        log.info(_("XEP-0446 (File Metadata Element) plugin initialization"))
        host.register_namespace("file-metadata", NS_FILE_METADATA)
        FileMetadata._hash = cast(XEP_0300, host.plugins["XEP-0300"])

    def generate_file_metadata(
        self,
        name: str | None = None,
        media_type: str | None = None,
        desc: str | None = None,
        size: int | None = None,
        file_hash: tuple[str, str] | None = None,
        date: float | int | None = None,
        width: int | None = None,
        height: int | None = None,
        length: int | None = None,
        thumbnail: str | None = None,
    ) -> FileMetadata:
        """Generate the element describing a file

        @param name: name of the file
        @param media_type: media-type
        @param desc: description
        @param size: size in bytes
        @param file_hash: (algo, hash)
        @param date: timestamp of the last modification datetime
        @param width: image width in pixels
        @param height: image height in pixels
        @param length: video length in seconds
        @param thumbnail: URL to a thumbnail
        @return: ``<file/>`` element
        """
        return FileMetadata(
            name=name,
            media_type=media_type,
            desc=desc,
            size=size,
            file_hash=file_hash,
            date=date,
            width=width,
            height=height,
            length=length,
            thumbnail=thumbnail,
        )

    def parse_file_metadata_elt(self, file_metadata_elt: domish.Element) -> FileMetadata:
        """Parse <file/> element

        @param file_metadata_elt: <file/> element
            a parent element can also be used
        @return: FileMetadata instance.
        @raise exceptions.NotFound: no <file/> element has been found
        """
        return FileMetadata.from_element(file_metadata_elt)