//! Types for extensible image message events ([MSC3552]).
//!
//! [MSC3552]: https://github.com/matrix-org/matrix-spec-proposals/pull/3552

use js_int::UInt;
use ruma_macros::EventContent;
use serde::{Deserialize, Serialize};

use super::{
    file::{EncryptedContent, FileContent},
    message::MessageContent,
    room::{
        message::{ImageMessageEventContent, MessageType, Relation, RoomMessageEventContent},
        ImageInfo, MediaSource, ThumbnailInfo,
    },
};
use crate::OwnedMxcUri;

/// The payload for an extensible image message.
///
/// This is the new primary type introduced in [MSC3552] and should not be sent before the end of
/// the transition period. See the documentation of the [`message`] module for more information.
///
/// `ImageEventContent` can be converted to a [`RoomMessageEventContent`] with a
/// [`MessageType::Image`]. You can convert it back with
/// [`ImageEventContent::from_image_room_message()`].
///
/// [MSC3552]: https://github.com/matrix-org/matrix-spec-proposals/pull/3552
/// [`message`]: super::message
/// [`RoomMessageEventContent`]: super::room::message::RoomMessageEventContent
/// [`MessageType::Image`]: super::room::message::MessageType::Image
#[derive(Clone, Debug, Serialize, Deserialize, EventContent)]
#[cfg_attr(not(feature = "unstable-exhaustive-types"), non_exhaustive)]
#[ruma_event(type = "m.image", kind = MessageLike)]
pub struct ImageEventContent {
    /// The text representation of the message.
    #[serde(flatten)]
    pub message: MessageContent,

    /// The file content of the message.
    #[serde(rename = "m.file")]
    pub file: FileContent,

    /// The image content of the message.
    #[serde(rename = "m.image")]
    pub image: Box<ImageContent>,

    /// The thumbnails of the message.
    #[serde(rename = "m.thumbnail", default, skip_serializing_if = "Vec::is_empty")]
    pub thumbnail: Vec<ThumbnailContent>,

    /// The captions of the message.
    #[serde(
        rename = "m.caption",
        with = "super::message::content_serde::as_vec",
        default,
        skip_serializing_if = "Option::is_none"
    )]
    pub caption: Option<MessageContent>,

    /// Information about related messages.
    #[serde(flatten, skip_serializing_if = "Option::is_none")]
    pub relates_to: Option<Relation>,
}

impl ImageEventContent {
    /// Creates a new `ImageEventContent` with the given plain text message and file.
    pub fn plain(message: impl Into<String>, file: FileContent) -> Self {
        Self {
            message: MessageContent::plain(message),
            file,
            image: Default::default(),
            thumbnail: Default::default(),
            caption: Default::default(),
            relates_to: None,
        }
    }

    /// Creates a new non-encrypted `ImageEventContent` with the given message and file.
    pub fn with_message(message: MessageContent, file: FileContent) -> Self {
        Self {
            message,
            file,
            image: Default::default(),
            thumbnail: Default::default(),
            caption: Default::default(),
            relates_to: None,
        }
    }

    /// Create a new `ImageEventContent` from the given `ImageMessageEventContent` and optional
    /// relation.
    pub fn from_image_room_message(
        content: ImageMessageEventContent,
        relates_to: Option<Relation>,
    ) -> Self {
        let ImageMessageEventContent {
            body,
            source,
            info,
            message,
            file,
            image,
            thumbnail,
            caption,
        } = content;
        let ImageInfo { height, width, mimetype, size, thumbnail_info, thumbnail_source, .. } =
            info.map(|info| *info).unwrap_or_default();

        let message = message.unwrap_or_else(|| MessageContent::plain(body));
        let file = file.unwrap_or_else(|| {
            FileContent::from_room_message_content(source, None, mimetype, size)
        });
        let image = image
            .or_else(|| ImageContent::from_room_message_content(width, height).map(Box::new))
            .unwrap_or_default();
        let thumbnail = thumbnail.unwrap_or_else(|| {
            ThumbnailContent::from_room_message_content(thumbnail_source, thumbnail_info)
                .into_iter()
                .collect()
        });

        Self { message, file, image, thumbnail, caption, relates_to }
    }
}

impl From<ImageEventContent> for RoomMessageEventContent {
    fn from(content: ImageEventContent) -> Self {
        let ImageEventContent { message, file, image, thumbnail, caption, relates_to } = content;

        Self {
            msgtype: MessageType::Image(ImageMessageEventContent::from_extensible_content(
                message, file, image, thumbnail, caption,
            )),
            relates_to,
        }
    }
}

/// Image content.
#[derive(Default, Clone, Debug, Serialize, Deserialize)]
#[cfg_attr(not(feature = "unstable-exhaustive-types"), non_exhaustive)]
pub struct ImageContent {
    /// The height of the image in pixels.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub height: Option<UInt>,

    /// The width of the image in pixels.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub width: Option<UInt>,
}

impl ImageContent {
    /// Creates a new empty `ImageContent`.
    pub fn new() -> Self {
        Self::default()
    }

    /// Creates a new `ImageContent` with the given width and height.
    pub fn with_size(width: UInt, height: UInt) -> Self {
        Self { height: Some(height), width: Some(width) }
    }

    /// Creates a new `ImageContent` with the given optional width and height.
    ///
    /// Returns `None` if the `ImageContent` would be empty.
    pub(crate) fn from_room_message_content(
        width: Option<UInt>,
        height: Option<UInt>,
    ) -> Option<Self> {
        if width.is_none() && height.is_none() {
            None
        } else {
            Some(Self { width, height })
        }
    }

    /// Whether this `ImageContent` is empty.
    pub fn is_empty(&self) -> bool {
        self.height.is_none() && self.width.is_none()
    }
}

/// Thumbnail content.
#[derive(Clone, Debug, Deserialize, Serialize)]
#[cfg_attr(not(feature = "unstable-exhaustive-types"), non_exhaustive)]
pub struct ThumbnailContent {
    /// The file info of the thumbnail.
    #[serde(flatten)]
    pub file: ThumbnailFileContent,

    /// The image info of the thumbnail.
    #[serde(flatten, skip_serializing_if = "Option::is_none")]
    pub image: Option<Box<ImageContent>>,
}

impl ThumbnailContent {
    /// Creates a `ThumbnailContent` with the given file and image info.
    pub fn new(file: ThumbnailFileContent, image: Option<Box<ImageContent>>) -> Self {
        Self { file, image }
    }

    /// Create a `ThumbnailContent` with the given thumbnail source and info.
    ///
    /// Returns `None` if no thumbnail was found.
    pub(crate) fn from_room_message_content(
        source: Option<MediaSource>,
        info: Option<Box<ThumbnailInfo>>,
    ) -> Option<Self> {
        source.map(|source| {
            let ThumbnailInfo { height, width, mimetype, size } = *info.unwrap_or_default();

            let file = ThumbnailFileContent::from_room_message_content(source, mimetype, size);
            let image = ImageContent::from_room_message_content(width, height).map(Box::new);

            Self { file, image }
        })
    }
}

/// Thumbnail file content.
#[derive(Clone, Debug, Serialize, Deserialize)]
#[cfg_attr(not(feature = "unstable-exhaustive-types"), non_exhaustive)]
pub struct ThumbnailFileContent {
    /// The URL to the thumbnail.
    pub url: OwnedMxcUri,

    /// Information about the uploaded thumbnail.
    #[serde(flatten, skip_serializing_if = "Option::is_none")]
    pub info: Option<Box<ThumbnailFileContentInfo>>,

    /// Information on the encrypted thumbnail.
    ///
    /// Required if the thumbnail is encrypted.
    #[serde(flatten, skip_serializing_if = "Option::is_none")]
    pub encryption_info: Option<Box<EncryptedContent>>,
}

impl ThumbnailFileContent {
    /// Creates a new non-encrypted `ThumbnailFileContent` with the given url and file info.
    pub fn plain(url: OwnedMxcUri, info: Option<Box<ThumbnailFileContentInfo>>) -> Self {
        Self { url, info, encryption_info: None }
    }

    /// Creates a new encrypted `ThumbnailFileContent` with the given url, encryption info and
    /// thumbnail file info.
    pub fn encrypted(
        url: OwnedMxcUri,
        encryption_info: EncryptedContent,
        info: Option<Box<ThumbnailFileContentInfo>>,
    ) -> Self {
        Self { url, info, encryption_info: Some(Box::new(encryption_info)) }
    }

    /// Create a `ThumbnailFileContent` with the given thumbnail source and info.
    fn from_room_message_content(
        source: MediaSource,
        mimetype: Option<String>,
        size: Option<UInt>,
    ) -> Self {
        let info =
            ThumbnailFileContentInfo::from_room_message_content(mimetype, size).map(Box::new);
        match source.into_extensible_content() {
            (url, None) => Self::plain(url, info),
            (url, Some(encryption_info)) => Self::encrypted(url, encryption_info, info),
        }
    }

    /// Whether the thumbnail file is encrypted.
    pub fn is_encrypted(&self) -> bool {
        self.encryption_info.is_some()
    }
}

/// Information about a thumbnail file content.
#[derive(Clone, Debug, Default, Serialize, Deserialize)]
#[cfg_attr(not(feature = "unstable-exhaustive-types"), non_exhaustive)]
pub struct ThumbnailFileContentInfo {
    /// The mimetype of the thumbnail, e.g. `image/png`.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub mimetype: Option<String>,

    /// The size of the thumbnail in bytes.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub size: Option<UInt>,
}

impl ThumbnailFileContentInfo {
    /// Creates an empty `ThumbnailFileContentInfo`.
    pub fn new() -> Self {
        Self::default()
    }

    /// Creates a new `ThumbnailFileContentInfo` with the given optional MIME type and size.
    ///
    /// Returns `None` if the `ThumbnailFileContentInfo` would be empty.
    fn from_room_message_content(mimetype: Option<String>, size: Option<UInt>) -> Option<Self> {
        if mimetype.is_none() && size.is_none() {
            None
        } else {
            Some(Self { mimetype, size })
        }
    }
}