use dioxus_core::Event;

pub type CompositionEvent = Event<CompositionData>;

pub struct CompositionData {
    inner: Box<dyn HasCompositionData>,
}

impl std::fmt::Debug for CompositionData {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.debug_struct("CompositionData")
            .field("data", &self.data())
            .finish()
    }
}

impl<E: HasCompositionData> From<E> for CompositionData {
    fn from(e: E) -> Self {
        Self { inner: Box::new(e) }
    }
}

impl PartialEq for CompositionData {
    fn eq(&self, other: &Self) -> bool {
        self.data() == other.data()
    }
}

impl CompositionData {
    /// Create a new CompositionData
    pub fn new(inner: impl HasCompositionData + 'static) -> Self {
        Self {
            inner: Box::new(inner),
        }
    }

    /// The characters generated by the input method that raised the event
    pub fn data(&self) -> String {
        self.inner.data()
    }

    pub fn downcast<T: 'static>(&self) -> Option<&T> {
        self.inner.as_any().downcast_ref()
    }
}

#[cfg(feature = "serialize")]
/// A serialized version of CompositionData
#[derive(serde::Serialize, serde::Deserialize, Debug, PartialEq, Clone)]
pub struct SerializedCompositionData {
    data: String,
}

#[cfg(feature = "serialize")]
impl From<&CompositionData> for SerializedCompositionData {
    fn from(data: &CompositionData) -> Self {
        Self { data: data.data() }
    }
}

#[cfg(feature = "serialize")]
impl HasCompositionData for SerializedCompositionData {
    fn data(&self) -> String {
        self.data.clone()
    }

    fn as_any(&self) -> &dyn std::any::Any {
        self
    }
}

#[cfg(feature = "serialize")]
impl serde::Serialize for CompositionData {
    fn serialize<S: serde::Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
        SerializedCompositionData::from(self).serialize(serializer)
    }
}

#[cfg(feature = "serialize")]
impl<'de> serde::Deserialize<'de> for CompositionData {
    fn deserialize<D: serde::Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
        let data = SerializedCompositionData::deserialize(deserializer)?;
        Ok(Self {
            inner: Box::new(data),
        })
    }
}

/// A trait for any object that has the data for a composition event
pub trait HasCompositionData: std::any::Any {
    /// The characters generated by the input method that raised the event
    fn data(&self) -> String;

    /// return self as Any
    fn as_any(&self) -> &dyn std::any::Any;
}

impl_event! [
    CompositionData;

    /// oncompositionstart
    oncompositionstart

    /// oncompositionend
    oncompositionend

    /// oncompositionupdate
    oncompositionupdate
];