//! Message types and conversion methods for `golgi`.

use std::fmt::Debug;

use kuska_ssb::api::dto::content::TypedMessage;
use serde::{Deserialize, Serialize};
use serde_json::Value;

use crate::error::GolgiError;

/// This is an alias to TypedMessage in kuska,
/// which is renamed as SsbMessageContent in golgi to fit the naming convention
/// of the other types (SsbMessageKVT and SsbMessageValue)
pub type SsbMessageContent = TypedMessage;

/// Data type representing the `value` of a message object (`KVT`). More information concerning the
/// data model can be found
/// in the [`Metadata` documentation](https://spec.scuttlebutt.nz/feed/messages.html#metadata).
#[derive(Serialize, Deserialize, Debug)]
#[serde(deny_unknown_fields)]
#[allow(missing_docs)]
pub struct SsbMessageValue {
    pub previous: Option<String>,
    pub author: String,
    pub sequence: u64,
    pub timestamp: f64,
    pub hash: String,
    pub content: Value,
    pub signature: String,
}

impl SsbMessageValue {

    /// Gets the type field of the message content if found,
    /// and if not returns "none"
    pub fn get_message_type(&self) -> String {
        let msg_type: String = self
            .content
            .get("type")
            .map(|msg_type| msg_type.to_string())
            .unwrap_or_else(|| "none".to_string());
        msg_type
    }

    /// Converts the content json value into an SsbMessageContent enum,
    /// using the "type" field as a tag to select which variant of the enum
    /// to deserialize into.
    ///
    /// See more info on this here https://serde.rs/enum-representations.html#internally-tagged
    pub fn into_ssb_message_content(self) -> Result<SsbMessageContent, GolgiError> {
        let m: SsbMessageContent = serde_json::from_value(self.content)?;
        Ok(m)
    }
}

/// Data type representing the `value` of a message object (`KVT`). More information concerning the
/// data model can be found
/// in the [`Metadata` documentation](https://spec.scuttlebutt.nz/feed/messages.html#metadata).
#[derive(Serialize, Deserialize, Debug)]
#[serde(deny_unknown_fields)]
#[allow(missing_docs)]
pub struct SsbKVT {
    pub key: String,
    pub value: SsbMessageValue,
    pub timestamp: f64,
    pub rts: Option<f64>,
}