use crate::error::{Error, Result};
use serde::{Deserialize, Deserializer, Serialize};
//use serde_json::json;
//use serde_json::Result;

#[derive(Serialize, Deserialize, PartialEq, Debug, Clone)]
pub struct Event {
    pub(crate) id: String,
    pub(crate) pubkey: String,
    pub(crate) created_at: u64,
    pub(crate) kind: u8,
    #[serde(deserialize_with = "tag_from_string")]
    pub(crate) tags: Vec<Vec<String>>,
    pub(crate) content: String,
    pub(crate) sig: String,
}

type Tag = Vec<Vec<String>>;

// handle a default value (empty vec) for null tags
fn tag_from_string<'de, D>(deserializer: D) -> Result<Tag, D::Error>
where
    D: Deserializer<'de>,
{
    let opt = Option::deserialize(deserializer)?;
    Ok(opt.unwrap_or_else(|| vec![]))
}

// Goals:
// Roundtrip from JSON-string to Event, and back to string.
// Perform validation on an Event to ensure the id and signature are correct.

impl Event {
    pub fn parse(json: &str) -> Result<Event> {
        let _e: Event = serde_json::from_str(json)?;
        Err(Error::EventParseFailed)
    }

    // check if this event is valid (should be propagated, stored) based on signature.
    pub fn is_valid(&self) -> bool {
        false
    }
    // check if given event is referenced in a tag
    pub fn event_tag_match(&self, event: &str) -> bool {
        for t in self.tags.iter() {
            if t.len() == 2 {
                if t.get(0).unwrap() == "#e" {
                    if t.get(1).unwrap() == event {
                        return true;
                    }
                }
            }
        }
        return false;
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    fn simple_event() -> Event {
        super::Event {
            id: "0".to_owned(),
            pubkey: "0".to_owned(),
            created_at: 0,
            kind: 0,
            tags: vec![],
            content: "".to_owned(),
            sig: "0".to_owned(),
        }
    }

    #[test]
    fn event_creation() {
        // create an event
        let event = simple_event();
        assert_eq!(event.id, "0");
    }

    #[test]
    fn event_serialize() -> Result<()> {
        // serialize an event to JSON string
        let event = simple_event();
        let j = serde_json::to_string(&event)?;
        assert_eq!(j, "{\"id\":\"0\",\"pubkey\":\"0\",\"created_at\":0,\"kind\":0,\"tags\":[],\"content\":\"\",\"sig\":\"0\"}");
        Ok(())
    }

    #[test]
    fn event_tags_serialize() -> Result<()> {
        // serialize an event with tags to JSON string
        let mut event = simple_event();
        event.tags = vec![
            vec![
                "e".to_owned(),
                "xxxx".to_owned(),
                "wss://example.com".to_owned(),
            ],
            vec![
                "p".to_owned(),
                "yyyyy".to_owned(),
                "wss://example.com:3033".to_owned(),
            ],
        ];
        let j = serde_json::to_string(&event)?;
        assert_eq!(j, "{\"id\":\"0\",\"pubkey\":\"0\",\"created_at\":0,\"kind\":0,\"tags\":[[\"e\",\"xxxx\",\"wss://example.com\"],[\"p\",\"yyyyy\",\"wss://example.com:3033\"]],\"content\":\"\",\"sig\":\"0\"}");
        Ok(())
    }

    #[test]
    fn event_deserialize() -> Result<()> {
        let raw_json = r#"{"id":"1384757da583e6129ce831c3d7afc775a33a090578f888dd0d010328ad047d0c","pubkey":"bbbd9711d357df4f4e498841fd796535c95c8e751fa35355008a911c41265fca","created_at":1612650459,"kind":1,"tags":null,"content":"hello world","sig":"59d0cc47ab566e81f72fe5f430bcfb9b3c688cb0093d1e6daa49201c00d28ecc3651468b7938642869ed98c0f1b262998e49a05a6ed056c0d92b193f4e93bc21"}"#;
        // id: 1384757da583e6129ce831c3d7afc775a33a090578f888dd0d010328ad047d0c
        // pubkey: bbbd9711d357df4f4e498841fd796535c95c8e751fa35355008a911c41265fca",
        // created_at: 1612650459
        // kind :1,
        // tags":null,
        // "content":"hello world",
        // "sig":"59d0cc47ab566e81f72fe5f430bcfb9b3c688cb0093d1e6daa49201c00d28ecc3651468b7938642869ed98c0f1b262998e49a05a6ed056c0d92b193f4e93bc21"}]"#;
        let e: Event = serde_json::from_str(raw_json)?;
        // assert that the kind is 1
        assert_eq!(e.kind, 1);
        assert_eq!(e.tags.len(), 0);
        Ok(())
    }
}