use serde::{
    de::{self, Deserializer},
    Deserialize, Serialize,
};
use std::convert::TryFrom;
use thiserror::Error;
use types::{Event, SubscriptionId};

pub mod client;
pub mod types;

#[derive(Debug, Error)]
pub enum Error {}

#[derive(Serialize, Debug, Clone)]
pub enum Message {
    Close(types::SubscriptionId),
    EventFromClient(types::Event),
    EventFromServer(types::SubscriptionId, types::Event),
    Request(client::Request),
    Notice(String),
    EndOfStoredEvents(String),
}

impl Message {
    pub fn as_request(&self) -> Option<&client::Request> {
        match self {
            Self::Request(x) => Some(x),
            _ => None,
        }
    }

    pub fn as_end_of_stored_events(&self) -> Option<&str> {
        match self {
            Self::EndOfStoredEvents(subscription_id) => Some(subscription_id),
            _ => None,
        }
    }

    pub fn as_event_from_server(&self) -> Option<(&types::SubscriptionId, &types::Event)> {
        match self {
            Self::EventFromServer(id, event) => Some((id, event)),
            _ => None,
        }
    }

    pub fn as_event_from_client(&self) -> Option<&types::Event> {
        match self {
            Self::EventFromClient(event) => Some(event),
            _ => None,
        }
    }

    pub fn as_notice(&self) -> Option<&str> {
        match self {
            Self::Notice(x) => Some(x),
            _ => None,
        }
    }

    pub fn as_close_subscription_id(&self) -> Option<&types::SubscriptionId> {
        match self {
            Self::Close(x) => Some(x),
            _ => None,
        }
    }
}

impl<'de> de::Deserialize<'de> for Message {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: Deserializer<'de>,
    {
        let array: Vec<serde_json::Value> = Deserialize::deserialize(deserializer)?;
        if array.is_empty() {
            return Err(de::Error::custom(
                "Invalid array length, expecting at least one",
            ));
        }

        let tag = array
            .get(0)
            .ok_or_else(|| de::Error::custom("Invalid array length, expecting at least one"))?
            .as_str()
            .ok_or_else(|| de::Error::custom("Invalid type for element 0 of the array"))?;

        match tag {
            "EOSE" => {
                if array.len() != 2 {
                    Err(de::Error::custom("Invalid length for EOSE"))
                } else {
                    Ok(Self::EndOfStoredEvents(
                        array[1]
                            .as_str()
                            .ok_or_else(|| {
                                de::Error::custom("Invalid subscription_id, expecting string")
                            })?
                            .to_owned(),
                    ))
                }
            }
            "EVENT" => match array.len() {
                3 => {
                    let subscription_id: SubscriptionId = array[1]
                        .as_str()
                        .map(TryFrom::try_from)
                        .transpose()
                        .map_err(|e: types::subscription_id::Error| {
                            de::Error::custom(e.to_string())
                        })?
                        .ok_or_else(|| de::Error::custom("Invalid subscription ID"))?;

                    let event: Event = serde_json::from_value(array[2].clone())
                        .map_err(|e: serde_json::Error| de::Error::custom(e.to_string()))?;

                    event
                        .is_valid()
                        .map_err(|e| de::Error::custom(e.to_string()))?;

                    Ok(Self::EventFromServer(subscription_id, event))
                }
                2 => {
                    let event: Event = serde_json::from_value(array[1].clone())
                        .map_err(|e: serde_json::Error| de::Error::custom(e.to_string()))?;

                    event
                        .is_valid()
                        .map_err(|e| de::Error::custom(e.to_string()))?;

                    Ok(Self::EventFromClient(event))
                }
                _ => Err(de::Error::custom("Invalid length for EVENT")),
            },

            "NOTICE" => Ok(Self::Notice(
                serde_json::from_value(
                    array
                        .get(1)
                        .ok_or_else(|| de::Error::custom("Missing element 1 of the array"))?
                        .clone(),
                )
                .map_err(|e: serde_json::Error| de::Error::custom(e.to_string()))?,
            )),
            "CLOSE" => Ok(Self::Close(
                serde_json::from_value(
                    array
                        .get(1)
                        .ok_or_else(|| de::Error::custom("Missing element 1 of the array"))?
                        .clone(),
                )
                .map_err(|e: serde_json::Error| de::Error::custom(e.to_string()))?,
            )),
            "REQ" => {
                let subscription_id = array
                    .get(1)
                    .ok_or_else(|| de::Error::custom("Missing element 1 in the array"))?
                    .as_str()
                    .ok_or_else(|| {
                        de::Error::custom("Invalid type for element 1, expecting a string")
                    })?
                    .try_into()
                    .map_err(|e: types::subscription_id::Error| {
                        de::Error::custom(format!("Invalid subscription id: {}", e))
                    })?;

                Ok(Self::Request(client::Request {
                    subscription_id,
                    filters: if array.len() > 2 {
                        serde_json::from_value::<Vec<types::Filter>>(serde_json::Value::Array(
                            array[2..].to_owned(),
                        ))
                        .map_err(|e: serde_json::Error| de::Error::custom(e.to_string()))?
                    } else {
                        vec![]
                    },
                }))
            }
            tag => Err(de::Error::custom(format!("{} is not a support tag", tag))),
        }
    }
}

#[cfg(test)]
mod test {
    use crate::types::{content::EncryptedData, Content};

    use super::*;

    #[test]
    fn unsupported() {
        let json = "[\"CLOSEX\", \"foo\"]";
        let message: Result<Message, _> = serde_json::from_str(json);
        assert!(message.is_err());
    }

    #[test]
    fn event_from_server() {
        let json = "[\"EVENT\",\"640bddcc93eae\",{\"content\":\"🤙\",\"created_at\":1676637072,\"id\":\"a3eaa71e4f46c1a69ac0596ae7c2af35807fc0b0d3b208b79a36eef67ef51743\",\"kind\":7,\"pubkey\":\"b2815682cfc83fcd2c3add05785cf4573dd388457069974cc6d8cca06b3c3b78\",\"sig\":\"93a3e9c4f6cb9a704885c4f77f6d7b16153e8eedc967603602606147f8c78d426f547d54120b80b33bd2101de638c06f2932df4daf53d66ca9b1341f2fd45729\",\"tags\":[[\"p\",\"8fe53b37518e3dbe9bab26d912292001d8b882de9456b7b08b615f912dc8bf4a\",\"\",\"mention\"],[\"e\",\"eb278e983fcedbb0d143c4250c879d078d037586c5dca8e1cf1a104f9846a460\"],[\"p\",\"2bda4f03446bc1c6ff00594e350a1e7ec57fb9cdc4a7b52694223d56ce0599e9\"]]}]";
        let message: Message = serde_json::from_str(json).expect("valid message");
        assert!(message.as_event_from_server().is_some());

        let (_, event) = message.as_event_from_server().expect("event");
        assert_eq!(
            "🤙".to_owned(),
            event.data.content.try_to_string().expect("string")
        );
    }

    #[test]
    fn follow_list() {
        let json = r#"["EVENT","640e914a22321",{"content":"{\"wss:\\/\\/nos.lol\":{\"write\":true,\"read\":true},\"wss:\\/\\/relay.damus.io\":{\"write\":true,\"read\":true},\"wss:\\/\\/brb.io\":{\"write\":true,\"read\":true},\"wss:\\/\\/nostr.orangepill.dev\":{\"write\":true,\"read\":true},\"wss:\\/\\/relay.current.fyi\":{\"write\":true,\"read\":true},\"wss:\\/\\/eden.nostr.land\":{\"write\":true,\"read\":true},\"wss:\\/\\/relay.snort.social\":{\"write\":true,\"read\":true}}","created_at":1678476548,"id":"b8d7f6a19c3d9625b9aade947166708fbc6ab2dd7e3f3af84f1de08ea10d6f38","kind":3,"pubkey":"b2815682cfc83fcd2c3add05785cf4573dd388457069974cc6d8cca06b3c3b78","sig":"352485a162805e72a1e278a4a7bc33facd54a71e0f4c23934f35eee57eaa38c62e6260bf7624e2bd96bc6bcf93373b06c5245e28a266bfe2fbf064224e713fd6","tags":[["p","3efdaebb1d8923ebd99c9e7ace3b4194ab45512e2be79c1b7d68d9243e0d2681"],["p","b2815682cfc83fcd2c3add05785cf4573dd388457069974cc6d8cca06b3c3b78"],["p","387519cafd325668ecffe59577f37238638da4cf2d985b82f932fc81d33da1e8"],["p","81d0ccce4591fc4e19e3ef752a2b003ef23a986cb31e7835ea7d8d7cd96d47ea"],["p","0861144c765ea10e39a48473a51bee604886e18abd0f831cc5ed7651e68a1caf"],["p","1779284c21126b5e1af6dcb84949ceacad781ce4ce0d1691292a41229465a54a"],["p","d7df5567015930b17c125b3a7cf29bef23aa5a68d09cd6518d291359606aab7b"],["p","82341f882b6eabcd2ba7f1ef90aad961cf074af15b9ef44a09f9d2a8fbfbe6a2"],["p","32e1827635450ebb3c5a7d12c1f8e7b2b514439ac10a67eef3d9fd9c5c68e245"],["p","a47457722e10ba3a271fbe7040259a3c4da2cf53bfd1e198138214d235064fc2"],["p","e1055729d51e037b3c14e8c56e2c79c22183385d94aadb32e5dc88092cd0fef4"],["p","2bda4f03446bc1c6ff00594e350a1e7ec57fb9cdc4a7b52694223d56ce0599e9"],["p","c57717ec7a6af20b836a9468282948dc0adba64d30abfb40aa8c6664dde3cfc7"],["p","6094dd769f94fab1a2915c1a3d8360e49cec84977f433a872bea1763466db784"]]}]"#;
        let message: Message = serde_json::from_str(json).expect("valid message");
        assert!(message.as_event_from_server().is_some());

        let (_, event) = message.as_event_from_server().expect("event");
        assert_eq!(event.data.tags.len(), 14);
        event
            .data
            .tags
            .iter()
            .map(|tag| {
                tag.is_pubkey();
            })
            .for_each(drop);
    }

    #[test]
    fn direct_message() {
        let json = r#"["EVENT","640e9851d461a",{"content":"/9Xk4PfEF8hU+C1wq4grww==?iv=XB/ytLhL0WKQ1of4wXIXCg==","created_at":1677726088,"id":"4643c79276730e25a8510163622335bb9d44aecdd0c596409804abb29910652d","kind":4,"pubkey":"b2815682cfc83fcd2c3add05785cf4573dd388457069974cc6d8cca06b3c3b78","sig":"23790fae080eaa87f2abf2df4e5fd49cecc67e58271910d7e871fb197641294cad92c2a6fff1501982d776648eecb1e4650ccfbb742a2d901226a9b00c310489","tags":[["p","b2815682cfc83fcd2c3add05785cf4573dd388457069974cc6d8cca06b3c3b78"]]}]"#;
        let message: Message = serde_json::from_str(json).expect("valid message");
        assert!(message.as_event_from_server().is_some());

        let (_, event) = message.as_event_from_server().expect("event");
        let content = Content::DirectMessage(EncryptedData {
            encrypted_message: vec![
                255, 213, 228, 224, 247, 196, 23, 200, 84, 248, 45, 112, 171, 136, 43, 195,
            ],
            iv: vec![
                255, 213, 228, 224, 247, 196, 23, 200, 84, 248, 45, 112, 171, 136, 43, 195,
            ],
        });
        assert_eq!(event.data.tags.len(), 1);
        assert_eq!(event.data.content, content);
    }

    #[test]
    fn close() {
        let json = "[\"CLOSE\", \"foo\"]";
        let message: Message = serde_json::from_str(json).expect("valid message");
        let subscription_id = message
            .as_close_subscription_id()
            .expect("valid subscription_id");

        assert_eq!("foo".to_owned(), subscription_id.to_string());
    }
}