use std::sync::Arc;

use database::{KeyValueDatabase, KvTree};
use ruma::{
	api::client::push::{set_pusher, Pusher},
	UserId,
};

use crate::{utils, Error, Result};

pub struct Data {
	senderkey_pusher: Arc<dyn KvTree>,
}

impl Data {
	pub(super) fn new(db: &Arc<KeyValueDatabase>) -> Self {
		Self {
			senderkey_pusher: db.senderkey_pusher.clone(),
		}
	}

	pub(super) fn set_pusher(&self, sender: &UserId, pusher: set_pusher::v3::PusherAction) -> Result<()> {
		match &pusher {
			set_pusher::v3::PusherAction::Post(data) => {
				let mut key = sender.as_bytes().to_vec();
				key.push(0xFF);
				key.extend_from_slice(data.pusher.ids.pushkey.as_bytes());
				self.senderkey_pusher
					.insert(&key, &serde_json::to_vec(&pusher).expect("Pusher is valid JSON value"))?;
				Ok(())
			},
			set_pusher::v3::PusherAction::Delete(ids) => {
				let mut key = sender.as_bytes().to_vec();
				key.push(0xFF);
				key.extend_from_slice(ids.pushkey.as_bytes());
				self.senderkey_pusher.remove(&key).map_err(Into::into)
			},
		}
	}

	pub(super) fn get_pusher(&self, sender: &UserId, pushkey: &str) -> Result<Option<Pusher>> {
		let mut senderkey = sender.as_bytes().to_vec();
		senderkey.push(0xFF);
		senderkey.extend_from_slice(pushkey.as_bytes());

		self.senderkey_pusher
			.get(&senderkey)?
			.map(|push| serde_json::from_slice(&push).map_err(|_| Error::bad_database("Invalid Pusher in db.")))
			.transpose()
	}

	pub(super) fn get_pushers(&self, sender: &UserId) -> Result<Vec<Pusher>> {
		let mut prefix = sender.as_bytes().to_vec();
		prefix.push(0xFF);

		self.senderkey_pusher
			.scan_prefix(prefix)
			.map(|(_, push)| serde_json::from_slice(&push).map_err(|_| Error::bad_database("Invalid Pusher in db.")))
			.collect()
	}

	pub(super) fn get_pushkeys<'a>(&'a self, sender: &UserId) -> Box<dyn Iterator<Item = Result<String>> + 'a> {
		let mut prefix = sender.as_bytes().to_vec();
		prefix.push(0xFF);

		Box::new(self.senderkey_pusher.scan_prefix(prefix).map(|(k, _)| {
			let mut parts = k.splitn(2, |&b| b == 0xFF);
			let _senderkey = parts.next();
			let push_key = parts
				.next()
				.ok_or_else(|| Error::bad_database("Invalid senderkey_pusher in db"))?;
			let push_key_string = utils::string_from_bytes(push_key)
				.map_err(|_| Error::bad_database("Invalid pusher bytes in senderkey_pusher"))?;

			Ok(push_key_string)
		}))
	}
}