use std::collections::{HashMap, HashSet};
use anyhow::Context;
use async_trait::async_trait;
use tokio::sync::RwLock;
use crate::{MatrixUser, ProvisionRequest};
struct MockUser {
    sub: String,
    avatar_url: Option<String>,
    displayname: Option<String>,
    devices: HashSet<String>,
    emails: Option<Vec<String>>,
    cross_signing_reset_allowed: bool,
    deactivated: bool,
}
pub struct HomeserverConnection {
    homeserver: String,
    users: RwLock<HashMap<String, MockUser>>,
    reserved_localparts: RwLock<HashSet<&'static str>>,
}
impl HomeserverConnection {
    pub fn new<H>(homeserver: H) -> Self
    where
        H: Into<String>,
    {
        Self {
            homeserver: homeserver.into(),
            users: RwLock::new(HashMap::new()),
            reserved_localparts: RwLock::new(HashSet::new()),
        }
    }
    pub async fn reserve_localpart(&self, localpart: &'static str) {
        self.reserved_localparts.write().await.insert(localpart);
    }
}
#[async_trait]
impl crate::HomeserverConnection for HomeserverConnection {
    fn homeserver(&self) -> &str {
        &self.homeserver
    }
    async fn query_user(&self, mxid: &str) -> Result<MatrixUser, anyhow::Error> {
        let users = self.users.read().await;
        let user = users.get(mxid).context("User not found")?;
        Ok(MatrixUser {
            displayname: user.displayname.clone(),
            avatar_url: user.avatar_url.clone(),
            deactivated: user.deactivated,
        })
    }
    async fn provision_user(&self, request: &ProvisionRequest) -> Result<bool, anyhow::Error> {
        let mut users = self.users.write().await;
        let inserted = !users.contains_key(request.mxid());
        let user = users.entry(request.mxid().to_owned()).or_insert(MockUser {
            sub: request.sub().to_owned(),
            avatar_url: None,
            displayname: None,
            devices: HashSet::new(),
            emails: None,
            cross_signing_reset_allowed: false,
            deactivated: false,
        });
        anyhow::ensure!(
            user.sub == request.sub(),
            "User already provisioned with different sub"
        );
        request.on_emails(|emails| {
            user.emails = emails.map(ToOwned::to_owned);
        });
        request.on_displayname(|displayname| {
            user.displayname = displayname.map(ToOwned::to_owned);
        });
        request.on_avatar_url(|avatar_url| {
            user.avatar_url = avatar_url.map(ToOwned::to_owned);
        });
        Ok(inserted)
    }
    async fn is_localpart_available(&self, localpart: &str) -> Result<bool, anyhow::Error> {
        if self.reserved_localparts.read().await.contains(localpart) {
            return Ok(false);
        }
        let mxid = self.mxid(localpart);
        let users = self.users.read().await;
        Ok(!users.contains_key(&mxid))
    }
    async fn create_device(&self, mxid: &str, device_id: &str) -> Result<(), anyhow::Error> {
        let mut users = self.users.write().await;
        let user = users.get_mut(mxid).context("User not found")?;
        user.devices.insert(device_id.to_owned());
        Ok(())
    }
    async fn delete_device(&self, mxid: &str, device_id: &str) -> Result<(), anyhow::Error> {
        let mut users = self.users.write().await;
        let user = users.get_mut(mxid).context("User not found")?;
        user.devices.remove(device_id);
        Ok(())
    }
    async fn sync_devices(
        &self,
        mxid: &str,
        devices: HashSet<String>,
    ) -> Result<(), anyhow::Error> {
        let mut users = self.users.write().await;
        let user = users.get_mut(mxid).context("User not found")?;
        user.devices = devices;
        Ok(())
    }
    async fn delete_user(&self, mxid: &str, erase: bool) -> Result<(), anyhow::Error> {
        let mut users = self.users.write().await;
        let user = users.get_mut(mxid).context("User not found")?;
        user.devices.clear();
        user.emails = None;
        user.deactivated = true;
        if erase {
            user.avatar_url = None;
            user.displayname = None;
        }
        Ok(())
    }
    async fn reactivate_user(&self, mxid: &str) -> Result<(), anyhow::Error> {
        let mut users = self.users.write().await;
        let user = users.get_mut(mxid).context("User not found")?;
        user.deactivated = false;
        Ok(())
    }
    async fn set_displayname(&self, mxid: &str, displayname: &str) -> Result<(), anyhow::Error> {
        let mut users = self.users.write().await;
        let user = users.get_mut(mxid).context("User not found")?;
        user.displayname = Some(displayname.to_owned());
        Ok(())
    }
    async fn unset_displayname(&self, mxid: &str) -> Result<(), anyhow::Error> {
        let mut users = self.users.write().await;
        let user = users.get_mut(mxid).context("User not found")?;
        user.displayname = None;
        Ok(())
    }
    async fn allow_cross_signing_reset(&self, mxid: &str) -> Result<(), anyhow::Error> {
        let mut users = self.users.write().await;
        let user = users.get_mut(mxid).context("User not found")?;
        user.cross_signing_reset_allowed = true;
        Ok(())
    }
}
#[cfg(test)]
mod tests {
    use super::*;
    use crate::HomeserverConnection as _;
    #[tokio::test]
    async fn test_mock_connection() {
        let conn = HomeserverConnection::new("example.org");
        let mxid = "@test:example.org";
        let device = "test";
        assert_eq!(conn.homeserver(), "example.org");
        assert_eq!(conn.mxid("test"), mxid);
        assert!(conn.query_user(mxid).await.is_err());
        assert!(conn.create_device(mxid, device).await.is_err());
        assert!(conn.delete_device(mxid, device).await.is_err());
        let request = ProvisionRequest::new("@test:example.org", "test")
            .set_displayname("Test User".into())
            .set_avatar_url("mxc://example.org/1234567890".into())
            .set_emails(vec!["test@example.org".to_owned()]);
        let inserted = conn.provision_user(&request).await.unwrap();
        assert!(inserted);
        let user = conn.query_user(mxid).await.unwrap();
        assert_eq!(user.displayname, Some("Test User".into()));
        assert_eq!(user.avatar_url, Some("mxc://example.org/1234567890".into()));
        assert!(conn.set_displayname(mxid, "John").await.is_ok());
        let user = conn.query_user(mxid).await.unwrap();
        assert_eq!(user.displayname, Some("John".into()));
        assert!(conn.unset_displayname(mxid).await.is_ok());
        let user = conn.query_user(mxid).await.unwrap();
        assert_eq!(user.displayname, None);
        assert!(conn.delete_device(mxid, device).await.is_ok());
        assert!(conn.create_device(mxid, device).await.is_ok());
        assert!(conn.create_device(mxid, device).await.is_ok());
        assert!(conn.delete_device(mxid, device).await.is_ok());
        assert!(!conn.is_localpart_available("test").await.unwrap());
        assert!(conn.is_localpart_available("alice").await.unwrap());
        conn.reserve_localpart("alice").await;
        assert!(!conn.is_localpart_available("alice").await.unwrap());
    }
}