// Copyright 2020 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

use crate::common_utils::common::get_proxy_or_connect;
use crate::weave::types::PairingState;
use anyhow::Error;
use fidl::endpoints::create_proxy;
use fidl_fuchsia_weave::{
    ErrorCode, FactoryDataManagerMarker, FactoryDataManagerProxy, PairingStateWatcherMarker,
    PairingStateWatcherProxy, StackMarker, StackProxy,
};
use parking_lot::RwLock;
use std::convert::From;

/// Perform Weave FIDL operations.
///
/// Note this object is shared among all threads created by server.
#[derive(Debug)]
pub struct WeaveFacade {
    factory_data_manager: RwLock<Option<FactoryDataManagerProxy>>,
    stack: RwLock<Option<StackProxy>>,
}

impl WeaveFacade {
    pub fn new() -> WeaveFacade {
        WeaveFacade { factory_data_manager: RwLock::new(None), stack: RwLock::new(None) }
    }

    /// Returns the FactoryDataManager proxy provided on instantiation
    /// or establishes a new connection.
    fn factory_data_manager(&self) -> Result<FactoryDataManagerProxy, Error> {
        get_proxy_or_connect::<FactoryDataManagerMarker>(&self.factory_data_manager)
    }

    /// Returns the Stack proxy provided on instantiation or establishes a new connection.
    fn stack(&self) -> Result<StackProxy, Error> {
        get_proxy_or_connect::<StackMarker>(&self.stack)
    }

    /// Returns the PairingStateWatcher proxy provided on instantiation.
    fn pairing_state_watcher(&self) -> Result<PairingStateWatcherProxy, Error> {
        let (pairing_proxy, pairing_server_end) = create_proxy::<PairingStateWatcherMarker>()?;
        self.stack()?.get_pairing_state_watcher(pairing_server_end)?;
        Ok(pairing_proxy)
    }

    /// Returns a string mapped from the provided Weave error code.
    fn map_weave_err(&self, code: ErrorCode) -> anyhow::Error {
        anyhow!(match code {
            ErrorCode::FileNotFound => "FileNotFound",
            ErrorCode::CryptoError => "CryptoError",
            ErrorCode::InvalidArgument => "InvalidArgument",
            ErrorCode::InvalidState => "InvalidState",
            ErrorCode::UnspecifiedError => "UnspecifiedError",
        })
    }

    /// Returns the pairing code from the FactoryDataManager proxy service.
    pub async fn get_pairing_code(&self) -> Result<Vec<u8>, Error> {
        self.factory_data_manager()?.get_pairing_code().await?.map_err(|e| self.map_weave_err(e))
    }

    /// Returns the qr code from the StackManager proxy service.
    pub async fn get_qr_code(&self) -> Result<String, Error> {
        self.stack()?
            .get_qr_code()
            .await?
            .map(|qr_code| qr_code.data)
            .map_err(|e| self.map_weave_err(e))
    }

    /// Returns the pairing state from the PairingStateWatcher service.
    pub async fn get_pairing_state(&self) -> Result<PairingState, Error> {
        let watch = self.pairing_state_watcher()?.watch_pairing_state().await;
        watch.map(|pairing_state| pairing_state.into()).map_err(anyhow::Error::from)
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use fidl::endpoints::create_proxy_and_stream;
    use fidl_fuchsia_weave::{
        FactoryDataManagerGetPairingCodeResult, FactoryDataManagerRequest,
        PairingStateWatcherRequest, QrCode, StackGetQrCodeResult, StackRequest,
    };
    use fuchsia_async as fasync;
    use futures::prelude::*;
    use lazy_static::lazy_static;
    use matches::assert_matches;

    lazy_static! {
        static ref PAIRING_CODE: Vec<u8> = b"ABC1234".to_vec();
        static ref QR_CODE: QrCode = QrCode { data: String::from("qrcodedata") };
        static ref PAIRING_STATE: PairingState = PairingState {
            is_wlan_provisioned: Some(true),
            is_fabric_provisioned: Some(true),
            is_service_provisioned: Some(false),
            is_weave_fully_provisioned: Some(false),
            is_thread_provisioned: Some(true)
        };
    }

    struct MockStackBuilder {
        expected_stack: Vec<Box<dyn FnOnce(StackRequest) + Send + 'static>>,
        expected_pair: Vec<Box<dyn FnOnce(PairingStateWatcherRequest) + Send + 'static>>,
    }

    impl MockStackBuilder {
        fn new() -> Self {
            Self { expected_stack: vec![], expected_pair: vec![] }
        }

        fn push_stack(mut self, request: impl FnOnce(StackRequest) + Send + 'static) -> Self {
            self.expected_stack.push(Box::new(request));
            self
        }

        fn push_pair(
            mut self,
            request: impl FnOnce(PairingStateWatcherRequest) + Send + 'static,
        ) -> Self {
            self.expected_pair.push(Box::new(request));
            self
        }

        fn expect_get_qr_code(self, mut result: StackGetQrCodeResult) -> Self {
            self.push_stack(move |req| match req {
                StackRequest::GetQrCode { responder } => responder.send(&mut result).unwrap(),
                req => panic!("unexpected request: {:?}", req),
            })
        }

        fn expect_get_pairing_state(self, result: PairingState) -> Self {
            self.push_pair(move |req| match req {
                PairingStateWatcherRequest::WatchPairingState { responder } => {
                    responder.send(fidl_fuchsia_weave::PairingState::from(result)).unwrap();
                }
            })
        }

        fn build_stack(self) -> (WeaveFacade, impl Future<Output = ()>) {
            let (proxy, mut stream) = create_proxy_and_stream::<StackMarker>().unwrap();
            let fut = async move {
                for expected in self.expected_stack {
                    expected(stream.next().await.unwrap().unwrap());
                }
                assert_matches!(stream.next().await, None);
            };
            (
                WeaveFacade {
                    stack: RwLock::new(Some(proxy)),
                    factory_data_manager: RwLock::new(None),
                },
                fut,
            )
        }
        fn build_stack_and_pairing_state_watcher(self) -> (WeaveFacade, impl Future<Output = ()>) {
            let (proxy, mut stream) = create_proxy_and_stream::<StackMarker>().unwrap();
            let stream_fut = async move {
                match stream.next().await {
                    Some(Ok(StackRequest::GetPairingStateWatcher {
                        watcher,
                        control_handle: _,
                    })) => {
                        let mut into_stream = watcher.into_stream().unwrap();
                        for expected in self.expected_pair {
                            expected(into_stream.next().await.unwrap().unwrap());
                        }
                        assert_matches!(into_stream.next().await, None);
                    }
                    err => panic!("Error in request handler: {:?}", err),
                }
            };
            (
                WeaveFacade {
                    stack: RwLock::new(Some(proxy)),
                    factory_data_manager: RwLock::new(None),
                },
                stream_fut,
            )
        }
    }

    struct MockFactoryDataManagerBuilder {
        expected: Vec<Box<dyn FnOnce(FactoryDataManagerRequest) + Send + 'static>>,
    }

    impl MockFactoryDataManagerBuilder {
        fn new() -> Self {
            Self { expected: vec![] }
        }

        fn push(
            mut self,
            request: impl FnOnce(FactoryDataManagerRequest) + Send + 'static,
        ) -> Self {
            self.expected.push(Box::new(request));
            self
        }

        fn expect_get_pairing_code(
            self,
            mut result: FactoryDataManagerGetPairingCodeResult,
        ) -> Self {
            self.push(move |req| match req {
                FactoryDataManagerRequest::GetPairingCode { responder } => {
                    responder.send(&mut result).unwrap()
                }
                _ => {}
            })
        }

        fn build(self) -> (WeaveFacade, impl Future<Output = ()>) {
            let (proxy, mut stream) =
                fidl::endpoints::create_proxy_and_stream::<FactoryDataManagerMarker>().unwrap();
            let fut = async move {
                for expected in self.expected {
                    expected(stream.next().await.unwrap().unwrap());
                }
                assert_matches!(stream.next().await, None);
            };
            (
                WeaveFacade {
                    stack: RwLock::new(None),
                    factory_data_manager: RwLock::new(Some(proxy)),
                },
                fut,
            )
        }
    }

    #[fasync::run_singlethreaded(test)]
    async fn test_get_pairing_code() {
        let (facade, pairing_code_fut) = MockFactoryDataManagerBuilder::new()
            .expect_get_pairing_code(Ok(PAIRING_CODE.to_vec()))
            .build();

        let facade_fut = async move {
            assert_eq!(facade.get_pairing_code().await.unwrap(), *PAIRING_CODE);
        };

        future::join(facade_fut, pairing_code_fut).await;
    }

    #[fasync::run_singlethreaded(test)]
    async fn test_get_qr_code() {
        let qr_clone: StackGetQrCodeResult = Ok((*QR_CODE).clone());
        let (facade, qr_code_fut) =
            MockStackBuilder::new().expect_get_qr_code(qr_clone).build_stack();

        let facade_fut = async move {
            assert_eq!(facade.get_qr_code().await.unwrap(), *QR_CODE.data);
        };

        future::join(facade_fut, qr_code_fut).await;
    }

    #[fasync::run_singlethreaded(test)]
    async fn test_get_pairing_state() {
        let (facade, pairing_state_fut) = MockStackBuilder::new()
            .expect_get_pairing_state(*PAIRING_STATE)
            .build_stack_and_pairing_state_watcher();

        let facade_fut = async move {
            let pairing_state = facade.get_pairing_state().await.unwrap();
            assert_eq!(pairing_state, *PAIRING_STATE);
        };

        future::join(facade_fut, pairing_state_fut).await;
    }
}