// Copyright (c) 2022-2024 Niko Bonnieure, Par le Peuple, NextGraph.org developers
// All rights reserved.
// Licensed under the Apache License, Version 2.0
// <LICENSE-APACHE2 or http://www.apache.org/licenses/LICENSE-2.0>
// or the MIT license <LICENSE-MIT or http://opensource.org/licenses/MIT>,
// at your option. All files in the project carrying such
// notice may not be copied, modified, or distributed except
// according to those terms.

//! Types for Verifier

use core::fmt;
//use oxigraph::io::{RdfFormat, RdfParser, RdfSerializer};
use oxigraph::store::Store;
//use oxigraph::model::GroundQuad;
#[cfg(not(target_family = "wasm"))]
use crate::rocksdb_user_storage::RocksDbUserStorage;
use crate::user_storage::{InMemoryUserStorage, UserStorage};
use std::path::PathBuf;

use ng_net::{
    types::*,
    utils::{Receiver, Sender},
};
use ng_repo::{
    errors::{NgError, StorageError},
    types::*,
};
use serde::{Deserialize, Serialize};
//use yrs::{StateVector, Update};

#[derive(Debug, Clone)]
pub enum VerifierType {
    /// nothing will be saved on disk during the session
    Memory,
    /// will save all user data locally, with RocksDb backend
    RocksDb,
    /// the verifier will be remote. a Noise connection will be opened
    /// optional peerId to connect to. If None, will try any that has the flag `can_verify`
    Remote(Option<PubKey>),
    /// IndexedDb based rocksdb compiled to WASM... not ready yet. obviously. only works in the browser
    WebRocksDb,
}

impl VerifierType {
    pub fn is_memory(&self) -> bool {
        match self {
            Self::Memory => true,
            _ => false,
        }
    }
}

//type LastSeqFn = fn(PubKey, u16) -> Result<u64, NgError>;
pub type LastSeqFn = dyn Fn(PubKey, u16) -> Result<u64, NgError> + 'static + Sync + Send;

// peer_id: PubKey, seq_num:u64, event_ser: vec<u8>,
pub type OutboxWriteFn =
    dyn Fn(PubKey, u64, Vec<u8>) -> Result<(), NgError> + 'static + Sync + Send;

// peer_id: PubKey,
pub type OutboxReadFn = dyn Fn(PubKey) -> Result<Vec<Vec<u8>>, NgError> + 'static + Sync + Send;

pub struct JsSaveSessionConfig {
    pub last_seq_function: Box<LastSeqFn>,
    pub outbox_write_function: Box<OutboxWriteFn>,
    pub outbox_read_function: Box<OutboxReadFn>,
}

impl fmt::Debug for JsSaveSessionConfig {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "JsSaveSessionConfig")
    }
}

#[derive(Debug)]
pub enum VerifierConfigType {
    /// nothing will be saved on disk during the session
    Memory,
    JsSaveSession(JsSaveSessionConfig),
    /// will save all user data locally, with RocksDb backend
    RocksDb(PathBuf),
    /// the verifier will be remote. a Noise connection will be opened
    /// optional peerId to connect to. If None, will try any that has the flag `can_verify`
    /// // TODO: Pass the AppConfig
    Remote(Option<PubKey>),
    /// IndexedDb based rocksdb compiled to WASM... not ready yet. obviously. only works in the browser
    WebRocksDb,
}

#[derive(Debug)]
pub struct VerifierConfig {
    pub config_type: VerifierConfigType,
    /// not used for Memory
    pub user_master_key: [u8; 32],
    /// not used for Memory
    pub peer_priv_key: PrivKey,
    pub user_priv_key: PrivKey,
    pub private_store_read_cap: ObjectRef,
}

pub type CancelFn = Box<dyn FnOnce()>;

pub struct Verifier {
    pub config: VerifierConfig,
    pub connected_server_id: Option<PubKey>,
    graph_dataset: Option<Store>,
    user_storage: Option<Box<dyn UserStorage>>,
}

impl fmt::Debug for Verifier {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        writeln!(f, "Verifier\nconfig: {:?}", self.config)?;
        writeln!(f, "connected_server_id: {:?}", self.connected_server_id)
    }
}

impl Verifier {
    pub fn new(config: VerifierConfig) -> Result<Self, StorageError> {
        let (graph, user) = match &config.config_type {
            VerifierConfigType::Memory | VerifierConfigType::JsSaveSession(_) => (
                Some(Store::new().unwrap()),
                Some(Box::new(InMemoryUserStorage::new()) as Box<dyn UserStorage>),
            ),
            #[cfg(not(target_family = "wasm"))]
            VerifierConfigType::RocksDb(path) => (
                // FIXME BIG TIME: we are reusing the same encryption key here.
                // this is very temporary, until we remove the code in oxi_rocksdb of oxigraph,
                // and have oxigraph use directly the UserStorage
                Some(Store::open_with_key(path, config.user_master_key).unwrap()),
                Some(
                    Box::new(RocksDbUserStorage::open(path, config.user_master_key)?)
                        as Box<dyn UserStorage>,
                ),
            ),
            VerifierConfigType::Remote(_) => (None, None),
            _ => unimplemented!(), // can be WebRocksDb or RocksDb on wasm platforms
        };
        Ok(Verifier {
            config,
            connected_server_id: None,
            graph_dataset: graph,
            user_storage: user,
        })
    }

    pub fn doc_fetch(
        &self,
        nuri: String,
        payload: Option<AppRequestPayload>,
    ) -> Result<(Receiver<AppResponse>, CancelFn), NgError> {
        unimplemented!();
    }
}

//
// APP PROTOCOL (between APP and VERIFIER)
//

#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct AppRequestV0 {}

#[derive(Clone, Debug, Serialize, Deserialize)]
pub enum AppRequest {
    V0(AppRequestV0),
}

#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct GraphUpdate {
    sparql_update: String,
}

#[derive(Clone, Debug, Serialize, Deserialize)]
pub enum DiscreteUpdate {
    /// A yrs::Update
    YMap(Vec<u8>),
    YXml(Vec<u8>),
    YText(Vec<u8>),
    /// An automerge::Patch
    Automerge(Vec<u8>),
}

#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct AppUpdate {
    heads: Vec<ObjectId>,
    graph: Option<GraphUpdate>,
    discrete: Option<DiscreteUpdate>,
}

#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct AppCreate {
    store: StoreRepo,
    content_type: BranchContentType,
}

#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct AppDelete {
    /// Nuri of doc to delete
    nuri: String,
}

#[derive(Clone, Debug, Serialize, Deserialize)]
pub enum AppRequestPayloadV0 {
    Create(AppCreate),
    Update(AppUpdate),
    Delete(AppDelete),
}

#[derive(Clone, Debug, Serialize, Deserialize)]
pub enum AppRequestPayload {
    V0(AppRequestPayloadV0),
}

#[derive(Clone, Debug, Serialize, Deserialize)]
pub enum DiscretePatch {
    /// A yrs::Update
    YMap(Vec<u8>),
    YXml(Vec<u8>),
    YText(Vec<u8>),
    /// An automerge::Patch
    Automerge(Vec<u8>),
}

#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct GraphPatch {
    /// oxigraph::model::GroundQuad serialized in turtle with oxrdfio
    pub adds: Vec<String>,
    pub removes: Vec<String>,
}

#[derive(Clone, Debug, Serialize, Deserialize)]
pub enum DiscreteState {
    /// A yrs::StateVector
    YMap(Vec<u8>),
    YXml(Vec<u8>),
    YText(Vec<u8>),
    // the output of Automerge::save()
    Automerge(Vec<u8>),
}

#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct GraphState {
    pub tuples: Vec<String>,
}

#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct AppState {
    heads: Vec<ObjectId>,
    graph: Option<GraphState>, // there is always a graph present in the branch. but it might not have been asked in the request
    discrete: Option<DiscreteState>,
}
#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct AppPatch {
    heads: Vec<ObjectId>,
    graph: Option<GraphPatch>,
    discrete: Option<DiscretePatch>,
}

#[derive(Clone, Debug, Serialize, Deserialize)]
pub enum AppResponseV0 {
    State(AppState),
    Patch(AppPatch),
}

#[derive(Clone, Debug, Serialize, Deserialize)]
pub enum AppResponse {
    V0(AppResponseV0),
}