#pragma once

#include <atomic>

#include <chrono>

#include <map>

#include <memory>

#include "envoy/common/exception.h"

#include "envoy/extensions/wasm/v3/wasm.pb.validate.h"

#include "envoy/http/filter.h"

#include "envoy/server/lifecycle_notifier.h"

#include "envoy/stats/scope.h"

#include "envoy/stats/stats.h"

#include "envoy/thread_local/thread_local_object.h"

#include "envoy/upstream/cluster_manager.h"

#include "source/common/common/assert.h"

#include "source/common/common/logger.h"

#include "source/common/config/datasource.h"

#include "source/common/stats/symbol_table.h"

#include "source/common/version/version.h"

#include "source/extensions/common/wasm/context.h"

#include "source/extensions/common/wasm/plugin.h"

#include "source/extensions/common/wasm/stats_handler.h"

#include "source/extensions/common/wasm/wasm_vm.h"

#include "include/proxy-wasm/exports.h"

#include "include/proxy-wasm/wasm.h"

namespace Envoy {

namespace Extensions {

namespace Common {

namespace Wasm {

using CreateContextFn =

    std::function<ContextBase*(Wasm* wasm, const std::shared_ptr<Plugin>& plugin)>;

class WasmHandle;

// Wasm execution instance. Manages the Envoy side of the Wasm interface.

class Wasm : public WasmBase, Logger::Loggable<Logger::Id::wasm> {

public:

  Wasm(WasmConfig& config, absl::string_view vm_key, const Stats::ScopeSharedPtr& scope,

       Api::Api& api, Upstream::ClusterManager& cluster_manager, Event::Dispatcher& dispatcher);

  Wasm(std::shared_ptr<WasmHandle> other, Event::Dispatcher& dispatcher);

  ~Wasm() override;

  Upstream::ClusterManager& clusterManager() const { return cluster_manager_; }

  Event::Dispatcher& dispatcher() { return dispatcher_; }

  Api::Api& api() { return api_; }

  Context* getRootContext(const std::shared_ptr<PluginBase>& plugin, bool allow_closed) {

    return static_cast<Context*>(WasmBase::getRootContext(plugin, allow_closed));

  }

  void setTimerPeriod(uint32_t root_context_id, std::chrono::milliseconds period) override;

  virtual void tickHandler(uint32_t root_context_id);

  std::shared_ptr<Wasm> sharedThis() { return std::static_pointer_cast<Wasm>(shared_from_this()); }

  Network::DnsResolverSharedPtr& dnsResolver() { return dns_resolver_; }

  // WasmBase

  void error(std::string_view message) override;

  proxy_wasm::CallOnThreadFunction callOnThreadFunction() override;

  ContextBase* createContext(const std::shared_ptr<PluginBase>& plugin) override;

  ContextBase* createRootContext(const std::shared_ptr<PluginBase>& plugin) override;

  ContextBase* createVmContext() override;

  void registerCallbacks() override;

  void getFunctions() override;

  // AccessLog::Instance

  void log(const PluginSharedPtr& plugin, const Formatter::HttpFormatterContext& log_context,

           const StreamInfo::StreamInfo& info);

  void onStatsUpdate(const PluginSharedPtr& plugin, Envoy::Stats::MetricSnapshot& snapshot);

  virtual std::string buildVersion() { return BUILD_VERSION_NUMBER; }

  void initializeLifecycle(Server::ServerLifecycleNotifier& lifecycle_notifier);

  uint32_t nextDnsToken() {

    do {

      dns_token_++;

    } while (!dns_token_);

    return dns_token_;

  }

  void setCreateContextForTesting(CreateContextFn create_context,

                                  CreateContextFn create_root_context) {

    create_context_for_testing_ = create_context;

    create_root_context_for_testing_ = create_root_context;

  }

  void setFailStateForTesting(proxy_wasm::FailState fail_state) { failed_ = fail_state; }

protected:

  friend class Context;

  void initializeStats();

  // Calls into the VM.

  proxy_wasm::WasmCallVoid<3> on_resolve_dns_;

  proxy_wasm::WasmCallVoid<2> on_stats_update_;

  Stats::ScopeSharedPtr scope_;

  Api::Api& api_;

  Stats::StatNamePool stat_name_pool_;

  const Stats::StatName custom_stat_namespace_;

  Upstream::ClusterManager& cluster_manager_;

  Event::Dispatcher& dispatcher_;

  Event::PostCb server_shutdown_post_cb_;

  absl::flat_hash_map<uint32_t, Event::TimerPtr> timer_; // per root_id.

  TimeSource& time_source_;

  // Lifecycle stats

  LifecycleStatsHandler lifecycle_stats_handler_;

  // Plugin stats

  absl::flat_hash_map<uint32_t, Stats::Counter*> counters_;

  absl::flat_hash_map<uint32_t, Stats::Gauge*> gauges_;

  absl::flat_hash_map<uint32_t, Stats::Histogram*> histograms_;

  CreateContextFn create_context_for_testing_;

  CreateContextFn create_root_context_for_testing_;

  Network::DnsResolverSharedPtr dns_resolver_;

  uint32_t dns_token_ = 1;

};

using WasmSharedPtr = std::shared_ptr<Wasm>;

class WasmHandle : public WasmHandleBase, public ThreadLocal::ThreadLocalObject {

public:

  explicit WasmHandle(const WasmSharedPtr& wasm)

      : WasmHandleBase(std::static_pointer_cast<WasmBase>(wasm)), wasm_(wasm) {}

  WasmSharedPtr& wasm() { return wasm_; }

private:

  WasmSharedPtr wasm_;

};

using WasmHandleSharedPtr = std::shared_ptr<WasmHandle>;

class PluginHandle : public PluginHandleBase {

public:

  explicit PluginHandle(const WasmHandleSharedPtr& wasm_handle, const PluginSharedPtr& plugin)

      : PluginHandleBase(std::static_pointer_cast<WasmHandleBase>(wasm_handle),

                         std::static_pointer_cast<PluginBase>(plugin)),

        plugin_(plugin), wasm_handle_(wasm_handle) {}

  WasmHandleSharedPtr& wasmHandle() { return wasm_handle_; }

  uint32_t rootContextId() { return wasm_handle_->wasm()->getRootContext(plugin_, false)->id(); }

private:

  PluginSharedPtr plugin_;

  WasmHandleSharedPtr wasm_handle_;

};

using PluginHandleSharedPtr = std::shared_ptr<PluginHandle>;

class PluginHandleSharedPtrThreadLocal : public ThreadLocal::ThreadLocalObject {

public:

  PluginHandleSharedPtrThreadLocal(PluginHandleSharedPtr handle) : handle_(handle){};

  PluginHandleSharedPtr& handle() { return handle_; }

private:

  PluginHandleSharedPtr handle_;

};

using CreateWasmCallback = std::function<void(WasmHandleSharedPtr)>;

// Returns false if createWasm failed synchronously. This is necessary because xDS *MUST* report

// all failures synchronously as it has no facility to report configuration update failures

// asynchronously. Callers should throw an exception if they are part of a synchronous xDS update

// because that is the mechanism for reporting configuration errors.

bool createWasm(const PluginSharedPtr& plugin, const Stats::ScopeSharedPtr& scope,

                Upstream::ClusterManager& cluster_manager, Init::Manager& init_manager,

                Event::Dispatcher& dispatcher, Api::Api& api,

                Envoy::Server::ServerLifecycleNotifier& lifecycle_notifier,

                Config::DataSource::RemoteAsyncDataProviderPtr& remote_data_provider,

                CreateWasmCallback&& callback,

                CreateContextFn create_root_context_for_testing = nullptr);

PluginHandleSharedPtr

getOrCreateThreadLocalPlugin(const WasmHandleSharedPtr& base_wasm, const PluginSharedPtr& plugin,

                             Event::Dispatcher& dispatcher,

                             CreateContextFn create_root_context_for_testing = nullptr);

void clearCodeCacheForTesting();

void setTimeOffsetForCodeCacheForTesting(MonotonicTime::duration d);

WasmEvent toWasmEvent(const std::shared_ptr<WasmHandleBase>& wasm);

} // namespace Wasm

} // namespace Common

} // namespace Extensions

} // namespace Envoy