/*
 * Copyright 2015 Cloudius Systems
 */

#include "messaging_service.hh"
#include "message/messaging_service.hh"
#include "rpc/rpc_types.hh"
#include "api/api-doc/messaging_service.json.hh"
#include <iostream>
#include <sstream>

using namespace httpd::messaging_service_json;
using namespace net;

namespace api {

using shard_info = messaging_service::shard_info;
using shard_id = messaging_service::shard_id;

static const int32_t num_verb = static_cast<int32_t>(messaging_verb::UNUSED_3) + 1;

std::vector<message_counter> map_to_message_counters(
        const std::unordered_map<gms::inet_address, unsigned long>& map) {
    std::vector<message_counter> res;
    for (auto i : map) {
        res.push_back(message_counter());
        res.back().ip = boost::lexical_cast<sstring>(i.first);
        res.back().count = i.second;
    }
    return res;
}

/**
 * Return a function that performs a map_reduce on messaging_service
 * For each instance it calls its foreach_client method set the value
 * according to a function that it gets as a parameter.
 *
 */
future_json_function get_client_getter(std::function<uint64_t(const shard_info&)> f) {
    return [f](std::unique_ptr<request> req) {
        using map_type = std::unordered_map<gms::inet_address, uint64_t>;
        auto get_shard_map = [f](messaging_service& ms) {
            std::unordered_map<gms::inet_address, unsigned long> map;
            ms.foreach_client([&map, f] (const shard_id& id, const shard_info& info) {
                map[id.addr] = f(info);
            });
            return map;
        };
        return  get_messaging_service().map_reduce0(get_shard_map, map_type(), map_sum<map_type>).
                then([](map_type&& map) {
            return make_ready_future<json::json_return_type>(map_to_message_counters(map));
        });
    };
}

void set_messaging_service(http_context& ctx, routes& r) {

    get_sent_messages.set(r, get_client_getter([](const shard_info& c) {
        return c.get_stats().sent_messages;
    }));

    get_exception_messages.set(r, get_client_getter([](const shard_info& c) {
        return c.get_stats().exception_received;
    }));

    get_pending_messages.set(r, get_client_getter([](const shard_info& c) {
        return c.get_stats().pending;
    }));

    get_respond_pending_messages.set(r, get_client_getter([](const shard_info& c) {
        return c.get_stats().wait_reply;
    }));

    get_dropped_messages.set(r, [](std::unique_ptr<request> req) {
        shared_ptr<std::vector<uint64_t>> map = make_shared<std::vector<uint64_t>>(num_verb, 0);

        return net::get_messaging_service().map_reduce([map](const uint64_t* local_map) mutable {
            for (auto i = 0; i < num_verb; i++) {
                (*map)[i]+= local_map[i];
            }
        },[](messaging_service& ms) {
            return make_ready_future<const uint64_t*>(ms.get_dropped_messages());
        }).then([map]{
            std::vector<verb_counter> res;
            for (auto i : verb_counter::verb_wrapper::all_items()) {
                verb_counter c;
                messaging_verb v = i; // for type safety we use messaging_verb values
                if ((*map)[static_cast<int32_t>(v)] > 0) {
                    c.count = (*map)[static_cast<int32_t>(v)];
                    c.verb = i;
                    res.push_back(c);
                }
            }
            return make_ready_future<json::json_return_type>(res);
        });
    });
}
}