// Copyright (c) 2010 Satoshi Nakamoto
// Copyright (c) 2009-2017 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include <rpc/protocol.h>

#include <random.h>
#include <tinyformat.h>
#include <util.h>
#include <utilstrencodings.h>
#include <utiltime.h>
#include <version.h>

#include <fstream>

/**
 * JSON-RPC protocol.  Bitcoin speaks version 1.0 for maximum compatibility,
 * but uses JSON-RPC 1.1/2.0 standards for parts of the 1.0 standard that were
 * unspecified (HTTP errors and contents of 'error').
 *
 * 1.0 spec: http://json-rpc.org/wiki/specification
 * 1.2 spec: http://jsonrpc.org/historical/json-rpc-over-http.html
 */

UniValue JSONRPCRequestObj(const std::string& strMethod, const UniValue& params, const UniValue& id)
{
    UniValue request(UniValue::VOBJ);
    request.push_back(Pair("method", strMethod));
    request.push_back(Pair("params", params));
    request.push_back(Pair("id", id));
    return request;
}

UniValue JSONRPCReplyObj(const UniValue& result, const UniValue& error, const UniValue& id)
{
    UniValue reply(UniValue::VOBJ);
    if (!error.isNull())
        reply.push_back(Pair("result", NullUniValue));
    else
        reply.push_back(Pair("result", result));
    reply.push_back(Pair("error", error));
    reply.push_back(Pair("id", id));
    return reply;
}

std::string JSONRPCReply(const UniValue& result, const UniValue& error, const UniValue& id)
{
    UniValue reply = JSONRPCReplyObj(result, error, id);
    return reply.write() + "\n";
}

UniValue JSONRPCError(int code, const std::string& message)
{
    UniValue error(UniValue::VOBJ);
    error.push_back(Pair("code", code));
    error.push_back(Pair("message", message));
    return error;
}

/** Username used when cookie authentication is in use (arbitrary, only for
 * recognizability in debugging/logging purposes)
 */
static const std::string COOKIEAUTH_USER = "__cookie__";
/** Default name for auth cookie file */
static const std::string COOKIEAUTH_FILE = ".cookie";

/** Get name of RPC authentication cookie file */
static fs::path GetAuthCookieFile(bool temp=false)
{
    std::string arg = gArgs.GetArg("-rpccookiefile", COOKIEAUTH_FILE);
    if (temp) {
        arg += ".tmp";
    }
    fs::path path(arg);
    if (!path.is_complete()) path = GetDataDir() / path;
    return path;
}

bool GenerateAuthCookie(std::string *cookie_out)
{
    const size_t COOKIE_SIZE = 32;
    unsigned char rand_pwd[COOKIE_SIZE];
    GetRandBytes(rand_pwd, COOKIE_SIZE);
    std::string cookie = COOKIEAUTH_USER + ":" + HexStr(rand_pwd, rand_pwd+COOKIE_SIZE);

    /** the umask determines what permissions are used to create this file -
     * these are set to 077 in init.cpp unless overridden with -sysperms.
     */
    std::ofstream file;
    fs::path filepath_tmp = GetAuthCookieFile(true);
    file.open(filepath_tmp.string().c_str());
    if (!file.is_open()) {
        LogPrintf("Unable to open cookie authentication file %s for writing\n", filepath_tmp.string());
        return false;
    }
    file << cookie;
    file.close();

    fs::path filepath = GetAuthCookieFile(false);
    if (!RenameOver(filepath_tmp, filepath)) {
        LogPrintf("Unable to rename cookie authentication file %s to %s\n", filepath_tmp.string(), filepath.string());
        return false;
    }
    LogPrintf("Generated RPC authentication cookie %s\n", filepath.string());

    if (cookie_out)
        *cookie_out = cookie;
    return true;
}

bool GetAuthCookie(std::string *cookie_out)
{
    std::ifstream file;
    std::string cookie;
    fs::path filepath = GetAuthCookieFile();
    file.open(filepath.string().c_str());
    if (!file.is_open())
        return false;
    std::getline(file, cookie);
    file.close();

    if (cookie_out)
        *cookie_out = cookie;
    return true;
}

void DeleteAuthCookie()
{
    try {
        fs::remove(GetAuthCookieFile());
    } catch (const fs::filesystem_error& e) {
        LogPrintf("%s: Unable to remove random auth cookie file: %s\n", __func__, e.what());
    }
}

std::vector<UniValue> JSONRPCProcessBatchReply(const UniValue &in, size_t num)
{
    if (!in.isArray()) {
        throw std::runtime_error("Batch must be an array");
    }
    std::vector<UniValue> batch(num);
    for (size_t i=0; i<in.size(); ++i) {
        const UniValue &rec = in[i];
        if (!rec.isObject()) {
            throw std::runtime_error("Batch member must be object");
        }
        size_t id = rec["id"].get_int();
        if (id >= num) {
            throw std::runtime_error("Batch member id larger than size");
        }
        batch[id] = rec;
    }
    return batch;
}