// Copyright (C) 2016-2022 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.

#include <config.h>

#include <pgsql/pgsql_exchange.h>
#include <exceptions/exceptions.h>

#include <boost/date_time/posix_time/posix_time.hpp>
#include <boost/lexical_cast.hpp>

#include <iomanip>
#include <sstream>
#include <vector>

using namespace isc::util;
using namespace isc::data;
using namespace boost::posix_time;

namespace isc {
namespace db {

const int PsqlBindArray::TEXT_FMT = 0;
const int PsqlBindArray::BINARY_FMT = 1;
const char* PsqlBindArray::TRUE_STR = "TRUE";
const char* PsqlBindArray::FALSE_STR = "FALSE";

void PsqlBindArray::add(const char* value) {
    if (!value) {
        isc_throw(BadValue, "PsqlBindArray::add - char* value cannot be NULL");
    }

    values_.push_back(value);
    lengths_.push_back(strlen(value));
    formats_.push_back(TEXT_FMT);
}

void PsqlBindArray::add(const std::string& value) {
    values_.push_back(value.c_str());
    lengths_.push_back(value.size());
    formats_.push_back(TEXT_FMT);
}

void PsqlBindArray::insert(const char* value, size_t index) {
    if (index && index >= values_.size()) {
        isc_throw(OutOfRange, "PsqlBindArray::insert - index: " << index
                  << ", is larger than the array size: " << values_.size());
    }

    values_.insert(values_.begin() + index, value);
    lengths_.insert(lengths_.begin() + index, strlen(value));
    formats_.insert(formats_.begin() + index, TEXT_FMT);
}

void PsqlBindArray::insert(const std::string& value, size_t index) {
    if (index && index >= values_.size()) {
        isc_throw(OutOfRange, "PsqlBindArray::insert - index: " << index
                  << ", is larger than the array size: " << values_.size());
    }

    bound_strs_.push_back(ConstStringPtr(new std::string(value)));

    values_.insert(values_.begin() + index, bound_strs_.back()->c_str());
    lengths_.insert(lengths_.begin() + index, value.size());
    formats_.insert(formats_.begin() + index, TEXT_FMT);
}

void PsqlBindArray::popBack() {
    if (values_.size() == 0) {
        isc_throw(OutOfRange, "PsqlBindArray::pop_back - array empty");
    }

    values_.erase(values_.end() - 1);
    lengths_.erase(lengths_.end() - 1);
    formats_.erase(formats_.end() - 1);
}

void PsqlBindArray::add(const std::vector<uint8_t>& data) {
    values_.push_back(reinterpret_cast<const char*>(&(data[0])));
    lengths_.push_back(data.size());
    formats_.push_back(BINARY_FMT);
}

void PsqlBindArray::addTempBinary(const std::vector<uint8_t>& data) {
    bound_strs_.push_back(ConstStringPtr(new std::string(
        reinterpret_cast<const char*>(data.data()), data.size())));

    values_.push_back(reinterpret_cast<const char*>(bound_strs_.back()->data()));
    lengths_.push_back(data.size());
    formats_.push_back(BINARY_FMT);
}

void PsqlBindArray::add(const uint8_t* data, const size_t len) {
    if (!data) {
        isc_throw(BadValue, "PsqlBindArray::add - uint8_t data cannot be NULL");
    }

    values_.push_back(reinterpret_cast<const char*>(&(data[0])));
    lengths_.push_back(len);
    formats_.push_back(BINARY_FMT);
}

void PsqlBindArray::addTempBuffer(const uint8_t* data, const size_t len) {
    if (!data) {
        isc_throw(BadValue, "PsqlBindArray::addTempBuffer - uint8_t data cannot be NULL");
    }

    bound_strs_.push_back(ConstStringPtr(new std::string(
        reinterpret_cast<const char*>(data), len)));

    values_.push_back(bound_strs_.back()->data());
    lengths_.push_back(len);
    formats_.push_back(BINARY_FMT);
}

void PsqlBindArray::add(const bool& value) {
    add(value ? TRUE_STR : FALSE_STR);
}

void PsqlBindArray::add(const uint8_t& byte) {
    // We static_cast to an unsigned int, otherwise lexical_cast may to
    // treat byte as a character, which yields "" for unprintable values
    addTempString(boost::lexical_cast<std::string>
                              (static_cast<unsigned int>(byte)));
}

void PsqlBindArray::add(const isc::asiolink::IOAddress& addr) {
    if (addr.isV4()) {
        addTempString(boost::lexical_cast<std::string>
                   (addr.toUint32()));
    } else {
        addTempString(addr.toText());
    }
}

void PsqlBindArray::addNull(const int format) {
    values_.push_back(NULL);
    lengths_.push_back(0);
    formats_.push_back(format);
}

void
PsqlBindArray::add(const Triplet<uint32_t>& triplet) {
    if (triplet.unspecified()) {
        addNull();
    } else {
        add<uint32_t>(triplet.get());
    }
}

void
PsqlBindArray::addMin(const Triplet<uint32_t>& triplet) {
    if (triplet.unspecified() || (triplet.getMin() == triplet.get())) {
        addNull();
    } else {
        add<uint32_t>(triplet.getMin());
    }
}

void
PsqlBindArray::addMax(const Triplet<uint32_t>& triplet) {
    if (triplet.unspecified() || (triplet.getMax() == triplet.get())) {
        addNull();
    } else {
        add<uint32_t>(triplet.getMax());
    }
}

/// @todo Eventually this could replace add(std::string&)? This would mean
/// all bound strings would be internally copies rather than perhaps belonging
/// to the originating object such as Host::hostname_.  One the one hand it
/// would make all strings handled one-way only, on the other hand it would
/// mean duplicating strings where it isn't strictly necessary.
void PsqlBindArray::addTempString(const std::string& str) {
    bound_strs_.push_back(ConstStringPtr(new std::string(str)));

    PsqlBindArray::add((bound_strs_.back())->c_str());
}

void
PsqlBindArray::addOptional(const util::Optional<std::string>& value) {
    if (value.unspecified()) {
        addNull();
    } else {
        addTempString(value);
    }
}

void
PsqlBindArray::addInet4(const isc::asiolink::IOAddress& value) {
    if (!value.isV4()) {
        isc_throw(BadValue, "unable to add address to PsqlBindAray '"
                  << value.toText() << "' is not an IPv4 address");
    }

    // inet columns are inserted as string addresses.
    addTempString(value.toText());
}

void
PsqlBindArray::addOptionalInet4(const util::Optional<isc::asiolink::IOAddress>& value) {
    // If the value is unspecified it doesn't matter what the value is.
    if (value.unspecified()) {
        addNull();
    } else {
        addInet4(value);
    }
}

void
PsqlBindArray::addInet6(const isc::asiolink::IOAddress& value) {
    if (!value.isV6()) {
        isc_throw(BadValue, "unable to add address to PsqlBindAray '"
                  << value.toText() << "' is not an IPv6 address");
    }

    // inet columns are inserted as string addresses.
    addTempString(value.toText());
}

void
PsqlBindArray::addOptionalInet6(const util::Optional<isc::asiolink::IOAddress>& value) {
    // If the value is unspecified it doesn't matter what the value is.
    if (value.unspecified()) {
        addNull();
    } else {
        addInet6(value);
    }
}

void
PsqlBindArray::addTimestamp(const boost::posix_time::ptime& timestamp) {
    // Convert the ptime to time_t, then use the existing conversion
    // function to make db time.
    //
    // Sadly boost::posix_time::to_time_t() was not added until 1.58,
    // so do it ourselves.
    ptime epoch(boost::gregorian::date(1970, 1, 1));
    if (timestamp < epoch) {
        isc_throw(isc::BadValue, "Time value is before the epoch");
    }
    ptime max_db_time = boost::posix_time::from_time_t(DatabaseConnection::MAX_DB_TIME);
    time_duration::sec_type since_epoch = (timestamp - epoch).total_seconds();
    time_t input_time(since_epoch);
    if (timestamp > max_db_time) {
        isc_throw(isc::BadValue, "Time value is too large: " <<
                  (input_time < 0 ?
                   static_cast<int64_t>(static_cast<uint32_t>(input_time)) :
                   input_time));
    }

    // Converts to timestamp to local date/time string.
    addTempString(PgSqlExchange::convertLocalToDatabaseTime(input_time));
}

void
PsqlBindArray::addTimestamp() {
    time_t now;
    time(&now);
    addTempString(PgSqlExchange::convertLocalToDatabaseTime(now));
}

void
PsqlBindArray::add(const ElementPtr& value) {
    if (!value) {
        addNull();
        return;
    }

    std::ostringstream ss;
    value->toJSON(ss);
    addTempString(ss.str());
}

void
PsqlBindArray::add(const ConstElementPtr& value) {
    if (!value) {
        addNull();
        return;
    }

    std::ostringstream ss;
    value->toJSON(ss);
    addTempString(ss.str());
}

std::string
PsqlBindArray::toText() const {
    std::ostringstream stream;

    if (values_.size() == 0) {
        return ("bindarray is empty");
    }

    for (int i = 0; i < values_.size(); ++i) {
        stream << i << " : ";

        if (lengths_[i] == 0) {
            stream << "empty" << std::endl;
            continue;
        }

        if (formats_[i] == TEXT_FMT) {
            stream << "\"" << values_[i] << "\"" << std::endl;
        } else {
            const char *data = values_[i];
            stream << "0x";
            for (int x = 0; x < lengths_[i]; ++x) {
                    stream << std::setfill('0') << std::setw(2)
                           << std::setbase(16)
                           << static_cast<unsigned int>(data[x]);
            }

            stream << std::endl << std::setbase(10);
        }
    }

    return (stream.str());
}

bool
PsqlBindArray::amNull(size_t index) const {
    if (values_.size() < index + 1) {
        isc_throw(OutOfRange, "The index " << index << " is larger than the "
        " array size " << values_.size());
    }

    // We assume lengths_.size() always equals values_.size(). If not, the
    // at() operator will throw.
    return ( (values_.at(index) == NULL) && (lengths_.at(index) == 0) );
}

std::string
PgSqlExchange::convertToDatabaseTime(const time_t input_time) {
    struct tm tinfo;
    char buffer[20];

    localtime_r(&input_time, &tinfo);

    // PostgreSQL will assume the value is already in local time since we
    // do not specify timezone in the string.
    strftime(buffer, sizeof(buffer), "%Y-%m-%d %H:%M:%S", &tinfo);
    return (std::string(buffer));
}

std::string
PgSqlExchange::convertLocalToDatabaseTime(const time_t input_time) {
    struct tm tinfo;
    char buffer[20];

    // We use gmtime_r to avoid adjustment as time_t is already local.
    gmtime_r(&input_time, &tinfo);

    // PostgreSQL will assume the value is already in local time since we
    // do not specify timezone in the string.
    strftime(buffer, sizeof(buffer), "%Y-%m-%d %H:%M:%S", &tinfo);
    return (std::string(buffer));
}


std::string
PgSqlExchange::convertToDatabaseTime(const time_t cltt,
                                     const uint32_t valid_lifetime) {
    // Calculate expiry time. Store it in the 64-bit value so as we can
    // detect overflows.
    int64_t expire_time_64 = static_cast<int64_t>(cltt)
                             + static_cast<int64_t>(valid_lifetime);

    // It has been observed that the PostgreSQL doesn't deal well with the
    // timestamp values beyond the DataSource::MAX_DB_TIME seconds since the
    // beginning of the epoch (around year 2038). The value is often
    // stored in the database but it is invalid when read back (overflow?).
    // Hence, the maximum timestamp value is restricted here.
    if (expire_time_64 > DatabaseConnection::MAX_DB_TIME) {
        isc_throw(isc::BadValue, "Time value is too large: " << expire_time_64);
    }

    return (convertToDatabaseTime(static_cast<time_t>(expire_time_64)));
}

time_t
PgSqlExchange::convertFromDatabaseTime(const std::string& db_time_val) {
    // Convert string time value to time_t
    time_t new_time;
    try {
        new_time = (boost::lexical_cast<time_t>(db_time_val));
    } catch (const std::exception& ex) {
        isc_throw(BadValue, "Database time value is invalid: " << db_time_val);
    }

    return (new_time);
}

void
PgSqlExchange::convertFromDatabaseTime(const std::string& db_time_val,
                                       boost::posix_time::ptime& conv_time) {
    time_t tmp_time = convertFromDatabaseTime(db_time_val);
    conv_time = boost::posix_time::from_time_t(tmp_time);
}

const char*
PgSqlExchange::getRawColumnValue(const PgSqlResult& r, const int row,
                                 const size_t col) {
    r.rowColCheck(row,col);
    const char* value = PQgetvalue(r, row, col);
    if (!value) {
        isc_throw(DbOperationError, "getRawColumnValue no data for :"
                    << getColumnLabel(r, col) << " row:" << row);
    }
    return (value);
}

bool
PgSqlExchange::isColumnNull(const PgSqlResult& r, const int row,
                            const size_t col) {
    r.rowColCheck(row,col);
    return (PQgetisnull(r, row, col));
}

void
PgSqlExchange::getColumnValue(const PgSqlResult& r, const int row,
                              const size_t col, std::string& value) {
    value = getRawColumnValue(r, row, col);
}

void
PgSqlExchange::getColumnValue(const PgSqlResult& r, const int row,
                              const size_t col, bool &value) {
    const char* data = getRawColumnValue(r, row, col);
    if (!strlen(data) || *data == 'f') {
        value = false;
    } else if (*data == 't') {
        value = true;
    } else {
        isc_throw(DbOperationError, "Invalid boolean data: " << data
                  << " for: " << getColumnLabel(r, col) << " row:" << row
                  << " : must be 't' or 'f'");
    }
}

void
PgSqlExchange::getColumnValue(const PgSqlResult& r, const int row,
                              const size_t col, uint8_t &value) {
    const char* data = getRawColumnValue(r, row, col);
    try {
        // lexically casting as uint8_t doesn't convert from char
        // so we use uint16_t and implicitly convert.
        value = boost::lexical_cast<uint16_t>(data);
    } catch (const std::exception& ex) {
        isc_throw(DbOperationError, "Invalid uint8_t data: " << data
                  << " for: " << getColumnLabel(r, col) << " row:" << row
                  << " : " << ex.what());
    }
}

void
PgSqlExchange::getColumnValue(const PgSqlResult& r, const int row,
                              const size_t col, boost::posix_time::ptime& value) {
    std::string db_time_val;
    PgSqlExchange::getColumnValue(r, row, col, db_time_val );
    PgSqlExchange::convertFromDatabaseTime(db_time_val, value);
}

void
PgSqlExchange::getColumnValue(const PgSqlResult& r, const int row,
                              const size_t col, ElementPtr& value) {
    const char* data = getRawColumnValue(r, row, col);
    try {
        value = Element::fromJSON(data);
    } catch (const std::exception& ex) {
        isc_throw(DbOperationError, "Cannot convert data: " << data
                  << " for: " << getColumnLabel(r, col) << " row:" << row
                  << " : " << ex.what());
    }
}

isc::asiolink::IOAddress
PgSqlExchange::getInetValue4(const PgSqlResult& r, const int row,
                             const size_t col) {
    const char* data = getRawColumnValue(r, row, col);
    try {
        asiolink::IOAddress addr(data);
        if (!addr.isV4()) {
            isc_throw(BadValue, "not a v4 address");
        }

        return (addr);
    } catch (const std::exception& ex) {
        isc_throw(DbOperationError, "Cannot convert data: " << data
                  << " for: " << getColumnLabel(r, col) << " row:" << row
                  << " : " << ex.what());
    }
}

isc::asiolink::IOAddress
PgSqlExchange::getInetValue6(const PgSqlResult& r, const int row,
                             const size_t col) {
    const char* data = getRawColumnValue(r, row, col);
    try {
        asiolink::IOAddress addr(data);
        if (!addr.isV6()) {
            isc_throw(BadValue, "not a v6 address");
        }

        return (addr);
    } catch (const std::exception& ex) {
        isc_throw(DbOperationError, "Cannot convert data: " << data
                  << " for: " << getColumnLabel(r, col) << " row:" << row
                  << " : " << ex.what());
    }
}

isc::asiolink::IOAddress
PgSqlExchange::getIPv6Value(const PgSqlResult& r, const int row,
                            const size_t col) {
    const char* data = getRawColumnValue(r, row, col);
    try {
        return (isc::asiolink::IOAddress(data));
    } catch (const std::exception& ex) {
        isc_throw(DbOperationError, "Cannot convert data: " << data
                  << " for: " << getColumnLabel(r, col) << " row:" << row
                  << " : " << ex.what());
    }
}

void
PgSqlExchange::convertFromBytea(const PgSqlResult& r, const int row,
                                const size_t col, uint8_t* buffer,
                                const size_t buffer_size,
                                size_t &bytes_converted) {
    // Returns converted bytes in a dynamically allocated buffer, and
    // sets bytes_converted.
    unsigned char* bytes = PQunescapeBytea((const unsigned char*)
                                           (getRawColumnValue(r, row, col)),
                                           &bytes_converted);

    // Unlikely it couldn't allocate it but you never know.
    if (!bytes) {
        isc_throw (DbOperationError, "PQunescapeBytea failed for:"
                   << getColumnLabel(r, col) << " row:" << row);
    }

    // Make sure it's not larger than expected.
    if (bytes_converted > buffer_size) {
        // Free the allocated buffer first!
        PQfreemem(bytes);
        isc_throw (DbOperationError, "Converted data size: "
                   << bytes_converted << " is too large for: "
                   << getColumnLabel(r, col) << " row:" << row);
    }

    // Copy from the allocated buffer to caller's buffer then free
    // the allocated buffer.
    memcpy(buffer, bytes, bytes_converted);
    PQfreemem(bytes);
}

void
PgSqlExchange::convertFromBytea(const PgSqlResult& r, const int row, const size_t col,
                                std::vector<uint8_t>& value) {
    // Returns converted bytes in a dynamically allocated buffer, and
    // sets bytes_converted.
    size_t bytes_converted = 0;
    unsigned char* bytes = PQunescapeBytea((const unsigned char*)
                                           (getRawColumnValue(r, row, col)),
                                           &bytes_converted);

    // Unlikely it couldn't allocate it but you never know.
    if (!bytes) {
        isc_throw (DbOperationError, "PQunescapeBytea failed for:"
                   << getColumnLabel(r, col) << " row:" << row);
    }

    // Copy from the allocated buffer to caller's buffer then free
    // the allocated buffer.
    if (bytes_converted) {
        value.assign(bytes, bytes + bytes_converted);
    } else {
        value.clear();
    }

    // Free the PostgreSQL buffer.
    PQfreemem(bytes);
}

Triplet<uint32_t>
PgSqlExchange::getTripletValue(const PgSqlResult& r, const int row,
                              const size_t col) {
    uint32_t col_value;
    if (isColumnNull(r, row, col)) {
        return (Triplet<uint32_t>());
    }

    getColumnValue(r, row, col, col_value);
    return (Triplet<uint32_t>(col_value));
}

Triplet<uint32_t>
PgSqlExchange::getTripletValue(const PgSqlResult& r, const int row,
                               const size_t def_col, const size_t min_col,
                               const size_t max_col) {
    if (isColumnNull(r, row, def_col)) {
        return (Triplet<uint32_t>());
    }

    uint32_t value;
    getColumnValue(r, row, def_col, value);

    uint32_t min_value = value;
    if (!isColumnNull(r, row, min_col)) {
        getColumnValue(r, row, min_col, min_value);
    }

    uint32_t max_value = value;
    if (!isColumnNull(r, row, max_col)) {
        getColumnValue(r, row, max_col, max_value);
    }

    return (Triplet<uint32_t>(min_value, value, max_value));
}

std::string
PgSqlExchange::getColumnLabel(const PgSqlResult& r, const size_t column) {
    return (r.getColumnLabel(column));
}

std::string
PgSqlExchange::dumpRow(const PgSqlResult& r, int row) {
    r.rowCheck(row);
    std::ostringstream stream;
    int columns = r.getCols();
    for (int col = 0; col < columns; ++col) {
        const char* val = getRawColumnValue(r, row, col);
        std::string name = r.getColumnLabel(col);
        int format = PQfformat(r, col);

        stream << col << "   " << name << " : " ;
        if (format == PsqlBindArray::TEXT_FMT) {
            stream << "\"" << val << "\"" << std::endl;
        } else {
            const char *data = val;
            int length = PQfsize(r, col);
            if (length == 0) {
                stream << "empty" << std::endl;
            } else {
                stream << "0x";
                for (int i = 0; i < length; ++i) {
                    stream << std::setfill('0') << std::setw(2)
                           << std::setbase(16)
                           << static_cast<unsigned int>(data[i]);
                }
                stream << std::endl;
            }
        }
    }

    return (stream.str());
}

PgSqlResultRowWorker::PgSqlResultRowWorker(const PgSqlResult& r, const int row)
    : r_(r), row_(row) {
    // Validate the desired row.
    r.rowCheck(row);
}

bool
PgSqlResultRowWorker::isColumnNull(const size_t col) {
    return (PgSqlExchange::isColumnNull(r_, row_, col));
}

std::string
PgSqlResultRowWorker::getString(const size_t col) {
    std::string tmp;
    PgSqlExchange::getColumnValue(r_, row_, col, tmp);
    return (tmp);
}

bool
PgSqlResultRowWorker::getBool(const size_t col) {
    bool tmp;
    PgSqlExchange::getColumnValue(r_, row_, col, tmp);
    return (tmp);
}

double
PgSqlResultRowWorker::getDouble(const size_t col) {
    double tmp;
    PgSqlExchange::getColumnValue(r_, row_, col, tmp);
    return (tmp);
}

const char*
PgSqlResultRowWorker::getRawColumnValue(const size_t col) {
    return (PgSqlExchange::getRawColumnValue(r_, row_, col));
}

uint64_t
PgSqlResultRowWorker::getBigInt(const size_t col) {
    uint64_t value;
    PgSqlExchange::getColumnValue(r_, row_, col, value);
    return (value);
}

uint32_t
PgSqlResultRowWorker::getInt(const size_t col) {
    uint32_t value;
    PgSqlExchange::getColumnValue(r_, row_, col, value);
    return (value);
}

uint16_t
PgSqlResultRowWorker::getSmallInt(const size_t col) {
    uint16_t value;
    PgSqlExchange::getColumnValue(r_, row_, col, value);
    return (value);
}

void
PgSqlResultRowWorker::getBytes(const size_t col, std::vector<uint8_t>& value) {
    PgSqlExchange::convertFromBytea(r_, row_, col, value);
}

isc::asiolink::IOAddress
PgSqlResultRowWorker::getInet4(const size_t col) {
    return (PgSqlExchange::getInetValue4(r_, row_, col));
}

isc::asiolink::IOAddress
PgSqlResultRowWorker::getInet6(const size_t col) {
    return (PgSqlExchange::getInetValue6(r_, row_, col));
}

boost::posix_time::ptime
PgSqlResultRowWorker::getTimestamp(const size_t col) {
    boost::posix_time::ptime value;
    getColumnValue(col, value);
    return (value);
};

data::ElementPtr
PgSqlResultRowWorker::getJSON(const size_t col) {
    data::ElementPtr value;
    getColumnValue(col, value);
    return (value);
}

isc::util::Triplet<uint32_t>
PgSqlResultRowWorker::getTriplet(const size_t col) {
    return (PgSqlExchange::getTripletValue(r_, row_, col));
}

isc::util::Triplet<uint32_t>
PgSqlResultRowWorker::getTriplet(const size_t def_col, const size_t min_col,
                                 const size_t max_col) {
    return (PgSqlExchange::getTripletValue(r_, row_, def_col, min_col, max_col));
}

std::string
PgSqlResultRowWorker::dumpRow() {
    return (PgSqlExchange::dumpRow(r_, row_));
}

} // end of isc::db namespace
} // end of isc namespace