#include <unistd.h>

#include <attn/attn_dbus.hpp>
#include <attn/attn_logging.hpp>
#include <attn/pel/pel_minimal.hpp>
#include <phosphor-logging/log.hpp>

namespace attn
{

/** @brief Journal entry of type INFO using phosphor logging */
template <>
void trace<INFO>(const char* i_message)
{
    phosphor::logging::log<phosphor::logging::level::INFO>(i_message);
}

template <>
void trace<ERROR>(const char* i_message)
{
    phosphor::logging::log<phosphor::logging::level::ERR>(i_message);
}

/** @brief Tuple containing information about ffdc files */
using FFDCTuple =
    std::tuple<util::FFDCFormat, uint8_t, uint8_t, sdbusplus::message::unix_fd>;

/** @brief Gather messages from the journal */
std::vector<std::string> sdjGetMessages(const std::string& field,
                                        const std::string& fieldValue,
                                        unsigned int max);

/**
 * Create FFDCTuple objects corresponding to the specified FFDC files.
 *
 * The D-Bus method to create an error log requires a vector of tuples to
 * pass in the FFDC file information.
 *
 * @param   files - FFDC files
 * @return  vector of FFDCTuple objects
 */
std::vector<FFDCTuple>
    createFFDCTuples(const std::vector<util::FFDCFile>& files)
{
    std::vector<FFDCTuple> ffdcTuples{};
    util::transformFFDC(files, ffdcTuples);

    return ffdcTuples;
}

/**
 * @brief Create an FFDCFile object containing raw data
 *
 * Throws an exception if an error occurs.
 *
 * @param   i_buffer - raw data to add to ffdc faw data file
 * @param   i_size - size of the raw data
 * @return  FFDCFile object
 */
util::FFDCFile createFFDCRawFile(void* i_buffer, size_t i_size)
{
    util::FFDCFile file{util::FFDCFormat::Custom};

    // Write buffer to file and then reset file description file offset
    int fd          = file.getFileDescriptor();
    size_t numBytes = write(fd, static_cast<char*>(i_buffer), i_size);
    if (i_size != numBytes)
    {
        std::stringstream traceMsg;
        traceMsg << file.getPath().c_str() << " only " << (int)numBytes
                 << " of " << (int)i_size << " bytes written";
        auto strobj = traceMsg.str();
        trace<level::ERROR>(strobj.c_str());
    }

    lseek(fd, 0, SEEK_SET);

    return file;
}

/**
 * @brief Create an FFDCFile object containing the specified lines of text data
 *
 * Throws an exception if an error occurs.
 *
 * @param   lines - lines of text data to write to file
 * @return  FFDCFile object
 */
util::FFDCFile createFFDCTraceFile(const std::vector<std::string>& lines)
{
    // Create FFDC file of type Text
    util::FFDCFile file{util::FFDCFormat::Text};
    int fd = file.getFileDescriptor();

    // Write FFDC lines to file
    std::string buffer;
    for (const std::string& line : lines)
    {
        // Copy line to buffer.  Add newline if necessary.
        buffer = line;
        if (line.empty() || (line.back() != '\n'))
        {
            buffer += '\n';
        }

        // write buffer to file
        size_t numBytes = write(fd, buffer.c_str(), buffer.size());
        if (buffer.size() != numBytes)
        {
            std::stringstream traceMsg;
            traceMsg << file.getPath().c_str() << " only " << (int)numBytes
                     << " of " << (int)buffer.size() << " bytes written";
            auto strobj = traceMsg.str();
            trace<level::ERROR>(strobj.c_str());
        }
    }

    // Seek to beginning of file so error logging system can read data
    lseek(fd, 0, SEEK_SET);

    return file;
}

/**
 * Create FDDC files from journal messages of relevant executables
 *
 * Parse the system journal looking for log entries created by the executables
 * of interest for logging. For each of these entries create a ffdc trace file
 * that will be used to create ffdc log entries. These files will be pushed
 * onto the stack of ffdc files.
 *
 * @param   i_files - vector of ffdc files that will become log entries
 */
void createFFDCTraceFiles(std::vector<util::FFDCFile>& i_files)
{
    // Executables of interest
    std::vector<std::string> executables{"openpower-hw-diags"};

    for (const std::string& executable : executables)
    {
        try
        {
            // get journal messages
            std::vector<std::string> messages =
                sdjGetMessages("SYSLOG_IDENTIFIER", executable, 30);

            // Create FFDC file containing the journal messages
            if (!messages.empty())
            {
                i_files.emplace_back(createFFDCTraceFile(messages));
            }
        }
        catch (const std::exception& e)
        {
            std::string traceMessage =
                "createFFDCTraceFiles: " + std::string(e.what());
            trace<level::INFO>(traceMessage.c_str());
        }
    }
}

/**
 * Create FFDCFile objects containing debug data to store in the error log.
 *
 * If an error occurs, the error is written to the journal but an exception
 * is not thrown.
 *
 * @param   i_buffer - raw data (if creating raw dump ffdc entry in log)
 * @return  vector of FFDCFile objects
 */
std::vector<util::FFDCFile> createFFDCFiles(char* i_buffer = nullptr,
                                            size_t i_size  = 0)
{
    std::vector<util::FFDCFile> files{};

    // Create raw dump file
    if ((nullptr != i_buffer) && (0 != i_size))
    {
        files.emplace_back(createFFDCRawFile(i_buffer, i_size));
    }

    // Create trace dump file
    createFFDCTraceFiles(files);

    return files;
}

/**
 * Create a PEL from an existing PEL
 *
 * Create a new PEL based on the specified raw PEL and submit the new PEL
 * to the backend logging code as a raw PEL. Note that  additional data map
 * here contains data to be committed to the PEL and it can also be used to
 * create the PEL as it contains needed information.
 *
 * @param   i_buffer - buffer containing a raw PEL
 * @param   i_additional - additional data to be added to the new PEL
 */
void createPelCustom(std::vector<uint8_t>& i_rawPel,
                     std::map<std::string, std::string> i_additional)
{
    // create PEL object from buffer
    auto tiPel = std::make_unique<pel::PelMinimal>(i_rawPel);

    // The additional data contains the TI info as well as the value for the
    // subystem that provided the TI info. Get the subystem from additional
    // data and then populate the prmary SRC and SRC words for the custom PEL
    // based on the sybsystem's TI info.
    uint8_t subsystem = std::stoi(i_additional["Subsystem"]);
    tiPel->setSubsystem(subsystem);

    if (static_cast<uint8_t>(pel::SubsystemID::hypervisor) == subsystem)
    {
        // populate hypervisor SRC words
        tiPel->setSrcWords(std::array<uint32_t, pel::numSrcWords>{
            (uint32_t)std::stoul(i_additional["0x10 SRC Word 12"], 0, 16),
            (uint32_t)std::stoul(i_additional["0x14 SRC Word 13"], 0, 16),
            (uint32_t)std::stoul(i_additional["0x18 SRC Word 14"], 0, 16),
            (uint32_t)std::stoul(i_additional["0x1c SRC Word 15"], 0, 16),
            (uint32_t)std::stoul(i_additional["0x20 SRC Word 16"], 0, 16),
            (uint32_t)std::stoul(i_additional["0x24 SRC Word 17"], 0, 16),
            (uint32_t)std::stoul(i_additional["0x28 SRC Word 18"], 0, 16),
            (uint32_t)std::stoul(i_additional["0x2c SRC Word 19"], 0, 16)});

        // populate hypervisor primary SRC
        std::array<char, pel::asciiStringSize> srcChars{'0'};
        std::string srcString = i_additional["SrcAscii"];
        srcString.copy(srcChars.data(),
                       std::min(srcString.size(), pel::asciiStringSize), 0);
        tiPel->setAsciiString(srcChars);
    }
    else
    {
        // Populate hostboot SRC words - note HB word 0 from the shared info
        // data (additional data "0x10 HB Word") is reflected in the PEL as
        // "reason code" so we zero it here. Also note that the first word
        // in this group of words starts at word 0 and word 1 does not exits.
        tiPel->setSrcWords(std::array<uint32_t, pel::numSrcWords>{
            (uint32_t)0x00000000,
            (uint32_t)std::stoul(i_additional["0x14 HB Word 2"], 0, 16),
            (uint32_t)std::stoul(i_additional["0x18 HB Word 3"], 0, 16),
            (uint32_t)std::stoul(i_additional["0x1c HB Word 4"], 0, 16),
            (uint32_t)std::stoul(i_additional["0x20 HB Word 5"], 0, 16),
            (uint32_t)std::stoul(i_additional["0x24 HB Word 6"], 0, 16),
            (uint32_t)std::stoul(i_additional["0x28 HB Word 7"], 0, 16),
            (uint32_t)std::stoul(i_additional["0x2c HB Word 8"], 0, 16)});

        // populate hostboot primary SRC
        std::array<char, pel::asciiStringSize> srcChars{'0'};
        std::string srcString = i_additional["0x30 error_data"];
        srcString.copy(srcChars.data(),
                       std::min(srcString.size(), pel::asciiStringSize), 0);
        tiPel->setAsciiString(srcChars);
    }

    // set severity, event type and action flags
    tiPel->setSeverity(static_cast<uint8_t>(pel::Severity::termination));
    tiPel->setType(static_cast<uint8_t>(pel::EventType::na));
    tiPel->setAction(static_cast<uint16_t>(pel::ActionFlags::service |
                                           pel::ActionFlags::report |
                                           pel::ActionFlags::call));

    // The raw PEL that we used as the basis for this custom PEL contains the
    // attention handler trace data and does not needed to be in this PEL so
    // we remove it here.
    tiPel->setSectionCount(tiPel->getSectionCount() - 1);

    // Update the raw PEL with the new custom PEL data
    tiPel->raw(i_rawPel);

    // create PEL from raw data
    createPelRaw(i_rawPel);
}

/**
 * Log an event handled by the attention handler
 *
 * Basic (non TI) events will generate a standard message-registry based PEL
 *
 * TI events will create two PEL's. One PEL will be informational and will
 * contain trace information relevent to attention handler. The second PEL
 * will be specific to the TI type (including the primary SRC) and will be
 * based off of the TI information provided to the attention handler through
 * shared TI info data area.
 *
 * @param  i_event - The event type
 * @param  i_additional - Additional PEL data
 * @param  i_ffdc - FFDC PEL data
 */
void event(EventType i_event, std::map<std::string, std::string>& i_additional,
           const std::vector<util::FFDCFile>& i_ffdc)
{
    bool eventValid = false; // assume no event created
    bool tiEvent    = false; // assume not a terminate event

    std::string eventName;

    switch (i_event)
    {
        case EventType::Checkstop:
            eventName  = "org.open_power.HwDiags.Error.Checkstop";
            eventValid = true;
            break;
        case EventType::Terminate:
            eventName  = "org.open_power.Attn.Error.Terminate";
            eventValid = true;
            tiEvent    = true;
            break;
        case EventType::Vital:
            eventName  = "org.open_power.Attn.Error.Vital";
            eventValid = true;
            break;
        case EventType::HwDiagsFail:
        case EventType::AttentionFail:
            eventName  = "org.open_power.Attn.Error.Fail";
            eventValid = true;
            break;
        default:
            eventValid = false;
            break;
    }

    if (true == eventValid)
    {
        // Create PEL with additional data and FFDC data. The newly created
        // PEL's platform log-id will be returned.
        auto pelId =
            createPel(eventName, i_additional, createFFDCTuples(i_ffdc));

        // If this is a TI event we will create an additional PEL that is
        // specific to the subsystem that generated the TI.
        if ((true == tiEvent) && (0 != pelId))
        {
            // get file descriptor and size of information PEL
            int pelFd = getPel(pelId);

            // if PEL found, read into buffer
            if (-1 != pelFd)
            {
                auto pelSize = lseek(pelFd, 0, SEEK_END);
                lseek(pelFd, 0, SEEK_SET);

                // read information PEL into buffer
                std::vector<uint8_t> buffer(pelSize);
                size_t numBytes = read(pelFd, buffer.data(), buffer.size());
                if (buffer.size() != numBytes)
                {
                    std::stringstream traceMsg;
                    traceMsg << "Error reading event log: " << (int)numBytes
                             << " of " << (int)buffer.size() << " bytes read";
                    auto strobj = traceMsg.str();
                    trace<level::ERROR>(strobj.c_str());
                }
                else
                {
                    // create PEL from buffer
                    createPelCustom(buffer, i_additional);
                }

                close(pelFd);
            }
        }
    }
}

/**
 * Commit special attention TI event to log
 *
 * Create a event log with provided additional information and standard
 * FFDC data plus TI FFDC data
 *
 * @param i_additional - Additional log data
 * @param i_ti_InfoData - TI FFDC data
 */
void eventTerminate(std::map<std::string, std::string> i_additionalData,
                    char* i_tiInfoData)
{

    uint32_t tiInfoSize = 0; // assume TI info was not available

    if (nullptr != i_tiInfoData)
    {
        tiInfoSize = 56; // assume not hypervisor TI

        uint8_t subsystem = std::stoi(i_additionalData["Subsystem"]);

        // If hypervisor
        if (static_cast<uint8_t>(pel::SubsystemID::hypervisor) == subsystem)
        {
            tiInfoSize = 1024; // assume hypervisor max

            // hypervisor may just want some of the data
            if (0 == (*(i_tiInfoData + 0x09) & 0x01))
            {
                uint32_t* additionalLength = (uint32_t*)(i_tiInfoData + 0x50);
                uint32_t tiAdditional      = be32toh(*additionalLength);
                tiInfoSize = std::min(tiInfoSize, (84 + tiAdditional));
            }
        }
    }

    std::string traceMsg = "TI info size = " + std::to_string(tiInfoSize);
    trace<level::INFO>(traceMsg.c_str());

    event(EventType::Terminate, i_additionalData,
          createFFDCFiles(i_tiInfoData, tiInfoSize));
}

/** @brief Commit SBE vital event to log */
void eventVital()
{
    // Additional data for log
    std::map<std::string, std::string> additionalData;

    // Create log event with additional data and FFDC data
    event(EventType::Vital, additionalData, createFFDCFiles(nullptr, 0));
}

/**
 * Commit attention handler failure event to log
 *
 * Create an event log containing the specified error code.
 *
 * @param i_error - Error code
 */
void eventAttentionFail(int i_error)
{
    // Additional data for log
    std::map<std::string, std::string> additionalData;
    additionalData["ERROR_CODE"] = std::to_string(i_error);

    // Create log event with additional data and FFDC data
    event(EventType::AttentionFail, additionalData,
          createFFDCFiles(nullptr, 0));
}

/**
 * Parse systemd journal message field
 *
 * Parse the journal looking for the specified field and return the journal
 * data for that field.
 *
 * @param  journal - The journal to parse
 * @param  field - Field containing the data to retrieve
 * @return Data for the speciefied field
 */
std::string sdjGetFieldValue(sd_journal* journal, const char* field)
{
    const char* data{nullptr};
    size_t length{0};

    // get field value
    if (0 == sd_journal_get_data(journal, field, (const void**)&data, &length))
    {
        size_t prefix{0};

        // The data returned  by sd_journal_get_data will be prefixed with the
        // field name and "="
        const void* eq = memchr(data, '=', length);
        if (nullptr != eq)
        {
            // get just data following the "="
            prefix = (const char*)eq - data + 1;
        }
        else
        {
            // all the data (should not happen)
            prefix = 0;
            std::string value{}; // empty string
        }

        return std::string{data + prefix, length - prefix};
    }
    else
    {
        return std::string{}; // empty string
    }
}

/**
 * Gather messages from the journal
 *
 * Fetch journal entry data for all entries with the specified field equal to
 * the specified value.
 *
 * @param   field - Field to search on
 * @param   fieldValue -  Value to search for
 * @param   max - Maximum number of messages fetch
 * @return  Vector of journal entry data
 */
std::vector<std::string> sdjGetMessages(const std::string& field,
                                        const std::string& fieldValue,
                                        unsigned int max)
{
    sd_journal* journal;
    std::vector<std::string> messages;

    if (0 == sd_journal_open(&journal, SD_JOURNAL_LOCAL_ONLY))
    {
        SD_JOURNAL_FOREACH_BACKWARDS(journal)
        {
            // Get input field
            std::string value = sdjGetFieldValue(journal, field.c_str());

            // Compare field value and read data
            if (value == fieldValue)
            {
                // Get SYSLOG_IDENTIFIER field (process that logged message)
                std::string syslog =
                    sdjGetFieldValue(journal, "SYSLOG_IDENTIFIER");

                // Get _PID field
                std::string pid = sdjGetFieldValue(journal, "_PID");

                // Get MESSAGE field
                std::string message = sdjGetFieldValue(journal, "MESSAGE");

                // Get timestamp
                uint64_t usec{0};
                if (0 == sd_journal_get_realtime_usec(journal, &usec))
                {

                    // Convert realtime microseconds to date format
                    char dateBuffer[80];
                    std::string date;
                    std::time_t timeInSecs = usec / 1000000;
                    strftime(dateBuffer, sizeof(dateBuffer), "%b %d %H:%M:%S",
                             std::localtime(&timeInSecs));
                    date = dateBuffer;

                    // Store value to messages
                    value = date + " " + syslog + "[" + pid + "]: " + message;
                    messages.insert(messages.begin(), value);
                }
            }

            // limit maximum number of messages
            if (messages.size() >= max)
            {
                break;
            }
        }

        sd_journal_close(journal); // close journal when done
    }

    return messages;
}

} // namespace attn