#include "db/engine/ExecutionEngine.h"
#include "ValidationUtil.h"
#include "Log.h"

#include <cuda_runtime.h>

#include <arpa/inet.h>

#include <regex>
#include <algorithm>

namespace zilliz {
namespace milvus {
namespace server {

constexpr size_t TABLE_NAME_SIZE_LIMIT = 255;
constexpr int64_t TABLE_DIMENSION_LIMIT = 16384;
constexpr int32_t INDEX_FILE_SIZE_LIMIT = 4096; //index trigger size max = 4096 MB

ErrorCode
ValidationUtil::ValidateTableName(const std::string &table_name) {

    // Table name shouldn't be empty.
    if (table_name.empty()) {
        SERVER_LOG_ERROR << "Empty table name";
        return SERVER_INVALID_TABLE_NAME;
    }

    // Table name size shouldn't exceed 16384.
    if (table_name.size() > TABLE_NAME_SIZE_LIMIT) {
        SERVER_LOG_ERROR << "Table name size exceed the limitation";
        return SERVER_INVALID_TABLE_NAME;
    }

    // Table name first character should be underscore or character.
    char first_char = table_name[0];
    if (first_char != '_' && std::isalpha(first_char) == 0) {
        SERVER_LOG_ERROR << "Table name first character isn't underscore or character: " << first_char;
        return SERVER_INVALID_TABLE_NAME;
    }

    int64_t table_name_size = table_name.size();
    for (int64_t i = 1; i < table_name_size; ++i) {
        char name_char = table_name[i];
        if (name_char != '_' && std::isalnum(name_char) == 0) {
            SERVER_LOG_ERROR << "Table name character isn't underscore or alphanumber: " << name_char;
            return SERVER_INVALID_TABLE_NAME;
        }
    }

    return SERVER_SUCCESS;
}

ErrorCode
ValidationUtil::ValidateTableDimension(int64_t dimension) {
    if (dimension <= 0 || dimension > TABLE_DIMENSION_LIMIT) {
        SERVER_LOG_ERROR << "Table dimension excceed the limitation: " << TABLE_DIMENSION_LIMIT;
        return SERVER_INVALID_VECTOR_DIMENSION;
    } else {
        return SERVER_SUCCESS;
    }
}

ErrorCode
ValidationUtil::ValidateTableIndexType(int32_t index_type) {
    int engine_type = (int)engine::EngineType(index_type);
    if(engine_type <= 0 || engine_type > (int)engine::EngineType::MAX_VALUE) {
        return SERVER_INVALID_INDEX_TYPE;
    }

    return SERVER_SUCCESS;
}

ErrorCode
ValidationUtil::ValidateTableIndexNlist(int32_t nlist) {
    if(nlist <= 0) {
        return SERVER_INVALID_INDEX_NLIST;
    }

    return SERVER_SUCCESS;
}

ErrorCode
ValidationUtil::ValidateTableIndexFileSize(int64_t index_file_size) {
    if(index_file_size <= 0 || index_file_size > INDEX_FILE_SIZE_LIMIT) {
        return SERVER_INVALID_INDEX_FILE_SIZE;
    }

    return SERVER_SUCCESS;
}

ErrorCode
ValidationUtil::ValidateTableIndexMetricType(int32_t metric_type) {
    if(metric_type != (int32_t)engine::MetricType::L2 && metric_type != (int32_t)engine::MetricType::IP) {
        return SERVER_INVALID_INDEX_METRIC_TYPE;
    }
    return SERVER_SUCCESS;
}

ErrorCode
ValidationUtil::ValidateSearchTopk(int64_t top_k, const engine::meta::TableSchema& table_schema) {
    if (top_k <= 0 || top_k > 2048) {
        return SERVER_INVALID_TOPK;
    }

    return SERVER_SUCCESS;
}

ErrorCode
ValidationUtil::ValidateSearchNprobe(int64_t nprobe, const engine::meta::TableSchema& table_schema) {
    if (nprobe <= 0 || nprobe > table_schema.nlist_) {
        return SERVER_INVALID_NPROBE;
    }

    return SERVER_SUCCESS;
}

ErrorCode
ValidationUtil::ValidateGpuIndex(uint32_t gpu_index) {
    int num_devices = 0;
    auto cuda_err = cudaGetDeviceCount(&num_devices);
    if (cuda_err) {
        SERVER_LOG_ERROR << "Failed to count video card: " << std::to_string(cuda_err);
        return SERVER_UNEXPECTED_ERROR;
    }

    if(gpu_index >= num_devices) {
        return SERVER_INVALID_ARGUMENT;
    }

    return SERVER_SUCCESS;
}

ErrorCode
ValidationUtil::GetGpuMemory(uint32_t gpu_index, size_t& memory) {
    cudaDeviceProp deviceProp;
    auto cuda_err = cudaGetDeviceProperties(&deviceProp, gpu_index);
    if (cuda_err) {
        SERVER_LOG_ERROR << "Failed to get video card properties: " << std::to_string(cuda_err);
        return SERVER_UNEXPECTED_ERROR;
    }

    memory = deviceProp.totalGlobalMem;
    return SERVER_SUCCESS;
}

ErrorCode
ValidationUtil::ValidateIpAddress(const std::string &ip_address)  {

    struct in_addr address;

    int result = inet_pton(AF_INET, ip_address.c_str(), &address);

    switch(result) {
        case 1:
            return SERVER_SUCCESS;
        case 0:
            SERVER_LOG_ERROR << "Invalid IP address: " << ip_address;
            return SERVER_INVALID_ARGUMENT;
        default:
            SERVER_LOG_ERROR << "inet_pton conversion error";
            return SERVER_UNEXPECTED_ERROR;
    }
}

ErrorCode
ValidationUtil::ValidateStringIsNumber(const std::string &string) {
    if (!string.empty() && std::all_of(string.begin(), string.end(), ::isdigit)) {
        return SERVER_SUCCESS;
    }
    else {
        return SERVER_INVALID_ARGUMENT;
    }
}

ErrorCode
ValidationUtil::ValidateStringIsBool(std::string &str) {
    std::transform(str.begin(), str.end(), str.begin(), ::tolower);
    if (str == "true" || str == "on" || str == "yes" || str == "1" ||
        str == "false" || str == "off" || str == "no" || str == "0" ||
        str.empty()) {
        return SERVER_SUCCESS;
    }
    else {
        return SERVER_INVALID_ARGUMENT;
    }
}

ErrorCode
ValidationUtil::ValidateStringIsDouble(const std::string &str, double &val) {
    char* end = nullptr;
    val = std::strtod(str.c_str(), &end);
    if (end != str.c_str() && *end == '\0' && val != HUGE_VAL) {
        return SERVER_SUCCESS;
    }
    else {
        return SERVER_INVALID_ARGUMENT;
    }
}

ErrorCode
ValidationUtil::ValidateDbURI(const std::string &uri) {
    std::string dialectRegex = "(.*)";
    std::string usernameRegex = "(.*)";
    std::string passwordRegex = "(.*)";
    std::string hostRegex = "(.*)";
    std::string portRegex = "(.*)";
    std::string dbNameRegex = "(.*)";
    std::string uriRegexStr = dialectRegex + "\\:\\/\\/" +
        usernameRegex + "\\:" +
        passwordRegex + "\\@" +
        hostRegex + "\\:" +
        portRegex + "\\/" +
        dbNameRegex;
    std::regex uriRegex(uriRegexStr);
    std::smatch pieces_match;

    bool okay = true;

    if (std::regex_match(uri, pieces_match, uriRegex)) {
        std::string dialect = pieces_match[1].str();
        std::transform(dialect.begin(), dialect.end(), dialect.begin(), ::tolower);
        if (dialect.find("mysql") == std::string::npos && dialect.find("sqlite") == std::string::npos) {
            SERVER_LOG_ERROR << "Invalid dialect in URI: dialect = " << dialect;
            okay = false;
        }

        std::string host = pieces_match[4].str();
        if (!host.empty() && host != "localhost") {
            if (ValidateIpAddress(host) != SERVER_SUCCESS) {
                SERVER_LOG_ERROR << "Invalid host ip address in uri = " << host;
                okay = false;
            }
        }

        std::string port = pieces_match[5].str();
        if (!port.empty()) {
            if (ValidateStringIsNumber(port) != SERVER_SUCCESS) {
                SERVER_LOG_ERROR << "Invalid port in uri = " << port;
                okay = false;
            }
        }
    } else {
        SERVER_LOG_ERROR << "Wrong URI format: URI = " << uri;
        okay = false;
    }

    return (okay ? SERVER_SUCCESS : SERVER_INVALID_ARGUMENT);
}

}
}
}