// Modifications copyright (C) 2017, Baidu.com, Inc.
// Copyright 2017 The Apache Software Foundation

// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

#include "exec/schema_scanner/schema_columns_scanner.h"

#include <sstream>
#include "runtime/primitive_type.h"
#include "runtime/string_value.h"
#include "runtime/datetime_value.h"
#include "exec/schema_scanner/frontend_helper.h"

namespace palo {

SchemaScanner::ColumnDesc SchemaColumnsScanner::_s_col_columns[] = {
    //   name,       type,          size,                     is_null
    { "TABLE_CATALOG",      TYPE_VARCHAR, sizeof(StringValue),   true  },
    { "TABLE_SCHEMA",       TYPE_VARCHAR, sizeof(StringValue),   false },
    { "TABLE_NAME",         TYPE_VARCHAR, sizeof(StringValue),   false },
    { "COLUMN_NAME",        TYPE_VARCHAR, sizeof(StringValue),   false },
    { "ORDINAL_POSITION",   TYPE_BIGINT, sizeof(int64_t),       false },
    { "COLUMN_DEFAULT",     TYPE_VARCHAR, sizeof(StringValue),   true  },
    { "IS_NULLABLE",        TYPE_VARCHAR, sizeof(StringValue),   false },
    { "DATA_TYPE",          TYPE_VARCHAR, sizeof(StringValue),   false },
    { "CHARACTER_MAXIMUM_LENGTH",   TYPE_BIGINT, sizeof(int64_t), true },
    { "CHARACTER_OCTET_LENGTH",     TYPE_BIGINT, sizeof(int64_t), true },
    { "NUMERIC_PRECISION",          TYPE_BIGINT, sizeof(int64_t), true },
    { "NUMERIC_SCALE",              TYPE_BIGINT, sizeof(int64_t), true },
    { "CHARACTER_SET_NAME", TYPE_VARCHAR, sizeof(StringValue),   true  },
    { "COLLATION_NAME",     TYPE_VARCHAR, sizeof(StringValue),   true  },
    { "COLUMN_TYPE",        TYPE_VARCHAR, sizeof(StringValue),   false },
    { "COLUMN_KEY",         TYPE_VARCHAR, sizeof(StringValue),   false },
    { "EXTRA",              TYPE_VARCHAR, sizeof(StringValue),   false },
    { "PRIVILEGES",         TYPE_VARCHAR, sizeof(StringValue),   false },
    { "COLUMN_COMMENT",     TYPE_VARCHAR, sizeof(StringValue),   false },
    { "COLUMN_SIZE",        TYPE_BIGINT,  sizeof(int64_t),   true },
    { "DECIMAL_DIGITS",     TYPE_BIGINT,  sizeof(int64_t),   true },
};

SchemaColumnsScanner::SchemaColumnsScanner() : 
        SchemaScanner(_s_col_columns, sizeof(_s_col_columns) / sizeof(SchemaScanner::ColumnDesc)),
        _db_index(0),
        _table_index(0),
        _column_index(0) {
}

SchemaColumnsScanner::~SchemaColumnsScanner() {
}

Status SchemaColumnsScanner::start(RuntimeState *state) {
    if (!_is_init) {
        return Status("schema columns scanner not inited.");
    }
    // get all database
    TGetDbsParams db_params;
    if (NULL != _param->db) {
        db_params.__set_pattern(*(_param->db));
    }
    if (NULL != _param->user) {
        db_params.__set_user(*(_param->user));
    }
    
    if (NULL != _param->ip && 0 != _param->port) {
        RETURN_IF_ERROR(FrontendHelper::get_db_names(*(_param->ip),
                    _param->port, db_params, &_db_result)); 
    } else {
        return Status("IP or port dosn't exists");
    }

    return Status::OK;
}

std::string SchemaColumnsScanner::type_to_string(TColumnDesc &desc) {
    switch (desc.columnType) {
        case TPrimitiveType::BOOLEAN:
            return "tinyint(4)";
        case TPrimitiveType::TINYINT:
            return "tinyint(4)";
        case TPrimitiveType::SMALLINT:
            return "smallint(6)";
        case TPrimitiveType::INT:
            return "int(11)";
        case TPrimitiveType::BIGINT:
            return "bigint(20)";
        case TPrimitiveType::LARGEINT:
            return "bigint(20) unsinged";
        case TPrimitiveType::FLOAT:
            return "float";
        case TPrimitiveType::DOUBLE:
            return "double";
        case TPrimitiveType::VARCHAR:
            if (desc.__isset.columnLength) {
                return "varchar(" + std::to_string(desc.columnLength) +")";
            } else {
                return "varchar(20)";
            }
        case TPrimitiveType::CHAR:
            if (desc.__isset.columnLength) {
                return "char(" + std::to_string(desc.columnLength) +")";
            } else {
                return "char(20)";
            }
        case TPrimitiveType::DATE:
            return "date";
        case TPrimitiveType::DATETIME:
            return "datetime";
        case TPrimitiveType::DECIMAL: {
            std::stringstream stream;
            stream << "decimal(";
            if (desc.__isset.columnPrecision) {
                stream << desc.columnPrecision;
            } else {
                stream << 27;
            }
            stream << ",";
            if (desc.__isset.columnScale) {
                stream << desc.columnScale;
            } else {
                stream << 9;
            }
            stream << ")";
            return stream.str();
        }
        default:
            return "unknown";
    }
}

Status SchemaColumnsScanner::fill_one_row(Tuple *tuple, MemPool *pool) {
    // set all bit to not null
    memset((void *)tuple, 0, _tuple_desc->num_null_bytes());

    // catalog
    {
        tuple->set_null(_tuple_desc->slots()[0]->null_indicator_offset());
    }
    // schema
    {
        void *slot = tuple->get_slot(_tuple_desc->slots()[1]->tuple_offset());
        StringValue* str_slot = reinterpret_cast<StringValue*>(slot);
        std::string db_name = FrontendHelper::extract_db_name(_db_result.dbs[_db_index - 1]);
        str_slot->ptr = (char *)pool->allocate(db_name.size());
        str_slot->len = db_name.size();
        memcpy(str_slot->ptr, db_name.c_str(), str_slot->len);
    }
    // table
    {
        void *slot = tuple->get_slot(_tuple_desc->slots()[2]->tuple_offset());
        StringValue* str_slot = reinterpret_cast<StringValue*>(slot);
        str_slot->ptr = (char *)pool->allocate(_table_result.tables[_table_index - 1].length());
        str_slot->len = _table_result.tables[_table_index - 1].length();
        memcpy(str_slot->ptr, _table_result.tables[_table_index - 1].c_str(), str_slot->len);
    }
    // column
    {
        void *slot = tuple->get_slot(_tuple_desc->slots()[3]->tuple_offset());
        StringValue* str_slot = reinterpret_cast<StringValue*>(slot);
        str_slot->ptr = (char *)pool->allocate(
                _desc_result.columns[_column_index].columnDesc.columnName.length());
        str_slot->len = _desc_result.columns[_column_index].columnDesc.columnName.length();
        memcpy(str_slot->ptr, 
               _desc_result.columns[_column_index].columnDesc.columnName.c_str(), 
               str_slot->len);
    }
    // ORDINAL_POSITION
    {
        void *slot = tuple->get_slot(_tuple_desc->slots()[4]->tuple_offset());
        int64_t* bigint_slot = reinterpret_cast<int64_t*>(slot);
        *bigint_slot = _column_index + 1;
    }
    // COLUMN_DEFAULT
    {
        tuple->set_null(_tuple_desc->slots()[5]->null_indicator_offset());
    }
    // IS_NULLABLE
    {
        void *slot = tuple->get_slot(_tuple_desc->slots()[6]->tuple_offset());
        StringValue* str_slot = reinterpret_cast<StringValue*>(slot);
        str_slot->len = strlen("NO") + 1;
        str_slot->ptr = (char *)pool->allocate(str_slot->len);
        memcpy(str_slot->ptr, "NO", str_slot->len);
    }
    // DATA_TYPE
    {
        void *slot = tuple->get_slot(_tuple_desc->slots()[7]->tuple_offset());
        StringValue* str_slot = reinterpret_cast<StringValue*>(slot);
        std::string buffer = type_to_string(_desc_result.columns[_column_index].columnDesc);
        str_slot->len = buffer.length();
        str_slot->ptr = (char *)pool->allocate(str_slot->len);
        memcpy(str_slot->ptr, buffer.c_str(), str_slot->len);
    }
    // CHARACTER_MAXIMUM_LENGTH
    {
        tuple->set_null(_tuple_desc->slots()[8]->null_indicator_offset());
    }
    // CHARACTER_OCTET_LENGTH
    {
        int data_type = _desc_result.columns[_column_index].columnDesc.columnType;
        if (data_type == TPrimitiveType::VARCHAR || data_type == TPrimitiveType::CHAR) {
            void *slot = tuple->get_slot(_tuple_desc->slots()[9]->tuple_offset());
            int64_t* str_slot = reinterpret_cast<int64_t*>(slot);
            if (_desc_result.columns[_column_index].columnDesc.__isset.columnLength) {
                *str_slot = _desc_result.columns[_column_index].columnDesc.columnLength;
            } else {
                tuple->set_null(_tuple_desc->slots()[9]->null_indicator_offset());
            }     
        } else {
            tuple->set_null(_tuple_desc->slots()[9]->null_indicator_offset());
        }
    }
    // NUMERIC_PRECISION
    {
        void *slot = tuple->get_slot(_tuple_desc->slots()[10]->tuple_offset());
        int64_t* str_slot = reinterpret_cast<int64_t*>(slot);
        if (_desc_result.columns[_column_index].columnDesc.__isset.columnPrecision) {
            *str_slot = _desc_result.columns[_column_index].columnDesc.columnPrecision;
        } else {
            tuple->set_null(_tuple_desc->slots()[10]->null_indicator_offset());
        }
    }
    // NUMERIC_SCALE
    {
        void *slot = tuple->get_slot(_tuple_desc->slots()[11]->tuple_offset());
        int64_t* str_slot = reinterpret_cast<int64_t*>(slot);
        if (_desc_result.columns[_column_index].columnDesc.__isset.columnScale) {
            *str_slot = _desc_result.columns[_column_index].columnDesc.columnScale;
        } else {
            tuple->set_null(_tuple_desc->slots()[11]->null_indicator_offset());
        }
    }
    // CHARACTER_SET_NAME
    {
        tuple->set_null(_tuple_desc->slots()[12]->null_indicator_offset());
    }
    // COLLATION_NAME
    {
        tuple->set_null(_tuple_desc->slots()[13]->null_indicator_offset());
    }
    // COLUMN_TYPE
    {
        void *slot = tuple->get_slot(_tuple_desc->slots()[14]->tuple_offset());
        StringValue* str_slot = reinterpret_cast<StringValue*>(slot);
        std::string buffer = type_to_string(_desc_result.columns[_column_index].columnDesc);
        str_slot->len = buffer.length();
        str_slot->ptr = (char *)pool->allocate(str_slot->len);
        memcpy(str_slot->ptr, buffer.c_str(), str_slot->len);
    }
    // COLUMN_KEY
    {
        void *slot = tuple->get_slot(_tuple_desc->slots()[15]->tuple_offset());
        StringValue* str_slot = reinterpret_cast<StringValue*>(slot);
        str_slot->len = strlen("") + 1;
        str_slot->ptr = (char *)pool->allocate(str_slot->len);
        memcpy(str_slot->ptr, "", str_slot->len);
    }
    // EXTRA
    {
        void *slot = tuple->get_slot(_tuple_desc->slots()[16]->tuple_offset());
        StringValue* str_slot = reinterpret_cast<StringValue*>(slot);
        str_slot->len = strlen("") + 1;
        str_slot->ptr = (char *)pool->allocate(str_slot->len);
        memcpy(str_slot->ptr, "", str_slot->len);
    }
    // PRIVILEGES
    {
        void *slot = tuple->get_slot(_tuple_desc->slots()[17]->tuple_offset());
        StringValue* str_slot = reinterpret_cast<StringValue*>(slot);
        str_slot->len = strlen("") + 1;
        str_slot->ptr = (char *)pool->allocate(str_slot->len);
        memcpy(str_slot->ptr, "", str_slot->len);
    }
    // COLUMN_COMMENT
    {
        void *slot = tuple->get_slot(_tuple_desc->slots()[18]->tuple_offset());
        StringValue* str_slot = reinterpret_cast<StringValue*>(slot);
        str_slot->ptr = 
            (char *)pool->allocate(_desc_result.columns[_column_index].comment.length());
        str_slot->len = _desc_result.columns[_column_index].comment.length();
        memcpy(str_slot->ptr, _desc_result.columns[_column_index].comment.c_str(), str_slot->len);
    }
    // COLUMN_SIZE
    {
        void *slot = tuple->get_slot(_tuple_desc->slots()[19]->tuple_offset());
        int64_t* str_slot = reinterpret_cast<int64_t*>(slot);
        if (_desc_result.columns[_column_index].columnDesc.__isset.columnLength) {
            *str_slot = _desc_result.columns[_column_index].columnDesc.columnLength;
        } else {
            tuple->set_null(_tuple_desc->slots()[19]->null_indicator_offset());
        }
    }
    // DECIMAL_DIGITS
    {
        void *slot = tuple->get_slot(_tuple_desc->slots()[20]->tuple_offset());
        int64_t* str_slot = reinterpret_cast<int64_t*>(slot);
        if (_desc_result.columns[_column_index].columnDesc.__isset.columnScale) {
            *str_slot = _desc_result.columns[_column_index].columnDesc.columnScale;
        } else {
            tuple->set_null(_tuple_desc->slots()[20]->null_indicator_offset());
        }
    }
    _column_index++;
    return Status::OK;
}

Status SchemaColumnsScanner::get_new_desc() {
    TDescribeTableParams desc_params;
    desc_params.__set_db(_db_result.dbs[_db_index - 1]);
    desc_params.__set_table_name(_table_result.tables[_table_index++]);
    if (NULL != _param->user) {
        desc_params.__set_user(*(_param->user));
    }
    if (NULL != _param->user_ip) {
        desc_params.__set_user_ip(*(_param->user_ip));
    }

    if (NULL != _param->ip && 0 != _param->port) {
        RETURN_IF_ERROR(FrontendHelper::describe_table(*(_param->ip),
                _param->port, desc_params, &_desc_result)); 
    } else {
        return Status("IP or port dosn't exists");
    }
    _column_index = 0;

    return Status::OK;
}

Status SchemaColumnsScanner::get_new_table() {
    TGetTablesParams table_params;
    table_params.__set_db(_db_result.dbs[_db_index++]);
    if (NULL != _param->table) {
        table_params.__set_pattern(*(_param->table));
    }
    if (NULL != _param->user) {
        table_params.__set_user(*(_param->user));
    }
    if (NULL != _param->user_ip) {
        table_params.__set_user_ip(*(_param->user_ip));
    }

    if (NULL != _param->ip && 0 != _param->port) {
        RETURN_IF_ERROR(FrontendHelper::get_table_names(*(_param->ip),
                _param->port, table_params, &_table_result)); 
    } else {
        return Status("IP or port dosn't exists");
    }
    _table_index = 0;
    return Status::OK;
}

Status SchemaColumnsScanner::get_next_row(Tuple *tuple, MemPool *pool, bool *eos) {
    if (!_is_init) {
        return Status("use this class before inited.");
    }
    if (NULL == tuple || NULL == pool || NULL == eos) {
        return Status("input parameter is NULL.");
    }
    while (_column_index >= _desc_result.columns.size()) {
        if (_table_index >= _table_result.tables.size()) {
            if (_db_index < _db_result.dbs.size()) {
                RETURN_IF_ERROR(get_new_table());
            } else {
                *eos = true;
                return Status::OK;
            }
        } else {
            RETURN_IF_ERROR(get_new_desc());
        }
    }

    *eos = false;
    return fill_one_row(tuple, pool);
}

}