// 2019 Rackspace, Inc.
//
// Licensed 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.

package raxSQL

import (
	"bytes"
	"database/sql"
	"strconv"
	"time"

	"github.com/sirupsen/logrus"
)

// Query method takes a MySql client receiver and returns a list of maps containing the
// query response values
func (c *Client) Query(qryValue string) (table []map[string]string, err error) {
	// Execute the query
	rows, err := c.DB.Query(qryValue)
	if err != nil {
		return
	}

	// Get column names
	columns, err := rows.Columns()
	if err != nil {
		return
	}

	// Make a slice for the values
	values := make([]sql.RawBytes, len(columns))

	// rows.Scan wants '[]interface{}' as an argument, so we must copy the
	// references into such a slice
	// See http://code.google.com/p/go-wiki/wiki/InterfaceSlice for details
	scanArgs := make([]interface{}, len(values))
	for i := range values {
		scanArgs[i] = &values[i]
	}

	// Iterate through the rows, gathering data
	for rows.Next() {
		// get RawBytes from data
		err = rows.Scan(scanArgs...)
		if err != nil {
			return
		}
		// Iterate through the row values and map them
		// to the associated column name
		var value string
		var column map[string]string
		for i, col := range values {
			value = string(col)

			// If this is the first column, set the map values
			if column == nil {
				column = map[string]string{columns[i]: value}
				continue
			}
			column[columns[i]] = value

		}
		// Add the column to the table
		table = append(table, column)
	}
	// If any errors occurred during the iteration process,
	// return an error here
	if err = rows.Err(); err != nil {
		return
	}
	return
}

// QueryMigrations method takes a MySql client receiver and returns a list of maps containing the
// query response values
func (c *Client) QueryInterface(qryValue string) (table []map[string]string, err error) {
	// Execute the query
	rows, err := c.DB.Query(qryValue)
	if err != nil {
		return
	}

	// Get column names
	columns, err := rows.Columns()
	if err != nil {
		return
	}
	scanValues := make([]interface{}, len(columns))

	// rows.Scan wants '[]interface{}' as an argument, so we must copy the
	// references into such a slice
	// See http://code.google.com/p/go-wiki/wiki/InterfaceSlice for details
	scanArgs := make([]interface{}, len(scanValues))
	for i := range scanValues {
		scanArgs[i] = &scanValues[i]
	}
	// Iterate through the rows, gathering data
	for rows.Next() {
		// get RawBytes from data
		err = rows.Scan(scanArgs...)
		if err != nil {
			return
		}
		// Iterate through the row values and map them
		// to the associated column name
		var value string
		var column map[string]string
		for i, col := range scanValues {
			switch t := col.(type) {
			case time.Time:
				value = time.Time(t).String()
			case string:
				value = string(t)
			case int:
				value = strconv.Itoa(t)
			case int64:
				value = strconv.FormatInt(t, 10)
			case []uint8:
				value = bytes.NewBuffer(t).String()
			case nil:
				value = ""
			default:
				logrus.Warnf("unable to convert type: %T:%v", col, col)
			}

			// If this is the first column, set the map values
			if column == nil {
				column = map[string]string{columns[i]: value}
				continue
			}
			column[columns[i]] = value

		}
		// Add the column to the table
		table = append(table, column)
	}
	// If any errors occurred during the iteration process,
	// return an error here
	if err = rows.Err(); err != nil {
		return
	}
	return
}