package main

import (
	"context"
	"database/sql"
	"fmt"
	"log"
	"strconv"

	_ "github.com/denisenkom/go-mssqldb"
)

var connectionString = "server=192.168.1.2;Port=1433;database=DB_s439397;trusted_connection=yes;encrypt=disable"

var db *sql.DB
var err error

func testConnection() {
	db, err = sql.Open("sqlserver", connectionString)
	if err != nil {
		log.Fatal("Error creating connection pool: ", err.Error())
	}
	//ctx := context.Background()
	err = db.Ping()
	//err = db.PingContext(ctx)
	if err != nil {
		log.Fatal(err.Error())
	}
	fmt.Printf("Connected!\n")
}

type iHasValue interface{}
type values []iHasValue

// ODCZYT Z BAZY DANYCH BEZ SORTOWANIA
func readDatabase(command string, tableName string) (iDatabaseModels, error) {
	ctx := context.Background()
	checkIsDatabaseAlive()
	rows, _ := db.QueryContext(ctx, command)
	defer rows.Close()
	var models iDatabaseModels
	models = nil
	switch tableName {
	case "Lekarze":
		var x doctors
		models = x.readModels(rows)
	case "Pacjenci":
		var x patients
		models = x.readModels(rows)
	case "Operacje":
		var x operations
		models = x.readModels(rows)
	case "Diagnozy":
		var x diagnoses
		models = x.readModels(rows)
	case "Przyjecia":
		var x admissions
		models = x.readModels(rows)
	case "Sale":
		var x rooms
		models = x.readModels(rows)
	}
	return models, nil
}
func updateRecord(tableName string, primaryKey string,
	primaryKeyName string, fieldToUpdate string, valueToInsert string) string {
	ctx := context.Background()
	checkIsDatabaseAlive()
	if valueToInsert == "null" {
		valueToInsert = "NULL"
	} else {
		valueToInsert = "'" + valueToInsert + "'"
	}
	tsql := "UPDATE " + tableName + " SET " + fieldToUpdate + " = " + valueToInsert +
		" WHERE " + primaryKeyName + " = '" + primaryKey + "'"
	result, er := db.ExecContext(ctx, tsql)
	if er == nil {
		toReturn, _ := result.RowsAffected()
		return (strconv.FormatInt(toReturn, 10))
	}
	return "ERROR"
}

func insertRecord(command string) string {
	ctx := context.Background()
	checkIsDatabaseAlive()
	result, er := db.ExecContext(ctx, command)
	if er == nil {
		toReturn, _ := result.RowsAffected()
		return (strconv.FormatInt(toReturn, 10))
	}
	return "ERROR"
}

func deleteRecord(command string) string {
	ctx := context.Background()
	checkIsDatabaseAlive()
	result, _ := db.ExecContext(ctx, command)
	toReturn, _ := result.RowsAffected()
	return (strconv.FormatInt(toReturn, 10))
}

func checkIsDatabaseAlive() error {
	err = db.Ping()
	if err != nil {
		log.Fatal(err.Error())

	}
	return nil
}