package main

import (
	"database/sql"
	"log"
	"time"
)

// DeviceType : holds information about a specific DeviceType
type DeviceType struct {
	ID        int       `json:"id"`
	Name      string    `json:"name"`
	CreatedAt time.Time `json:"createdAt"`
	UpdatedAt time.Time `json:"updatedAt"`
}

// DeviceTypes : a list of DeviceType items
type DeviceTypes []DeviceType

const deviceTypeTableCreationQuery = `CREATE TABLE IF NOT EXISTS deviceTypes (
	id int(10) unsigned AUTO_INCREMENT,
	name varchar(255),
	createdAt datetime,
	updatedAt datetime,
	UNIQUE KEY name (name),
	PRIMARY KEY (id)
  )`

func ensureDeviceTypeTableExists(db *sql.DB) {
	if _, err := db.Exec(deviceTypeTableCreationQuery); err != nil {
		log.Fatal(err)
	}
}

func seedDeviceTypeData(db *sql.DB) {
	sqlQuery := `INSERT INTO deviceTypes VALUES 
	(1,'CLX','2016-10-13 15:05:32','2016-10-13 15:05:32'),
	(2,'Micro800','2016-10-13 15:05:32','2016-10-13 15:05:32');`
	insStmt, insErr := db.Prepare(sqlQuery)

	if insErr != nil {
		panic(insErr.Error()) // proper error handling instead of panic in your app
	}
	defer insStmt.Close() // Close the statement when we leave main() / the program terminates

	insStmt.Exec()
}

// getDeviceType : used during GET command
func (c *DeviceType) getDeviceType(db *sql.DB) error {
	return db.QueryRow("SELECT name, createdAt, updatedAt FROM deviceTypes WHERE id=?", c.ID).Scan(&c.Name, &c.CreatedAt, &c.UpdatedAt)
}

// updateDeviceType : used during PUT command
func (c *DeviceType) updateDeviceType(db *sql.DB) error {
	updStmt, updErr := db.Prepare("UPDATE deviceTypes SET name=?, updatedAt=? WHERE id=?")
	if updErr != nil {
		panic(updErr.Error()) // proper error handling instead of panic in your app
	}
	defer updStmt.Close() // Close the statement when we leave main() / the program terminates

	_, err := updStmt.Exec(c.Name, time.Now(), c.ID)
	return err
}

// deleteDeviceType : used during DELETE command
func (c *DeviceType) deleteDeviceType(db *sql.DB) error {
	_, err := db.Exec("DELETE FROM deviceTypes WHERE id=?", c.ID)
	return err
}

// createDeviceType : used during PUSH command
func (c *DeviceType) createDeviceType(db *sql.DB) error {
	stmtIns, insErr := db.Prepare("INSERT INTO deviceTypes (name, createdAt, updatedAt) VALUES (?, ?, ?);")
	if insErr != nil {
		panic(insErr.Error()) // proper error handling instead of panic in your app
	}
	defer stmtIns.Close() // Close the statement when we leave main() / the program terminates

	_, err := stmtIns.Exec(c.Name, time.Now(), time.Now())
	return err
}

// getDeviceTypes : used during GET command for all
func getDeviceTypes(db *sql.DB, start, count int) (DeviceTypes, error) {
	rows, err := db.Query(
		"SELECT id, name, createdAt, updatedAt FROM deviceTypes LIMIT ? OFFSET ?",
		count, start)

	if err != nil {
		return nil, err
	}

	defer rows.Close()

	deviceTypes := DeviceTypes{}

	for rows.Next() {
		var c DeviceType
		if err := rows.Scan(&c.ID, &c.Name, &c.CreatedAt, &c.UpdatedAt); err != nil {
			return nil, err
		}
		deviceTypes = append(deviceTypes, c)
	}

	return deviceTypes, nil
}