/*
Copyright © 2019 Devan Carpenter <mail@dvn.me>

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
// functions for database actions
package db

import (
	"fmt"
	"time"

	"boxen/config"
	"github.com/bvinc/go-sqlite-lite/sqlite3"
)

func DBinit() error {
	// Open DB file. File will be created if non-existent.
	conn, err := sqlite3.Open(config.ConfigPath + "boxen.db")
	if err != nil {
		return fmt.Errorf("failed to open database: %v", err)
	}
	defer conn.Close()

	// Busy timeout
	conn.BusyTimeout(5 * time.Second)

	// Create a new table to store device info, if it doesn't already exist.
	err = conn.Exec(`CREATE TABLE if not exists devices(device_name TEXT, device_ego TEXT, service_name TEXT, service_record TEXT, owner INTEGER, UNIQUE(device_name, device_ego, service_name, service_record, owner))`)
	if err != nil {
		return fmt.Errorf("failed to create database table: %v", err)
	}

	// Create a new table to store device info, if it doesn't already exist.
	err = conn.Exec(`CREATE TABLE if not exists friends(device_name TEXT, friend_name TEXT, friend_ego TEXT, UNIQUE(ego))`)
	if err != nil {
		return fmt.Errorf("failed to create database table: %v", err)
	}

	return nil
}

func InsertDevice(device_name string, device_ego string, service_name string, service_record string, owner int) error {
	// Open DB file. File will be created if non-existent.
	conn, err := sqlite3.Open(config.ConfigPath + "boxen.db")
	if err != nil {
		return fmt.Errorf("failed to open database: %v", err)
	}
	defer conn.Close()

	// Busy timeout
	conn.BusyTimeout(5 * time.Second)

	err = conn.WithTx(func() error {
		return insertDevices(conn, device_name, device_ego, service_name, service_record, owner)
	})
	if err != nil {
		return fmt.Errorf("failed to insert device: %v", err)
	}

	return nil
}

func insertDevices(conn *sqlite3.Conn, device_name string, device_ego string, service_name string, service_record string, owner int) error {
	// Create a prepared statement
	stmt, err := conn.Prepare(`INSERT OR IGNORE INTO devices(device_name, device_ego, service_name, service_record, owner) VALUES (?, ?, ?, ?, ?)`)
	if err != nil {
		return fmt.Errorf("failed to prepare to insert to students table: %v", err)
	}
	defer stmt.Close()

	// Even more convenient, Exec will call Bind, Step as many times as needed
	// and always Reset the statement
	if err = stmt.Exec(device_name, device_ego, service_name, service_record, owner); err != nil {
		return fmt.Errorf("failed to insert student: %v", err)
	}

	return nil
}

func queryStudents(conn *sqlite3.Conn) error {
	// Prepare can prepare a statement and optionally also bind arguments
	stmt, err := conn.Prepare(`SELECT * FROM devices`)
	if err != nil {
		return fmt.Errorf("failed to select from students table: %v", err)
	}
	defer stmt.Close()

	for {
		hasRow, err := stmt.Step()
		if err != nil {
			return fmt.Errorf("step failed while querying students: %v", err)
		}
		if !hasRow {
			break
		}

		// Use Scan to access column data from a row
		var name string
		var services string
		var friends string
		var owner int
		err = stmt.Scan(&name, &services, &friends, &owner)
		if err != nil {
			return fmt.Errorf("scan failed while querying students: %v", err)
		}

		fmt.Println("name:", name, "services:", services, "friends:", friends, "owner:", owner)
	}

	return nil
}