memberDB/handlers/events.go

package handlers

import (
	"encoding/json"
	"errors"
	"fmt"
	"slices"
	"strings"
	"time"

	"gitea.tecamino.com/paadi/memberDB/models"
)

func (dh *DatabaseHandler) CreateNewEventTable() error {
	createTableSQL := `
	CREATE TABLE IF NOT EXISTS events (
		id INTEGER PRIMARY KEY AUTOINCREMENT,
		name TEXT NOT NULL,
		date TEXT UNIQUE NOT NULL,
		attendees TEXT NOT NULL,
		count INTEGER NOT NULL
	);`

	_, err := dh.database.Exec(createTableSQL)
	if err != nil {
		return fmt.Errorf("failed to create table: %w", err)
	}
	return nil
}

func (dh *DatabaseHandler) StartNewEvent(name string) error {
	_, err := dh.database.Exec("INSERT INTO events (name, date, attendees, count) VALUES (?, ?, ?, ?)", name, time.Now().Format("2006-01-02 15:04:05"), "[]", 0)
	return err
}

func (dh *DatabaseHandler) GetEvent(id int) (attendees []models.Event, err error) {
	var args any
	query := `SELECT id, name, date, attendees, count FROM events`

	if id > 0 {
		query += ` WHERE id = ?`
		args = id
	}

	rows, err := dh.database.Query(query, args)
	if err != nil {
		return
	}
	defer rows.Close()

	for rows.Next() {
		var id, count int
		var name, date, attendance string
		if err = rows.Scan(&id, &name, &date, &attendance, &count); err != nil {
			return
		}

		var a []models.Person

		if err := json.Unmarshal([]byte(attendance), &a); err != nil {
			return attendees, err
		}

		attendees = append(attendees, models.Event{
			Id:        id,
			Name:      name,
			Date:      date,
			Attendees: a,
			Count:     count,
		})
	}

	return attendees, nil
}

func (dh *DatabaseHandler) DeleteEvent(ids ...int) error {
	if len(ids) == 0 {
		return errors.New("no ids given to be deleted")
	}

	placeholders := make([]string, len(ids))
	args := make([]any, len(ids))
	for i, id := range ids {
		placeholders[i] = "?"
		args[i] = id
	}
	query := fmt.Sprintf("DELETE FROM events WHERE id IN (%s)", strings.Join(placeholders, ","))

	_, err := dh.database.Exec(query, args...)
	return err
}

func (dh *DatabaseHandler) AddAttendeesToEvent(event models.Event) error {

	//get event from database by id
	row := dh.database.QueryRow(`SELECT attendees FROM events WHERE id = ?`, event.Id)

	var attendeesString string
	if err := row.Scan(&attendeesString); err != nil {
		return err
	}
	fmt.Println(attendeesString)

	var attendees []models.Person
	err := json.Unmarshal([]byte(attendeesString), &attendees)
	if err != nil {
		return err
	}

next:
	for _, newAttendee := range event.Attendees {
		for _, attendee := range attendees {
			if attendee.FirstName == newAttendee.FirstName && attendee.LastName == newAttendee.LastName {
				continue next
			}
		}
		attendees = append(attendees, newAttendee)
	}

	attendeesByte, err := json.Marshal(attendees)
	if err != nil {
		return err
	}

	count := len(attendees)
	_, err = dh.database.Exec("UPDATE events SET attendees= ? count= ? WHERE id= ?", string(attendeesByte), event.Id, count)
	if err != nil {
		return err
	}

	return nil
}

func (dh *DatabaseHandler) DeleteAttendeesFromEvent(event models.Event) error {
	//get event from database by id
	row := dh.database.QueryRow(`SELECT attendees FROM events WHERE id = ?`, event.Id)

	var attendeesString string
	if err := row.Scan(&attendeesString); err != nil {
		return err
	}
	fmt.Println(attendeesString)

	var attendees []models.Person
	err := json.Unmarshal([]byte(attendeesString), &attendees)
	if err != nil {
		return err
	}

	for _, newAttendee := range event.Attendees {
		for i, attendee := range attendees {
			if attendee.FirstName == newAttendee.FirstName && attendee.LastName == newAttendee.LastName {
				attendees = slices.Delete(attendees, i, i+1)
			}
		}
	}

	attendeesByte, err := json.Marshal(attendees)
	if err != nil {
		return err
	}

	count := len(attendees)
	_, err = dh.database.Exec("UPDATE events SET attendees= ? count= ? WHERE id= ?", string(attendeesByte), event.Id, count)
	if err != nil {
		return err
	}

	return nil
}