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|
package models
import (
"context"
"crypto/rand"
"errors"
"fmt"
"log/slog"
"time"
"github.com/ncruces/go-sqlite3"
_ "github.com/ncruces/go-sqlite3/embed"
"github.com/ncruces/go-sqlite3/gormlite"
"github.com/oklog/ulid/v2"
slogGorm "github.com/orandin/slog-gorm"
"gorm.io/gorm"
gormPrometheus "gorm.io/plugin/prometheus"
)
var (
ErrCantSwitchToYourself = errors.New("models: you can't switch to yourself")
)
type DAO struct {
db *gorm.DB
backupDBLoc string
}
func (d *DAO) DB() *gorm.DB {
return d.db
}
func (d *DAO) Ping(ctx context.Context) error {
if err := d.db.WithContext(ctx).Exec("select 1+1").Error; err != nil {
return err
}
return nil
}
func New(dbLoc, backupDBLoc string) (*DAO, error) {
db, err := gorm.Open(gormlite.Open(dbLoc), &gorm.Config{
Logger: slogGorm.New(
slogGorm.WithErrorField("err"),
slogGorm.WithRecordNotFoundError(),
),
})
if err != nil {
return nil, fmt.Errorf("failed to connect to database: %w", err)
}
if err := db.AutoMigrate(
&Member{},
&Switch{},
&Blogpost{},
&Event{},
); err != nil {
return nil, fmt.Errorf("failed to migrate schema: %w", err)
}
db.Use(gormPrometheus.New(gormPrometheus.Config{
DBName: "mi",
}))
return &DAO{db: db, backupDBLoc: backupDBLoc}, nil
}
func (d *DAO) Members(ctx context.Context) ([]Member, error) {
var result []Member
if err := d.db.WithContext(ctx).Find(&result).Error; err != nil {
return nil, err
}
return result, nil
}
func (d *DAO) WhoIsFront(ctx context.Context) (*Switch, error) {
var sw Switch
if err := d.db.Joins("Member").Order("created_at DESC").First(&sw).Error; err != nil {
return nil, err
}
return &sw, nil
}
func (d *DAO) SwitchFront(ctx context.Context, memberName string) (*Switch, *Switch, error) {
var old Switch
tx := d.db.Begin()
if err := tx.WithContext(ctx).Joins("Member").Where("ended_at IS NULL").First(&old).Error; err != nil {
tx.Rollback()
return nil, nil, err
}
if old.Member.Name == memberName {
tx.WithContext(ctx).Rollback()
return nil, nil, ErrCantSwitchToYourself
}
now := time.Now()
old.EndedAt = &now
if err := tx.WithContext(ctx).Save(&old).Error; err != nil {
tx.Rollback()
return nil, nil, err
}
var newMember Member
if err := tx.WithContext(ctx).Where("name = ?", memberName).First(&newMember).Error; err != nil {
tx.Rollback()
return nil, nil, err
}
new := Switch{
ID: ulid.MustNew(ulid.Now(), rand.Reader).String(),
MemberID: newMember.ID,
}
if err := tx.WithContext(ctx).Create(&new).Error; err != nil {
tx.Rollback()
return nil, nil, err
}
if err := tx.WithContext(ctx).Commit().Error; err != nil {
tx.Rollback()
return nil, nil, err
}
return &old, &new, nil
}
func (d *DAO) GetSwitch(ctx context.Context, id string) (*Switch, error) {
var sw Switch
if err := d.db.WithContext(ctx).
Joins("Member").
Where("switches.id = ?", id).
First(&sw).Error; err != nil {
return nil, err
}
return &sw, nil
}
func (d *DAO) ListSwitches(ctx context.Context, count, page int) ([]Switch, error) {
var switches []Switch
if err := d.db.WithContext(ctx).
Joins("Member").
Order("created_at DESC").
Limit(count).
Offset(count * page).
Find(&switches).Error; err != nil {
return nil, err
}
return switches, nil
}
func (d *DAO) Backup() {
slog.Info("starting backup")
ctx, cancel := context.WithTimeout(context.Background(), 5*time.Minute)
defer cancel()
err := d.backup(ctx, d.backupDBLoc)
if err != nil {
slog.Error("failed to backup database", "err", err)
}
slog.Info("backup done")
}
func (d *DAO) backup(ctx context.Context, to string) error {
db, err := d.db.DB()
if err != nil {
return fmt.Errorf("failed to get database connection: %w", err)
}
if err := db.Ping(); err != nil {
return fmt.Errorf("failed to ping database: %w", err)
}
conn, err := db.Conn(ctx)
if err != nil {
return fmt.Errorf("failed to get database connection: %w", err)
}
defer conn.Close()
if err := conn.Raw(func(dca any) error {
conn, ok := dca.(sqlite3.DriverConn)
if !ok {
return fmt.Errorf("db connection is not a sqlite3 connection, it is %T", dca)
}
bu, err := conn.Raw().BackupInit("main", to)
if err != nil {
return fmt.Errorf("failed to initialize backup: %w", err)
}
defer bu.Close()
var done bool
for !done {
done, err = bu.Step(bu.Remaining())
if err != nil {
return fmt.Errorf("failed to backup database: %w", err)
}
}
if err := bu.Close(); err != nil {
return fmt.Errorf("failed to close backup: %w", err)
}
return nil
}); err != nil {
return fmt.Errorf("failed to backup database: %w", err)
}
return nil
}
|
