cmd/mi: move front tracking to a shim

Signed-off-by: Xe Iaso <me@xeiaso.net>

1 files changed, 112 insertions, 0 deletions

diff --git a/cmd/mi/models/dao.go b/cmd/mi/models/dao.go
new file mode 100644
index 0000000..9830bfe
--- /dev/null
+++ b/cmd/mi/models/dao.go
@@ -0,0 +1,112 @@
+package models
+
+import (
+	"context"
+	"crypto/rand"
+	"errors"
+	"time"
+
+	"github.com/oklog/ulid/v2"
+	"gorm.io/gorm"
+)
+
+var (
+	ErrCantSwitchToYourself = errors.New("models: you can't switch to yourself")
+)
+
+type DAO struct {
+	db *gorm.DB
+}
+
+func New(db *gorm.DB) *DAO {
+	return &DAO{db: db}
+}
+
+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("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("rowid DESC").
+		Limit(count).
+		Offset(count * page).
+		Find(&switches).Error; err != nil {
+		return nil, err
+	}
+
+	return switches, nil
+}