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|
package model
import (
"database/sql"
"encoding/json"
"errors"
"fmt"
)
type Step struct {
Id string `json:"id"`
Index string `json:"index"`
Text string `json:"text"`
Recipe string `json:"recipe"`
Ingredients []Ingredient `json:"ingredients"`
}
func (s Step) String() string {
b, _ := json.MarshalIndent(s, "", " ")
return string(b)
}
func (s *Step) Validate() error {
var err error
if s.Id != "" {
err = isPositiveOrZeroInt(s.Id)
if err != nil {
return fmt.Errorf("Invalid step ID: %w", err)
}
}
if s.Index != "" {
err = isPositiveOrZeroInt(s.Index)
if err != nil {
return fmt.Errorf("Invalid step index: %w", err)
}
}
if s.Text == "" {
return fmt.Errorf("Step text must not be empty")
}
err = isPositiveOrZeroInt(s.Recipe)
if err != nil {
return fmt.Errorf("Step does not reference a valid recipe ID: %w", err)
}
return nil
}
func (s *Step) Create(tx *sql.Tx) error {
if s.Id != "" {
return fmt.Errorf("Cannot create step if ID is given")
}
err := s.Validate()
if err != nil {
return err
}
cmd := `
INSERT INTO steps
('index', text, recipe)
VALUES
(?, ?, ?)
`
result, err := tx.Exec(cmd, s.Index, s.Text, s.Recipe)
if err != nil {
return err
}
id, err := result.LastInsertId()
if err != nil {
return err
}
s.Id = fmt.Sprint(id)
for i := range s.Ingredients {
s.Ingredients[i].Step = s.Id
s.Ingredients[i].Index = fmt.Sprint(i)
err = s.Ingredients[i].Create(tx)
if err != nil {
return err
}
}
return nil
}
func (s *Step) getIngredientIds(tx *sql.Tx) ([]Ingredient, error) {
retval := make([]Ingredient, 0)
cmd := `
SELECT
id
FROM
ingredients
WHERE
step = ?
ORDER BY
'index' ASC
`
rows, err := tx.Query(cmd, s.Id)
if err != nil {
return retval, err
}
defer rows.Close()
for rows.Next() {
i := Ingredient{}
err = rows.Scan(&i.Id)
if err != nil {
return retval, err
}
retval = append(retval, i)
}
return retval, nil
}
func (s *Step) Read(tx *sql.Tx) error {
cmd := `
SELECT
"index", text, recipe
FROM
steps
WHERE
id = ?
`
rows, err := tx.Query(cmd, s.Id)
if err != nil {
return err
}
defer rows.Close()
if !rows.Next() {
return sql.ErrNoRows
}
err = rows.Scan(&s.Index, &s.Text, &s.Recipe)
if err != nil {
return err
}
s.Ingredients, err = s.getIngredientIds(tx)
if err != nil {
return err
}
for i := range s.Ingredients {
err = s.Ingredients[i].Read(tx)
if err != nil {
return err
}
}
return s.Validate()
}
func (s *Step) Update(tx *sql.Tx) error {
err := s.Validate()
if err != nil {
return err
}
oldIngredients, err := s.getIngredientIds(tx)
if err != nil {
return err
}
for i := range oldIngredients {
err = oldIngredients[i].Delete(tx)
if err != nil {
return err
}
}
for i := range s.Ingredients {
s.Ingredients[i].Index = fmt.Sprint(i)
s.Ingredients[i].Step = s.Id
err = s.Ingredients[i].Create(tx)
if err != nil {
return err
}
}
cmd := `
UPDATE
steps
SET
index = ?,
text = ?,
recipe = ?
WHERE
id = ?`
res, err := tx.Exec(cmd, s.Index, s.Text, s.Recipe, s.Id)
if err != nil {
return err
}
affected, err := res.RowsAffected()
if err != nil {
return err
}
if affected != 1 {
return fmt.Errorf("Step update affected %d rows instead of 1", affected)
}
return nil
}
func (s *Step) Delete(tx *sql.Tx) error {
oldIngredients, err := s.getIngredientIds(tx)
if err != nil {
return err
}
for i := range oldIngredients {
err = oldIngredients[i].Delete(tx)
if err != nil {
return err
}
}
cmd := `
DELETE FROM
steps
WHERE
id = ?
`
result, err := tx.Exec(cmd, s.Id)
if err != nil {
return err
}
rows, err := result.RowsAffected()
if rows != 1 {
return errors.New("Step deletion did not affect exactly one row")
}
return nil
}
|
