model: Add per-step ingredients

1 files changed, 121 insertions, 0 deletions

diff --git a/model/ingredient.go b/model/ingredient.go
new file mode 100644
index 0000000..85a4729
--- /dev/null
+++ b/model/ingredient.go
@@ -0,0 +1,121 @@
+package model
+
+import (
+	"database/sql"
+	"errors"
+	"fmt"
+)
+
+type Ingredient struct {
+	Id     string `json:"id"`
+	Index  string `json:"index"`
+	Amount string `json:"amount"`
+	Unit   string `json:"unit"`
+	Type   string `json:"type"`
+	Step   string `json:"step"`
+}
+
+func (i *Ingredient) Create(tx *sql.Tx) error {
+	if i.Id != "" {
+		return fmt.Errorf("Cannot create ingredient if ID is given")
+	}
+
+	cmd := `
+INSERT INTO ingredients
+    ('index', amount, unit, 'type', step)
+VALUES
+    (?, ?, ?, ?, ?)
+`
+
+	result, err := tx.Exec(cmd, i.Index, i.Amount, i.Unit, i.Type, i.Step)
+	if err != nil {
+		return err
+	}
+
+	id, err := result.LastInsertId()
+	if err != nil {
+		return err
+	}
+
+	i.Id = fmt.Sprint(id)
+
+	return nil
+}
+
+func (i *Ingredient) Read(tx *sql.Tx) error {
+	cmd := `
+SELECT
+    "index", amount, unit, "type", step
+FROM
+    ingredients
+WHERE
+    id = ?
+`
+
+	rows, err := tx.Query(cmd, i.Id)
+	if err != nil {
+		return err
+	}
+	defer rows.Close()
+
+	if !rows.Next() {
+		return sql.ErrNoRows
+	}
+
+	err = rows.Scan(&i.Index, &i.Amount, &i.Unit, &i.Type, &i.Step)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (i *Ingredient) Update(tx *sql.Tx) error {
+	cmd := `
+UPDATE
+    ingredients
+SET
+    index = ?,
+    amount = ?,
+    unit = ?,
+    type = ?,
+    step = ?
+WHERE
+    id = ?`
+
+	res, err := tx.Exec(cmd, i.Index, i.Amount, i.Unit, i.Type, i.Step, i.Id)
+	if err != nil {
+		return err
+	}
+
+	affected, err := res.RowsAffected()
+	if err != nil {
+		return err
+	}
+	if affected != 1 {
+		return fmt.Errorf("Ingredient update affected %d rows instead of 1", affected)
+	}
+
+	return nil
+}
+
+func (i *Ingredient) Delete(tx *sql.Tx) error {
+	cmd := `
+DELETE FROM
+    ingredients
+WHERE
+    id = ?
+`
+
+	result, err := tx.Exec(cmd, i.Id)
+	if err != nil {
+		return err
+	}
+
+	rows, err := result.RowsAffected()
+	if rows != 1 {
+		return errors.New("Ingredient deletion did not affect exactly one row")
+	}
+
+	return nil
+}