add revenue now workd through shell command

internal/model/periode.go

@@ -2,10 +2,65 @@
 package model
 
 import (
+	"database/sql"
 	"fmt"
 	"time"
 )
 
+// PeriodType defines the granularity of the revenue entry
+type PeriodType string
+
+const (
+	PeriodQuarter  PeriodType = "Q"
+	PeriodHalfYear PeriodType = "H"
+	PeriodYear     PeriodType = "Y"
+)
+
+// Period holds the actual time range for a revenue entry
+type Period struct {
+	ID    int
+	Type  PeriodType
+	Year  int
+	Index int // Q1=1 Q2=2 Q3=3 Q4=4 | H1=1 H2=2 | FY=1
+	Start time.Time
+	End   time.Time
+}
+
+func (p *Period) Validate(checkID bool) error {
+	if p.ID == 0 && checkID {
+		return fmt.Errorf("No ID Set")
+	} else if p.Type == PeriodQuarter && (p.Index > 4 || p.Index < 1) {
+		return fmt.Errorf("Not Valid Quarter index")
+	} else if p.Type == PeriodHalfYear && (p.Index > 2 || p.Index < 1) {
+		return fmt.Errorf("Not Valid HalfYear index")
+	} else if p.Type == PeriodHalfYear && (p.Index != 1 || p.Year < 1) {
+		return fmt.Errorf("Not Valid Year index")
+	}
+	return nil
+}
+
+func (p *Period) Insert(db *sql.DB) error {
+	_, err := db.Exec(
+		`INSERT INTO periods (type, year, idx, start_date, end_date) VALUES (?, ?, ?, ?, ?)
+         ON CONFLICT(type, year, idx) DO UPDATE SET start_date=excluded.start_date, end_date=excluded.end_date`,
+		string(p.Type), p.Year, p.Index, p.Start.Format("2006-01-02"), p.End.Format("2006-01-02"),
+	)
+	if err != nil {
+		return fmt.Errorf("upsert period: %w", err)
+	}
+
+	var id int
+	err = db.QueryRow(
+		`SELECT id FROM periods WHERE type = ? AND year = ? AND idx = ?`,
+		string(p.Type), p.Year, p.Index,
+	).Scan(&id)
+	if err != nil {
+		return fmt.Errorf("select period: %w", err)
+	}
+	p.ID = id
+	return nil
+}
+
 func QuarterPeriod(year, q int) Period {
 	months := map[int][2]int{
 		1: {1, 3}, 2: {4, 6}, 3: {7, 9}, 4: {10, 12},