first commit of restructured project

trahn-trade-backend/internal/repository/price.go

@@ -0,0 +1,110 @@
+package repository
+
+import (
+	"context"
+	"time"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+	"github.com/kjannette/trahn-backend/internal/models"
+)
+
+type PriceRepo struct {
+	pool *pgxpool.Pool
+}
+
+func NewPriceRepo(pool *pgxpool.Pool) *PriceRepo {
+	return &PriceRepo{pool: pool}
+}
+
+func (r *PriceRepo) Record(ctx context.Context, price float64, ts time.Time) (*models.PricePoint, error) {
+	td := TradingDay(ts)
+	row := r.pool.QueryRow(ctx,
+		`INSERT INTO price_history (timestamp, price, trading_day, source)
+		 VALUES ($1, $2, $3, $4) RETURNING *`,
+		ts, price, td, "coingecko",
+	)
+	return scanPrice(row)
+}
+
+func (r *PriceRepo) GetByDay(ctx context.Context, tradingDay string) ([]models.PricePoint, error) {
+	rows, err := r.pool.Query(ctx,
+		`SELECT * FROM price_history WHERE trading_day = $1 ORDER BY timestamp ASC`,
+		tradingDay,
+	)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	return collectPrices(rows)
+}
+
+func (r *PriceRepo) GetAvailableDays(ctx context.Context) ([]string, error) {
+	rows, err := r.pool.Query(ctx,
+		`SELECT DISTINCT trading_day FROM price_history ORDER BY trading_day DESC LIMIT 30`,
+	)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var days []string
+	for rows.Next() {
+		var d time.Time
+		if err := rows.Scan(&d); err != nil {
+			return nil, err
+		}
+		days = append(days, d.Format("2006-01-02"))
+	}
+	return days, rows.Err()
+}
+
+func (r *PriceRepo) GetLatest(ctx context.Context) (*models.PricePoint, error) {
+	row := r.pool.QueryRow(ctx,
+		`SELECT * FROM price_history ORDER BY timestamp DESC LIMIT 1`,
+	)
+	p, err := scanPrice(row)
+	if err != nil {
+		if err.Error() == "no rows in result set" {
+			return nil, nil
+		}
+		return nil, err
+	}
+	return p, nil
+}
+
+// --- scan helpers ---
+
+type scannable interface {
+	Scan(dest ...any) error
+}
+
+func scanPrice(row scannable) (*models.PricePoint, error) {
+	var p models.PricePoint
+	var td time.Time
+	err := row.Scan(&p.ID, &p.Timestamp, &p.Price, &td, &p.Source, &p.CreatedAt)
+	if err != nil {
+		return nil, err
+	}
+	p.TradingDay = td.Format("2006-01-02")
+	return &p, nil
+}
+
+type rowsIter interface {
+	Next() bool
+	Scan(dest ...any) error
+	Err() error
+}
+
+func collectPrices(rows rowsIter) ([]models.PricePoint, error) {
+	var out []models.PricePoint
+	for rows.Next() {
+		var p models.PricePoint
+		var td time.Time
+		if err := rows.Scan(&p.ID, &p.Timestamp, &p.Price, &td, &p.Source, &p.CreatedAt); err != nil {
+			return nil, err
+		}
+		p.TradingDay = td.Format("2006-01-02")
+		out = append(out, p)
+	}
+	return out, rows.Err()
+}