From e5b1b407dee0da6a2c004728d9db4a7b75516e90 Mon Sep 17 00:00:00 2001
From: nquidox <nquidox@gmail.com>
Date: Wed, 11 Mar 2026 19:32:14 +0300
Subject: [PATCH] zero prices methods

---
 internal/merch/dto.go        | 13 ++++++
 internal/merch/repository.go | 83 ++++++++++++++++++++++++++++++++++++
 2 files changed, 96 insertions(+)

diff --git a/internal/merch/dto.go b/internal/merch/dto.go
index 89e0218..2d95fe6 100644
--- a/internal/merch/dto.go
+++ b/internal/merch/dto.go
@@ -62,3 +62,16 @@ type PricesResponse struct {
 	MerchUuid string             `json:"merch_uuid"`
 	Origins   []OriginWithPrices `json:"origins"`
 }
+
+type ZeroPrice struct {
+	Id        int64     `json:"id,omitempty"`
+	CreatedAt time.Time `json:"created_at,omitempty"`
+	MerchUuid string    `json:"merch_uuid"`
+	Name      string    `json:"name"`
+	Origin    string    `json:"origin"`
+}
+
+type DeleteZeroPrices struct {
+	Id        int64  `json:"id"`
+	MerchUuid string `json:"merch_uuid"`
+}
diff --git a/internal/merch/repository.go b/internal/merch/repository.go
index 5e93631..8940d86 100644
--- a/internal/merch/repository.go
+++ b/internal/merch/repository.go
@@ -42,6 +42,10 @@ type Prices interface {
 	insertPrices(ctx context.Context, prices []Price) error
 	getPricesWithDays(ctx context.Context, userId int64, days time.Time) ([]Price, error)
 	getDistinctPrices(ctx context.Context, userId int64, merchUuid string, days time.Time) ([]Price, error)
+
+	getZeroPrices(ctx context.Context, userId int64) ([]ZeroPrice, error)
+	deleteZeroPricesPeriod(ctx context.Context, userId int64, start, end time.Time, now sql.NullTime) error
+	deleteZeroPrices(ctx context.Context, now sql.NullTime, list []int64) error
 }
 
 type Tasks interface {
@@ -469,3 +473,82 @@ func (r *repo) getDistinctPrices(ctx context.Context, userId int64, merchUuid st
 	}
 	return result, nil
 }
+
+func (r *repo) getZeroPrices(ctx context.Context, userId int64) ([]ZeroPrice, error) {
+	q := `
+		WITH price_with_neighbors AS (
+            SELECT
+				p.id, p.created_at, p.merch_id, p.price, p.origin_id, m.name,
+				LAG(price) OVER (PARTITION BY p.merch_id, p.origin_id ORDER BY p.created_at, p.id) AS prev_price,
+				LEAD(price) OVER (PARTITION BY p.merch_id, p.origin_id ORDER BY p.created_at, p.id) AS next_price
+			FROM merch_prices AS p
+			JOIN merch as m ON m.id = p.merch_id
+			WHERE p.deleted_at IS NULL
+            AND m.deleted_at IS NULL
+			AND m.user_id = 3)
+
+		SELECT
+			pwn.id, pwn.created_at, pwn.merch_uuid, pwn.name, mo.name
+		FROM price_with_neighbors AS pwn
+        JOIN merch_origins AS mo ON mo.id = pwn.origin_id
+		WHERE
+			pwn.price = 0
+			AND pwn.prev_price IS NOT NULL
+			AND pwn.prev_price > 0
+			AND pwn.next_price IS NOT NULL
+			AND pwn.next_price > 0
+		ORDER BY pwn.created_at DESC
+	`
+
+	rows, err := r.db.Query(ctx, q, userId)
+	if err != nil {
+		return nil, err
+	}
+
+	var zeroPrices []ZeroPrice
+	for rows.Next() {
+		var p ZeroPrice
+		if err = rows.Scan(&p.Id, &p.CreatedAt, &p.MerchUuid, &p.Name, &p.Origin); err != nil {
+			rows.Close()
+			return nil, err
+		}
+		zeroPrices = append(zeroPrices, p)
+	}
+
+	rows.Close()
+	if err = rows.Err(); err != nil {
+		return nil, err
+	}
+
+	return zeroPrices, nil
+}
+
+func (r *repo) deleteZeroPricesPeriod(ctx context.Context, userId int64, start, end time.Time, now sql.NullTime) error {
+	q := `
+		UPDATE merch_prices
+		SET deleted_at = $1
+		FROM merch
+		WHERE merch_prices.merch_id = merch.id
+		  AND merch.user_id = $2                    
+		  AND merch_prices.price = 0
+		  AND merch_prices.deleted_at IS NULL
+		  AND merch_prices.created_at BETWEEN $3 AND $4;
+	`
+
+	_, err := r.db.Exec(ctx, q, now, userId, start, end)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (r *repo) deleteZeroPrices(ctx context.Context, now sql.NullTime, list []int64) error {
+	q := `UPDATE merch_prices SET deleted_at = $1 WHERE id IN $2`
+
+	_, err := r.db.Exec(ctx, q, now, list)
+	if err != nil {
+		return err
+	}
+	return nil
+}