Ecommerce pricing + catalog

Go service: catalog (Postgres) + cart + pricing / quotes. Folders: cmd/ (binaries), internal/ (app code).

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Quick start

1. Create a Postgres database.
2. Copy env.example → .env (repo root) and set ECOMMERCE_DATABASE_URL (or ECOMMERCE_DB_*) and ECOMMERCE_AUTH_SECRET (used to sign login tokens).
3. Run the API (migrations apply on startup):

go run ./cmd/catalog-server

Default listen address: :8787 (override with ECOMMERCE_HTTP_ADDR).

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HTTP API (v1)

Base URL: http://localhost:8787 (or your ECOMMERCE_HTTP_ADDR).

Products

Method	Path	Purpose
GET	/v1/products	List (limit, offset, category, status)
GET	/v1/products/{id}	One product
POST	/v1/products	Create (sku, name, description, category, base_price, optional status)
PATCH	/v1/products/{id}	Partial update
DELETE	/v1/products/{id}	Archive

Categories: electronics, apparel. Status: draft, active, archived.

Cart (persisted in Postgres)

Method	Path	Purpose
POST	/v1/carts/add	Add line; omit cart_id to create a cart, then reuse that id
GET	/v1/carts/{id}	Cart snapshot (lines + discount fields)
POST	/v1/carts/{id}/discount	Set discount (catalog offer or inline JSON; see models)
POST	/v1/carts/{id}/quote	Price this cart (read-only; returns totals)
POST	/v1/carts/{id}/checkout	Clear lines + discounts; same cart_id for next order

Add to cart body (internal/models/cart/types.go):

{ "cart_id": "", "product_id": "1", "qty": 2 }

Omit cart_id (or use "") on the first request; store the returned cart_id for later calls.

Users + auth

Method	Path	Purpose
POST	/v1/users/register	Body: email, password, name
POST	/v1/users/login	Body: email, password → { "access_token", "user" }
GET	/v1/users/me	Current user (header Authorization: Bearer <token>)
PATCH	/v1/users/me	Update name and/or password (same header)

Passwords are stored with bcrypt. Tokens are HMAC-signed (not JWT); set a strong ECOMMERCE_AUTH_SECRET in production.

Cart for logged-in user (one cart per user)

All routes require Authorization: Bearer <token> from login.

Method	Path	Purpose
GET	/v1/me/cart	Get or create the user’s cart; snapshot includes user_id
POST	/v1/me/cart/add	Body: product_id, qty (same as guest add, no cart_id)
POST	/v1/me/cart/discount	Same body as POST /v1/carts/{id}/discount
POST	/v1/me/cart/quote	Same body as POST /v1/carts/{id}/quote
POST	/v1/me/cart/checkout	Clear that user’s cart (same cart row next time)

Discount offers (catalog)

Method	Path	Purpose
GET	/v1/discount-offers	List (active_only, code, limit, offset)

Rows live in discount_offers; carts can reference them via discount_offer_id.

Stateless quote (no server cart)

Method	Path	Purpose
POST	/v1/checkout/quote	Quote from JSON lines + tax/shipping/rules/promos in one request

Response shape: subtotal, discount, shipping, tax, total (see internal/models/checkout/types.go).

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Other commands

Pricing demo (no DB):

go run ./cmd/pricing-demo

Migrations only:

go run ./cmd/migrate up
go run ./cmd/migrate down

Uses the same DB env vars as catalog-server.

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Where things live (short)

• internal/db/migrations/ — SQL (001 products, 002 carts, 003 discount offers, 004 users + carts.user_id)
• internal/repository/ — Postgres: products, carts, discount offers
• internal/service/ — product, cart, discount_offer
• internal/handlers/ — HTTP
• internal/pricing/ — rules, promos, quote computation