🌿 SuperMarketPL — MiniSuper FrescaVida

An information system for the MiniSuper FrescaVida grocery store, built entirely in SWI-Prolog. It combines a logic-based knowledge base with an embedded web server, letting you browse products, prices, locations, and business rules straight from the browser.

📸 Screenshots

📦 Stack

Layer	Technology
Backend / Logic	SWI-Prolog + `http_server`
Proxy / Networking	nginx + Docker Compose
Frontend	Static HTML · CSS · JS

📁 Project Structure

SuperMarketPL/
├── prolog/
│   ├── server.pl          ← Entry point; HTTP handlers
│   ├── db.pl               ← Facts (products, locations, prices, sections, offers)
│   ├── rules.pl             ← Business rules
│   ├── queries.pl           ← Composite query predicates (JSON-ready)
│   └── templates/
│       ├── layout.pl        ← Topbar and global HTML wrapper
│       ├── home.pl           ← Main view (section grid)
│       ├── map.pl            ← Interactive store map
│       ├── section.pl        ← Product-category view
│       └── office.pl         ← Info and contact
├── public/
│   ├── css/                  ← Stylesheets (tokens, components)
│   └── js/                    ← app.js (SPA router, fetch helpers)
├── nginx.conf
└── docker-compose.yml

🚀 Requirements

Docker Desktop 4.x or later (includes Docker Compose v2)
Windows 10/11 with WSL 2, macOS 12+, or Linux (Ubuntu 20.04+)
Port 80 available on the host
Internet connection only needed for the first build

⚙️ Installation

1. Clone the repository

git clone https://github.com/your-username/SuperMarketPL.git
cd SuperMarketPL

2. Build and start

docker compose up --build

The first run can take 2-3 minutes. When you see this in the console, it's ready:

🌿 MiniSuper FrescaVida — server started
   http://localhost:8080

3. Open in your browser

http://localhost

🛠️ Useful Commands

# Start without rebuilding (faster)
docker compose up

# Stop and remove containers
docker compose down

# Full rebuild (required after changing .pl files)
docker compose up --build

# Restart only nginx (after changing nginx.conf)
docker compose restart nginx

# View the Prolog server logs
docker compose logs prolog --tail=30

# Follow all logs in real time
docker compose logs -f

🧠 Prolog Knowledge Base

The system's logic is split into three files: db.pl (facts), rules.pl (derived rules), and queries.pl (query predicates that shape the JSON responses served by the API).

Facts — `db.pl`

`producto/6`

Defines each product in the store.

producto(Tipo, Marca, Nombre, Presentacion, Precio, Comentario).

% Examples:
producto('Leche', 'Lala', 'Entera', '1L', 33, 'Entera cremosa fresca').
producto('Refresco', 'Coca-Cola', 'Original', '600ml', 18, 'Sabor clásico dulce').
producto('Queso', 'Chilchota', 'Manchego', '400g', 68, 'Rebanado curado').

`lugar/2`

Maps each product category to a location within the store.

lugar('Lacteo', 'Refrigerador zona A').
lugar('Bebida', 'Pasillo D').

`categoria/2`

Groups product types into higher-level categories.

categoria('Lacteo', 'Leche').
categoria('Lacteo', 'Queso').
categoria('Bebida', 'Refresco').

`seccion/6`

Defines each storefront section shown on the home page and the map (id, name, description, icon, color, aisle).

seccion('lacteos', 'Lácteos', 'Frescos de granja seleccionados', '🥛', '#eaf6f0', 'A-01').
seccion('bebidas', 'Bebidas', 'Refrescantes y energizantes', '🧃', '#dbeeff', 'D-01').

`oferta/4`

Current promotions shown on the home page (id, description, badge, related section).

oferta(1, 'Yogures — hasta agotar existencias', '2×1', 'lacteos').
oferta(3, 'Refresco 2L + botana desde $38', 'Combo', 'bebidas').

Rules — `rules.pl`

`donde/2` — Locate a product

donde(Tipo, Lugar) :-
    categoria(Categoria, Tipo),
    lugar(Categoria, Lugar).

Returns the aisle where a product type is located.

donde('Leche', Lugar).
% Lugar = 'Refrigerador zona A'

`productos_de_seccion/3` — Products in a storefront section

productos_de_seccion(SeccionId, Productos, Lugar) :-
    seccion_a_categoria(SeccionId, Categoria),
    findall(
        producto(Tipo, Marca, Nombre, Pres, Precio, Com),
        (categoria(Categoria, Tipo), producto(Tipo, Marca, Nombre, Pres, Precio, Com)),
        Productos
    ),
    lugar(Categoria, Lugar).

Bridges the frontend's section id (e.g. 'lacteos') to the underlying category and returns every matching product plus its location.

`seccion_a_categoria/2` — Frontend section → domain category

seccion_a_categoria('lacteos',    'Lacteo').
seccion_a_categoria('bebidas',    'Bebida').
seccion_a_categoria('snacks',     'Snack').
seccion_a_categoria('frutas',     'FrutaVerdura').
seccion_a_categoria('carnes',     'Carnes').
seccion_a_categoria('harinas',    'Harinas').
seccion_a_categoria('limpieza',   'Limpieza').
seccion_a_categoria('congelados', 'Congelado').
seccion_a_categoria('abarrotes',  'Abarrote').

A lookup table that maps the short ids used in URLs and the UI to the category atoms used in db.pl.

`precio_max/5` — Filter by budget

precio_max(Max, Tipo, Marca, Nombre, Precio) :-
    producto(Tipo, Marca, Nombre, _, Precio, _),
    Precio =< Max.

Returns every product priced at or below the given maximum.

precio_max(20, Tipo, Marca, Nombre, Precio).
% Every product priced $20 or less

`mas_barato/3` — Cheapest of its type

mas_barato(Tipo, Nombre, Precio) :-
    producto(Tipo, _, Nombre, _, Precio, _),
    \+ (
        producto(Tipo, _, _, _, OtroPrecio, _),
        OtroPrecio < Precio
    ).

Uses negation as failure (\+): a product is the cheapest if no other product of the same type has a lower price. The idiomatic way to express a minimum in Prolog.

mas_barato('Leche', Nombre, Precio).

`mas_caro/3` — Most expensive of its type

mas_caro(Tipo, Nombre, Precio) :-
    producto(Tipo, _, Nombre, _, Precio, _),
    \+ (
        producto(Tipo, _, _, _, OtroPrecio, _),
        OtroPrecio > Precio
    ).

Same idea as mas_barato/3, but negating the opposite comparison to find a maximum instead.

`buscar_por_nombre/5` — Search by name

buscar_por_nombre(Query, Tipo, Marca, Nombre, Precio) :-
    downcase_atom(Query, QueryLower),
    producto(Tipo, Marca, Nombre, _, Precio, _),
    downcase_atom(Nombre, NombreLower),
    sub_atom(NombreLower, _, _, _, QueryLower).

Case-insensitive substring search over product names — powers the search bar.

buscar_por_nombre('cola', Tipo, Marca, Nombre, Precio).

`misma_categoria/2` — Compare two products

misma_categoria(Nombre1, Nombre2) :-
    producto(Tipo, _, Nombre1, _, _, _),
    producto(Tipo, _, Nombre2, _, _, _),
    Nombre1 \= Nombre2.

Checks whether two products are of the same type. Nombre1 \= Nombre2 keeps a product from matching itself.

misma_categoria('Entera', 'Deslactosada').  % true
misma_categoria('Entera', 'Cola').          % false

`todas_las_secciones/1` and `todas_las_ofertas/1`

Collect every seccion/6 and oferta/4 fact into a list, ready to be turned into JSON for the home page.

`info_producto/6` — Full product detail

info_producto(Nombre, Tipo, Marca, Presentacion, Precio, Comentario) :-
    producto(Tipo, Marca, Nombre, Presentacion, Precio, Comentario).

Looks up a product by name and returns all of its stored fields; query_info_producto/2 in queries.pl then attaches its location via donde/2.

info_producto('Manchego', Tipo, Marca, Presentacion, Precio, Comentario).

Quick Reference

Predicate	Arity	File	Description
`producto`	6	`db.pl`	Fact. A product with type, brand, name, packaging, price, and comment.
`lugar`	2	`db.pl`	Fact. Aisle or zone for each category.
`categoria`	2	`db.pl`	Fact. Groups product types into higher-level categories.
`seccion`	6	`db.pl`	Fact. A storefront section (id, name, description, icon, color, aisle).
`oferta`	4	`db.pl`	Fact. A current promotion tied to a section.
`donde`	2	`rules.pl`	Rule. Returns a product type's aisle.
`productos_de_seccion`	3	`rules.pl`	Rule. Lists every product in a storefront section.
`seccion_a_categoria`	2	`rules.pl`	Rule. Maps a section id to its domain category.
`precio_max`	5	`rules.pl`	Rule. Filters products priced at or below a given maximum.
`mas_barato`	3	`rules.pl`	Rule. The cheapest product of its type (negation as failure).
`mas_caro`	3	`rules.pl`	Rule. The most expensive product of its type.
`buscar_por_nombre`	5	`rules.pl`	Rule. Case-insensitive search by product name.
`misma_categoria`	2	`rules.pl`	Rule. Checks if two products share a type.
`todas_las_secciones`	1	`rules.pl`	Rule. Collects all storefront sections.
`todas_las_ofertas`	1	`rules.pl`	Rule. Collects all current offers.
`info_producto`	6	`rules.pl`	Rule. Full detail of a single product.

🌐 Server Routes

Views (server-rendered)

Route	Description
`/` and `/views/home`	Home page — section grid and offers
`/map` and `/views/map`	Interactive store map
`/section` and `/views/section`	Category view with its product list
`/office` and `/views/office`	Info, hours, and contact

JSON API

Route	Description
`/api/secciones`	All storefront sections
`/api/seccion`	Products for a given section
`/api/seccion/filtro`	Products for a section, filtered by product type
`/api/buscar`	Search products by name
`/api/precio`	Filter products by maximum price
`/api/barato`	Cheapest product of a given type
`/api/caro`	Most expensive product of a given type
`/api/producto`	Full detail of a single product
`/api/ofertas`	Current promotions
`/api/oficina`	Office / contact information

💻 Querying from the Terminal

To try it without Docker, load the files directly in SWI-Prolog (type queries without the ?-, Prolog adds it for you):

% Load
consult('/path/to/project/prolog/db.pl').
consult('/path/to/project/prolog/rules.pl').

% By type
producto('Leche', Marca, Nombre, Pres, Precio, Com).

% Location
donde('Botana', Lugar).

% Products in a storefront section
productos_de_seccion('lacteos', Productos, Lugar).

% By budget
precio_max(25, Tipo, Marca, Nombre, Precio).

% The cheapest one
mas_barato('Refresco', Nombre, Precio).

% Full detail
info_producto('Manchego', Tipo, Marca, Presentacion, Precio, Comentario).

Press ; to see the next result, . to stop.

🐛 Troubleshooting

Symptom	Fix
403 error when opening `localhost`	`nginx.conf` isn't proxying `/` to Prolog. See Fix 3.
`_G1234` variables showing on screen	SSR template with an incomplete predicate. Check `format/2` in `home.pl`.
`deprecated source_search_working_directory` warning	`consult` is using relative paths. Switch to `/app/prolog/...`. See Fix 1.
`ERROR: Exported procedure X/N is not defined`	The arity in `:- module(..., [pred/N])` doesn't match the actual definition. See Fix 2.
Port 80 already in use	Change it in `docker-compose.yml`: `ports: ["8090:80"]` and open `localhost:8090`.
Changes in `.pl` files don't show up	Use `docker compose up --build` to rebuild.

📋 Fixes Applied

#	Description	File	Status
Fix 1	Deprecated relative paths in `consult`	`server.pl`	✅ Resolved
Fix 2	`render_topbar/3` exported but defined as `/2`	`layout.pl`	✅ Resolved
Fix 3	403 error — nginx not proxying to Prolog	`nginx.conf`	✅ Resolved
Fix 4	`render_home_body` missing a `page-body` wrapper	`home.pl`	⏳ Pending
Fix 5	Discontiguous predicates in `home.pl`	`home.pl`	✅ Resolved
Fix 6	SPA navigation with `data-link`	`app.js`	✅ Verified
Fix 7	`--sidebar-width` too narrow (200px → 220-240px)	`tokens.css`	⏳ Pending
Fix 8	Emoji icons instead of monochrome SVG	`home.pl`, `section.pl`	⏳ Pending

🗺️ Roadmap

Fix 4 — page-body wrapper in render_home_body
Fix 7 — adjust --sidebar-width
Fix 8 — replace emojis with SVG icons
Dark mode (CSS variables already in place)
Search with section highlighting on the map
Admin panel to edit products without touching code

🌿 MiniSuper FrescaVida — SuperMarketPL v1.0 -By: Daniela Keeh

Name		Name	Last commit message	Last commit date
Latest commit History 22 Commits
prolog		prolog
public		public
.gitattributes		.gitattributes
.gitignore		.gitignore
Dockerfile		Dockerfile
README.md		README.md
docker-compose.yml		docker-compose.yml
dockerignore		dockerignore
nginx.conf		nginx.conf

Navigation Menu

Repository files navigation

🌿 SuperMarketPL — MiniSuper FrescaVida

📸 Screenshots

📦 Stack

📁 Project Structure

🚀 Requirements

⚙️ Installation

🛠️ Useful Commands

🧠 Prolog Knowledge Base

Facts — `db.pl`

`producto/6`

`lugar/2`

`categoria/2`

`seccion/6`

`oferta/4`

Rules — `rules.pl`

`donde/2` — Locate a product

`productos_de_seccion/3` — Products in a storefront section

`seccion_a_categoria/2` — Frontend section → domain category

`precio_max/5` — Filter by budget

`mas_barato/3` — Cheapest of its type

`mas_caro/3` — Most expensive of its type

`buscar_por_nombre/5` — Search by name

`misma_categoria/2` — Compare two products

`todas_las_secciones/1` and `todas_las_ofertas/1`

`info_producto/6` — Full product detail

Quick Reference

🌐 Server Routes

Views (server-rendered)

JSON API

💻 Querying from the Terminal

🐛 Troubleshooting

📋 Fixes Applied

🗺️ Roadmap

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Repository files navigation

🌿 SuperMarketPL — MiniSuper FrescaVida

📸 Screenshots

📦 Stack

📁 Project Structure

🚀 Requirements

⚙️ Installation

🛠️ Useful Commands

🧠 Prolog Knowledge Base

Facts — db.pl

producto/6

lugar/2

categoria/2

seccion/6

oferta/4

Rules — rules.pl

donde/2 — Locate a product

productos_de_seccion/3 — Products in a storefront section

seccion_a_categoria/2 — Frontend section → domain category

precio_max/5 — Filter by budget

mas_barato/3 — Cheapest of its type

mas_caro/3 — Most expensive of its type

buscar_por_nombre/5 — Search by name

misma_categoria/2 — Compare two products

todas_las_secciones/1 and todas_las_ofertas/1

info_producto/6 — Full product detail

Quick Reference

🌐 Server Routes

Views (server-rendered)

JSON API

💻 Querying from the Terminal

🐛 Troubleshooting

📋 Fixes Applied

🗺️ Roadmap

About

Resources

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Facts — `db.pl`

`producto/6`

`lugar/2`

`categoria/2`

`seccion/6`

`oferta/4`

Rules — `rules.pl`

`donde/2` — Locate a product

`productos_de_seccion/3` — Products in a storefront section

`seccion_a_categoria/2` — Frontend section → domain category

`precio_max/5` — Filter by budget

`mas_barato/3` — Cheapest of its type

`mas_caro/3` — Most expensive of its type

`buscar_por_nombre/5` — Search by name

`misma_categoria/2` — Compare two products

`todas_las_secciones/1` and `todas_las_ofertas/1`

`info_producto/6` — Full product detail