flickr-mail/AGENTS.md

Agent Guidelines for Flickr Mail

This document provides context for AI agents working on this codebase.

Project Overview

Flickr Mail is a Flask web application that helps users find photos on Flickr for Wikipedia articles and contact photographers to request Creative Commons licensing.

Architecture

• main.py: Single-file Flask application containing all routes and logic
• templates/: Jinja2 templates using Bootstrap 5 for styling
  • base.html: Base template with Bootstrap CSS/JS
  • combined.html: Main UI template for search, results, and message composition
  • message.jinja: Template for the permission request message body
  • show_error.html: Error display template

Key Components

Flickr Search (search_flickr, parse_flickr_search_results)

Searches Flickr by scraping the search results page. The page embeds JSON data in a modelExport JavaScript variable which contains photo metadata.

• Uses browser-like headers (BROWSER_HEADERS) to avoid blocks
• Parses embedded JSON by counting braces (not regex) to handle nested structures
• Accepts optional page parameter for pagination (25 photos per page)
• Returns SearchResult dataclass containing photos and pagination metadata

SearchResult Dataclass

Contains search results with pagination info:

• photos: List of FlickrPhoto instances
• total_photos: Total number of matching photos
• current_page: Current page number (1-indexed)
• total_pages: Total number of pages (capped at 160 due to Flickr's 4000 result limit)

FlickrPhoto Dataclass

Represents a photo with:

• id, title, path_alias, owner_nsid, username, realname
• license (int): Flickr license code (0=ARR, 4=CC BY, 5=CC BY-SA, etc.)
• thumb_url, medium_url: Static image URLs
• flickr_url property: URL to photo page
• license_name property: Human-readable license name

License Codes

Wikipedia-compatible licenses (can be used): 4 (CC BY), 5 (CC BY-SA), 7 (No known copyright), 8 (US Government), 9 (CC0), 10 (Public Domain).

Not compatible: 0 (All Rights Reserved), 1-3 (NC variants), 6 (ND).

URL Validation (is_valid_flickr_image_url)

Validates that image URLs passed via query params are from legitimate Flickr static image servers:

• live.staticflickr.com
• farm*.staticflickr.com
• c1.staticflickr.com, c2.staticflickr.com

NSID Lookup (flickr_usrename_to_nsid)

Converts a Flickr username/path alias to the NSID (internal user ID) needed for the Flickr mail URL. Scrapes the user's profile page for embedded params.

Request Flow

1. User enters Wikipedia article title/URL → start() extracts article name
2. search_flickr() fetches and parses Flickr search results
3. Results displayed as clickable photo grid with license badges
4. User clicks photo → page reloads with flickr and img params
5. flickr_usrename_to_nsid() looks up the photographer's NSID
6. Message template rendered with photo details
7. User copies message and clicks link to Flickr's mail compose page

Testing Changes

Run the Flask app locally:

python3 main.py

Then visit http://localhost:5000/

Test search functionality:

from main import search_flickr
result = search_flickr("Big Ben", page=1)
print(f"{len(result.photos)} photos, {result.total_pages} pages")
print(result.photos[0].title, result.photos[0].license_name)

Potential Improvements

• Cache search results to reduce Flickr requests
• Add filtering by license type
• Handle Flickr rate limiting/blocks more gracefully
• Add tests for the parsing logic