┌─────────────────────────────────────────────────────────────────┐
│              CONTENT ACCESS DECISION HIERARCHY                   │
├─────────────────────────────────────────────────────────────────┤
│                                                                  │
│  1. FULLY LEGAL (Always try first)                              │
│     ├─ Library databases (PressReader, ProQuest, JSTOR)         │
│     ├─ Open access tools (Unpaywall, CORE, PubMed Central)     │
│     ├─ Author direct contact                                    │
│     └─ Interlibrary loan                                        │
│                                                                  │
│  2. LEGAL (Browser features)                                    │
│     ├─ Reader Mode (Safari, Firefox, Edge)                      │
│     ├─ Wayback Machine archives                                 │
│     └─ Google Scholar "All versions"                            │
│                                                                  │
│  3. GREY AREA (Use with caution)                               │
│     ├─ Archive.is for individual articles                       │
│     ├─ Disable JavaScript (breaks functionality)                │
│     └─ VPNs for geo-blocked content                            │
│                                                                  │
│  4. NOT RECOMMENDED                                             │
│     ├─ Credential sharing                                       │
│     ├─ Systematic scraping                                      │
│     └─ Commercial use of bypassed content                       │
│                                                                  │
└─────────────────────────────────────────────────────────────────┘

# Unpaywall API (free, requires email for identification)
import requests

def find_open_access(doi: str, email: str) -> dict:
    """Find open access version of a paper using Unpaywall API.

    Args:
        doi: Digital Object Identifier (e.g., "10.1038/nature12373")
        email: Your email for API identification

    Returns:
        Dict with best open access URL if available
    """
    url = f"https://api.unpaywall.org/v2/{doi}?email={email}"

    response = requests.get(url, timeout=30)

    if response.status_code != 200:
        return {'error': f'Status {response.status_code}'}

    data = response.json()

    if data.get('is_oa'):
        best_location = data.get('best_oa_location', {})
        return {
            'is_open_access': True,
            'oa_url': best_location.get('url_for_pdf') or best_location.get('url'),
            'oa_status': data.get('oa_status'),  # gold, green, bronze, hybrid
            'host_type': best_location.get('host_type'),  # publisher, repository
            'version': best_location.get('version')  # publishedVersion, acceptedVersion
        }

    return {
        'is_open_access': False,
        'title': data.get('title'),
        'journal': data.get('journal_name')
    }

# Usage
result = find_open_access("10.1038/nature12373", "researcher@example.com")
if result.get('is_open_access'):
    print(f"Free PDF at: {result['oa_url']}")

# CORE API - requires free API key from https://core.ac.uk/

import requests

class CORESearch:
    def __init__(self, api_key: str):
        self.api_key = api_key
        self.base_url = "https://api.core.ac.uk/v3"

    def search(self, query: str, limit: int = 10) -> list:
        """Search CORE database for open access papers."""

        headers = {'Authorization': f'Bearer {self.api_key}'}
        params = {
            'q': query,
            'limit': limit
        }

        response = requests.get(
            f"{self.base_url}/search/works",
            headers=headers,
            params=params,
            timeout=30
        )

        if response.status_code != 200:
            return []

        data = response.json()
        results = []

        for item in data.get('results', []):
            results.append({
                'title': item.get('title'),
                'authors': [a.get('name') for a in item.get('authors', [])],
                'year': item.get('yearPublished'),
                'doi': item.get('doi'),
                'download_url': item.get('downloadUrl'),
                'abstract': item.get('abstract', '')[:500]
            })

        return results

    def get_by_doi(self, doi: str) -> dict:
        """Get paper by DOI."""
        headers = {'Authorization': f'Bearer {self.api_key}'}

        response = requests.get(
            f"{self.base_url}/works/{doi}",
            headers=headers,
            timeout=30
        )

        return response.json() if response.status_code == 200 else {}

# Semantic Scholar API - free, no key required for basic use

import requests

def search_semantic_scholar(query: str, limit: int = 10) -> list:
    """Search Semantic Scholar for papers with open access links."""

    url = "https://api.semanticscholar.org/graph/v1/paper/search"
    params = {
        'query': query,
        'limit': limit,
        'fields': 'title,authors,year,abstract,openAccessPdf,citationCount'
    }

    response = requests.get(url, params=params, timeout=30)

    if response.status_code != 200:
        return []

    results = []
    for paper in response.json().get('data', []):
        oa_pdf = paper.get('openAccessPdf', {})
        results.append({
            'title': paper.get('title'),
            'authors': [a.get('name') for a in paper.get('authors', [])],
            'year': paper.get('year'),
            'citations': paper.get('citationCount', 0),
            'open_access_url': oa_pdf.get('url') if oa_pdf else None,
            'abstract': paper.get('abstract', '')[:500] if paper.get('abstract') else ''
        })

    return results

def get_paper_by_doi(doi: str) -> dict:
    """Get paper details by DOI."""
    url = f"https://api.semanticscholar.org/graph/v1/paper/DOI:{doi}"
    params = {
        'fields': 'title,authors,year,abstract,openAccessPdf,references,citations'
    }

    response = requests.get(url, params=params, timeout=30)
    return response.json() if response.status_code == 200 else {}

// Bookmarklet to trigger Firefox-style reader mode
// Works on some soft paywalls that load content before blocking

javascript:(function(){
    // Try to extract article content
    var article = document.querySelector('article') ||
                  document.querySelector('[role="main"]') ||
                  document.querySelector('.article-body') ||
                  document.querySelector('.post-content');

    if (article) {
        // Remove paywall overlays
        document.querySelectorAll('[class*="paywall"], [class*="subscribe"], [id*="paywall"]')
            .forEach(el => el.remove());

        // Remove fixed position overlays
        document.querySelectorAll('*').forEach(el => {
            var style = getComputedStyle(el);
            if (style.position === 'fixed' && style.zIndex > 100) {
                el.remove();
            }
        });

        // Re-enable scrolling
        document.body.style.overflow = 'auto';
        document.documentElement.style.overflow = 'auto';

        console.log('Overlay removed. Content may now be visible.');
    }
})();

# Most library databases require authentication
# This shows how to structure library API access

class LibraryAccess:
    """Access pattern for library databases."""

    # Common library database endpoints
    DATABASES = {
        'pressreader': {
            'base': 'https://www.pressreader.com',
            'auth': 'library_card',
            'content': '7000+ newspapers/magazines'
        },
        'proquest': {
            'base': 'https://www.proquest.com',
            'auth': 'institutional',
            'content': 'news, dissertations, documents'
        },
        'jstor': {
            'base': 'https://www.jstor.org',
            'auth': 'institutional',
            'content': 'academic journals, books'
        },
        'nexis_uni': {
            'base': 'https://www.nexisuni.com',
            'auth': 'institutional',
            'content': 'legal, news, business'
        }
    }

    @staticmethod
    def get_pressreader_access_methods():
        """Ways to access PressReader through libraries."""
        return {
            'in_library': 'Connect to library WiFi, visit pressreader.com',
            'remote': 'Log in with library card credentials',
            'app': 'Download PressReader app, link library card',
            'note': 'Access typically 30-48 hours per session'
        }

# Interlibrary Loan (ILL) workflow
def request_via_ill(paper_info: dict, library_email: str) -> str:
    """Generate interlibrary loan request.

    ILL is free through most libraries and can get almost any paper.
    Turnaround: typically 3-7 days.
    """

    request = f"""
    INTERLIBRARY LOAN REQUEST

    Title: {paper_info.get('title')}
    Author(s): {paper_info.get('authors')}
    Journal: {paper_info.get('journal')}
    Year: {paper_info.get('year')}
    DOI: {paper_info.get('doi')}
    Volume/Issue: {paper_info.get('volume')}/{paper_info.get('issue')}
    Pages: {paper_info.get('pages')}

    Requested by: {library_email}
    """

    return request.strip()

## Legitimate VPN use cases for journalists/researchers

### APPROPRIATE:
- Accessing region-specific news sources
- Researching how content appears in other countries
- Bypassing government censorship (in some contexts)
- Protecting source communications
- Verifying geo-targeted content

### INAPPROPRIATE:
- Circumventing legitimate access controls
- Accessing content you're contractually prohibited from viewing
- Evading bans or blocks placed on your account

import requests

def check_geo_access(url: str, regions: list = None) -> dict:
    """Check if URL is accessible from different regions.

    Note: This requires VPN/proxy services for actual testing.
    This function shows the concept.
    """

    regions = regions or ['US', 'UK', 'EU', 'JP', 'AU']

    results = {}

    # Direct access test
    try:
        response = requests.get(url, timeout=10)
        results['direct'] = {
            'accessible': response.status_code == 200,
            'status_code': response.status_code
        }
    except Exception as e:
        results['direct'] = {'accessible': False, 'error': str(e)}

    # Would need VPN/proxy integration for regional testing
    # results[region] = test_through_proxy(url, region)

    return results

import requests
from urllib.parse import quote

def get_archived_article(url: str) -> str:
    """Try to get article from Archive.today.

    Archive.today often captures full article content
    because it renders JavaScript and captures the result.

    Legal status varies by jurisdiction - use for research purposes.
    """

    # Check for existing archive
    search_url = f"https://archive.today/{quote(url, safe='')}"

    try:
        response = requests.get(search_url, timeout=30, allow_redirects=True)

        if response.status_code == 200 and 'archive.today' in response.url:
            return response.url

        # No existing archive - could request one
        # Note: This may violate ToS, use responsibly
        return None

    except Exception:
        return None

def get_wayback_article(url: str) -> str:
    """Get article from Wayback Machine.

    100% legal - the Internet Archive is a recognized library.
    May have older versions of articles (before paywall implemented).
    """

    # Check availability
    api_url = f"http://archive.org/wayback/available?url={url}"

    try:
        response = requests.get(api_url, timeout=10)
        data = response.json()

        snapshot = data.get('archived_snapshots', {}).get('closest', {})

        if snapshot.get('available'):
            return snapshot['url']

        return None
    except Exception:
        return None

def find_free_via_scholar(title: str) -> list:
    """Search strategies for finding free paper versions.

    Google Scholar often links to:
    - Author's personal website copies
    - Institutional repository versions
    - ResearchGate/Academia.edu uploads
    """

    strategies = [
        {
            'method': 'scholar_all_versions',
            'description': 'Click "All X versions" under result',
            'success_rate': 'Medium-High'
        },
        {
            'method': 'scholar_pdf_link',
            'description': 'Look for [PDF] link on right side',
            'success_rate': 'Medium'
        },
        {
            'method': 'title_plus_pdf',
            'description': f'Search: "{title}" filetype:pdf',
            'success_rate': 'Medium'
        },
        {
            'method': 'author_site',
            'description': 'Find author\'s academic page',
            'success_rate': 'Medium'
        },
        {
            'method': 'preprint_servers',
            'description': 'Search arXiv, SSRN, bioRxiv',
            'success_rate': 'Field-dependent'
        }
    ]

    return strategies

def generate_paper_request_email(paper: dict, requester: dict) -> str:
    """Generate professional email requesting paper from author.

    Authors are typically happy to share their work.
    Success rate: Very high (70-90%).
    """

    template = f"""
Subject: Request for paper: {paper['title'][:50]}...

Dear Dr./Prof. {paper['author_last_name']},

I am a {requester['role']} at {requester['institution']}, researching
{requester['research_area']}.

I came across your paper "{paper['title']}" published in
{paper['journal']} ({paper['year']}), and I believe it would be
highly relevant to my work on {requester['specific_project']}.

Unfortunately, I don't have access through my institution. Would you
be willing to share a copy?

I would be happy to properly cite your work in any resulting publications.

Thank you for your time and for your contribution to the field.

Best regards,
{requester['name']}
{requester['title']}
{requester['institution']}
{requester['email']}
"""

    return template.strip()

## News article access strategies

1. **Library PressReader** - 7,000+ publications worldwide
2. **Reader Mode** - Works on ~50% of soft paywalls
3. **Archive.org** - For older articles
4. **Archive.today** - For recent articles (grey area)
5. **Google search** - Sometimes cached versions appear

## Tips:
- Many newspapers offer free articles for .edu emails
- Press releases often contain same info as paywalled articles
- Local library cards often include digital news access
- Some publications have free tiers (5-10 articles/month)

## Academic paper access strategies (in order)

1. **Unpaywall extension** - Check first, automatic
2. **Google Scholar** - Click "All versions", look for [PDF]
3. **Author's website** - Check their academic page
4. **Institutional repository** - Search university library
5. **Preprint servers** - arXiv, SSRN, bioRxiv, medRxiv
6. **ResearchGate/Academia.edu** - Author-uploaded copies
7. **CORE.ac.uk** - 295M open access papers
8. **PubMed Central** - For biomedical papers
9. **Contact author directly** - High success rate
10. **Interlibrary Loan** - Free, gets almost anything

## Book/report access strategies

1. **Library digital lending** - Internet Archive, OverDrive
2. **Google Books** - Often has preview or full text
3. **HathiTrust** - Academic library consortium
4. **Project Gutenberg** - Public domain books
5. **OpenLibrary** - Internet Archive's book lending
6. **Publisher open access** - Some chapters/reports free
7. **Author/organization website** - Reports often available
8. **Interlibrary Loan** - Physical books, scanned chapters

## Fair Use Factors (17 U.S.C. § 107)

1. **Purpose and character of use**
   - Transformative use (commentary, criticism) favored
   - Non-commercial/educational use favored
   - Journalism generally protected

2. **Nature of copyrighted work**
   - Factual works (news, research) - broader fair use
   - Creative works (fiction, art) - narrower fair use

3. **Amount used relative to whole**
   - Using only necessary portions favored
   - Heart of the work disfavored

4. **Effect on market**
   - Not replacing purchase disfavored
   - No market impact favored

## Journalism privilege:
News reporting is explicitly listed as fair use purpose.
However, wholesale copying of entire articles still problematic.

## Ethical content access guidelines

### DO:
- Use library resources first (supports the ecosystem)
- Try open access tools before circumvention
- Contact authors directly (they want citations)
- Cite properly regardless of how you accessed content
- Budget for subscriptions to frequently-used sources

### DON'T:
- Share login credentials
- Systematically download entire databases
- Use bypassed content for commercial purposes
- Redistribute paywalled content
- Rely solely on bypass methods