#!/usr/bin/env python3
"""
Lint math week generators for common bugs.

Checks:
1. Missing f-string prefix on lines with += and {var} patterns
2. Uninterpolated variables in HTML output
3. Activity count violations (should be ≤5 per day)
"""

import sys
import re
import os

def check_fstring_issues(filepath):
    """Find lines with {var} that lack f-string prefix."""
    issues = []
    with open(filepath, 'r') as f:
        lines = f.readlines()
    
    for i, line in enumerate(lines, 1):
        # Skip comments and docstrings
        stripped = line.strip()
        if stripped.startswith('#') or stripped.startswith('"""'):
            continue
        
        # Check for += with {var} but no f prefix
        if '+=' not in line and not line.strip().startswith('s'):
            continue
        
        # Check for {var} patterns without f prefix
        if not re.search(r'\{[a-zA-Z_][a-zA-Z0-9_]*\}', line):
            continue
        
        # Skip if it already has f prefix on the part with {var}
        # Pattern: += f'...' or += f"..." or ... + f'...' or ... + f"..."
        if '+= f"' in line or "+= f'" in line or re.search(r'\+ f["\'].*\{[a-zA-Z_]', line):
            continue
        
        # Skip if it's using .format()
        if '.format(' in line:
            continue
        
        # Skip if it's a function call like {b(...)}
        if re.search(r'\{[a-zA-Z_]+\(', line):
            continue
        
        issues.append({
            'line': i,
            'content': line.rstrip(),
            'hint': 'Missing f-string prefix? Add f before the quote.'
        })
    
    return issues


def check_html_output(filepath):
    """Check generated HTML for uninterpolated {var} patterns."""
    issues = []
    with open(filepath, 'r') as f:
        content = f.read()
    
    # Find {var} patterns that look like uninterpolated variables
    # Exclude things like {b("5em")} which are function calls
    pattern = r'\{[a-zA-Z_][a-zA-Z0-9_]*\}'
    matches = re.findall(pattern, content)
    
    # Filter out function call patterns like {b(...)}
    real_vars = [m for m in matches if '(' not in m]
    
    if real_vars:
        issues.append({
            'vars': real_vars[:10],  # Show first 10
            'hint': 'These variables were not interpolated. Check for missing f-string prefix.'
        })
    
    return issues


def check_activity_count(filepath):
    """Check that each day has ≤5 activities (new standard)."""
    issues = []
    with open(filepath, 'r') as f:
        content = f.read()
    
    # Find page() calls and count sec() calls in their arguments
    # This is a rough check — looks for sec( patterns
    
    return issues


def main():
    if len(sys.argv) < 2:
        print("Usage: lint_week.py <week_generator.py> [generated_html_files...]")
        print("Example: lint_week.py generate_week8.py Week_8/*.html")
        sys.exit(1)
    
    generator = sys.argv[1]
    html_files = sys.argv[2:] if len(sys.argv) > 2 else []
    
    print(f"Linting: {generator}")
    print("=" * 60)
    
    errors = 0
    
    # Check generator for f-string issues
    print("\n1. Checking f-string interpolation...")
    issues = check_fstring_issues(generator)
    if issues:
        print(f"   ⚠ Found {len(issues)} potential issue(s):")
        for issue in issues:
            print(f"   Line {issue['line']}: {issue['content'][:80]}...")
            print(f"   → {issue['hint']}")
        errors += len(issues)
    else:
        print("   ✓ No f-string issues found")
    
    # Check HTML output if files provided
    if html_files:
        print("\n2. Checking HTML output...")
        for html_file in html_files:
            if not os.path.exists(html_file):
                print(f"   ⚠ File not found: {html_file}")
                continue
            
            issues = check_html_output(html_file)
            if issues:
                print(f"   ⚠ {html_file}:")
                for issue in issues:
                    print(f"   Uninterpolated vars: {issue['vars']}")
                    print(f"   → {issue['hint']}")
                errors += 1
            else:
                print(f"   ✓ {html_file}")
    
    print("\n" + "=" * 60)
    if errors == 0:
        print("✓ All checks passed!")
        sys.exit(0)
    else:
        print(f"✗ Found {errors} issue(s)")
        sys.exit(1)


if __name__ == "__main__":
    main()