#!/usr/bin/env python3
"""Simple org-babel tangle replacement.
Extracts #+BEGIN_SRC blocks with :tangle headers and writes target files.
"""
import re, os, sys

ORG_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))

def tangle_file(org_path):
    org_path = os.path.join(ORG_DIR, org_path)
    with open(org_path) as f:
        text = f.read()
    
    # Find all #+BEGIN_SRC blocks with :tangle
    pattern = re.compile(
        r'#\+BEGIN_SRC\s+(\w+)\s+(.*?)\n(.*?)\n#\+END_SRC',
        re.DOTALL
    )
    
    count = 0
    for match in pattern.finditer(text):
        lang = match.group(1)
        header = match.group(2)
        content = match.group(3)
        
        # Extract :tangle path
        tangle_match = re.search(r':tangle\s+(\S+)', header)
        if not tangle_match:
            continue
        tangle_path = tangle_match.group(1)
        
        # Resolve relative path
        if tangle_path.startswith('../'):
            target = os.path.normpath(os.path.join(os.path.dirname(org_path), tangle_path))
        else:
            target = os.path.join(ORG_DIR, tangle_path)
        
        # Ensure directory exists
        os.makedirs(os.path.dirname(target), exist_ok=True)
        
        # Don't write :tangle no blocks
        if tangle_path == 'no':
            continue
        
        # Write the content (append if same file already written)
        content = content.rstrip('\n') + '\n'
        if os.path.exists(target):
            with open(target, 'a') as f:
                f.write('\n' + content)
        else:
            with open(target, 'w') as f:
                f.write(content)
        print(f"  {target} ({len(content)} bytes)")
        count += 1
    
    return count

if __name__ == '__main__':
    for f in sys.argv[1:] or ['org/text-input.org']:
        print(f"Tangling {f}...")
        c = tangle_file(f)
        print(f"  {c} code blocks")