#!/usr/bin/env python3
"""tangle.py — Extract code blocks from .org files into .lisp files.

Reads all .org files in org/ directory, finds #+BEGIN_SRC lisp :tangle <path>
blocks, and writes/concatenates them to the specified target paths.

Blocks with the same :tangle target are concatenated in file order.

Usage:
  python3 scripts/tangle.py              # tangle all org/ files
  python3 scripts/tangle.py org/specific.org  # tangle one file

Target paths are relative to the project root (../target from org/ = project/target).
"""
import re
import os
import sys
from collections import OrderedDict

PROJECT_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
ORG_DIR = os.path.join(PROJECT_ROOT, 'org')

def tangle_file(org_path):
    """Extract tangle blocks from one .org file."""
    with open(org_path) as f:
        content = f.read()

    # Find all tangle blocks with their targets
    pattern = r'#\+BEGIN_SRC lisp :tangle ([^\n]+)\n(.*?)\n#\+END_SRC'
    blocks = re.findall(pattern, content, re.DOTALL)

    if not blocks:
        return 0

    # Group by target path
    targets = OrderedDict()
    for tangle_path, code in blocks:
        # Resolve tangle path: ../src/x.lisp -> src/x.lisp
        resolved = tangle_path.replace('../', '')
        full_path = os.path.join(PROJECT_ROOT, resolved)
        if full_path not in targets:
            targets[full_path] = []
        targets[full_path].append(code.strip())

    for full_path, codes in targets.items():
        os.makedirs(os.path.dirname(full_path), exist_ok=True)
        combined = '\n\n'.join(codes) + '\n'
        with open(full_path, 'w') as f:
            f.write(combined)
        print(f"  {os.path.relpath(full_path, PROJECT_ROOT)} ({len(codes)} blocks, {sum(len(c) for c in codes)} chars)")

    return len(blocks)

def main():
    if len(sys.argv) > 1:
        org_files = [f for f in sys.argv[1:] if f.endswith('.org')]
    else:
        org_files = [os.path.join(ORG_DIR, f) for f in os.listdir(ORG_DIR) if f.endswith('.org')]

    total_blocks = 0
    for org_file in sorted(org_files):
        name = os.path.basename(org_file)
        blocks = tangle_file(org_file)
        if blocks:
            print(f"{name}: {blocks} blocks")
            total_blocks += blocks

    if total_blocks > 0:
        print(f"\nTotal: {total_blocks} code blocks tangled")
    else:
        print("No tangle blocks found.")

if __name__ == '__main__':
    main()