"""Show or compare the config Klipper builds from macros/klipper-macros.cfg.

Klipper expands [include ...] in order and merges sections with the same
name (the last value of an option wins). This script does the same, so a
refactor can be checked for unintended changes.

  python tools/effective_config.py                 list sections of the working tree
  python tools/effective_config.py HEAD            compare HEAD with the working tree
  python tools/effective_config.py A B             compare two git refs
  python tools/effective_config.py HEAD -v         also print old/new values
"""
import configparser
import os
import re
import subprocess
import sys
import tempfile

ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
BASE = os.path.join('macros', 'klipper-macros.cfg')


def expand(path):
    lines = []
    with open(path, encoding='utf-8') as f:
        for line in f.read().replace('\r\n', '\n').split('\n'):
            m = re.match(r'^\[include ([^\]]+)\]', line.split('#')[0])
            if m:
                inc = os.path.join(os.path.dirname(path), m.group(1).strip())
                lines += expand(inc)
            else:
                lines.append(line)
    return lines


def load(root):
    cp = configparser.RawConfigParser(strict=False,
                                      inline_comment_prefixes=(';', '#'))
    cp.read_string('\n'.join(expand(os.path.join(root, BASE))))
    return {s: dict(cp.items(s)) for s in cp.sections()}


def checkout(ref, tmp):
    archive = subprocess.run(['git', '-C', ROOT, 'archive', ref, 'macros'],
                             check=True, capture_output=True).stdout
    subprocess.run(['tar', '-x', '-C', tmp], input=archive, check=True)
    return tmp


def main(argv):
    verbose = '-v' in argv
    refs = [a for a in argv if a != '-v']
    with tempfile.TemporaryDirectory() as t1, tempfile.TemporaryDirectory() as t2:
        if not refs:
            for s in sorted(load(ROOT)):
                print(s)
            return 0
        old = load(checkout(refs[0], t1))
        new = load(checkout(refs[1], t2) if len(refs) > 1 else ROOT)
    added, removed = sorted(set(new) - set(old)), sorted(set(old) - set(new))
    changed = 0
    for s in added:
        print('added   ', s)
    for s in removed:
        print('removed ', s)
    for s in sorted(set(old) & set(new)):
        keys = sorted(k for k in set(old[s]) | set(new[s])
                      if old[s].get(k) != new[s].get(k))
        if keys:
            changed += 1
            print('changed ', s, keys)
            if verbose:
                for k in keys:
                    print('   old %s: %r' % (k, old[s].get(k)))
                    print('   new %s: %r' % (k, new[s].get(k)))
    print('%d sections, %d added, %d removed, %d changed'
          % (len(new), len(added), len(removed), changed))
    return 0


if __name__ == '__main__':
    sys.exit(main(sys.argv[1:]))