#!/usr/bin/env python3
"""Aggregate directive bodies from a preset markdown file."""
from __future__ import annotations

import argparse
import re
import sys
from pathlib import Path

if hasattr(sys.stdout, "reconfigure"):
 try:
  sys.stdout.reconfigure(encoding="utf-8")
 except Exception:
  pass
if hasattr(sys.stderr, "reconfigure"):
 try:
  sys.stderr.reconfigure(encoding="utf-8")
 except Exception:
  pass

REPO_ROOT = Path(__file__).resolve().parent.parent
ENTRY_RE = re.compile(r"^\s*-\s+(?P<name>[A-Za-z0-9_]+)\s*:\s*(?P<path>\S+)\s*$")
EXPECTED_PATTERN_TEMPLATE = r"^conductor/directives/{name}/v\d+\.md$"


def parse_preset(preset_path: Path) -> list[tuple[str, Path]]:
 entries: list[tuple[str, Path]] = []
 for line in preset_path.read_text(encoding="utf-8").splitlines():
  m = ENTRY_RE.match(line)
  if not m:
   continue
  name = m.group("name")
  rel_path = m.group("path")
  abs_path = (REPO_ROOT / rel_path).resolve()
  entries.append((name, abs_path))
 return entries


def aggregate(preset_path: Path, output_path: Path | None) -> int:
 entries = parse_preset(preset_path)
 if not entries:
  print("ERROR: no directive entries found in " + str(preset_path), file=sys.stderr)
  return 1
 missing: list[tuple[str, Path]] = []
 bodies: list[tuple[str, str]] = []
 for name, path in entries:
  if not path.exists():
   missing.append((name, path))
   continue
  rel = path.relative_to(REPO_ROOT).as_posix()
  pattern = EXPECTED_PATTERN_TEMPLATE.format(name=re.escape(name))
  if not re.match(pattern, rel):
   print("WARNING: " + name + ": path " + str(path) + " does not match pattern conductor/directives/" + name + "/vN.md; including anyway", file=sys.stderr)
  try:
   body = path.read_text(encoding="utf-8")
  except UnicodeDecodeError as e:
   print("ERROR: " + name + ": UTF-8 decode error in " + str(path) + ": " + str(e), file=sys.stderr)
   continue
  bodies.append((name, body))
 if missing:
  for name, path in missing:
   print("ERROR: missing file for directive '" + name + "': " + str(path), file=sys.stderr)
  return 1
 out_lines: list[str] = []
 for name, body in bodies:
  out_lines.append("=" * 40)
  out_lines.append(name)
  out_lines.append("=" * 40)
  out_lines.append("")
  out_lines.append(body.rstrip(chr(10)))
  out_lines.append("")
  out_lines.append("")
 rendered = chr(10).join(out_lines)
 if output_path:
  output_path.write_text(rendered, encoding="utf-8")
  print("Wrote " + str(len(bodies)) + " directives to " + str(output_path), file=sys.stderr)
 else:
  sys.stdout.write(rendered)
  if not rendered.endswith(chr(10)):
   sys.stdout.write(chr(10))
 return 0


def main() -> int:
 parser = argparse.ArgumentParser(description="Aggregate directive bodies from a preset markdown file.")
 parser.add_argument("preset", type=Path, help="Path to the preset markdown file")
 parser.add_argument("-o", "--output", type=Path, default=None, help="Write output to file instead of stdout")
 args = parser.parse_args()
 if not args.preset.exists():
  print("ERROR: preset file not found: " + str(args.preset), file=sys.stderr)
  return 1
 output = args.output.resolve() if args.output else None
 return aggregate(args.preset.resolve(), output)


if __name__ == "__main__":
 sys.exit(main())