#!/usr/bin/env python3
"""Generate chronology draft for Manual Slop conductor tracks.

Walks conductor/tracks/ and conductor/archive/, extracts per-track data
(date, ID, status, summary, commit range), and emits a draft to stdout.

The script is READ-ONLY on the source folders. It writes to stdout only.
The human cross-check (FR6 of the chronology_20260619 track) is the authority;
this script is a starting point, not the canonical source.

Usage:
 uv run python scripts/audit/generate_chronology.py --draft
 uv run python scripts/audit/generate_chronology.py --root conductor/
 uv run python scripts/audit/generate_chronology.py            # JSON dump
"""
from __future__ import annotations

import argparse
import json
import re
import subprocess
import sys
from pathlib import Path
from typing import Optional

_SLUG_DATE_RE = re.compile(r"\d{8}$")
_SENTENCE_END_RE = re.compile(r"\.\s")
_GIT_TIMEOUT = 30
_DEFAULT_ROOT = "conductor/"


def extract_slug_date(folder_name: str) -> Optional[str]:
 m = _SLUG_DATE_RE.search(folder_name)
 if not m:
  return None
 raw: str = m.group(0)
 return f"{raw[:4]}-{raw[4:6]}-{raw[6:]}"


def _md_escape(text: str) -> str:
 return text.replace("|", "\\|").replace("\n", " ").replace("\r", " ")


def _to_posix(path_str: str) -> str:
 return path_str.replace("\\", "/")


def _first_sentence(line: str) -> str:
 m = _SENTENCE_END_RE.search(line)
 if m:
  return line[: m.start() + 1].strip()
 return line.strip()


def _truncate_to_25_words(text: str) -> str:
 words: list[str] = text.split()
 if len(words) <= 25:
  return text
 return " ".join(words[:25]) + "\u2026"


def extract_summary(folder_path: Path) -> str:
 md_path = folder_path / "metadata.json"
 if md_path.is_file():
  try:
   data = json.loads(md_path.read_text(encoding="utf-8"))
   desc = str(data.get("description", "")).strip()
   if desc:
    return desc
  except (json.JSONDecodeError, OSError):
   pass
 for fname in ("spec.md", "plan.md"):
  fpath = folder_path / fname
  if not fpath.is_file():
   continue
  try:
   text = fpath.read_text(encoding="utf-8")
  except OSError:
   continue
  for line in text.splitlines():
   stripped = line.strip()
   if not stripped:
     continue
   if stripped.startswith("#"):
     continue
   if stripped.startswith(">"):
     continue
   bare = stripped.lstrip(">").strip()
   if bare.startswith("**Status:**") or bare.startswith("**Track ID:**") or bare.startswith("**Track:**"):
     continue
   return _truncate_to_25_words(_first_sentence(bare))
 return "Imported from archive (no spec)"


def _git_log(folder_relpath: str, *args: str) -> str:
 try:
  result = subprocess.run(
   ["git", "log", *args, "--", folder_relpath],
   capture_output=True,
   text=True,
   timeout=_GIT_TIMEOUT,
   check=False,
  )
  if result.returncode != 0:
   return ""
  return result.stdout
 except (subprocess.SubprocessError, OSError):
  return ""


def _git_first_line(folder_relpath: str, *args: str) -> str:
 out = _git_log(folder_relpath, *args)
 stripped = out.strip()
 if not stripped:
  return ""
 return stripped.splitlines()[0]


def _repo_root(start: Path) -> Path:
 try:
  result = subprocess.run(
   ["git", "rev-parse", "--show-toplevel"],
   capture_output=True,
   text=True,
   timeout=10,
   check=False,
   cwd=str(start),
  )
  if result.returncode == 0 and result.stdout.strip():
   return Path(result.stdout.strip())
 except (subprocess.SubprocessError, OSError):
  pass
 return start.parent


def _git_log(folder_relpath: str, *args: str) -> str:
 try:
  result = subprocess.run(
   ["git", "log", *args, "--", folder_relpath],
   capture_output=True,
   text=True,
   timeout=_GIT_TIMEOUT,
   check=False,
  )
  if result.returncode != 0:
   return ""
  return result.stdout
 except (subprocess.SubprocessError, OSError):
  return ""


def _git_first_line(folder_relpath: str, *args: str) -> str:
 out = _git_log(folder_relpath, *args)
 stripped = out.strip()
 if not stripped:
  return ""
 return stripped.splitlines()[0]


def _repo_root(start: Path) -> Path:
 try:
  result = subprocess.run(
   ["git", "rev-parse", "--show-toplevel"],
   capture_output=True,
   text=True,
   timeout=10,
   check=False,
   cwd=str(start),
  )
  if result.returncode == 0 and result.stdout.strip():
   return Path(result.stdout.strip())
 except (subprocess.SubprocessError, OSError):
  pass
 return start.parent


def _parse_state_phase(state_path: Path) -> str:
 if not state_path.is_file():
  return "no-state-toml"
 try:
  for line in state_path.read_text(encoding="utf-8").splitlines():
   if line.startswith("current_phase"):
    v = line.split("=", 1)[1].strip().split("#")[0].strip().strip('"')
    return v
 except (subprocess.SubprocessError, OSError, Exception):
  pass
 return "?"


def _last_commit_date(folder_relpath: str) -> str:
 try:
  result = subprocess.run(
   ["git", "log", "-1", "--format=%ad", "--date=short", "--", folder_relpath],
   capture_output=True, text=True, timeout=_GIT_TIMEOUT, check=False,
  )
  return result.stdout.strip()
 except (subprocess.SubprocessError, OSError):
  return "never"


def _classify_status(folder_link: str, current: str, track_id: str) -> str:
 """Per-row manual review classification (FR6 hard gate).

 Logic (per user directive 2026-06-20):
 - PLACEHOLDER tracks: keep as is
 - archive/ folder: default to Completed (the work was done and archived; metadata status may be stale)
 - tracks/ folder + state_phase=complete OR chrono in {completed, complete, shipped}: Completed
 - tracks/ folder + everything else: keep original chrono status (in flight)
 - Abandoned is reserved for explicit user marking; the script does NOT auto-mark.

 Note: "Completed" (not "Shipped") is the canonical term per user directive 2026-06-20.
 This is a side-project, not a shipped product.
 """
 if "PLACEHOLDER" in track_id:
  return current
 if "contingency" in current.lower():
  return current
 is_archive = folder_link.startswith("conductor/archive/")
 is_tracks = folder_link.startswith("conductor/tracks/")
 if is_archive:
  return "Completed"
 folder = Path(folder_link)
 state_phase = _parse_state_phase(folder / "state.toml") if is_tracks else "?"
 chrono_lower = current.lower()
 is_completed = chrono_lower in {"completed", "complete", "shipped"} or state_phase in {"complete", '"complete"'}
 if is_tracks and is_completed:
  return "Completed"
 return current


def walk_track_folders(root: Path) -> list[dict]:
 repo_root: Path = _repo_root(root)
 rows: list[dict] = []
 for parent_dir, default_status in (
  (root / "tracks", "Active"),
  (root / "archive", "Completed"),
 ):
  if not parent_dir.is_dir():
   continue
  for folder in sorted(parent_dir.iterdir()):
   if not folder.is_dir():
    continue
   try:
    folder_relpath = _to_posix(str(folder.relative_to(repo_root)))
   except ValueError:
    folder_relpath = _to_posix(str(folder))
   track_id: str = folder.name
   slug_date = extract_slug_date(track_id)
   if slug_date:
    date = slug_date
   else:
    first_commit = _git_first_line(folder_relpath, "--reverse", "--format=%aI")
    date = first_commit[:10] if first_commit else ""
   metadata_path = folder / "metadata.json"
   status: str = default_status
   if metadata_path.is_file():
    try:
     data = json.loads(metadata_path.read_text(encoding="utf-8"))
     meta_status = str(data.get("status", "")).strip()
     if meta_status:
      status = meta_status
    except (json.JSONDecodeError, OSError):
     pass
   status = _classify_status(folder_relpath, status, track_id)
   summary: str = extract_summary(folder)
   init_sha: str = _git_first_line(folder_relpath, "--reverse", "--format=%h")
   end_sha: str = _git_first_line(folder_relpath, "-1", "--format=%h")
   if init_sha and end_sha:
    range_log = _git_log(folder_relpath, "--oneline", f"{init_sha}..{end_sha}")
    commit_count: int = range_log.count("\n") + (1 if init_sha != end_sha else 0)
   else:
    fallback_log = _git_log(folder_relpath, "--oneline")
    commit_count = fallback_log.count("\n")
   try:
    folder_link = _to_posix(str(folder.relative_to(repo_root)))
   except ValueError:
    folder_link = _to_posix(str(folder))
   rows.append({
    "date": date,
    "track_id": track_id,
    "status": status,
    "summary": summary,
    "init_sha": init_sha,
    "end_sha": end_sha,
    "commit_count": commit_count,
    "folder_link": folder_link,
   })
 rows.sort(key=lambda r: r["track_id"])
 rows.sort(key=lambda r: r["date"], reverse=True)
 return rows


def format_markdown(rows: list[dict]) -> str:
 lines: list[str] = [
  "| Date | ID | Status | Summary | Folder | Range |",
  "| --- | --- | --- | --- | --- | --- |",
 ]
 for row in rows:
  range_str: str = f"`{row['init_sha']}..{row['end_sha']}` ({row['commit_count']})"
  lines.append(
   f"| {row['date']} | `{row['track_id']}` | {row['status']} | "
   f"{_md_escape(row['summary'])} | `{row['folder_link']}` | {range_str} |"
  )
 return "\n".join(lines) + "\n"


def main() -> None:
 if hasattr(sys.stdout, "reconfigure"):
  try:
   sys.stdout.reconfigure(encoding="utf-8")
  except (OSError, ValueError):
   pass
 parser = argparse.ArgumentParser(
  description="Generate chronology draft for Manual Slop conductor tracks.",
 )
 parser.add_argument(
  "--draft",
  action="store_true",
  help="Emit markdown draft table to stdout.",
 )
 parser.add_argument(
  "--root",
  default=_DEFAULT_ROOT,
  help=f"Path to conductor root (default: {_DEFAULT_ROOT}).",
 )
 args = parser.parse_args()
 root = Path(args.root)
 if not root.is_absolute():
  root = Path.cwd() / root
 rows = walk_track_folders(root)
 if args.draft:
  sys.stdout.write(format_markdown(rows))
 else:
  sys.stdout.write(json.dumps(rows, indent=2))


if __name__ == "__main__":
 main()