#!/usr/bin/env python3
"""retention-archive-jobs.py — Retention Piece 2: Job definition archival & pruning.

Archives retired manual job definitions from jobs/ to jobs/archive/ via git mv,
preventing scheduler parsing overhead while preserving full git history and readability.

Guards active jobs dynamically:
  1. Systemd user units (~/.config/systemd/user/job-*.service)
  2. Active pipeline runs in pipelines.json (and linked on_success/on_failure/chain_next)
  3. Core baseline fleet jobs (heartbeat, refine-system, canary-test)

Usage:
  retention-archive-jobs.py scan [--dry-run] [--limit N] [--json]
  retention-archive-jobs.py archive <name> [--dry-run] [--force] [--json]
  retention-archive-jobs.py unarchive <name> [--dry-run] [--json]
  retention-archive-jobs.py list [--json]
"""

import argparse
import json
import os
import re
import subprocess
import sys
from pathlib import Path

NETVM_ROOT = Path(os.environ.get("NETVM_ROOT", "/home/super/Projects/NetVM"))
JOBS_DIR = NETVM_ROOT / "jobs"
ARCHIVE_DIR = JOBS_DIR / "archive"
PIPELINES_FILE = NETVM_ROOT / "pipelines.json"
SYSTEMD_USER_DIR = Path(os.path.expanduser("~/.config/systemd/user"))

CORE_PROTECTED = frozenset({"heartbeat", "refine-system", "canary-test"})


def run_git(*args, cwd=None):
    """Run git command safely and return (returncode, stdout, stderr)."""
    cwd = cwd or NETVM_ROOT
    try:
        r = subprocess.run(["git"] + list(args), cwd=cwd, capture_output=True, text=True, check=False)
        return r.returncode, r.stdout.strip(), r.stderr.strip()
    except Exception as e:
        return 1, "", str(e)


def is_git_tracked(rel_path, root_dir=None):
    """Check if a file is tracked in git."""
    rc, stdout, _ = run_git("ls-files", str(rel_path), cwd=root_dir)
    return rc == 0 and bool(stdout.strip())


def get_protected_jobs(root_dir=None):
    """Return dict of {job_name: reason} for all dynamically protected jobs."""
    root = Path(root_dir) if root_dir else NETVM_ROOT
    jobs_dir = root / "jobs"
    protected = {k: "core baseline" for k in CORE_PROTECTED}

    # 1. Systemd user timers / services
    systemd_dirs = [SYSTEMD_USER_DIR, root / "systemd"]
    for sdir in systemd_dirs:
        if not sdir.exists():
            continue
        for sfile in sdir.glob("job-*.service"):
            try:
                content = sfile.read_text()
                for line in content.splitlines():
                    if "job-dispatch.py" in line and line.strip().startswith("ExecStart="):
                        m = re.search(r"job-dispatch\.py\s+([A-Za-z0-9_-]+)", line)
                        if m:
                            protected[m.group(1)] = f"systemd unit: {sfile.name}"
            except Exception:
                pass

    # 2. In-flight pipelines from pipelines.json
    pipe_file = root / "pipelines.json"
    if pipe_file.exists():
        try:
            data = json.loads(pipe_file.read_text())
            for run_id, run_data in data.items():
                status = str(run_data.get("status", "")).lower()
                if status in ("running", "dispatched", "pending"):
                    pname = run_data.get("pipeline_name")
                    if pname:
                        protected[pname] = f"active pipeline {run_id}"
                    for step in run_data.get("steps", []):
                        sjob = step.get("job_name")
                        if sjob:
                            protected[sjob] = f"active pipeline {run_id} (step)"
        except Exception:
            pass

    # 3. Chained job targets (transitive expansion of on_success, on_failure, chain_next)
    to_expand = list(protected.keys())
    visited = set()
    while to_expand:
        cur = to_expand.pop(0)
        if cur in visited:
            continue
        visited.add(cur)
        jpath = jobs_dir / f"{cur}.json"
        if not jpath.exists():
            continue
        try:
            d = json.loads(jpath.read_text())
            for field in ("chain_next", "on_success", "on_failure"):
                target = d.get(field)
                if isinstance(target, str) and target.strip():
                    tname = target.strip()
                    # Skip common literal alerts like 'alert' unless an actual job definition exists
                    if tname == "alert" and not (jobs_dir / "alert.json").exists():
                        continue
                    if tname not in protected:
                        protected[tname] = f"linked by {cur} ({field})"
                        if tname not in visited:
                            to_expand.append(tname)
        except Exception:
            pass

    return protected


def is_eligible(job_path, protected_jobs):
    """Determine if a job file is eligible for archival. Returns (bool, reason)."""
    try:
        data = json.loads(job_path.read_text())
    except Exception as e:
        return False, f"unreadable/invalid JSON: {e}"

    name = data.get("name") or job_path.stem
    if name in protected_jobs:
        return False, f"protected: {protected_jobs[name]}"

    schedule = str(data.get("schedule", "")).strip().lower()
    if schedule == "manual" or not schedule:
        return True, "manual schedule and not protected"

    return False, f"active recurring schedule: {schedule}"


def archive_job(name, dry_run=False, force=False, root_dir=None):
    """Archive a single job by name. Returns dict with operation details."""
    root = Path(root_dir) if root_dir else NETVM_ROOT
    jobs_dir = root / "jobs"
    archive_dir = jobs_dir / "archive"
    src_file = jobs_dir / f"{name}.json"
    dest_file = archive_dir / f"{name}.json"

    if not src_file.exists():
        if dest_file.exists():
            return {"name": name, "status": "already_archived", "path": str(dest_file)}
        return {"name": name, "status": "error", "error": f"Job file not found: {src_file}"}

    # Verify JSON syntax
    try:
        content = json.loads(src_file.read_text())
    except Exception as e:
        return {"name": name, "status": "error", "error": f"Invalid source JSON: {e}"}

    protected_jobs = get_protected_jobs(root)
    if name in protected_jobs and not force:
        return {"name": name, "status": "rejected", "error": f"Job is protected: {protected_jobs[name]}"}

    if dry_run:
        return {
            "name": name,
            "status": "dry_run",
            "action": "would_archive",
            "from": str(src_file),
            "to": str(dest_file),
        }

    archive_dir.mkdir(parents=True, exist_ok=True)
    tracked = is_git_tracked(src_file.relative_to(root), root_dir=root)

    if tracked:
        rc, _, err = run_git("mv", str(src_file), str(dest_file), cwd=root)
        if rc != 0:
            # Fallback to direct move + git add/rm
            src_file.rename(dest_file)
            run_git("add", str(dest_file), cwd=root)
            run_git("rm", "-q", str(src_file), cwd=root)
    else:
        src_file.rename(dest_file)

    # Verify destination file
    try:
        json.loads(dest_file.read_text())
    except Exception as e:
        return {"name": name, "status": "error", "error": f"Destination JSON verification failed: {e}"}

    return {
        "name": name,
        "status": "archived",
        "from": str(src_file),
        "to": str(dest_file),
        "git_tracked": tracked,
    }


def unarchive_job(name, dry_run=False, root_dir=None):
    """Restore an archived job back to jobs/. Returns dict with operation details."""
    root = Path(root_dir) if root_dir else NETVM_ROOT
    jobs_dir = root / "jobs"
    archive_dir = jobs_dir / "archive"
    src_file = archive_dir / f"{name}.json"
    dest_file = jobs_dir / f"{name}.json"

    if not src_file.exists():
        if dest_file.exists():
            return {"name": name, "status": "already_active", "path": str(dest_file)}
        return {"name": name, "status": "error", "error": f"Archived job not found: {src_file}"}

    try:
        content = json.loads(src_file.read_text())
    except Exception as e:
        return {"name": name, "status": "error", "error": f"Invalid archived JSON: {e}"}

    if dry_run:
        return {
            "name": name,
            "status": "dry_run",
            "action": "would_unarchive",
            "from": str(src_file),
            "to": str(dest_file),
        }

    tracked = is_git_tracked(src_file.relative_to(root), root_dir=root)

    if tracked:
        rc, _, _ = run_git("mv", str(src_file), str(dest_file), cwd=root)
        if rc != 0:
            src_file.rename(dest_file)
            run_git("add", str(dest_file), cwd=root)
            run_git("rm", "-q", str(src_file), cwd=root)
    else:
        src_file.rename(dest_file)

    try:
        json.loads(dest_file.read_text())
    except Exception as e:
        return {"name": name, "status": "error", "error": f"Destination JSON verification failed: {e}"}

    return {
        "name": name,
        "status": "unarchived",
        "from": str(src_file),
        "to": str(dest_file),
        "git_tracked": tracked,
    }


def scan_and_archive(dry_run=False, limit=None, root_dir=None):
    """Scan jobs/ for all eligible jobs and archive them."""
    root = Path(root_dir) if root_dir else NETVM_ROOT
    jobs_dir = root / "jobs"
    archive_dir = jobs_dir / "archive"

    protected_jobs = get_protected_jobs(root)
    eligible = []
    skipped = []

    for jpath in sorted(jobs_dir.glob("*.json")):
        name = jpath.stem
        is_el, reason = is_eligible(jpath, protected_jobs)
        if is_el:
            eligible.append((name, jpath))
        else:
            skipped.append((name, reason))

    to_process = eligible[:limit] if limit else eligible
    results = []

    for name, _ in to_process:
        res = archive_job(name, dry_run=dry_run, root_dir=root)
        results.append(res)

    archived_count = sum(1 for r in results if r["status"] in ("archived", "dry_run"))

    # Commit git changes if not dry_run and we actually archived tracked files
    commit_sha = None
    if not dry_run and archived_count > 0:
        names_str = ", ".join(r["name"] for r in results if r["status"] == "archived")
        commit_msg = f"chore(retention): archive retired jobs [{names_str}]"
        rc, out, err = run_git("commit", "-m", commit_msg, cwd=root)
        if rc == 0:
            _, sha, _ = run_git("rev-parse", "--short", "HEAD", cwd=root)
            commit_sha = sha

    return {
        "scanned": len(list(jobs_dir.glob("*.json"))),
        "eligible": len(eligible),
        "archived": archived_count,
        "protected_total": len(protected_jobs),
        "dry_run": dry_run,
        "commit": commit_sha,
        "results": results,
    }


def list_archived(root_dir=None):
    """List all currently archived jobs."""
    root = Path(root_dir) if root_dir else NETVM_ROOT
    archive_dir = root / "jobs" / "archive"
    if not archive_dir.exists():
        return []

    jobs = []
    for p in sorted(archive_dir.glob("*.json")):
        try:
            d = json.loads(p.read_text())
            jobs.append({
                "name": d.get("name") or p.stem,
                "agent": d.get("agent", "-"),
                "schedule": d.get("schedule", "-"),
                "description": d.get("description", ""),
                "archived_path": str(p),
            })
        except Exception:
            jobs.append({"name": p.stem, "error": "unreadable JSON", "archived_path": str(p)})
    return jobs


def main():
    parser = argparse.ArgumentParser(description="NetVM Job Definition Retention & Archival Driver (P2)")
    sub = parser.add_subparsers(dest="subcommand", required=True)

    # scan
    p_scan = sub.add_parser("scan", help="Scan jobs/ and archive all eligible retired manual jobs")
    p_scan.add_argument("--dry-run", action="store_true", help="Print actions without modifying files")
    p_scan.add_argument("--limit", type=int, default=None, help="Max jobs to archive in this run")
    p_scan.add_argument("--json", action="store_true", help="Output machine-readable JSON")

    # archive
    p_arch = sub.add_parser("archive", help="Archive a specific job by name")
    p_arch.add_argument("name", help="Job name")
    p_arch.add_argument("--dry-run", action="store_true", help="Simulate without modifying files")
    p_arch.add_argument("--force", action="store_true", help="Force archive even if marked protected")
    p_arch.add_argument("--commit", action="store_true", help="Create a git commit for the archive move")
    p_arch.add_argument("--json", action="store_true", help="Output machine-readable JSON")

    # unarchive
    p_unarch = sub.add_parser("unarchive", help="Restore an archived job to jobs/")
    p_unarch.add_argument("name", help="Job name")
    p_unarch.add_argument("--dry-run", action="store_true", help="Simulate without modifying files")
    p_unarch.add_argument("--commit", action="store_true", help="Create a git commit for the unarchive move")
    p_unarch.add_argument("--json", action="store_true", help="Output machine-readable JSON")

    # list
    p_list = sub.add_parser("list", help="List archived jobs in jobs/archive/")
    p_list.add_argument("--json", action="store_true", help="Output machine-readable JSON")

    args = parser.parse_args()

    if args.subcommand == "scan":
        res = scan_and_archive(dry_run=args.dry_run, limit=args.limit)
        if args.json:
            print(json.dumps(res, indent=2))
        else:
            mode = " [DRY-RUN]" if args.dry_run else ""
            print(f"=== Retention Job Archival Scan{mode} ===")
            print(f"Scanned jobs: {res['scanned']}")
            print(f"Eligible for archival: {res['eligible']}")
            print(f"Archived count: {res['archived']}")
            if res.get("commit"):
                print(f"Committed as: {res['commit']}")
            for item in res["results"]:
                status = item["status"]
                print(f"  • {item['name']:25} -> {status}")
            print("========================================")

    elif args.subcommand == "archive":
        res = archive_job(args.name, dry_run=args.dry_run, force=args.force)
        if not args.dry_run and args.commit and res.get("status") == "archived":
            run_git("commit", "-m", f"chore(retention): archive job {args.name}")
        if args.json:
            print(json.dumps(res, indent=2))
        else:
            if res.get("status") in ("archived", "dry_run"):
                print(f"✔ Job '{args.name}' archived to jobs/archive/{args.name}.json")
            else:
                print(f"✖ Failed to archive job '{args.name}': {res.get('error') or res.get('status')}", file=sys.stderr)
                sys.exit(1)

    elif args.subcommand == "unarchive":
        res = unarchive_job(args.name, dry_run=args.dry_run)
        if not args.dry_run and args.commit and res.get("status") == "unarchived":
            run_git("commit", "-m", f"chore(retention): unarchive job {args.name}")
        if args.json:
            print(json.dumps(res, indent=2))
        else:
            if res.get("status") in ("unarchived", "dry_run"):
                print(f"✔ Job '{args.name}' unarchived to jobs/{args.name}.json")
            else:
                print(f"✖ Failed to unarchive job '{args.name}': {res.get('error') or res.get('status')}", file=sys.stderr)
                sys.exit(1)

    elif args.subcommand == "list":
        items = list_archived()
        if args.json:
            print(json.dumps(items, indent=2))
        else:
            print(f"\n=== ARCHIVED JOBS ({len(items)}) ===")
            for item in items:
                print(f"  • {item['name']:25} [{item.get('agent', '-')}] {item.get('description', '')[:50]}")
            print()


if __name__ == "__main__":
    main()