#!/usr/bin/env python3
"""
cron-audit — Audit and clean up dead cron jobs.

Finds jobs with zero completions, low success rates, or stale schedules.
Can disable or delete dead jobs.

Usage:
    python scripts/cron_audit.py                    # Show dead jobs
    python scripts/cron_audit.py --disable          # Disable dead jobs
    python scripts/cron_audit.py --delete           # Delete dead jobs
    python scripts/cron_audit.py --threshold 0      # Jobs with 0 completions
    python scripts/cron_audit.py --older-than 7d    # Jobs with no runs in 7 days
"""

import argparse
import json
import sys
from pathlib import Path
from typing import Any, Dict, List

HERMES_HOME = Path.home() / ".hermes"
JOBS_FILE = HERMES_HOME / "cron" / "jobs.json"


def load_jobs() -> List[Dict[str, Any]]:
    """Load cron jobs from jobs.json."""
    if not JOBS_FILE.exists():
        print(f"Error: {JOBS_FILE} not found")
        return []
    with open(JOBS_FILE) as f:
        data = json.load(f)
    return data.get("jobs", [])


def save_jobs(jobs: List[Dict[str, Any]]):
    """Save jobs back to jobs.json."""
    JOBS_FILE.parent.mkdir(parents=True, exist_ok=True)
    with open(JOBS_FILE, "r") as f:
        data = json.load(f)
    data["jobs"] = jobs
    with open(JOBS_FILE, "w") as f:
        json.dump(data, f, indent=2)


def find_dead_jobs(
    jobs: List[Dict[str, Any]],
    completion_threshold: int = 0,
) -> List[Dict[str, Any]]:
    """Find jobs with completions at or below threshold."""
    dead = []
    for job in jobs:
        repeat = job.get("repeat", {})
        completed = repeat.get("completed", 0)
        if completed <= completion_threshold:
            dead.append(job)
    return dead


def find_stale_jobs(
    jobs: List[Dict[str, Any]],
    max_age_hours: float = 168,  # 7 days
) -> List[Dict[str, Any]]:
    """Find jobs that haven't run in max_age_hours."""
    import time
    from datetime import datetime, timezone
    
    stale = []
    now = time.time()
    
    for job in jobs:
        last_run = job.get("last_run_at")
        if not last_run:
            # Never ran — check creation time
            created = job.get("created_at")
            if created:
                try:
                    dt = datetime.fromisoformat(created.replace("Z", "+00:00"))
                    age_hours = (now - dt.timestamp()) / 3600
                    if age_hours > max_age_hours:
                        stale.append(job)
                except Exception:
                    stale.append(job)
            else:
                stale.append(job)
        else:
            try:
                dt = datetime.fromisoformat(last_run.replace("Z", "+00:00"))
                age_hours = (now - dt.timestamp()) / 3600
                if age_hours > max_age_hours:
                    stale.append(job)
            except Exception:
                pass
    
    return stale


def format_job(job: Dict[str, Any]) -> str:
    """Format a job for display."""
    name = job.get("name", job.get("id", "?"))
    schedule = job.get("schedule_display", "?")
    repeat = job.get("repeat", {})
    completed = repeat.get("completed", 0)
    times = repeat.get("times")
    enabled = job.get("enabled", True)
    state = job.get("state", "unknown")
    last_run = job.get("last_run_at", "never")
    
    status = "enabled" if enabled else "disabled"
    if state == "paused":
        status = "paused"
    
    repeat_str = f"{completed}/{times}" if times else f"{completed}/∞"
    
    return f"  {name:40s} | {schedule:20s} | done: {repeat_str:8s} | {status}"


def main():
    parser = argparse.ArgumentParser(description="Audit and clean up dead cron jobs")
    parser.add_argument("--disable", action="store_true", help="Disable dead jobs")
    parser.add_argument("--delete", action="store_true", help="Delete dead jobs")
    parser.add_argument("--threshold", type=int, default=0, help="Completion threshold (default: 0)")
    parser.add_argument("--older-than", type=str, help="Find jobs with no runs in N days (e.g., 7d)")
    parser.add_argument("--dry-run", action="store_true", help="Show what would change")
    args = parser.parse_args()
    
    jobs = load_jobs()
    if not jobs:
        print("No jobs found.")
        return
    
    print(f"Total jobs: {len(jobs)}")
    
    # Find dead jobs
    dead = find_dead_jobs(jobs, args.threshold)
    print(f"Jobs with <= {args.threshold} completions: {len(dead)}")
    
    if args.older_than:
        days = int(args.older_than.rstrip("d"))
        stale = find_stale_jobs(jobs, max_age_hours=days * 24)
        print(f"Jobs with no runs in {days} days: {len(stale)}")
        dead = list({j["id"]: j for j in dead + stale}.values())
    
    if not dead:
        print("No dead jobs found.")
        return
    
    print(f"\nDead jobs ({len(dead)}):")
    for job in dead:
        print(format_job(job))
    
    if args.disable:
        if args.dry_run:
            print(f"\nDRY RUN: Would disable {len(dead)} jobs")
            return
        
        job_ids = {j["id"] for j in dead}
        for job in jobs:
            if job["id"] in job_ids:
                job["enabled"] = False
                job["state"] = "disabled"
        
        save_jobs(jobs)
        print(f"\nDisabled {len(dead)} jobs.")
    
    elif args.delete:
        if args.dry_run:
            print(f"\nDRY RUN: Would delete {len(dead)} jobs")
            return
        
        job_ids = {j["id"] for j in dead}
        jobs = [j for j in jobs if j["id"] not in job_ids]
        save_jobs(jobs)
        print(f"\nDeleted {len(dead)} jobs.")
    
    else:
        print(f"\nUse --disable or --delete to take action. Add --dry-run to preview.")


if __name__ == "__main__":
    main()