#!/usr/bin/env python3
"""box-ctl.py — allowlisted bl helper for Box API mutations.

The board server (VM) never runs raw systemctl or shell over SSH.
All bl mutations go through this helper, invoked as:

    /home/super/Projects/NetVM/bin/box-ctl.py <action> [args...]

Security properties:
- Fixed verb set; every argument validated before acting.
- <name> must match ^[a-z0-9-]{1,64}$ (kills path traversal).
- Unit files generated from a fixed template; only the validated
  name is interpolated. User-controlled strings never appear in
  unit files.
- No shell=True anywhere. No string interpolation into commands.
- Job JSON schema-validated before writing; changes git-committed.
- Every action audit-logged to box-ctl.jsonl with caller identity.

Output: JSON to stdout ({"ok": true, ...} or {"ok": false, ...}),
exit 0 on success, nonzero on failure.
"""

import json
import os
import re
import subprocess
import sys
from datetime import datetime, timezone
from pathlib import Path

NETVM_ROOT = Path("/home/super/Projects/NetVM")
BIN = NETVM_ROOT / "bin"
JOBS_DIR = NETVM_ROOT / "jobs"
SYSTEMD_USER = Path.home() / ".config" / "systemd" / "user"
CTL_LOG = NETVM_ROOT / "box-ctl.jsonl"
JOB_LOG = NETVM_ROOT / "job-log.jsonl"
DISPATCHER = BIN / "job-dispatch.py"
DM_PY = BIN / "dm.py"

NAME_RE = re.compile(r"^[a-z0-9-]{1,64}$")
VALID_AGENTS = {"muse", "pip", "646", "opm"}
VALID_ON_FAILURE = {"retry", "alert", "ignore"}
KNOWN_PLACEHOLDERS = {"job_id", "job_name", "datetime", "date", "last_run"}
PROTOCOL_LITERALS = ("[REQ", "[CONFIRM", "[JOB", "[RESULT")
DOW_NAMES = ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"]


def utcnow():
    return datetime.now(timezone.utc).strftime("%Y-%m-%dT%H:%M:%SZ")


def out(ok, **kw):
    payload = {"ok": ok}
    payload.update(kw)
    print(json.dumps(payload))


def fail(code, error, detail=None, exit_code=1):
    payload = {"ok": False, "code": code, "error": error}
    if detail is not None:
        payload["detail"] = detail
    print(json.dumps(payload))
    sys.exit(exit_code)


def audit(action, name=None):
    """Append {ts, action, name, caller} to the bl-side log."""
    try:
        entry = {
            "ts": utcnow(),
            "action": action,
            "name": name,
            "caller": os.environ.get("BOX_CALLER", "unknown"),
        }
        with open(CTL_LOG, "a") as f:
            f.write(json.dumps(entry) + "\n")
    except Exception:
        pass  # audit failure must not break the action


def check_name(name):
    if not name or not NAME_RE.match(name):
        fail("BAD_NAME",
             "name must match ^[a-z0-9-]{1,64}$",
             {"field": "name", "value": name})
    return name


def run(cmd, timeout=30):
    """Run a command with no shell. Returns CompletedProcess."""
    return subprocess.run(cmd, capture_output=True, text=True, timeout=timeout)


# ---------------------------------------------------------------------------
# Cron validation and conversion
# ---------------------------------------------------------------------------

CRON_RANGES = {
    0: (0, 59),   # minute
    1: (0, 23),   # hour
    2: (1, 31),   # day of month
    3: (1, 12),   # month
    4: (0, 7),    # day of week (0 and 7 = Sunday)
}


def validate_cron_field(field, idx):
    """Validate one cron field. Returns True/False."""
    lo, hi = CRON_RANGES[idx]
    if field == "*":
        return True
    for part in field.split(","):
        # step: base/n
        if "/" in part:
            base, step = part.split("/", 1)
            if not step.isdigit() or int(step) < 1:
                return False
            if base != "*" and not validate_cron_field(base, idx):
                return False
            continue
        # range: a-b
        if "-" in part:
            a, b = part.split("-", 1)
            if not (a.isdigit() and b.isdigit()):
                return False
            if not (lo <= int(a) <= hi and lo <= int(b) <= hi):
                return False
            if int(a) > int(b):
                return False
            continue
        # single value
        if not part.isdigit():
            return False
        if not (lo <= int(part) <= hi):
            return False
    return True


def validate_cron(schedule):
    """Validate a 5-field cron string. Returns (ok, reason)."""
    parts = schedule.split()
    if len(parts) != 5:
        return False, "schedule must have exactly 5 fields (M H dom mon dow)"
    for i, p in enumerate(parts):
        if not validate_cron_field(p, i):
            return False, f"schedule field {i + 1} ({p!r}) is invalid"
    return True, ""


def cron_to_oncalendar(schedule):
    """Convert common cron patterns to systemd OnCalendar.

    Returns the OnCalendar string, or None if the pattern is not
    supported (caller rejects with INVALID_SCHEDULE).
    """
    m, h, dom, mon, dow = schedule.split()

    def is_star(f):
        return f == "*"

    # */n * * * * -> *:0/n  (every n minutes)
    if m.startswith("*/") and m[2:].isdigit() and all(is_star(f) for f in (h, dom, mon, dow)):
        return f"*:0/{m[2:]}"
    # M * * * * -> hourly or *:M
    if m.isdigit() and all(is_star(f) for f in (h, dom, mon, dow)):
        if m == "0":
            return "hourly"
        return f"*:{int(m):02d}"
    # M H * * * -> HH:MM (daily)
    if m.isdigit() and h.isdigit() and all(is_star(f) for f in (dom, mon, dow)):
        return f"{int(h):02d}:{int(m):02d}"
    # M H * * DOW -> Dow HH:MM (weekly)
    if m.isdigit() and h.isdigit() and dow != "*" and is_star(dom) and is_star(mon):
        # take first dow value for the weekly form
        d = dow.split(",")[0].split("-")[0].split("/")[0]
        if d.isdigit() and 0 <= int(d) <= 7:
            return f"{DOW_NAMES[int(d) % 7]} {int(h):02d}:{int(m):02d}"
        return None
    # M H DOM * * -> *-*-DOM HH:MM:00 (monthly)
    if m.isdigit() and h.isdigit() and dom.isdigit() and is_star(mon) and is_star(dow):
        return f"*-*-{int(dom):02d} {int(h):02d}:{int(m):02d}:00"
    # M H * * * with stepped hour: M */n * * * -> 0/n:MM
    if m.isdigit() and h.startswith("*/") and h[2:].isdigit() and all(is_star(f) for f in (dom, mon, dow)):
        return f"0/{h[2:]}:{int(m):02d}"
    return None


def validate_oncalendar(expr):
    """Check an OnCalendar expression with systemd-analyze."""
    r = run(["systemd-analyze", "calendar", expr, "--iterations=2"], timeout=15)
    return r.returncode == 0


# ---------------------------------------------------------------------------
# Job schema validation (§6 of the design doc)
# ---------------------------------------------------------------------------

def validate_job(data):
    """Validate a job definition dict. Returns (ok, field, reason)."""
    if not isinstance(data, dict):
        return False, None, "job must be a JSON object"

    # name
    name = data.get("name")
    if not isinstance(name, str) or not NAME_RE.match(name):
        return False, "name", "must match ^[a-z0-9-]{1,64}$"

    # description
    desc = data.get("description")
    if desc is not None:
        if not isinstance(desc, str) or len(desc) > 280:
            return False, "description", "must be a string ≤ 280 chars"

    # schedule
    sched = data.get("schedule")
    if not isinstance(sched, str):
        return False, "schedule", "is required and must be a string"
    ok, reason = validate_cron(sched)
    if not ok:
        return False, "schedule", reason
    oc = cron_to_oncalendar(sched)
    if oc is None:
        return False, "schedule", (
            "cron pattern not supported for OnCalendar conversion; "
            "supported: */n * * * *, M * * * *, M H * * *, M H * * DOW, M H DOM * *"
        )
    if not validate_oncalendar(oc):
        return False, "schedule", f"converted OnCalendar {oc!r} rejected by systemd-analyze"

    # scheduler
    scheduler = data.get("scheduler", "systemd")
    if scheduler != "systemd":
        return False, "scheduler", 'v1 accepts only "systemd"'

    # agent
    agent = data.get("agent")
    if agent not in VALID_AGENTS:
        return False, "agent", f"must be one of {sorted(VALID_AGENTS)}"

    # prompt_template
    pt = data.get("prompt_template")
    if not isinstance(pt, str) or not (1 <= len(pt) <= 4000):
        return False, "prompt_template", "must be a string of 1–4000 chars"
    for lit in PROTOCOL_LITERALS:
        if lit in pt:
            return False, "prompt_template", (
                f"must not contain {lit!r} literal (protocol framing is added by the dispatcher)"
            )
    for ph in re.findall(r"\{([a-zA-Z_][a-zA-Z0-9_]*)\}", pt):
        if ph not in KNOWN_PLACEHOLDERS:
            return False, "prompt_template", f"unknown placeholder {{{ph}}}"

    # timeout
    timeout = data.get("timeout", 300)
    if not isinstance(timeout, int) or isinstance(timeout, bool) or not (60 <= timeout <= 3600):
        return False, "timeout", "must be an integer 60–3600"

    # on_failure
    onf = data.get("on_failure", "alert")
    if onf not in VALID_ON_FAILURE:
        return False, "on_failure", f"must be one of {sorted(VALID_ON_FAILURE)}"

    # chain_next
    cn = data.get("chain_next")
    if cn is not None:
        if not isinstance(cn, str) or not NAME_RE.match(cn):
            return False, "chain_next", "must be null or a valid job name"
        if not (JOBS_DIR / f"{cn}.json").exists():
            return False, "chain_next", f"job {cn!r} does not exist (dangling chain)"

    # sidechat
    sc = data.get("sidechat")
    if sc is not None:
        if not isinstance(sc, dict):
            return False, "sidechat", "must be an object"
        create = sc.get("create", False)
        if not isinstance(create, bool):
            return False, "sidechat.create", "must be a boolean"
        nt = sc.get("name_template")
        if nt is not None:
            if not isinstance(nt, str) or len(nt) > 120:
                return False, "sidechat.name_template", "must be a string ≤ 120 chars"
            for ph in re.findall(r"\{([a-zA-Z_][a-zA-Z0-9_]*)\}", nt):
                if ph not in {"job_name", "date", "job_id"}:
                    return False, "sidechat.name_template", f"unknown placeholder {{{ph}}}"
        rk = sc.get("reuse_key")
        if rk is not None:
            if not isinstance(rk, str) or not NAME_RE.match(rk):
                return False, "sidechat.reuse_key", "must match ^[a-z0-9-]{1,64}$"

    return True, None, ""


# ---------------------------------------------------------------------------
# Unit file templates (fixed; only <name> interpolated, regex-validated)
# ---------------------------------------------------------------------------

SERVICE_TEMPLATE = """[Unit]
Description=Dispatch {name} job
After=network.target

[Service]
Type=oneshot
ExecStart=/home/super/Projects/NetVM/bin/job-dispatch.py {name}
User=super
WorkingDirectory=/home/super/Projects/NetVM
"""

TIMER_TEMPLATE = """[Unit]
Description=Run {name} job on schedule

[Timer]
OnCalendar={oncalendar}
Persistent=true
AccuracySec=1min

[Install]
WantedBy=timers.target
"""


def unit_path(name, kind):
    return SYSTEMD_USER / f"job-{name}.{kind}"


def systemctl(*args, timeout=30):
    return run(["systemctl", "--user"] + list(args), timeout=timeout)


# ---------------------------------------------------------------------------
# Actions
# ---------------------------------------------------------------------------

def act_timer_list():
    timers = []
    try:
        entries = sorted(SYSTEMD_USER.glob("job-*.timer"))
    except Exception:
        entries = []
    for p in entries:
        unit = p.name
        name = unit[len("job-"):-len(".timer")]
        active = systemctl("is-active", unit).stdout.strip() == "active"
        enabled_out = systemctl("is-enabled", unit).stdout.strip()
        enabled = enabled_out == "enabled"
        job_path = JOBS_DIR / f"{name}.json"
        timers.append({
            "name": name,
            "unit": unit,
            "active": active,
            "enabled": enabled,
            "orphan": not job_path.exists(),
        })
    audit("timer-list")
    out(True, timers=timers)


def _timer_show_property(unit, prop):
    r = systemctl("show", unit, f"--property={prop}", "--value")
    if r.returncode != 0:
        return None
    return r.stdout.strip() or None


def act_timer_status(name):
    check_name(name)
    unit = f"job-{name}.timer"
    if not unit_path(name, "timer").exists():
        fail("NOT_FOUND", f"no such timer: {unit}")
    active = systemctl("is-active", unit).stdout.strip() == "active"
    enabled = systemctl("is-enabled", unit).stdout.strip() == "enabled"
    last_usec = _timer_show_property(unit, "LastTriggerUSec")
    next_usec = _timer_show_property(unit, "NextElapseUSec")
    oncalendar_raw = _timer_show_property(unit, "TimersCalendar")
    # TimersCalendar returns "{ OnCalendar=... ; next_elapse=... }" — extract just the expr
    oncalendar = oncalendar_raw
    if oncalendar_raw:
        m = re.search(r"OnCalendar=([^;}]+)", oncalendar_raw)
        if m:
            oncalendar = m.group(1).strip()
    result = _timer_show_property(unit, "Result")

    def usec_to_iso(v):
        if not v or v in ("0", "n/a"):
            return None
        try:
            ts = int(v) / 1_000_000
            return datetime.fromtimestamp(ts, tz=timezone.utc).strftime("%Y-%m-%dT%H:%M:%SZ")
        except Exception:
            return None

    # last_result from job-log.jsonl
    last_result = "unknown"
    try:
        if JOB_LOG.exists():
            for line in reversed(JOB_LOG.read_text().splitlines()[-500:]):
                try:
                    e = json.loads(line)
                except Exception:
                    continue
                if e.get("job_name") != name and not str(e.get("job_id", "")).startswith(name + "-"):
                    continue
                t = e.get("type")
                if t in ("job_dispatched",):
                    last_result = "success"
                    break
                if t in ("job_failed", "job_timeout"):
                    last_result = "failed"
                    break
    except Exception:
        pass

    job_def = None
    job_path = JOBS_DIR / f"{name}.json"
    if job_path.exists():
        try:
            job_def = json.loads(job_path.read_text())
        except Exception:
            job_def = None

    audit("timer-status", name)
    out(True, name=name, unit=unit, active=active, enabled=enabled,
        last_run=usec_to_iso(last_usec), next_run=usec_to_iso(next_usec),
        last_result=last_result, oncalendar=oncalendar,
        job_definition=job_def)


def act_timer_create(name):
    check_name(name)
    job_path = JOBS_DIR / f"{name}.json"
    if not job_path.exists():
        fail("NOT_FOUND", f"job definition missing: jobs/{name}.json — create the job first")
    try:
        job = json.loads(job_path.read_text())
    except Exception as e:
        fail("INVALID_JOB", f"job JSON unreadable: {e}")
    ok, field, reason = validate_job(job)
    if not ok:
        fail("INVALID_JOB", f"job validation failed: {field}: {reason}",
             {"field": field, "reason": reason})
    if unit_path(name, "timer").exists():
        fail("ALREADY_EXISTS", f"timer job-{name}.timer already exists — delete it first")

    oncalendar = cron_to_oncalendar(job["schedule"])
    if oncalendar is None or not validate_oncalendar(oncalendar):
        fail("INVALID_SCHEDULE", "schedule did not convert to a valid OnCalendar")

    SYSTEMD_USER.mkdir(parents=True, exist_ok=True)
    unit_path(name, "service").write_text(SERVICE_TEMPLATE.format(name=name))
    unit_path(name, "timer").write_text(
        TIMER_TEMPLATE.format(name=name, oncalendar=oncalendar))

    r = systemctl("daemon-reload")
    if r.returncode != 0:
        fail("TIMER_CREATE_FAILED", f"daemon-reload failed: {r.stderr.strip()}")
    r = systemctl("enable", "--now", f"job-{name}.timer")
    if r.returncode != 0:
        fail("TIMER_CREATE_FAILED", f"enable --now failed: {r.stderr.strip()}")

    audit("timer-create", name)
    out(True, name=name, unit=f"job-{name}.timer", created=True,
        oncalendar=oncalendar)


def act_timer_delete(name, keep_job=False):
    check_name(name)
    unit = f"job-{name}.timer"
    if not unit_path(name, "timer").exists():
        fail("NOT_FOUND", f"no such timer: {unit}")
    systemctl("stop", unit)
    systemctl("disable", unit)
    for kind in ("timer", "service"):
        p = unit_path(name, kind)
        try:
            p.unlink()
        except FileNotFoundError:
            pass
    r = systemctl("daemon-reload")
    if r.returncode != 0:
        fail("TIMER_CREATE_FAILED", f"daemon-reload failed: {r.stderr.strip()}")
    audit("timer-delete", name)
    out(True, name=name, unit=unit, deleted=True, job_kept=keep_job or (JOBS_DIR / f"{name}.json").exists())


def act_timer_control(name, op):
    check_name(name)
    unit = f"job-{name}.timer"
    if not unit_path(name, "timer").exists():
        fail("NOT_FOUND", f"no such timer: {unit}")
    valid = {"start", "stop", "enable", "disable"}
    if op not in valid:
        fail("BAD_NAME", f"unknown timer op: {op}")
    args = ["--now", unit] if op == "enable" else [unit]
    r = systemctl(op, *args)
    if r.returncode != 0:
        fail("TIMER_CREATE_FAILED", f"systemctl {op} failed: {r.stderr.strip()}")
    audit(f"timer-{op}", name)
    out(True, name=name, unit=unit, op=op)


def _job_summary(name, path):
    try:
        d = json.loads(path.read_text())
    except Exception:
        return {"name": name, "error": "unreadable"}
    return {
        "name": name,
        "description": d.get("description"),
        "schedule": d.get("schedule"),
        "agent": d.get("agent"),
        "timeout": d.get("timeout", 300),
    }


def act_job_list():
    jobs = []
    if JOBS_DIR.exists():
        for p in sorted(JOBS_DIR.glob("*.json")):
            jobs.append(_job_summary(p.stem, p))
    audit("job-list")
    out(True, jobs=jobs)


def act_job_get(name):
    check_name(name)
    p = JOBS_DIR / f"{name}.json"
    if not p.exists():
        fail("NOT_FOUND", f"no such job: {name}")
    try:
        data = json.loads(p.read_text())
    except Exception as e:
        fail("INVALID_JOB", f"job JSON unreadable: {e}")
    audit("job-get", name)
    out(True, job=data)


def _git(*args):
    return run(["git", "-C", str(NETVM_ROOT)] + list(args), timeout=30)


def act_job_put(name):
    check_name(name)
    raw = sys.stdin.read()
    try:
        data = json.loads(raw)
    except Exception as e:
        fail("INVALID_JOB", f"stdin is not valid JSON: {e}")
    if data.get("name") != name:
        fail("NAME_MISMATCH", "path name != body name",
             {"path": name, "body": data.get("name")})
    ok, field, reason = validate_job(data)
    if not ok:
        fail("INVALID_JOB", f"schema validation failed: {field}: {reason}",
             {"field": field, "reason": reason})
    existed = (JOBS_DIR / f"{name}.json").exists()
    JOBS_DIR.mkdir(parents=True, exist_ok=True)
    (JOBS_DIR / f"{name}.json").write_text(json.dumps(data, indent=2) + "\n")
    r = _git("add", f"jobs/{name}.json")
    if r.returncode != 0:
        fail("DISPATCH_FAILED", f"git add failed: {r.stderr.strip()}")
    msg = f"{'Update' if existed else 'Add'} job {name} via box-ctl"
    r = _git("-c", "user.name=box-ctl", "-c", "user.email=box-ctl@bl.local",
             "commit", "-m", msg)
    if r.returncode != 0 and "nothing to commit" not in (r.stdout + r.stderr):
        fail("DISPATCH_FAILED", f"git commit failed: {r.stderr.strip()}")
    audit("job-put", name)
    out(True, name=name, created=not existed, updated=existed)


def act_job_delete(name, force=False):
    check_name(name)
    p = JOBS_DIR / f"{name}.json"
    if not p.exists():
        fail("NOT_FOUND", f"no such job: {name}")
    if unit_path(name, "timer").exists() and not force:
        fail("TIMER_STILL_ACTIVE",
             f"timer job-{name}.timer still exists — delete it first or use --force")
    r = _git("rm", "-q", f"jobs/{name}.json")
    if r.returncode != 0:
        fail("DISPATCH_FAILED", f"git rm failed: {r.stderr.strip()}")
    r = _git("-c", "user.name=box-ctl", "-c", "user.email=box-ctl@bl.local",
             "commit", "-m", f"Delete job {name} via box-ctl")
    if r.returncode != 0:
        fail("DISPATCH_FAILED", f"git commit failed: {r.stderr.strip()}")
    audit("job-delete", name)
    out(True, name=name, deleted=True)


def act_job_trigger(name):
    check_name(name)
    p = JOBS_DIR / f"{name}.json"
    if not p.exists():
        fail("NOT_FOUND", f"no such job: {name}")
    r = run([sys.executable, str(DISPATCHER), name], timeout=300)
    if r.returncode != 0:
        fail("DISPATCH_FAILED", f"job-dispatch.py failed: {(r.stderr or r.stdout).strip()[-500:]}")
    audit("job-trigger", name)
    out(True, name=name, triggered=True)


def act_notify(agent, message):
    if agent not in VALID_AGENTS:
        fail("BAD_NAME", f"agent must be one of {sorted(VALID_AGENTS)}")
    if not message or len(message) > 1000:
        fail("INVALID_JOB", "message must be 1–1000 chars")
    # dm.py send --agent opm --to <agent> --target main "<message>"
    r = run([sys.executable, str(DM_PY), "send",
             "--agent", "opm", "--to", agent, "--target", "main", message],
            timeout=120)
    if r.returncode != 0:
        fail("DISPATCH_FAILED", f"dm.py send failed: {(r.stderr or r.stdout).strip()[-500:]}")
    audit("notify", agent)
    out(True, agent=agent, sent=True)


# ---------------------------------------------------------------------------
# CLI
# ---------------------------------------------------------------------------

USAGE = """usage: box-ctl.py <action> [args]

timer actions:
  timer-list
  timer-status <name>
  timer-create <name>
  timer-delete <name> [--keep-job]
  timer-start|timer-stop|timer-enable|timer-disable <name>

job actions:
  job-list
  job-get <name>
  job-put <name>            (job JSON on stdin)
  job-delete <name> [--force]
  job-trigger <name>

notify:
  notify <agent> <message>"""


def main(argv):
    if len(argv) < 2:
        print(USAGE, file=sys.stderr)
        sys.exit(2)
    action = argv[1]
    rest = argv[2:]

    if action == "timer-list":
        act_timer_list()
    elif action == "timer-status":
        if len(rest) != 1:
            fail("BAD_NAME", "usage: timer-status <name>")
        act_timer_status(rest[0])
    elif action == "timer-create":
        if len(rest) != 1:
            fail("BAD_NAME", "usage: timer-create <name>")
        act_timer_create(rest[0])
    elif action == "timer-delete":
        if not rest or len(rest) > 2:
            fail("BAD_NAME", "usage: timer-delete <name> [--keep-job]")
        keep = "--keep-job" in rest[1:]
        act_timer_delete(rest[0], keep_job=keep)
    elif action in ("timer-start", "timer-stop", "timer-enable", "timer-disable"):
        if len(rest) != 1:
            fail("BAD_NAME", f"usage: {action} <name>")
        act_timer_control(rest[0], action[len("timer-"):])
    elif action == "job-list":
        act_job_list()
    elif action == "job-get":
        if len(rest) != 1:
            fail("BAD_NAME", "usage: job-get <name>")
        act_job_get(rest[0])
    elif action == "job-put":
        if len(rest) != 1:
            fail("BAD_NAME", "usage: job-put <name>  (JSON on stdin)")
        act_job_put(rest[0])
    elif action == "job-delete":
        if not rest or len(rest) > 2:
            fail("BAD_NAME", "usage: job-delete <name> [--force]")
        force = "--force" in rest[1:]
        act_job_delete(rest[0], force=force)
    elif action == "job-trigger":
        if len(rest) != 1:
            fail("BAD_NAME", "usage: job-trigger <name>")
        act_job_trigger(rest[0])
    elif action == "notify":
        if len(rest) != 2:
            fail("BAD_NAME", "usage: notify <agent> <message>")
        act_notify(rest[0], rest[1])
    else:
        print(USAGE, file=sys.stderr)
        fail("BAD_NAME", f"unknown action: {action}")


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