"""Echo Core heartbeat — periodic health checks.

Python checks are configured via config.json heartbeat section.
If personality/HEARTBEAT.md has extra instructions beyond basic rules,
a Claude CLI session is triggered to handle them.
"""

import json
import logging
import subprocess
from datetime import datetime, date, timezone
from pathlib import Path

log = logging.getLogger(__name__)

PROJECT_ROOT = Path(__file__).resolve().parent.parent
STATE_FILE = PROJECT_ROOT / "memory" / "heartbeat-state.json"
TOOLS_DIR = PROJECT_ROOT / "tools"
HEARTBEAT_MD = PROJECT_ROOT / "personality" / "HEARTBEAT.md"

# Defaults (overridable via config.json heartbeat section)
DEFAULT_CHECKS = {
    "email": True,
    "calendar": True,
    "kb_index": True,
    "git": True,
    "embeddings": True,
}

DEFAULT_COOLDOWNS = {
    "email": 1800,       # 30 min
    "calendar": 0,       # every run
    "kb_index": 14400,   # 4h
    "git": 14400,        # 4h
    "embeddings": 3600,  # 1h
}

DEFAULT_QUIET_HOURS = [23, 8]


def run_heartbeat(config: dict | None = None) -> str:
    """Run all heartbeat checks. Returns summary string.

    Config is read from config["heartbeat"]. Python checks run first,
    then Claude CLI is called if HEARTBEAT.md has extra instructions.
    """
    hb_config = (config or {}).get("heartbeat", {})
    quiet_hours = tuple(hb_config.get("quiet_hours", DEFAULT_QUIET_HOURS))
    check_flags = {**DEFAULT_CHECKS, **hb_config.get("checks", {})}
    cooldowns = {**DEFAULT_COOLDOWNS, **hb_config.get("cooldowns", {})}

    now = datetime.now(timezone.utc)
    hour = datetime.now().hour  # local hour
    is_quiet = _is_quiet_hour(hour, quiet_hours)

    state = _load_state()
    checks = state.setdefault("checks", {})
    results = []
    critical = []

    # Check 1: Email
    if check_flags.get("email") and _should_run("email", checks, now, cooldowns):
        email_result = _check_email(state)
        if email_result:
            results.append(email_result)
        checks["email"] = now.isoformat()

    # Check 2: Calendar — daily summary + next-event reminder (no quiet hours bypass)
    if check_flags.get("calendar") and not is_quiet and _should_run("calendar", checks, now, cooldowns):
        cal_result = _check_calendar_smart(state, quiet_hours)
        if cal_result:
            results.append(cal_result)
        checks["calendar"] = now.isoformat()

    # Check 3: KB index freshness + auto-reindex
    if check_flags.get("kb_index") and _should_run("kb_index", checks, now, cooldowns):
        kb_result = _check_kb_index()
        if kb_result:
            results.append(kb_result)
        checks["kb_index"] = now.isoformat()

    # Check 4: Git status
    if check_flags.get("git") and _should_run("git", checks, now, cooldowns):
        git_result = _check_git()
        if git_result:
            results.append(git_result)
        checks["git"] = now.isoformat()

    # Check 5: Incremental embeddings index
    if check_flags.get("embeddings") and _should_run("embeddings", checks, now, cooldowns):
        emb_result = _check_embeddings()
        if emb_result:
            results.append(emb_result)
        checks["embeddings"] = now.isoformat()

    # Claude CLI: run if HEARTBEAT.md has extra instructions
    if not is_quiet:
        claude_result = _run_claude_extra(
            hb_config, critical + results, is_quiet
        )
        if claude_result:
            results.append(claude_result)

    # Update state
    state["last_run"] = now.isoformat()
    _save_state(state)

    # Critical items always get through (even quiet hours)
    if is_quiet:
        if critical:
            return " | ".join(critical)
        return "HEARTBEAT_OK"

    all_results = critical + results
    if not all_results:
        return "HEARTBEAT_OK"

    return " | ".join(all_results)


def _should_run(check_name: str, checks: dict, now: datetime,
                cooldowns: dict | None = None) -> bool:
    """Check if enough time has passed since last run of this check."""
    cd = cooldowns or DEFAULT_COOLDOWNS
    cooldown = cd.get(check_name, 0)
    if cooldown == 0:
        return True
    last_run_str = checks.get(check_name)
    if not last_run_str:
        return True
    try:
        last_run = datetime.fromisoformat(last_run_str)
        return (now - last_run).total_seconds() >= cooldown
    except (ValueError, TypeError):
        return True


def _is_quiet_hour(hour: int, quiet_hours: tuple[int, int]) -> bool:
    """Check if current hour is in quiet range. Handles overnight (23-08)."""
    start, end = quiet_hours
    if start > end:  # overnight
        return hour >= start or hour < end
    return start <= hour < end


def _check_email(state: dict) -> str | None:
    """Check for new emails via tools/email_check.py. Parses JSON output."""
    script = TOOLS_DIR / "email_check.py"
    if not script.exists():
        return None
    try:
        result = subprocess.run(
            ["python3", str(script)],
            capture_output=True, text=True, timeout=30,
            cwd=str(PROJECT_ROOT)
        )
        if result.returncode != 0:
            return None
        output = result.stdout.strip()
        if not output:
            return None
        data = json.loads(output)
        if not data.get("ok"):
            return None
        count = data.get("unread_count", 0)
        if count == 0:
            return None
        emails = data.get("emails", [])
        subjects = [e.get("subject", "?") for e in emails[:5]]
        subject_list = ", ".join(subjects)
        return f"Email: {count} necitite ({subject_list})"
    except json.JSONDecodeError:
        # Fallback: treat as plain text
        output = result.stdout.strip()
        if output and output != "0":
            return f"Email: {output}"
        return None
    except Exception as e:
        log.warning("Email check failed: %s", e)
        return None


def _check_calendar_smart(state: dict, quiet_hours: tuple) -> str | None:
    """Smart calendar check: daily summary once, then only next-event reminders.

    - First run after quiet hours: full day summary (all events today)
    - Subsequent runs: only the nearest event within 45 min, deduplicated
    """
    script = TOOLS_DIR / "calendar_check.py"
    if not script.exists():
        return None

    today_str = date.today().isoformat()
    cal_state = state.setdefault("calendar", {})
    sent_summary_date = cal_state.get("daily_summary_date")
    reminded_events = cal_state.get("reminded_events", {})

    # Clean old reminded_events (from previous days)
    reminded_events = {
        k: v for k, v in reminded_events.items() if v == today_str
    }
    cal_state["reminded_events"] = reminded_events

    is_first_run_today = sent_summary_date != today_str

    if is_first_run_today:
        # Daily summary: all events for today
        return _calendar_daily_summary(cal_state, today_str)
    else:
        # Next-event reminder (within 45 min, deduplicated)
        return _calendar_next_reminder(cal_state, today_str, reminded_events)


def _calendar_daily_summary(cal_state: dict, today_str: str) -> str | None:
    """Fetch all today's events and return a daily summary."""
    script = TOOLS_DIR / "calendar_check.py"
    try:
        result = subprocess.run(
            ["python3", str(script), "today"],
            capture_output=True, text=True, timeout=30,
            cwd=str(PROJECT_ROOT)
        )
        if result.returncode != 0:
            return None
        output = result.stdout.strip()
        if not output:
            return None
        data = json.loads(output)
        today_events = data.get("today", [])
        if not today_events:
            cal_state["daily_summary_date"] = today_str
            return None

        parts = []
        for event in today_events:
            time = event.get("time", "")
            name = event.get("summary", "?")
            parts.append(f"  {time} — {name}")

        cal_state["daily_summary_date"] = today_str
        return "📅 Program azi:\n" + "\n".join(parts)
    except Exception as e:
        log.warning("Calendar daily summary failed: %s", e)
        return None


def _calendar_next_reminder(cal_state: dict, today_str: str,
                            reminded_events: dict) -> str | None:
    """Remind only for the next upcoming event within 45 min, if not already reminded."""
    script = TOOLS_DIR / "calendar_check.py"
    try:
        result = subprocess.run(
            ["python3", str(script), "soon", "1"],
            capture_output=True, text=True, timeout=30,
            cwd=str(PROJECT_ROOT)
        )
        if result.returncode != 0:
            return None
        output = result.stdout.strip()
        if not output:
            return None
        data = json.loads(output)
        upcoming = data.get("upcoming", [])
        if not upcoming:
            return None

        event = upcoming[0]
        mins = event.get("minutes_until", 999)
        name = event.get("summary", "?")
        time = event.get("time", "")

        # Only remind if within 45 minutes
        if isinstance(mins, (int, float)) and mins > 45:
            return None

        # Dedup key: event name + time
        dedup_key = f"{name}@{time}"
        if dedup_key in reminded_events:
            return None

        # Mark as reminded
        reminded_events[dedup_key] = today_str
        cal_state["reminded_events"] = reminded_events

        return f"⏰ in {mins} min — {name} ({time})"
    except Exception as e:
        log.warning("Calendar next reminder failed: %s", e)
        return None


def _check_kb_index() -> str | None:
    """Check if .md files in memory/kb/ are newer than index.json. Auto-reindex."""
    index_file = PROJECT_ROOT / "memory" / "kb" / "index.json"
    if not index_file.exists():
        _run_reindex()
        log.info("KB: index regenerat")
        return None

    index_mtime = index_file.stat().st_mtime
    kb_dir = PROJECT_ROOT / "memory" / "kb"

    newer = 0
    for md in kb_dir.rglob("*.md"):
        if md.stat().st_mtime > index_mtime:
            newer += 1

    if newer > 0:
        _run_reindex()
        log.info("KB: %d fișiere reindexate", newer)
    return None


def _run_reindex() -> None:
    """Run tools/update_notes_index.py to regenerate KB index."""
    script = TOOLS_DIR / "update_notes_index.py"
    if not script.exists():
        log.warning("KB reindex script not found: %s", script)
        return
    try:
        subprocess.run(
            ["python3", str(script)],
            capture_output=True, text=True, timeout=60,
            cwd=str(PROJECT_ROOT)
        )
    except Exception as e:
        log.warning("KB reindex failed: %s", e)


def _check_embeddings() -> str | None:
    """Incremental re-index of memory/ embeddings for semantic search."""
    try:
        from src.memory_search import incremental_index
        result = incremental_index()
        indexed = result.get("indexed", 0)
        if indexed > 0:
            chunks = result.get("chunks", 0)
            log.info("Embeddings: %d fisiere reindexate (%d chunks)", indexed, chunks)
        return None
    except ConnectionError:
        log.warning("Embeddings check skipped: Ollama unreachable")
        return None
    except Exception as e:
        log.warning("Embeddings check failed: %s", e)
        return None


def _check_git() -> str | None:
    """Check for uncommitted files in project."""
    try:
        result = subprocess.run(
            ["git", "status", "--porcelain"],
            capture_output=True, text=True, timeout=10,
            cwd=str(PROJECT_ROOT)
        )
        if result.returncode == 0:
            lines = [l for l in result.stdout.strip().split("\n") if l.strip()]
            if lines:
                return f"Git: {len(lines)} uncommitted"
        return None
    except Exception:
        return None


def _get_extra_instructions() -> str | None:
    """Read HEARTBEAT.md and return extra instructions if any.

    Skips the basic structure (title, quiet hours rules).
    Returns None if only boilerplate remains.
    """
    if not HEARTBEAT_MD.exists():
        return None
    content = HEARTBEAT_MD.read_text(encoding="utf-8").strip()
    if not content:
        return None
    # Strip lines that are just headers, empty, or the standard rules
    meaningful = []
    for line in content.split("\n"):
        stripped = line.strip()
        if not stripped:
            continue
        if stripped.startswith("# HEARTBEAT"):
            continue
        if stripped.startswith("## Reguli"):
            continue
        if "HEARTBEAT_OK" in stripped:
            continue
        if "quiet" in stripped.lower() or "noapte" in stripped.lower():
            continue
        if "nu spama" in stripped.lower() or "nu deranja" in stripped.lower():
            continue
        meaningful.append(line)
    if not meaningful:
        return None
    return "\n".join(meaningful).strip()


def _run_claude_extra(hb_config: dict, python_results: list[str],
                      is_quiet: bool) -> str | None:
    """Run Claude CLI if HEARTBEAT.md has extra instructions."""
    from src.claude_session import CLAUDE_BIN, _safe_env

    extra = _get_extra_instructions()
    if not extra:
        return None

    model = hb_config.get("model", "haiku")

    # Build prompt with context
    context_parts = ["Heartbeat tick."]
    if python_results:
        context_parts.append(
            f"Check-uri Python: {' | '.join(python_results)}"
        )
    else:
        context_parts.append("Check-urile Python nu au găsit nimic.")
    context_parts.append(f"Instrucțiuni extra din HEARTBEAT.md:\n{extra}")
    context_parts.append(
        "Execută instrucțiunile de mai sus. "
        "Răspunde DOAR cu rezultatul (scurt, fără explicații). "
        "Dacă nu e nimic de raportat, răspunde cu HEARTBEAT_OK."
    )
    prompt = "\n\n".join(context_parts)

    cmd = [
        CLAUDE_BIN, "-p", prompt,
        "--model", model,
        "--output-format", "json",
    ]

    try:
        proc = subprocess.run(
            cmd,
            capture_output=True, text=True, timeout=120,
            env=_safe_env(),
            cwd=str(PROJECT_ROOT),
        )
        if proc.returncode != 0:
            log.warning("Claude heartbeat extra failed (exit %d): %s",
                        proc.returncode, proc.stderr[:200])
            return None
        data = json.loads(proc.stdout)
        result = data.get("result", "").strip()
        if not result or result == "HEARTBEAT_OK":
            return None
        return result
    except subprocess.TimeoutExpired:
        log.warning("Claude heartbeat extra timed out")
        return None
    except Exception as e:
        log.warning("Claude heartbeat extra error: %s", e)
        return None


def _load_state() -> dict:
    """Load heartbeat state from JSON file."""
    if STATE_FILE.exists():
        try:
            return json.loads(STATE_FILE.read_text(encoding="utf-8"))
        except (json.JSONDecodeError, OSError):
            pass
    return {"last_run": None, "checks": {}}


def _save_state(state: dict) -> None:
    """Save heartbeat state to JSON file."""
    STATE_FILE.parent.mkdir(parents=True, exist_ok=True)
    STATE_FILE.write_text(
        json.dumps(state, indent=2, ensure_ascii=False) + "\n",
        encoding="utf-8"
    )