"""Abandoned onboarding → Lead CRM — Spec 012 Phase B."""

from __future__ import annotations

import json
import os
import sqlite3
from datetime import datetime, timedelta, timezone
from typing import Any

ONBOARD_STALE_HOURS = int(os.getenv("ONBOARD_STALE_HOURS", "24"))
ONBOARD_SOURCE = "vm112-onboard"

FUNNEL_EVENT_RANK = {
    "onboarding.started": 1,
    "domain.validated": 2,
    "dns.applied": 3,
    "account.created": 4,
    "infra.synced": 5,
    "onboarding.completed": 6,
    "onboarding.failed": 99,
}

FUNNEL_STAGE_BY_RANK = {
    1: "started",
    2: "domain_validated",
    3: "dns_applied",
    4: "account_created",
    5: "infra_synced",
    6: "completed",
    99: "failed",
}

LEAD_PROMOTE_STATUSES = frozenset({"open", "escalated"})
SKIP_STAGES = frozenset({"completed", "failed"})


def _parse_payload(raw: str | None) -> dict:
    if not raw:
        return {}
    try:
        return json.loads(raw)
    except json.JSONDecodeError:
        return {}


def _now() -> str:
    return datetime.now(timezone.utc).isoformat()


def session_funnel_state(conn: sqlite3.Connection, session_id: str) -> dict[str, Any]:
    sid = (session_id or "").strip()
    if not sid:
        return {"stage": "unknown", "last_event_at": None, "failed": False}
    rows = conn.execute(
        """
        SELECT event_type, payload, created_at
        FROM webhook_events
        WHERE source = ?
        ORDER BY id ASC
        """,
        (ONBOARD_SOURCE,),
    ).fetchall()
    max_rank = 0
    last_event_at = None
    domain = None
    failed = False
    for row in rows:
        payload = _parse_payload(row["payload"])
        if (payload.get("session_id") or "").strip() != sid:
            continue
        if payload.get("domain"):
            domain = payload.get("domain")
        last_event_at = row["created_at"]
        if row["event_type"] == "onboarding.failed":
            failed = True
            max_rank = max(max_rank, 99)
        else:
            rank = FUNNEL_EVENT_RANK.get(row["event_type"], 0)
            if rank > max_rank and not failed:
                max_rank = rank
    if failed:
        stage = "failed"
    else:
        stage = FUNNEL_STAGE_BY_RANK.get(max_rank, "started")
    return {
        "stage": stage,
        "last_event_at": last_event_at,
        "failed": failed,
        "domain": domain,
    }


def is_session_stale(last_event_at: str | None, stage: str, stale_hours: int) -> bool:
    if not last_event_at or stage in SKIP_STAGES:
        return False
    cutoff = (datetime.now(timezone.utc) - timedelta(hours=stale_hours)).isoformat()
    return last_event_at < cutoff


def promote_stale_leads(conn: sqlite3.Connection, stale_hours: int | None = None) -> dict[str, Any]:
    hours = stale_hours if stale_hours is not None else ONBOARD_STALE_HOURS
    now = _now()
    promoted_ids: list[int] = []
    rows = conn.execute(
        """
        SELECT id, status, session_id, subject, payload, created_at
        FROM tickets
        WHERE session_id IS NOT NULL AND session_id != ''
        ORDER BY id DESC
        LIMIT 500
        """
    ).fetchall()
    for row in rows:
        payload = _parse_payload(row["payload"])
        crm_track = payload.get("crm_track") or "onboarding"
        if crm_track != "onboarding":
            continue
        if row["status"] not in LEAD_PROMOTE_STATUSES:
            continue
        sid = (row["session_id"] or payload.get("session_id") or "").strip()
        if not sid:
            continue
        meta = session_funnel_state(conn, sid)
        if not is_session_stale(meta.get("last_event_at"), meta.get("stage", ""), hours):
            continue
        payload["crm_track"] = "lead"
        payload["lead_detected_at"] = now
        payload["lead_reason"] = "stale_session"
        payload["lead_funnel_stage"] = meta.get("stage")
        payload["lead_last_event_at"] = meta.get("last_event_at")
        conn.execute(
            "UPDATE tickets SET payload = ? WHERE id = ?",
            (json.dumps(payload), int(row["id"])),
        )
        promoted_ids.append(int(row["id"]))
    if promoted_ids:
        conn.commit()
    return {
        "promoted": len(promoted_ids),
        "ticket_ids": promoted_ids,
        "stale_hours": hours,
        "ran_at": now,
    }


def lead_from_ticket(row: sqlite3.Row, conn: sqlite3.Connection | None = None) -> dict[str, Any]:
    payload = _parse_payload(row["payload"])
    sid = (row["session_id"] or payload.get("session_id") or "").strip()
    stage = payload.get("lead_funnel_stage")
    last_event = payload.get("lead_last_event_at")
    domain = payload.get("domain")
    if conn and sid and (not stage or not last_event):
        meta = session_funnel_state(conn, sid)
        stage = stage or meta.get("stage")
        last_event = last_event or meta.get("last_event_at")
        domain = domain or meta.get("domain")
    email = payload.get("account_email") or (payload.get("data") or {}).get("email")
    return {
        "ticket_id": int(row["id"]),
        "session_id": sid,
        "domain": domain,
        "email": email,
        "subject": row["subject"],
        "status": row["status"],
        "crm_track": payload.get("crm_track"),
        "lead_detected_at": payload.get("lead_detected_at"),
        "lead_reason": payload.get("lead_reason"),
        "funnel_stage": stage,
        "last_event_at": last_event,
        "created_at": row["created_at"],
        "assigned_to": row["assigned_to"] if "assigned_to" in row.keys() else None,
    }


def list_leads(conn: sqlite3.Connection, limit: int = 100) -> list[dict[str, Any]]:
    rows = conn.execute(
        """
        SELECT id, status, session_id, subject, payload, created_at, assigned_to
        FROM tickets
        ORDER BY id DESC
        LIMIT 500
        """
    ).fetchall()
    leads = []
    for row in rows:
        payload = _parse_payload(row["payload"])
        if payload.get("crm_track") != "lead":
            continue
        leads.append(lead_from_ticket(row, conn))
        if len(leads) >= limit:
            break
    leads.sort(key=lambda x: x.get("lead_detected_at") or "", reverse=True)
    return leads


def count_leads(conn: sqlite3.Connection) -> int:
    rows = conn.execute("SELECT payload FROM tickets").fetchall()
    return sum(1 for row in rows if _parse_payload(row["payload"]).get("crm_track") == "lead")