"""Unified monitors management surface (/monitors) — ping, DNS, HTTP.

Replaces the former /ping, /dns and /plugins/http pages. One list, one
type-aware add/edit form, one dashboard widget. A monitor may be linked to a
Host (host_id) or watch a free-standing custom destination (host_id = NULL).
"""
from __future__ import annotations
import uuid
from datetime import datetime, timezone

from quart import Blueprint, current_app, render_template, request, redirect, url_for

from steward.auth.middleware import require_role
from steward.core import renames
from steward.core.audit import audit_request
from steward.models.users import UserRole
from steward.models.monitors import Monitor, MonitorType, MONITOR_TYPE_VALUES
from steward.core.status import _heartbeat_title, streak_start
from steward.core.time_range import DEFAULT_RANGE
from steward.models.hosts import Host
from steward.monitors import service as monitor_svc

monitors_bp = Blueprint("monitors", __name__, url_prefix="/monitors")


def _form_opts(form, mtype: str) -> dict:
    """The submitted fields of `mtype`'s config, for monitor_svc.build_config.
    An unchecked checkbox is absent from the form, so it reads as False."""
    if mtype == MonitorType.tcp.value:
        return {"port": form.get("port")}
    if mtype == MonitorType.dns.value:
        return {"expected_ip": form.get("expected_ip")}
    if mtype == MonitorType.http.value:
        return {
            "method": form.get("method"),
            "expected_status": form.get("expected_status"),
            "content_match": form.get("content_match"),
            "headers": form.get("headers_json"),
            "timeout_seconds": form.get("timeout_seconds"),
            "follow_redirects": "follow_redirects" in form,
            "verify_ssl": "verify_ssl" in form,
        }
    return {}


@monitors_bp.get("/")
@require_role(UserRole.viewer)
async def index():
    poll_interval = current_app.config.get("MONITORS_POLL_INTERVAL", 60)
    return await render_template(
        "monitors/index.html",
        poll_interval=poll_interval,
        current_range=request.args.get("range", DEFAULT_RANGE),
    )


@monitors_bp.get("/rows")
@require_role(UserRole.viewer)
async def rows():
    async with current_app.db_sessionmaker() as db:
        data, counts, range_key = await monitor_svc.monitor_rows(
            db, request.args.get("range", DEFAULT_RANGE), current_app.config.get("THRESHOLDS", {}))
    return await render_template(
        "monitors/rows.html",
        monitor_data=data, counts=counts, range_key=range_key,
    )


@monitors_bp.post("/add")
@require_role(UserRole.operator)
async def add_monitor():
    form = await request.form
    mtype = form.get("type", "").strip()
    try:
        fields = monitor_svc.monitor_fields(
            mtype, target=form.get("target", ""), name=form.get("name", ""),
            check_interval_seconds=form.get("check_interval_seconds"),
            opts=_form_opts(form, mtype))
    except ValueError as exc:
        return await _new_form(form, mtype, str(exc)), 400

    host_id = form.get("host_id", "").strip() or None
    monitor = Monitor(id=str(uuid.uuid4()), host_id=host_id, enabled=True,
                      created_at=datetime.now(timezone.utc), **fields)
    async with current_app.db_sessionmaker() as db:
        async with db.begin():
            try:
                await monitor_svc.check_name_free(db, monitor.type, monitor.name)
            except ValueError as exc:
                return await _new_form(form, mtype, str(exc)), 400
            db.add(monitor)

    # A host-scoped add returns to that host's hub; otherwise the new monitor's page.
    if host_id:
        return redirect(url_for("hosts.host_detail", host_id=host_id))
    return redirect(url_for("monitors.detail", monitor_id=monitor.id))


async def _new_form(form, mtype: str, error: str | None = None) -> str:
    """The add form, holding what was typed when `error` sends it back."""
    values = {k: form.get(k, "") for k in ("name", "target", "host_id")}
    values["check_interval_seconds"] = form.get("check_interval_seconds", 0)
    return await render_template(
        "monitors/form.html", monitor=None, values=values,
        mtype=mtype if mtype in MONITOR_TYPE_VALUES else MonitorType.icmp.value,
        config=_form_opts(form, mtype) if error and mtype in MONITOR_TYPE_VALUES else {},
        types=list(MonitorType), error=error,
    )


@monitors_bp.get("/new")
@require_role(UserRole.operator)
async def new_form():
    return await _new_form({"host_id": request.args.get("host_id", "")}, MonitorType.icmp.value)


@monitors_bp.get("/<monitor_id>")
@require_role(UserRole.viewer)
async def detail(monitor_id: str):
    async with current_app.db_sessionmaker() as db:
        m = await db.get(Monitor, monitor_id)
        if not m:
            return redirect(url_for("monitors.index"))
        st = (await monitor_svc.monitor_states(db, [m]))[m.id]
        failures = await monitor_svc.recent_failures(db, m.id)
        host = await db.get(Host, m.host_id) if m.host_id else None
    thresholds = current_app.config.get("THRESHOLDS", {})
    latest = st["latest"]
    since, since_at_least = streak_start(st["recent"])
    if st["down_since"]:
        since, since_at_least = st["down_since"], False
    tls_days = None
    if latest and latest.tls_expires_at:
        tls_days = (latest.tls_expires_at - datetime.now(timezone.utc)).total_seconds() / 86400.0
    return await render_template(
        "monitors/detail.html", monitor=m, host=host, latest=latest, failures=failures,
        state=monitor_svc.row_state(m, latest, st["uptime"].get("24h"), thresholds),
        since=since, since_at_least=since_at_least, uptime=st["uptime"], tls_days=tls_days,
        heartbeat=[{"state": "up" if r.is_up else "down", "title": _heartbeat_title(m.type, r)}
                   for r in st["recent"]],
    )


@monitors_bp.get("/<monitor_id>/edit")
@require_role(UserRole.operator)
async def edit_form(monitor_id: str):
    async with current_app.db_sessionmaker() as db:
        m = await db.get(Monitor, monitor_id)
    if not m:
        return redirect(url_for("monitors.index"))
    return await render_template(
        "monitors/form.html", monitor=m, values=None, mtype=m.type, config=m.config,
        types=list(MonitorType), error=None,
    )


@monitors_bp.post("/<monitor_id>/edit")
@require_role(UserRole.operator)
async def edit_monitor(monitor_id: str):
    form = await request.form
    async with current_app.db_sessionmaker() as db:
        async with db.begin():
            m = await db.get(Monitor, monitor_id)
            if not m:
                return redirect(url_for("monitors.index"))
            # Type is immutable on edit (changes the meaning of config/target);
            # to switch type, delete and re-add.
            try:
                fields = monitor_svc.monitor_fields(
                    m.type, target=form.get("target", m.target), name=form.get("name", ""),
                    check_interval_seconds=form.get("check_interval_seconds"),
                    opts=_form_opts(form, m.type))
                if fields["name"] != m.name:
                    await monitor_svc.check_name_free(db, m.type, fields["name"], exclude_id=m.id)
            except ValueError as exc:
                return str(exc), 400
            old_name = m.name
            for k, v in fields.items():
                setattr(m, k, v)
            # Its rules, windows and history go by (type, name): move them with it.
            moved = await renames.carry_rename(db, ((m.type, None),), old_name, m.name)
    if moved:
        await audit_request("monitor.updated", "monitor", m.name,
                            {"monitor_id": m.id, "renamed_from": old_name, "carried": moved})
    return redirect(url_for("monitors.detail", monitor_id=m.id))


@monitors_bp.post("/<monitor_id>/toggle")
@require_role(UserRole.operator)
async def toggle_monitor(monitor_id: str):
    async with current_app.db_sessionmaker() as db:
        async with db.begin():
            m = await db.get(Monitor, monitor_id)
            if m:
                m.enabled = not m.enabled
    return redirect(request.referrer or url_for("monitors.index"))


@monitors_bp.post("/<monitor_id>/delete")
@require_role(UserRole.operator)
async def delete_monitor(monitor_id: str):
    async with current_app.db_sessionmaker() as db:
        async with db.begin():
            m = await db.get(Monitor, monitor_id)
            if m:
                await db.delete(m)
    referrer = request.referrer or ""
    if f"/monitors/{monitor_id}" in referrer:
        return redirect(url_for("monitors.index"))
    return redirect(referrer or url_for("monitors.index"))


@monitors_bp.get("/widget")
@require_role(UserRole.viewer)
async def widget():
    type_filter = request.args.get("type_filter", "all")
    show_down_only = request.args.get("show_down_only", "no") == "yes"
    limit = max(1, min(50, int(request.args.get("limit", 10) or 10)))
    widget_id = request.args.get("wid", "0")

    async with current_app.db_sessionmaker() as db:
        data, counts, _ = await monitor_svc.monitor_rows(
            db, DEFAULT_RANGE, current_app.config.get("THRESHOLDS", {}))
    up, down, pending = counts["up"], counts["down"], counts["pending"]
    if type_filter in MONITOR_TYPE_VALUES:
        data = [d for d in data if d["monitor"].type == type_filter]
    if show_down_only:
        data = [d for d in data if not (d["latest"] and d["latest"].is_up)]

    return await render_template(
        "monitors/widget.html",
        monitor_data=data[:limit], up=up, down=down, pending=pending,
        show_down_only=show_down_only, widget_id=widget_id,
    )