import logging
from datetime import timedelta

from odoo import api, fields, models

try:
    import requests
except ImportError:
    requests = None

_logger = logging.getLogger(__name__)

HTTP_CHECK_TIMEOUT = 20  # seconds
HTTP_KO_CONFIRMATION_DELAY = timedelta(minutes=10)


class ServiceInstance(models.Model):
    _inherit = "service.instance"

    last_http_status_code = fields.Integer(
        string="Last HTTP Status Code",
        readonly=True,
        default=0,
    )
    last_http_check_date = fields.Datetime(
        string="Last HTTP Check Date",
        readonly=True,
    )
    http_status_ok = fields.Boolean(
        string="HTTP Status OK",
        readonly=True,
        default=True,
    )
    http_maintenance_request = fields.Many2one(
        "maintenance.request",
        string="HTTP Maintenance Request",
        readonly=True,
    )
    http_first_ko_at = fields.Datetime(
        string="First HTTP KO Check (current streak)",
        readonly=True,
    )

    def check_http_status(self):
        """
        Perform HTTP check for each record and return the KO recordset.

        Writes last_http_status_code, last_http_check_date and http_status_ok on every
        checked record. Does NOT create maintenance.request — the cron only opens one
        once the service has been continuously KO for at least
        HTTP_KO_CONFIRMATION_DELAY, to avoid flagging transient outages (e.g. a short
        server overload) as real incidents.
        """
        ko_records = self.browse()
        for rec in self:
            if not rec.service_url or not rec.equipment_id:
                continue
            if rec.equipment_id.maintenance_mode:
                continue
            status_ok = False
            status_code = -1
            now = fields.Datetime.now()
            url = rec.service_url
            if not url.lower().startswith("https://"):
                url = "https://" + url.removeprefix("http://").removeprefix("HTTP://")
            try:
                response = requests.get(url, timeout=HTTP_CHECK_TIMEOUT)
                status_code = response.status_code
                status_ok = status_code == 200
            except requests.exceptions.RequestException as e:
                _logger.warning("HTTP check failed for %s: %s", rec.service_url, e)
            rec.write(
                {
                    "last_http_status_code": status_code,
                    "last_http_check_date": now,
                    "http_status_ok": status_ok,
                }
            )
            if not status_ok:
                ko_records |= rec
        return ko_records

    def _close_http_maintenance_request(self):
        """
        Close the open maintenance.request for each recovered service.

        Moves the request to the first done stage, posts a chatter note as OdooBot, and
        clears http_maintenance_request on the service instance.
        """
        done_stage = self.env["maintenance.stage"].search(
            [("done", "=", True)], limit=1
        )
        if not done_stage:
            return
        odoobot = self.env.ref("base.partner_root")
        for rec in self:
            request = rec.http_maintenance_request
            if not request or request.stage_id.done:
                continue
            request.sudo().write({"stage_id": done_stage.id})
            request.sudo().message_post(
                body=(
                    f"Service {rec.service_url} is back online. "
                    "This request has been automatically closed by the monitoring cron."
                ),
                author_id=odoobot.id,
                message_type="comment",
                subtype_xmlid="mail.mt_note",
            )
            rec.http_maintenance_request = False

    @api.model
    def cron_check_http_services(self):
        """
        Check all active services with a URL.

        A service must be continuously KO for at least HTTP_KO_CONFIRMATION_DELAY
        before a maintenance.request is created — this tolerates transient outages
        (e.g. a temporary server overload) regardless of how often this cron runs.
        Services that had an open request and are now OK are auto-resolved.
        """
        now = fields.Datetime.now()
        domain = [
            ("active", "=", True),
            ("service_url", "!=", False),
            ("equipment_id", "!=", False),
        ]
        services = self.search(domain).filtered(
            lambda s: not s.equipment_id.maintenance_mode
        )

        # Snapshot services that currently have an open request before the check
        services_with_open_request = services.filtered(
            lambda s: s.http_maintenance_request
            and not s.http_maintenance_request.stage_id.done
        )

        ko_services = services.check_http_status()

        # Auto-resolve services that recovered
        recovered = services_with_open_request.filtered(lambda s: s.http_status_ok)
        if recovered:
            recovered._close_http_maintenance_request()

        ok_services = services - ko_services
        if ok_services:
            ok_services.write({"http_first_ko_at": False})

        new_ko = ko_services.filtered(lambda s: not s.http_first_ko_at)
        if new_ko:
            new_ko.write({"http_first_ko_at": now})

        confirmed_ko = ko_services.filtered(
            lambda s: now - s.http_first_ko_at >= HTTP_KO_CONFIRMATION_DELAY
        )
        for service in confirmed_ko:
            service.equipment_id.create_http_maintenance_request(service)