package checker

import (
	"context"
	"fmt"
	"strings"

	sdk "git.happydns.org/checker-sdk-go/checker"
)

// Port 0 is valid on the wire but no client can connect to it; null targets are exempt since their port is irrelevant.

type rulePortValid struct{}

func RulePortValid() sdk.CheckRule { return &rulePortValid{} }
func (rulePortValid) Name() string { return "srv_port_valid" }
func (rulePortValid) Description() string {
	return "SRV records advertise a non-zero port that clients can actually connect to."
}
func (rulePortValid) Evaluate(ctx context.Context, obs sdk.ObservationGetter, _ sdk.CheckerOptions) []sdk.CheckState {
	d, cs := getData(ctx, obs)
	if cs != nil {
		return []sdk.CheckState{*cs}
	}
	var bad []string
	var checked int
	for _, r := range d.Records {
		if r.IsNullTarget {
			continue
		}
		checked++
		if r.Port == 0 {
			bad = append(bad, fmt.Sprintf("%s (port %d)", r.Owner, r.Port))
		}
	}
	if checked == 0 {
		return []sdk.CheckState{{Status: sdk.StatusInfo, Code: "srv_port_na",
			Message: "No active SRV targets to check ports on."}}
	}
	if len(bad) == 0 {
		return []sdk.CheckState{{Status: sdk.StatusOK, Code: "srv_port_ok",
			Message: fmt.Sprintf("All %d SRV record(s) advertise a non-zero port.", checked)}}
	}
	return []sdk.CheckState{{Status: sdk.StatusCrit, Code: "srv_port_zero",
		Message: fmt.Sprintf("SRV record(s) advertise port 0: %s", strings.Join(bad, ", "))}}
}