package checker

import (
	"encoding/json"
	"fmt"
	"time"

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

// Implements sdk.CheckerMetricsReporter.
func (p *authoritativeConsistencyProvider) ExtractMetrics(ctx sdk.ReportContext, collectedAt time.Time) ([]sdk.CheckMetric, error) {
	var data ObservationData
	if err := json.Unmarshal(ctx.Data(), &data); err != nil {
		return nil, fmt.Errorf("checker: decoding observation: %w", err)
	}

	var out []sdk.CheckMetric

	for name, r := range data.Results {
		labels := map[string]string{"zone": data.Zone, "ns": name}

		up := float64(0)
		if r.UDPReachable && r.Authoritative {
			up = 1
		}
		out = append(out, sdk.CheckMetric{
			Name:      "authoritative_consistency_ns_up",
			Value:     up,
			Labels:    labels,
			Timestamp: collectedAt,
		})

		tcp := float64(0)
		if r.TCPReachable {
			tcp = 1
		}
		out = append(out, sdk.CheckMetric{
			Name:      "authoritative_consistency_ns_tcp",
			Value:     tcp,
			Labels:    labels,
			Timestamp: collectedAt,
		})

		if r.LatencyMs > 0 {
			out = append(out, sdk.CheckMetric{
				Name:      "authoritative_consistency_ns_latency_ms",
				Value:     float64(r.LatencyMs),
				Unit:      "ms",
				Labels:    labels,
				Timestamp: collectedAt,
			})
		}

		if r.Serial > 0 {
			out = append(out, sdk.CheckMetric{
				Name:      "authoritative_consistency_ns_serial",
				Value:     float64(r.Serial),
				Labels:    labels,
				Timestamp: collectedAt,
			})
		}
	}

	uniqueSerials := map[uint32]struct{}{}
	for _, r := range data.Results {
		if r.Serial != 0 {
			uniqueSerials[r.Serial] = struct{}{}
		}
	}
	out = append(out, sdk.CheckMetric{
		Name:      "authoritative_consistency_unique_serials",
		Value:     float64(len(uniqueSerials)),
		Labels:    map[string]string{"zone": data.Zone},
		Timestamp: collectedAt,
	})

	// Severity counters: skipped entirely when the host doesn't provide
	// states (metrics-only render path), rather than re-deriving from data.
	states := ctx.States()
	if states != nil {
		var crit, warn, info int
		for _, st := range states {
			switch st.Status {
			case sdk.StatusCrit:
				crit++
			case sdk.StatusWarn:
				warn++
			case sdk.StatusInfo:
				info++
			}
		}
		for _, x := range []struct {
			name string
			val  int
		}{
			{"authoritative_consistency_findings_critical", crit},
			{"authoritative_consistency_findings_warning", warn},
			{"authoritative_consistency_findings_info", info},
		} {
			out = append(out, sdk.CheckMetric{
				Name:      x.name,
				Value:     float64(x.val),
				Labels:    map[string]string{"zone": data.Zone},
				Timestamp: collectedAt,
			})
		}
	}

	return out, nil
}