// refusalWatch turns D1's refusal records (release.Refusal, written by the
// root pass) into one alert each and a status row each. It runs on the
// agent's metrics tick. A record older than refusalAlertWindow when first
// seen is not alerted, so an agent restart does not re-send old news.
package host

import (
	"context"
	"log"
	"sync/atomic"
	"time"

	"github.com/carlosframework/platform/internal/release"
	"github.com/carlosframework/platform/internal/status"
)

const refusalAlertWindow = 30 * time.Minute

type refusalWatch struct{ seen map[string]time.Time }

func (w *refusalWatch) tick(ctx context.Context, bakeDir string, sinks *alertSinks, now time.Time) []status.ReleaseRefusal {
	if w.seen == nil {
		w.seen = map[string]time.Time{}
	}
	recs, err := release.ListRefusals(bakeDir)
	if err != nil {
		log.Printf("agent: refusals: %v", err)
		return nil
	}
	// A move's held-stage refusals (D3-held) live in their own namespace
	// (final review finding 3) and are surfaced as they were when they
	// shared adoption's: a row and an alert each, seen under their own key.
	held, err := release.ListHeldRefusals(bakeDir)
	if err != nil {
		log.Printf("agent: held refusals: %v", err)
	}
	var rows []status.ReleaseRefusal
	for i, r := range append(recs, held...) {
		row := status.ReleaseRefusal{Host: r.Host, Version: r.Version, Reason: r.Reason, RefusedAt: r.RefusedAt, Kind: r.Kind}
		if !r.Recovered {
			row.RecoveryError = recoveryError(r)
		}
		rows = append(rows, row)
		key := r.Host
		if i >= len(recs) {
			key = "held/" + r.Host
		}
		if last, ok := w.seen[key]; ok && !r.RefusedAt.After(last) {
			continue
		}
		w.seen[key] = r.RefusedAt
		if now.Sub(r.RefusedAt) <= refusalAlertWindow {
			sinks.deliverRelease(ctx, r)
		}
	}
	return rows
}

// releaseRefusals is the metrics loop's latest answer, read by the status
// loop's probe. They are separate goroutines, so this is the seam between
// them (the same shape as processAlertCounters). Nil until the first tick.
var releaseRefusals atomic.Pointer[[]status.ReleaseRefusal]

// releaseRefusalProbe feeds status.Probes.ReleaseRefusals.
func releaseRefusalProbe() []status.ReleaseRefusal {
	if p := releaseRefusals.Load(); p != nil {
		return append([]status.ReleaseRefusal(nil), (*p)...)
	}
	return nil
}