package web

import (
	"context"
	"sort"
	"strings"
	"sync"
	"time"
)

// R-546 — is the box READY to run the escrow ceremony?
//
// Measured 2026-09-16/17 (chaos night Phase 0): after a fresh bind the box has no PBS storage for ~17
// minutes. The agent's preflight is red, the ceremony refuses, and the R-543 reminder bar (v0.245.0)
// was on every page urging the household into it. The escrow page itself already hid its start form
// behind a red checklist — but it said nothing about WAITING, and a direct POST /api/escrow/start
// (the path chaos night used) ran the ceremony and returned the agent's raw "-storage" stderr.
//
// THE DEFINITION IS THE AGENT'S OWN `ok`: every blocking preflight item (pbs_storage_id, dr_tier,
// age_binary, hub_upload, sudo_grant; staged_secret is informational). Not a controller-side copy of
// one of those items — the escrow.pbs_storage_id reading of R-546 was the SYMPTOM that box showed, and
// a copy of one item is a second definition that drifts when the agent grows a sixth.
//
// Three answers, and UNKNOWN keeps today's behaviour (the bar shows): an unreachable agent must not
// silence a reminder that R-543 made loud on purpose.
//
// Cost: the bar hangs off every page render, so the answer is cached for escrowReadyTTL, and a probe
// is only ever made while the box is paused (escrowPaused gates it) — a finished box never asks.

const (
	escrowReadyTTL     = 60 * time.Second
	escrowReadyTimeout = 3 * time.Second
)

type escrowReadinessCache struct {
	mu        sync.Mutex
	ready     bool
	known     bool
	checkedAt time.Time
	lastState string // for transition-only INFO logging
}

// escrowReadiness returns (ready, known). fresh=true skips the cache (the escrow page and the start
// API, where one request justifies one probe); fresh=false is the bar's cached read.
func (s *Server) escrowReadiness(ctx context.Context, fresh bool) (ready, known bool) {
	c := &s.escrowReady
	c.mu.Lock()
	defer c.mu.Unlock()
	if !fresh && !c.checkedAt.IsZero() && time.Since(c.checkedAt) < escrowReadyTTL {
		return c.ready, c.known
	}
	pctx, cancel := context.WithTimeout(ctx, escrowReadyTimeout)
	defer cancel()
	ready, known, why := s.probeEscrowReadiness(pctx)
	c.ready, c.known, c.checkedAt = ready, known, time.Now()

	state := "unknown"
	if known && ready {
		state = "ready"
	} else if known {
		state = "not-ready"
	}
	if state != c.lastState {
		switch state {
		case "ready":
			s.logger.Printf("[INFO] [web] escrow readiness: READY (agent preflight ok) — the recovery-code reminder is shown")
		case "not-ready":
			s.logger.Printf("[INFO] [web] escrow readiness: NOT READY (%s) — reminder held back; the escrow page says the box is still preparing", why)
		default:
			s.logger.Printf("[INFO] [web] escrow readiness: UNKNOWN (%s) — reminder shown (fail loud)", why)
		}
		c.lastState = state
	} else if s.isDebug() {
		s.logger.Printf("[DEBUG] [web] escrow readiness: %s (%s)", state, why)
	}
	return ready, known
}

// probeEscrowReadiness asks the agent. Never an error to the caller: failure is "unknown".
func (s *Server) probeEscrowReadiness(ctx context.Context) (ready, known bool, why string) {
	agent, err := s.escrowAgentConn()
	if err != nil {
		return false, false, "agent unavailable: " + err.Error()
	}
	pf, err := agent.EscrowPreflight(ctx)
	if err != nil {
		return false, false, "preflight failed: " + err.Error()
	}
	if pf.OK {
		return true, true, "preflight ok"
	}
	var failing []string
	for _, it := range pf.Items {
		if !it.OK && it.ID != "staged_secret" {
			failing = append(failing, it.ID)
		}
	}
	sort.Strings(failing)
	return false, true, "failing: " + strings.Join(failing, ", ")
}

// escrowNotReadyMessage is the one Hungarian sentence for "wait" — the page card and the API refusal
// say the same thing.
const escrowNotReadyMessage = "A doboz még készül — a távoli mentés kulcsát pár perc múlva tudod létrehozni. Ez az oldal magától frissül."