package app

import (
	"os"
	"strings"
	"time"
)

func defaultDNSAttemptPolicy(dnsCount int) dnsAttemptPolicy {
	tryLimit := envInt("RESOLVE_DNS_TRY_LIMIT", 2)
	if tryLimit < 1 {
		tryLimit = 1
	}
	if dnsCount > 0 && tryLimit > dnsCount {
		tryLimit = dnsCount
	}
	budgetMS := envInt("RESOLVE_DNS_DOMAIN_BUDGET_MS", 1200)
	if budgetMS < 200 {
		budgetMS = 200
	}
	if budgetMS > 15000 {
		budgetMS = 15000
	}
	return dnsAttemptPolicy{
		TryLimit:     tryLimit,
		DomainBudget: time.Duration(budgetMS) * time.Millisecond,
		StopOnNX:     resolveNXEarlyStopEnabled(),
	}
}

func directDNSAttemptPolicy(dnsCount int) dnsAttemptPolicy {
	tryLimit := envInt("RESOLVE_DIRECT_TRY_LIMIT", 2)
	if tryLimit < 1 {
		tryLimit = 1
	}
	if tryLimit > 3 {
		tryLimit = 3
	}
	if dnsCount > 0 && tryLimit > dnsCount {
		tryLimit = dnsCount
	}
	budgetMS := envInt("RESOLVE_DIRECT_BUDGET_MS", 1200)
	if budgetMS < 200 {
		budgetMS = 200
	}
	if budgetMS > 15000 {
		budgetMS = 15000
	}
	return dnsAttemptPolicy{
		TryLimit:     tryLimit,
		DomainBudget: time.Duration(budgetMS) * time.Millisecond,
		StopOnNX:     resolveNXEarlyStopEnabled(),
	}
}

func wildcardDNSAttemptPolicy(dnsCount int) dnsAttemptPolicy {
	tryLimit := envInt("RESOLVE_WILDCARD_TRY_LIMIT", 1)
	if tryLimit < 1 {
		tryLimit = 1
	}
	if tryLimit > 2 {
		tryLimit = 2
	}
	if dnsCount > 0 && tryLimit > dnsCount {
		tryLimit = dnsCount
	}
	budgetMS := envInt("RESOLVE_WILDCARD_BUDGET_MS", 1200)
	if budgetMS < 200 {
		budgetMS = 200
	}
	if budgetMS > 15000 {
		budgetMS = 15000
	}
	return dnsAttemptPolicy{
		TryLimit:     tryLimit,
		DomainBudget: time.Duration(budgetMS) * time.Millisecond,
		StopOnNX:     resolveNXEarlyStopEnabled(),
	}
}

func resolveNXEarlyStopEnabled() bool {
	switch strings.ToLower(strings.TrimSpace(os.Getenv("RESOLVE_NX_EARLY_STOP"))) {
	case "0", "false", "no", "off":
		return false
	default:
		return true
	}
}

func resolveNXHardQuarantineEnabled() bool {
	switch strings.ToLower(strings.TrimSpace(os.Getenv("RESOLVE_NX_HARD_QUARANTINE"))) {
	case "1", "true", "yes", "on":
		return true
	default:
		return false
	}
}