package domain

import "strings"

// ContentAccessTier controls whether learners need an active subscription to consume content.
// Effective tier cascades at read time: any PREMIUM ancestor makes descendants PREMIUM.
type ContentAccessTier string

const (
	ContentAccessFree    ContentAccessTier = "FREE"
	ContentAccessPremium ContentAccessTier = "PREMIUM"
)

// ContentAccessTierFromDB normalizes persisted values.
func ContentAccessTierFromDB(raw string) ContentAccessTier {
	switch strings.TrimSpace(strings.ToUpper(raw)) {
	case string(ContentAccessFree):
		return ContentAccessFree
	default:
		return ContentAccessPremium
	}
}

// ContentAccessTierFromCreateInput resolves create body: omit → premium; explicit value validated separately.
func ContentAccessTierFromCreateInput(raw *string) ContentAccessTier {
	if raw == nil || strings.TrimSpace(*raw) == "" {
		return ContentAccessPremium
	}
	return ContentAccessTierFromDB(*raw)
}

// EffectiveContentAccessTier returns PREMIUM when any tier in the chain is PREMIUM.
func EffectiveContentAccessTier(tiers ...ContentAccessTier) ContentAccessTier {
	for _, tier := range tiers {
		if tier == ContentAccessPremium {
			return ContentAccessPremium
		}
	}
	return ContentAccessFree
}

// RequiresSubscription is true when the effective tier needs an active plan.
func (t ContentAccessTier) RequiresSubscription() bool {
	return t == ContentAccessPremium
}