package billing

// Config holds appview billing/Stripe configuration.
// Parsed from the appview config YAML's billing section.
type Config struct {
	// Stripe secret key (sk_test_... or sk_live_...).
	// Can also be set via STRIPE_SECRET_KEY env var (takes precedence over config).
	// Billing is enabled automatically when this key is set (requires -tags billing build).
	StripeSecretKey string `yaml:"stripe_secret_key" comment:"Stripe secret key. Can also be set via STRIPE_SECRET_KEY env var (takes precedence). Billing is enabled automatically when set."`

	// Stripe webhook signing secret (whsec_...).
	// Can also be set via STRIPE_WEBHOOK_SECRET env var (takes precedence over config).
	WebhookSecret string `yaml:"webhook_secret" comment:"Stripe webhook signing secret. Can also be set via STRIPE_WEBHOOK_SECRET env var (takes precedence)."`

	// Currency code for Stripe checkout (e.g. "usd").
	Currency string `yaml:"currency" comment:"ISO 4217 currency code (e.g. \"usd\")."`

	// URL to redirect after successful checkout. {base_url} is replaced at runtime.
	SuccessURL string `yaml:"success_url" comment:"Redirect URL after successful checkout. Use {base_url} placeholder."`

	// URL to redirect after cancelled checkout. {base_url} is replaced at runtime.
	CancelURL string `yaml:"cancel_url" comment:"Redirect URL after cancelled checkout. Use {base_url} placeholder."`

	// Subscription tiers with Stripe price IDs.
	Tiers []BillingTierConfig `yaml:"tiers" comment:"Subscription tiers ordered by rank (lowest to highest)."`
}

// BillingTierConfig represents a single tier with optional Stripe pricing.
type BillingTierConfig struct {
	// Tier name (matches hold quota tier names for rank mapping).
	Name string `yaml:"name" comment:"Tier name. Position in list determines rank (0-based)."`

	// Short description shown on the plan card.
	Description string `yaml:"description,omitempty" comment:"Short description shown on the plan card."`

	// List of features included in this tier (rendered as bullet points).
	Features []string `yaml:"features,omitempty" comment:"List of features included in this tier."`

	// Stripe price ID for monthly billing. Empty = free tier.
	StripePriceMonthly string `yaml:"stripe_price_monthly,omitempty" comment:"Stripe price ID for monthly billing. Empty = free tier."`

	// Stripe price ID for yearly billing.
	StripePriceYearly string `yaml:"stripe_price_yearly,omitempty" comment:"Stripe price ID for yearly billing."`

	// Stripe product ID backing this tier. Entitlements resolve on this, not
	// on the price IDs above, so a price change does not strand subscribers.
	StripeProduct string `yaml:"stripe_product,omitempty" comment:"Stripe product ID for this tier. Entitlements resolve on this, so changing a price does not remove features from existing subscribers. Falls back to the price IDs when empty."`

	// Maximum number of webhooks for this tier (-1 = unlimited).
	MaxWebhooks int `yaml:"max_webhooks" comment:"Maximum webhooks for this tier (-1 = unlimited)."`

	// Whether all webhook trigger types are available (not just first-scan).
	WebhookAllTriggers bool `yaml:"webhook_all_triggers" comment:"Allow all webhook trigger types (not just first-scan)."`

	// Whether AI Image Advisor is available for this tier.
	AIAdvisor bool `yaml:"ai_advisor" comment:"Enable AI Image Advisor for this tier."`

	// Whether this tier earns a supporter badge on user profiles.
	SupporterBadge bool `yaml:"supporter_badge" comment:"Show supporter badge on user profiles for subscribers at this tier."`
}

// GetTierByProductID finds the tier backed by the given Stripe product ID.
// Returns the tier name and rank, or empty string and -1 if not found.
//
// Product rather than price is the durable key for an entitlement. Stripe
// prices are immutable, so changing what a tier costs means creating a new
// price under the same product, and existing subscribers keep billing on the
// old one indefinitely — Stripe never migrates them. Resolving entitlements by
// price ID therefore un-tiers precisely the subscribers a price change is
// meant to leave alone. Resolving by product grandfathers them for free.
//
// Prices stay the key in the other direction: checkout has to name a specific
// price to charge.
func (c *Config) GetTierByProductID(productID string) (string, int) {
	if c == nil || productID == "" {
		return "", -1
	}
	for i, tier := range c.Tiers {
		if tier.StripeProduct == productID {
			return tier.Name, i
		}
	}
	return "", -1
}

// GetTierByPriceID finds the tier that contains the given Stripe price ID.
// Returns the tier name and rank, or empty string and -1 if not found.
//
// Kept as the fallback for tiers with no stripe_product configured, so an
// existing config keeps resolving unchanged.
func (c *Config) GetTierByPriceID(priceID string) (string, int) {
	if c == nil || priceID == "" {
		return "", -1
	}
	for i, tier := range c.Tiers {
		if tier.StripePriceMonthly == priceID || tier.StripePriceYearly == priceID {
			return tier.Name, i
		}
	}
	return "", -1
}

// TierRank returns the 0-based rank of a tier by name, or -1 if not found.
func (c *Config) TierRank(name string) int {
	if c == nil {
		return -1
	}
	for i, tier := range c.Tiers {
		if tier.Name == name {
			return i
		}
	}
	return -1
}