package billing

import (
	"context"
	"errors"
	"time"

	"aigw/internal/domain"
)

var (
	ErrInsufficientBalance = errors.New("insufficient balance")
	ErrStripeDisabled      = errors.New("Stripe top-ups are disabled")
	ErrInvalidAmount       = errors.New("invalid amount")
	ErrQuotaExceeded       = errors.New("monthly spend quota exceeded")
)

type Meter interface {
	Authorize(context.Context, Authorization) error
	Settle(context.Context, domain.UsageEvent) error
}

type Authorization struct {
	RequestID string
	Principal domain.Principal
	Model     domain.Model
	Body      []byte
	Policy    domain.LimitPolicy
}

type Options struct {
	DatabaseURL            string
	Currency               string
	DefaultMaxOutputTokens int64
	MinTopUpMinor          int64
	MaxTopUpMinor          int64
	StripeEnabled          bool
	StripeAPIKey           string
	StripeWebhookSecret    string
	StripeSuccessURL       string
	StripeCancelURL        string
}

type Account struct {
	TenantID        string    `json:"tenant_id"`
	TenantName      string    `json:"tenant_name"`
	Currency        string    `json:"currency"`
	BalanceMicros   int64     `json:"balance_micros"`
	ReservedMicros  int64     `json:"reserved_micros"`
	AvailableMicros int64     `json:"available_micros"`
	UpdatedAt       time.Time `json:"updated_at"`
}

type LedgerEntry struct {
	ID                 string    `json:"id"`
	TenantID           string    `json:"tenant_id"`
	ProjectID          string    `json:"project_id,omitempty"`
	Currency           string    `json:"currency"`
	AmountMicros       int64     `json:"amount_micros"`
	BalanceAfterMicros int64     `json:"balance_after_micros"`
	Kind               string    `json:"kind"`
	SourceType         string    `json:"source_type"`
	SourceID           string    `json:"source_id"`
	Description        string    `json:"description"`
	CreatedAt          time.Time `json:"created_at"`
}

type AdjustmentInput struct {
	TenantID     string `json:"tenant_id"`
	AmountMicros int64  `json:"amount_micros"`
	Description  string `json:"description"`
}

type CheckoutInput struct {
	TenantID    string `json:"tenant_id"`
	AmountMinor int64  `json:"amount_minor"`
}

type CheckoutResult struct {
	OrderID   string `json:"order_id"`
	SessionID string `json:"session_id"`
	URL       string `json:"url"`
}