package budget

import (
	"context"
	"time"
)

// BudgetStorage is the persistence seam behind DBBudget: one budget row per
// user, with an atomic Add that rolls the 7-day window over transparently. Mort
// backs this with GORM/MySQL (the skill_budgets table); Memory() is the
// zero-dependency default; contrib/store adds a durable SQLite one.
type BudgetStorage interface {
	// Initialize runs any schema setup. Safe to call repeatedly.
	Initialize(ctx context.Context) error
	// Get returns the user's current budget row, or (nil, nil) if none exists.
	Get(ctx context.Context, userID string) (*SkillBudget, error)
	// Add increments seconds_used + runs_count atomically, rolling the window
	// over when WindowStart is older than 7 days (reset to now, fresh count).
	// Creates the row if absent.
	Add(ctx context.Context, userID string, secondsUsed float64, now time.Time) error
}

// SkillBudget is one user's rolling-window usage row.
type SkillBudget struct {
	UserID      string
	WindowStart time.Time
	SecondsUsed float64
	RunsCount   int
	UpdatedAt   time.Time
}

// budgetWindow is the rolling window length the storage rolls over at.
const budgetWindow = 7 * 24 * time.Hour