forecast

type BurnPoint struct {
	Date      time.Time
	Remaining int
}

type Forecast struct {
	Goal        string
	GeneratedAt time.Time

	// Task counts
	TotalTasks      int
	DoneTasks       int
	SkippedTasks    int
	FailedTasks     int
	PendingTasks    int
	BlockedTasks    int
	InProgressTasks int

	// Velocity metrics (time-based: tasks/day)
	BaseVelocityPerDay float64 // tasks/day (baseline)
	AvgTaskDuration    time.Duration
	ProjectStartDate   time.Time

	// Velocity metrics (minute-based: actual vs estimated)
	VelocityRatio       float64 // sum(actual_minutes)/sum(estimated_minutes); 1.0 if no data
	AvgEstimatedMinutes float64 // average EstimatedMinutes across all tasks with estimates
	MinuteDataPoints    int     // number of tasks with both estimated and actual minutes

	// Scenarios
	Optimistic  Scenario
	Expected    Scenario
	Pessimistic Scenario

	// Historical burn-down data (one point per completed task, chronological)
	BurnPoints []BurnPoint

	// Per-task schedule projections for remaining work
	TaskWindows []TaskWindow

	// AI-generated narrative
	AIText string
}

type Scenario struct {
	Label          string
	VelocityFactor float64 // multiplier applied to baseline velocity
	DaysRemaining  float64 // -1 = cannot compute
	CompletionDate time.Time
	Confidence     string // "high" | "medium" | "low"
}

type TaskWindow struct {
	TaskID           int       `json:"task_id"`
	Title            string    `json:"title"`
	Status           string    `json:"status"`
	Priority         int       `json:"priority"`
	EstimatedMinutes int       `json:"estimated_minutes"`
	AdjustedMinutes  int       `json:"adjusted_minutes"` // estimated * VelocityRatio
	ProjectedStart   time.Time `json:"projected_start"`
	ProjectedEnd     time.Time `json:"projected_end"`
}