package observability

import (
	"context"
	"errors"
	"time"
)

// BusinessSnapshot 是存储层返回的固定基数业务快照。
// Map 的键只由存储层固定状态集合产生，Registry 仍只向目录中的标签写值。
type BusinessSnapshot struct {
	// TaskStates Pulse 任务状态的有界计数。
	TaskStates map[string]uint64
	// TaskOldestAgeSeconds 未完成任务中最早可处理记录的年龄。
	TaskOldestAgeSeconds float64
	// DeliveryStates 结果交付状态的有界计数。
	DeliveryStates map[string]uint64
	// DeliveryOldestAgeSeconds 待处理交付中最早可处理记录的年龄。
	DeliveryOldestAgeSeconds float64
	// WorkflowStates Weave 实例状态的有界计数。
	WorkflowStates map[string]uint64
	// WorkflowOldestAgeSeconds 未终结流程中最早更新时间的年龄。
	WorkflowOldestAgeSeconds float64
	// Truncated 是否至少有一类状态达到采样上限。
	Truncated bool
	// RecentEvents 固定事件类别在最近窗口内的有界数量。
	RecentEvents map[string]uint64
}

// RecordBusinessSnapshot records one bounded database sample. A failed sample
// does not overwrite the last successful state, so stale data remains visible
// together with an error counter and alertable last-success timestamp.
func (r *Registry) RecordBusinessSnapshot(snapshot BusinessSnapshot, started time.Time, err error) {
	if r == nil {
		return
	}
	outcome := "success"
	if err != nil {
		outcome = "error"
		if errors.Is(err, context.DeadlineExceeded) {
			outcome = "timeout"
		}
	}
	r.AddCounter("orbit_business_snapshot_total", 1, Labels{"outcome": outcome})
	r.ObserveHistogram("orbit_business_snapshot_duration_seconds", time.Since(started).Seconds(), nil)
	if err != nil {
		return
	}
	for _, state := range taskStates {
		r.SetGauge("orbit_pulse_tasks_state", float64(snapshot.TaskStates[state]), Labels{"state": state})
	}
	for _, state := range deliveryStates {
		r.SetGauge("orbit_result_deliveries_state", float64(snapshot.DeliveryStates[state]), Labels{"state": state})
	}
	for _, state := range workflowStates {
		r.SetGauge("orbit_weave_workflows_state", float64(snapshot.WorkflowStates[state]), Labels{"state": state})
	}
	for _, eventType := range eventTypes {
		r.SetGauge("orbit_business_events_recent", float64(snapshot.RecentEvents[eventType]), Labels{"event": eventType})
	}
	r.SetGauge("orbit_pulse_tasks_oldest_age_seconds", snapshot.TaskOldestAgeSeconds, nil)
	r.SetGauge("orbit_result_delivery_oldest_age_seconds", snapshot.DeliveryOldestAgeSeconds, nil)
	r.SetGauge("orbit_weave_workflow_oldest_age_seconds", snapshot.WorkflowOldestAgeSeconds, nil)
	truncated := 0.0
	if snapshot.Truncated {
		truncated = 1
	}
	r.SetGauge("orbit_business_snapshot_truncated", truncated, nil)
	r.SetGauge("orbit_business_snapshot_last_success_timestamp_seconds", float64(time.Now().Unix()), nil)
}