package domain

import (
	"time"

	"git.cin.su/m/Assistant/contracts/work"
)

type RunLivenessState string

const (
	RunLivenessLive    RunLivenessState = "LIVE"
	RunLivenessStale   RunLivenessState = "STALE"
	RunLivenessInvalid RunLivenessState = "INVALID"
	RunLivenessNotRun  RunLivenessState = "NOT_RUNNING"
)

type RunLiveness struct {
	State      RunLivenessState
	Age        time.Duration
	ObservedAt time.Time
}

func AssessRunLiveness(run work.AgentRun, observedAt time.Time, heartbeatTimeout time.Duration) RunLiveness {
	result := RunLiveness{ObservedAt: observedAt}
	if observedAt.IsZero() || heartbeatTimeout <= 0 || run.UpdatedAtUnixMillis < 1 {
		result.State = RunLivenessInvalid
		return result
	}
	if run.State != work.AgentRunStarted && run.State != work.AgentRunRunning {
		result.State = RunLivenessNotRun
		return result
	}
	updated := time.UnixMilli(run.UpdatedAtUnixMillis)
	result.Age = observedAt.Sub(updated)
	if result.Age < 0 {
		result.State = RunLivenessInvalid
		return result
	}
	result.State = RunLivenessLive
	if result.Age > heartbeatTimeout {
		result.State = RunLivenessStale
	}
	return result
}