policy

type Environment interface {
	// DebugLog appends a line to the triage text log.
	DebugLog(format string, args ...any)
}

type Func func(Environment, In) Out

type In struct {
	// Now is the time when the policy function was called.
	Now time.Time
	// ActiveInvocations is a set of currently running invocations of the job.
	ActiveInvocations []int64
	// Triggers is a list of pending triggers sorted by time, more recent last.
	Triggers []*internal.Trigger
}

type Out struct {
	// Requests is a list of requests to start new invocations (if any).
	//
	// Each request contains parameters that will be passed to a new invocation by
	// the engine. The policy is responsible for filling them in.
	//
	// Triggers specified in the each request will be removed from the set of
	// pending triggers (they are consumed).
	Requests []task.Request

	// Discard is a list of triggers that the policy decided aren't needed anymore
	// and should be discarded by the engine.
	//
	// A trigger associated with a request must not be also slated for discard.
	Discard []*internal.Trigger
}

type RequestBuilder struct {
	task.Request
	// contains filtered or unexported fields
}

type SimulatedEnvironment struct {
	OnDebugLog func(format string, args ...any)
}

type SimulatedInvocation struct {
	// Request is the original invocation request as emitted by the policy.
	Request task.Request
	// Created is when the invocation was created, relative to the epoch.
	Created time.Duration
	// Duration of the invocation, as returned by OnRequest.
	Duration time.Duration
	// Running is true if the invocation is still running.
	Running bool
}

type Simulator struct {
	// Policy is the policy function under test.
	//
	// Must be set by the caller.
	Policy Func

	// OnRequest is called whenever a new invocation request is emitted by the
	// policy.
	//
	// It decides for how long the invocation will run.
	//
	// Must be set by the caller.
	OnRequest func(s *Simulator, r task.Request) time.Duration

	// OnDebugLog is called whenever the triggering policy logs something.
	//
	// May be set by the caller to collect the policy logs.
	OnDebugLog func(format string, args ...any)

	// Epoch is the timestamp of when the simulation started.
	//
	// Used to calculate SimulatedInvocation.Created. It is fine to leave it
	// default if you aren't looking at absolute times (which will be weird with
	// zero epoch time).
	Epoch time.Time

	// Now is the current time inside the simulation.
	//
	// It is advanced on various events (like new triggers or finishing
	// invocations). Use AdvanceTime to move it manually.
	Now time.Time

	// PendingTriggers is a set of currently pending triggers, sorted by time
	// (most recent last).
	//
	// Do not modify this list directly, use AddTrigger instead.
	PendingTriggers []*internal.Trigger

	// Invocations is a log of all produced invocations.
	//
	// They are ordered by the creation time. Contains invocations that are still
	// running (based on Now). Use Last() as a shortcut to get the last item of
	// this list.
	Invocations []*SimulatedInvocation

	// DiscardedTriggers is a log of all triggers that were discarded, sorted by time
	// (most recent last).
	DiscardedTriggers []*internal.Trigger
	// contains filtered or unexported fields
}