package app

import (
	"testing"

	cfgpkg "github.com/jan/fm-rds-tx/internal/config"
	"github.com/jan/fm-rds-tx/internal/output"
	"github.com/jan/fm-rds-tx/internal/platform"
)

func TestEngineRuntimeStateReporting(t *testing.T) {
	e := NewEngine(cfgpkg.Default(), platform.NewSimulatedDriver(nil))

	if got := e.Stats().State; got != string(RuntimeStateIdle) {
		t.Fatalf("expected initial state idle, got %s", got)
	}

	e.setRuntimeState(RuntimeStatePrebuffering)
	if got := e.Stats().State; got != string(RuntimeStatePrebuffering) {
		t.Fatalf("expected prebuffering, got %s", got)
	}

	e.setRuntimeState(RuntimeStateRunning)
	if got := e.currentRuntimeState(); got != RuntimeStateRunning {
		t.Fatalf("currentRuntimeState mismatch: %s", got)
	}
}

func TestEngineRuntimeStateTransitions(t *testing.T) {
	e := NewEngine(cfgpkg.Default(), platform.NewSimulatedDriver(nil))
	e.setRuntimeState(RuntimeStatePrebuffering)

	queue := output.QueueStats{Depth: 1, FillLevel: 0.75, Health: output.QueueHealthNormal}
	e.evaluateRuntimeState(queue, false)
	if got := e.currentRuntimeState(); got != RuntimeStateRunning {
		t.Fatalf("expected running after full buffer, got %s", got)
	}

	queue.Health = output.QueueHealthCritical
	for i := 0; i < queueCriticalStreakThreshold; i++ {
		e.evaluateRuntimeState(queue, false)
	}
	if got := e.currentRuntimeState(); got != RuntimeStateDegraded {
		t.Fatalf("expected degraded on queue critical streak, got %s", got)
	}

	queue.Health = output.QueueHealthNormal
	e.evaluateRuntimeState(queue, false)
	if got := e.currentRuntimeState(); got != RuntimeStateRunning {
		t.Fatalf("expected running once queue healthy, got %s", got)
	}

	e.evaluateRuntimeState(queue, true)
	if got := e.currentRuntimeState(); got != RuntimeStateDegraded {
		t.Fatalf("expected degraded when late buffers seen, got %s", got)
	}
}

func TestEngineRuntimeStateMuteOnPersistentQueueCritical(t *testing.T) {
	e := NewEngine(cfgpkg.Default(), platform.NewSimulatedDriver(nil))
	e.setRuntimeState(RuntimeStateRunning)

	queue := output.QueueStats{Depth: 1, Health: output.QueueHealthCritical}
	for i := 0; i < queueMutedStreakThreshold; i++ {
		e.evaluateRuntimeState(queue, false)
	}

	if got := e.currentRuntimeState(); got != RuntimeStateMuted {
		t.Fatalf("expected muted after prolonged queue critical, got %s", got)
	}

	muteFault := e.LastFault()
	if muteFault == nil {
		t.Fatal("expected fault recorded for the mute transition")
	}
	if muteFault.Reason != FaultReasonQueueCritical {
		t.Fatalf("expected queue critical reason, got %s", muteFault.Reason)
	}
	if muteFault.Severity != FaultSeverityMuted {
		t.Fatalf("expected muted severity, got %s", muteFault.Severity)
	}

	queue.Health = output.QueueHealthNormal
	for i := 0; i < queueMutedRecoveryThreshold-1; i++ {
		e.evaluateRuntimeState(queue, false)
		if got := e.currentRuntimeState(); got != RuntimeStateMuted {
			t.Fatalf("expected still muted while recovery window builds, got %s", got)
		}
	}

	e.evaluateRuntimeState(queue, false)
	if got := e.currentRuntimeState(); got != RuntimeStateDegraded {
		t.Fatalf("expected degrade once mute recovery threshold reached, got %s", got)
	}

	recoveryFault := e.LastFault()
	if recoveryFault == nil {
		t.Fatal("expected recovery fault entry after leaving mute")
	}
	if recoveryFault.Severity != FaultSeverityDegraded {
		t.Fatalf("expected degraded severity for recovery event, got %s", recoveryFault.Severity)
	}
	if recoveryFault.Reason != FaultReasonQueueCritical {
		t.Fatalf("expected queue critical reason for recovery event, got %s", recoveryFault.Reason)
	}

	e.evaluateRuntimeState(queue, false)
	if got := e.currentRuntimeState(); got != RuntimeStateRunning {
		t.Fatalf("expected running after recovery, got %s", got)
	}
}