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)
	}
}