// Package fixtures provides test fixtures and helpers
package tests

import (
	"context"
	"fmt"
	"testing"
	"time"

	"github.com/jfraeys/fetch_ml/internal/scheduler"
)

// WaitForEvent waits for a specific event type from the scheduler's state events
// with a timeout. It polls the state events until the event is found or timeout.
// Returns the matching event and true if found, nil and false if timeout.
func WaitForEvent(
	t *testing.T,
	hub *scheduler.SchedulerHub,
	eventType scheduler.StateEventType,
	timeout time.Duration,
) (*scheduler.StateEvent, bool) {
	t.Helper()

	deadline := time.Now().Add(timeout)
	for time.Now().Before(deadline) {
		events, err := hub.GetStateEvents()
		if err != nil {
			t.Logf("WaitForEvent: error getting state events: %v", err)
			time.Sleep(50 * time.Millisecond)
			continue
		}

		for _, event := range events {
			if event.Type == eventType {
				return &event, true
			}
		}

		time.Sleep(50 * time.Millisecond)
	}

	return nil, false
}

// WaitForEventWithFilter waits for a specific event type that matches a filter function
func WaitForEventWithFilter(
	t *testing.T,
	hub *scheduler.SchedulerHub,
	eventType scheduler.StateEventType,
	filter func(scheduler.StateEvent) bool,
	timeout time.Duration,
) (*scheduler.StateEvent, bool) {
	t.Helper()

	deadline := time.Now().Add(timeout)
	for time.Now().Before(deadline) {
		events, err := hub.GetStateEvents()
		if err != nil {
			t.Logf("WaitForEventWithFilter: error getting state events: %v", err)
			time.Sleep(50 * time.Millisecond)
			continue
		}

		for _, event := range events {
			if event.Type == eventType && filter(event) {
				return &event, true
			}
		}

		time.Sleep(50 * time.Millisecond)
	}

	return nil, false
}

// WaitForTaskStatus waits for a task to reach a specific status
func WaitForTaskStatus(
	t *testing.T,
	hub *scheduler.SchedulerHub,
	taskID string,
	status string,
	timeout time.Duration,
) bool {
	t.Helper()

	deadline := time.Now().Add(timeout)
	for time.Now().Before(deadline) {
		task := hub.GetTask(taskID)
		if task != nil && task.Status == status {
			return true
		}
		time.Sleep(50 * time.Millisecond)
	}

	return false
}

// WaitForMetric waits for a metric to satisfy a condition
func WaitForMetric(
	t *testing.T,
	hub *scheduler.SchedulerHub,
	metricKey string,
	condition func(interface{}) bool,
	timeout time.Duration,
) bool {
	t.Helper()

	deadline := time.Now().Add(timeout)
	for time.Now().Before(deadline) {
		metrics := hub.GetMetricsPayload()
		if value, ok := metrics[metricKey]; ok {
			if condition(value) {
				return true
			}
		}
		time.Sleep(50 * time.Millisecond)
	}

	return false
}

// PollWithTimeout repeatedly calls a function until it returns true or timeout
func PollWithTimeout(
	t *testing.T,
	name string,
	fn func() bool,
	timeout time.Duration,
	interval time.Duration,
) bool {
	t.Helper()

	ctx, cancel := context.WithTimeout(context.Background(), timeout)
	defer cancel()

	ticker := time.NewTicker(interval)
	defer ticker.Stop()

	for {
		select {
		case <-ctx.Done():
			t.Logf("PollWithTimeout %s: timeout after %v", name, timeout)
			return false
		case <-ticker.C:
			if fn() {
				return true
			}
		}
	}
}

// AssertEventReceived asserts that an event of the specified type was received
func AssertEventReceived(
	t *testing.T,
	hub *scheduler.SchedulerHub,
	eventType scheduler.StateEventType,
	timeout time.Duration,
) *scheduler.StateEvent {
	t.Helper()

	event, found := WaitForEvent(t, hub, eventType, timeout)
	if !found {
		t.Fatalf("Expected event type %v within %v, but was not received", eventType, timeout)
	}
	return event
}

// AssertTaskStatus asserts that a task reaches the expected status
func AssertTaskStatus(
	t *testing.T,
	hub *scheduler.SchedulerHub,
	taskID string,
	expectedStatus string,
	timeout time.Duration,
) {
	t.Helper()

	if !WaitForTaskStatus(t, hub, taskID, expectedStatus, timeout) {
		task := hub.GetTask(taskID)
		if task == nil {
			t.Fatalf("Task %s not found (expected status: %s)", taskID, expectedStatus)
		}
		t.Fatalf("Task %s has status %s, expected %s (timeout: %v)",
			taskID, task.Status, expectedStatus, timeout)
	}
}

// WaitForCondition waits for a condition to be true with a timeout
// Returns true if condition was met, false if timeout
func WaitForCondition(
	t *testing.T,
	name string,
	condition func() bool,
	timeout time.Duration,
) bool {
	t.Helper()

	deadline := time.Now().Add(timeout)
	for time.Now().Before(deadline) {
		if condition() {
			return true
		}
		time.Sleep(50 * time.Millisecond)
	}

	t.Logf("WaitForCondition %s: timeout after %v", name, timeout)
	return false
}

// RetryWithBackoff retries an operation with exponential backoff
func RetryWithBackoff(
	t *testing.T,
	name string,
	maxRetries int,
	baseDelay time.Duration,
	fn func() error,
) error {
	t.Helper()

	var err error
	delay := baseDelay

	for i := 0; i < maxRetries; i++ {
		err = fn()
		if err == nil {
			return nil
		}

		t.Logf("RetryWithBackoff %s: attempt %d/%d failed: %v", name, i+1, maxRetries, err)

		if i < maxRetries-1 {
			time.Sleep(delay)
			delay *= 2 // exponential backoff
		}
	}

	return fmt.Errorf("%s failed after %d attempts: %w", name, maxRetries, err)
}