package integration

import (
	"context"
	"fmt"
	"log"
	"os/exec"
	"runtime"
	"testing"
	"time"

	"github.com/ethereum/go-ethereum/ethclient"
)

// setupForkedArbitrum sets up a forked Arbitrum test environment using anvil
func setupForkedArbitrum(t testing.TB) (*ethclient.Client, func()) {
	// Check if anvil is available
	if _, err := exec.LookPath("anvil"); err != nil {
		t.Skip("anvil not found in PATH - install Foundry to run fork tests")
	}

	// Start anvil with Arbitrum fork
	arbitrumRPC := "https://arb1.arbitrum.io/rpc"
	port := "8545"

	cmd := exec.Command("anvil",
		"--fork-url", arbitrumRPC,
		"--port", port,
		"--gas-limit", "30000000",
		"--gas-price", "10000000000", // 10 gwei
		"--block-time", "1", // 1 second blocks
		"--accounts", "10", // 10 test accounts
		"--balance", "1000", // 1000 ETH per account
	)

	// Start anvil in background
	if err := cmd.Start(); err != nil {
		t.Fatalf("Failed to start anvil: %v", err)
	}

	// Wait for anvil to be ready
	time.Sleep(3 * time.Second)

	// Connect to the forked network
	client, err := ethclient.Dial(fmt.Sprintf("http://localhost:%s", port))
	if err != nil {
		cmd.Process.Kill()
		t.Fatalf("Failed to connect to forked Arbitrum: %v", err)
	}

	// Verify connection by getting chain ID
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

	chainID, err := client.ChainID(ctx)
	if err != nil {
		cmd.Process.Kill()
		t.Fatalf("Failed to get chain ID: %v", err)
	}

	if chainID.Uint64() != 42161 {
		t.Logf("Warning: Expected Arbitrum chain ID 42161, got %d", chainID.Uint64())
	}

	// Return cleanup function
	cleanup := func() {
		client.Close()
		if cmd.Process != nil {
			cmd.Process.Kill()
			cmd.Wait()
		}
	}

	return client, cleanup
}

// getMemStats returns current memory statistics
func getMemStats() runtime.MemStats {
	var m runtime.MemStats
	runtime.ReadMemStats(&m)
	return m
}

// logMemoryUsage logs current memory usage for debugging
func logMemoryUsage(t testing.TB, label string) {
	var m runtime.MemStats
	runtime.ReadMemStats(&m)

	t.Logf("%s - Memory: Alloc=%d KB, TotalAlloc=%d KB, Sys=%d KB, NumGC=%d",
		label,
		m.Alloc/1024,
		m.TotalAlloc/1024,
		m.Sys/1024,
		m.NumGC,
	)
}

// waitForAnvil waits for anvil to be ready and responsive
func waitForAnvil(port string, timeout time.Duration) error {
	deadline := time.Now().Add(timeout)

	for time.Now().Before(deadline) {
		client, err := ethclient.Dial(fmt.Sprintf("http://localhost:%s", port))
		if err == nil {
			ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
			_, err := client.ChainID(ctx)
			cancel()
			client.Close()

			if err == nil {
				return nil
			}
		}

		time.Sleep(500 * time.Millisecond)
	}

	return fmt.Errorf("anvil not ready after %v", timeout)
}

// createTestLogger creates a test logger for debugging
func createTestLogger(t testing.TB) *log.Logger {
	return log.New(&testWriter{t: t}, "[TEST] ", log.LstdFlags|log.Lshortfile)
}

// testWriter implements io.Writer for test logging
type testWriter struct {
	t testing.TB
}

func (tw *testWriter) Write(p []byte) (n int, err error) {
	tw.t.Log(string(p))
	return len(p), nil
}