package web_test

import (
	"fmt"
	"io"
	"net"
	"net/http"
	"os"
	"strings"
	"testing"
	"time"

	web "git.sharkk.net/Go/Web"
)

// testServer starts a server on a random port, runs the given test function,
// and ensures proper server shutdown afterward.
func testServer(t *testing.T, s web.Server, test func(port string)) {
	// Get a free port by letting the OS assign one
	listener, err := net.Listen("tcp", ":0")
	if err != nil {
		t.Fatalf("Failed to find available port: %v", err)
	}
	port := listener.Addr().(*net.TCPAddr).Port
	portStr := fmt.Sprintf(":%d", port)
	listener.Close()

	// Start the server in a goroutine
	ready := make(chan bool)
	done := make(chan bool)

	go func() {
		// Signal that we're about to start the server
		ready <- true

		// Start the server (this blocks until interrupted)
		s.Run(portStr)

		// Signal that the server has shut down
		done <- true
	}()

	// Wait for server to begin starting
	<-ready

	// Give it a moment to actually start listening
	time.Sleep(50 * time.Millisecond)

	// Run the test function with the assigned port
	test(portStr)

	// Send interrupt to stop the server
	p, _ := os.FindProcess(os.Getpid())
	p.Signal(os.Interrupt)

	// Wait for server to confirm shutdown with timeout
	select {
	case <-done:
		// Server shutdown properly
	case <-time.After(100 * time.Millisecond):
		t.Log("Warning: Server didn't shut down within timeout")
	}
}

func TestRun(t *testing.T) {
	s := web.NewServer()

	// Add a handler for the root path
	s.Get("/", func(ctx web.Context) error {
		return ctx.String("Hello")
	})

	testServer(t, s, func(port string) {
		resp, err := http.Get("http://127.0.0.1" + port + "/")
		if err != nil {
			t.Fatalf("Error making request: %v", err)
		}
		defer resp.Body.Close()

		if resp.StatusCode != 200 {
			t.Errorf("Expected status 200, got %d", resp.StatusCode)
		}

		body, err := io.ReadAll(resp.Body)
		if err != nil {
			t.Fatalf("Error reading response body: %v", err)
		}

		if string(body) != "Hello" {
			t.Errorf("Expected body 'Hello', got '%s'", string(body))
		}
	})
}

func TestBadRequest(t *testing.T) {
	s := web.NewServer()

	testServer(t, s, func(port string) {
		conn, err := net.Dial("tcp", "127.0.0.1"+port)
		if err != nil {
			t.Fatalf("Error connecting: %v", err)
		}
		defer conn.Close()

		_, err = io.WriteString(conn, "BadRequest\r\n\r\n")
		if err != nil {
			t.Fatalf("Error writing: %v", err)
		}

		response, err := io.ReadAll(conn)
		if err != nil {
			t.Fatalf("Error reading: %v", err)
		}

		if string(response) != "HTTP/1.1 400 Bad Request\r\n\r\n" {
			t.Errorf("Expected 400 response, got: %s", string(response))
		}
	})
}

func TestBadRequestHeader(t *testing.T) {
	s := web.NewServer()

	s.Get("/", func(ctx web.Context) error {
		return ctx.String("Hello")
	})

	testServer(t, s, func(port string) {
		conn, err := net.Dial("tcp", "127.0.0.1"+port)
		if err != nil {
			t.Fatalf("Error connecting: %v", err)
		}
		defer conn.Close()

		_, err = io.WriteString(conn, "GET / HTTP/1.1\r\nBadHeader\r\nGood: Header\r\n\r\n")
		if err != nil {
			t.Fatalf("Error writing: %v", err)
		}

		buffer := make([]byte, len("HTTP/1.1 200"))
		_, err = conn.Read(buffer)
		if err != nil {
			t.Fatalf("Error reading: %v", err)
		}

		if string(buffer) != "HTTP/1.1 200" {
			t.Errorf("Expected '200' response, got: %s", string(buffer))
		}
	})
}

func TestBadRequestMethod(t *testing.T) {
	s := web.NewServer()

	testServer(t, s, func(port string) {
		conn, err := net.Dial("tcp", "127.0.0.1"+port)
		if err != nil {
			t.Fatalf("Error connecting: %v", err)
		}
		defer conn.Close()

		_, err = io.WriteString(conn, "BAD-METHOD / HTTP/1.1\r\n\r\n")
		if err != nil {
			t.Fatalf("Error writing: %v", err)
		}

		response, err := io.ReadAll(conn)
		if err != nil {
			t.Fatalf("Error reading: %v", err)
		}

		if string(response) != "HTTP/1.1 400 Bad Request\r\n\r\n" {
			t.Errorf("Expected 400 response, got: %s", string(response))
		}
	})
}

func TestBadRequestProtocol(t *testing.T) {
	s := web.NewServer()

	s.Get("/", func(ctx web.Context) error {
		return ctx.String("Hello")
	})

	testServer(t, s, func(port string) {
		conn, err := net.Dial("tcp", "127.0.0.1"+port)
		if err != nil {
			t.Fatalf("Error connecting: %v", err)
		}
		defer conn.Close()

		_, err = io.WriteString(conn, "GET /\r\n\r\n")
		if err != nil {
			t.Fatalf("Error writing: %v", err)
		}

		buffer := make([]byte, len("HTTP/1.1 200"))
		_, err = conn.Read(buffer)
		if err != nil {
			t.Fatalf("Error reading: %v", err)
		}

		if string(buffer) != "HTTP/1.1 200" {
			t.Errorf("Expected '200' response, got: %s", string(buffer))
		}
	})
}

func TestEarlyClose(t *testing.T) {
	s := web.NewServer()

	testServer(t, s, func(port string) {
		conn, err := net.Dial("tcp", "127.0.0.1"+port)
		if err != nil {
			t.Fatalf("Error connecting: %v", err)
		}

		_, err = io.WriteString(conn, "GET /\r\n")
		if err != nil {
			t.Fatalf("Error writing: %v", err)
		}

		// Close the connection early
		err = conn.Close()
		if err != nil {
			t.Fatalf("Error closing connection: %v", err)
		}

		// No assertion needed - if the server doesn't crash, the test passes
	})
}

func TestUnavailablePort(t *testing.T) {
	// Get a port and keep it occupied
	listener, err := net.Listen("tcp", ":0")
	if err != nil {
		t.Fatalf("Failed to find available port: %v", err)
	}
	port := listener.Addr().(*net.TCPAddr).Port
	portStr := fmt.Sprintf(":%d", port)
	defer listener.Close()

	// Try to run the server on the occupied port
	s := web.NewServer()

	// Run in a goroutine with a timeout
	errChan := make(chan error, 1)
	go func() {
		errChan <- s.Run(portStr)
	}()

	// Check if we get an error within a reasonable time
	select {
	case err := <-errChan:
		if err == nil {
			t.Error("Expected error when binding to unavailable port")
		}
	case <-time.After(100 * time.Millisecond):
		t.Error("Server.Run() didn't return with error on unavailable port")
		// Try to stop the server anyway
		p, _ := os.FindProcess(os.Getpid())
		p.Signal(os.Interrupt)
	}
}

func TestBodyContent(t *testing.T) {
	s := web.NewServer()

	s.Post("/", func(ctx web.Context) error {
		body := ctx.Request().Body()
		return ctx.String(string(body))
	})

	testServer(t, s, func(port string) {
		// Make a POST request with a body
		client := &http.Client{}
		req, err := http.NewRequest("POST", "http://127.0.0.1"+port+"/", strings.NewReader("Hello"))
		if err != nil {
			t.Fatalf("Error creating request: %v", err)
		}

		resp, err := client.Do(req)
		if err != nil {
			t.Fatalf("Error making request: %v", err)
		}
		defer resp.Body.Close()

		if resp.StatusCode != 200 {
			t.Errorf("Expected status 200, got %d", resp.StatusCode)
		}

		body, err := io.ReadAll(resp.Body)
		if err != nil {
			t.Fatalf("Error reading response body: %v", err)
		}

		if string(body) != "Hello" {
			t.Errorf("Expected body 'Hello', got '%s'", string(body))
		}
	})
}