package integration

import (
	"io"
	"net/http/httptest"
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"

	"github.com/break/junhong_cmp_fiber/internal/middleware"
	"github.com/break/junhong_cmp_fiber/pkg/errors"
	"github.com/break/junhong_cmp_fiber/pkg/logger"
	"github.com/break/junhong_cmp_fiber/pkg/response"
	"github.com/bytedance/sonic"
	"github.com/gofiber/fiber/v2"
	"github.com/gofiber/fiber/v2/middleware/requestid"
	"github.com/google/uuid"
)

// TestPanicRecovery 测试 panic 恢复功能（T052）
func TestPanicRecovery(t *testing.T) {
	// 创建临时目录用于日志
	tempDir := t.TempDir()

	// 初始化日志系统
	err := logger.InitLoggers("info", false,
		logger.LogRotationConfig{
			Filename:   filepath.Join(tempDir, "app-panic.log"),
			MaxSize:    10,
			MaxBackups: 3,
			MaxAge:     7,
			Compress:   false,
		},
		logger.LogRotationConfig{
			Filename:   filepath.Join(tempDir, "access-panic.log"),
			MaxSize:    10,
			MaxBackups: 3,
			MaxAge:     7,
			Compress:   false,
		},
	)
	if err != nil {
		t.Fatalf("Failed to initialize loggers: %v", err)
	}
	defer func() { _ = logger.Sync() }()

	appLogger := logger.GetAppLogger()

	// 创建应用
	app := fiber.New()

	// 注册中间件（recover 必须第一个）
	app.Use(middleware.Recover(appLogger))
	app.Use(requestid.New(requestid.Config{
		Generator: func() string {
			return uuid.NewString()
		},
	}))

	// 创建会 panic 的 handler
	app.Get("/panic", func(c *fiber.Ctx) error {
		panic("intentional panic for testing")
	})

	// 创建正常的 handler
	app.Get("/ok", func(c *fiber.Ctx) error {
		return c.SendString("ok")
	})

	tests := []struct {
		name           string
		path           string
		shouldPanic    bool
		expectedStatus int
		expectedCode   int
	}{
		{
			name:           "panic endpoint returns 500",
			path:           "/panic",
			shouldPanic:    true,
			expectedStatus: 500,
			expectedCode:   errors.CodeInternalError,
		},
		{
			name:           "normal endpoint works after panic",
			path:           "/ok",
			shouldPanic:    false,
			expectedStatus: 200,
			expectedCode:   0,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			req := httptest.NewRequest("GET", tt.path, nil)
			resp, err := app.Test(req)
			if err != nil {
				t.Fatalf("Failed to execute request: %v", err)
			}
			defer resp.Body.Close()

			// 验证 HTTP 状态码
			if resp.StatusCode != tt.expectedStatus {
				t.Errorf("Expected status %d, got %d", tt.expectedStatus, resp.StatusCode)
			}

			// 解析响应
			body, err := io.ReadAll(resp.Body)
			if err != nil {
				t.Fatalf("Failed to read response body: %v", err)
			}

			if tt.shouldPanic {
				// panic 应该返回统一错误响应
				var response response.Response
				if err := sonic.Unmarshal(body, &response); err != nil {
					t.Fatalf("Failed to unmarshal response: %v", err)
				}

				if response.Code != tt.expectedCode {
					t.Errorf("Expected code %d, got %d", tt.expectedCode, response.Code)
				}

				if response.Data != nil {
					t.Error("Error response data should be nil")
				}
			}
		})
	}
}

// TestPanicLogging 测试 panic 日志记录和堆栈跟踪（T053）
func TestPanicLogging(t *testing.T) {
	// 创建临时目录用于日志
	tempDir := t.TempDir()
	appLogFile := filepath.Join(tempDir, "app-panic-log.log")

	// 初始化日志系统
	err := logger.InitLoggers("info", false,
		logger.LogRotationConfig{
			Filename:   appLogFile,
			MaxSize:    10,
			MaxBackups: 3,
			MaxAge:     7,
			Compress:   false,
		},
		logger.LogRotationConfig{
			Filename:   filepath.Join(tempDir, "access-panic-log.log"),
			MaxSize:    10,
			MaxBackups: 3,
			MaxAge:     7,
			Compress:   false,
		},
	)
	if err != nil {
		t.Fatalf("Failed to initialize loggers: %v", err)
	}
	defer func() { _ = logger.Sync() }()

	appLogger := logger.GetAppLogger()

	// 创建应用
	app := fiber.New()

	// 注册中间件
	app.Use(middleware.Recover(appLogger))
	app.Use(requestid.New(requestid.Config{
		Generator: func() string {
			return uuid.NewString()
		},
	}))

	// 创建不同类型的 panic
	app.Get("/panic-string", func(c *fiber.Ctx) error {
		panic("string panic message")
	})

	app.Get("/panic-error", func(c *fiber.Ctx) error {
		panic(fiber.NewError(500, "error panic message"))
	})

	app.Get("/panic-struct", func(c *fiber.Ctx) error {
		panic(struct{ Message string }{"struct panic message"})
	})

	tests := []struct {
		name            string
		path            string
		expectedInLog   []string
		unexpectedInLog []string
	}{
		{
			name: "string panic logs correctly",
			path: "/panic-string",
			expectedInLog: []string{
				"Panic 已恢复",
				"string panic message",
				"stack",
				"request_id",
				"method",
				"path",
			},
		},
		{
			name: "error panic logs correctly",
			path: "/panic-error",
			expectedInLog: []string{
				"Panic 已恢复",
				"error panic message",
				"stack",
			},
		},
		{
			name: "struct panic logs correctly",
			path: "/panic-struct",
			expectedInLog: []string{
				"Panic 已恢复",
				"stack",
				"Message",
			},
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			// 执行会 panic 的请求
			req := httptest.NewRequest("GET", tt.path, nil)
			resp, err := app.Test(req)
			if err != nil {
				t.Fatalf("Failed to execute request: %v", err)
			}
			resp.Body.Close()

			// 刷新日志缓冲区
			logger.Sync()
			time.Sleep(100 * time.Millisecond)

			// 读取日志内容
			logContent, err := os.ReadFile(appLogFile)
			if err != nil {
				t.Fatalf("Failed to read app log: %v", err)
			}

			content := string(logContent)

			// 验证日志包含预期内容
			for _, expected := range tt.expectedInLog {
				if !strings.Contains(content, expected) {
					t.Errorf("Log should contain '%s'", expected)
				}
			}

			// 验证日志不包含意外内容
			for _, unexpected := range tt.unexpectedInLog {
				if strings.Contains(content, unexpected) {
					t.Errorf("Log should NOT contain '%s'", unexpected)
				}
			}

			// 验证堆栈跟踪包含文件和行号
			if !strings.Contains(content, "recover_test.go") {
				t.Error("Stack trace should contain source file name")
			}

			t.Logf("Panic log contains stack trace: %v", strings.Contains(content, "stack"))
		})
	}
}

// TestSubsequentRequestsAfterPanic 测试 panic 后后续请求正常处理（T054）
func TestSubsequentRequestsAfterPanic(t *testing.T) {
	// 创建临时目录用于日志
	tempDir := t.TempDir()

	// 初始化日志系统
	err := logger.InitLoggers("info", false,
		logger.LogRotationConfig{
			Filename:   filepath.Join(tempDir, "app.log"),
			MaxSize:    10,
			MaxBackups: 3,
			MaxAge:     7,
			Compress:   false,
		},
		logger.LogRotationConfig{
			Filename:   filepath.Join(tempDir, "access.log"),
			MaxSize:    10,
			MaxBackups: 3,
			MaxAge:     7,
			Compress:   false,
		},
	)
	if err != nil {
		t.Fatalf("Failed to initialize loggers: %v", err)
	}
	defer func() { _ = logger.Sync() }()

	appLogger := logger.GetAppLogger()

	// 创建应用
	app := fiber.New()

	// 注册中间件
	app.Use(middleware.Recover(appLogger))
	app.Use(requestid.New(requestid.Config{
		Generator: func() string {
			return uuid.NewString()
		},
	}))

	callCount := 0

	app.Get("/test", func(c *fiber.Ctx) error {
		callCount++
		// 第 1、3、5 次调用会 panic
		if callCount%2 == 1 {
			panic("test panic")
		}
		// 第 2、4、6 次调用正常返回
		return c.JSON(fiber.Map{
			"call_count": callCount,
			"status":     "ok",
		})
	})

	// 执行多次请求，验证 panic 不影响后续请求
	for i := 1; i <= 6; i++ {
		req := httptest.NewRequest("GET", "/test", nil)
		resp, err := app.Test(req)
		if err != nil {
			t.Fatalf("Request %d failed: %v", i, err)
		}

		body, _ := io.ReadAll(resp.Body)
		resp.Body.Close()

		if i%2 == 1 {
			// 奇数次应该返回 500
			if resp.StatusCode != 500 {
				t.Errorf("Request %d: expected status 500, got %d", i, resp.StatusCode)
			}
		} else {
			// 偶数次应该返回 200
			if resp.StatusCode != 200 {
				t.Errorf("Request %d: expected status 200, got %d", i, resp.StatusCode)
			}

			// 验证响应内容
			var response map[string]any
			if err := sonic.Unmarshal(body, &response); err != nil {
				t.Fatalf("Request %d: failed to unmarshal response: %v", i, err)
			}

			if status, ok := response["status"].(string); !ok || status != "ok" {
				t.Errorf("Request %d: expected status 'ok', got %v", i, response["status"])
			}
		}

		t.Logf("Request %d completed: status=%d", i, resp.StatusCode)
	}

	// 验证所有 6 次调用都执行了
	if callCount != 6 {
		t.Errorf("Expected 6 calls, got %d", callCount)
	}
}

// TestPanicWithRequestID 测试 panic 日志包含 Request ID（T053）
func TestPanicWithRequestID(t *testing.T) {
	// 创建临时目录用于日志
	tempDir := t.TempDir()
	appLogFile := filepath.Join(tempDir, "app-panic-reqid.log")

	// 初始化日志系统
	err := logger.InitLoggers("info", false,
		logger.LogRotationConfig{
			Filename:   appLogFile,
			MaxSize:    10,
			MaxBackups: 3,
			MaxAge:     7,
			Compress:   false,
		},
		logger.LogRotationConfig{
			Filename:   filepath.Join(tempDir, "access-panic-reqid.log"),
			MaxSize:    10,
			MaxBackups: 3,
			MaxAge:     7,
			Compress:   false,
		},
	)
	if err != nil {
		t.Fatalf("Failed to initialize loggers: %v", err)
	}
	defer func() { _ = logger.Sync() }()

	appLogger := logger.GetAppLogger()

	// 创建应用
	app := fiber.New()

	// 注册中间件（顺序重要）
	app.Use(middleware.Recover(appLogger))
	app.Use(requestid.New(requestid.Config{
		Generator: func() string {
			return uuid.NewString()
		},
	}))

	app.Get("/panic", func(c *fiber.Ctx) error {
		panic("test panic with request id")
	})

	// 执行请求
	req := httptest.NewRequest("GET", "/panic", nil)
	resp, err := app.Test(req)
	if err != nil {
		t.Fatalf("Failed to execute request: %v", err)
	}
	resp.Body.Close()

	// 获取 Request ID
	requestID := resp.Header.Get("X-Request-ID")
	if requestID == "" {
		t.Error("X-Request-ID header should be set even after panic")
	}

	// 刷新日志缓冲区
	logger.Sync()
	time.Sleep(100 * time.Millisecond)

	// 读取日志内容
	logContent, err := os.ReadFile(appLogFile)
	if err != nil {
		t.Fatalf("Failed to read app log: %v", err)
	}

	content := string(logContent)

	// 验证日志包含 Request ID
	if !strings.Contains(content, requestID) {
		t.Errorf("Panic log should contain request ID '%s'", requestID)
	}

	// 验证日志包含关键字段
	requiredFields := []string{
		"request_id",
		"method",
		"path",
		"panic",
		"stack",
	}

	for _, field := range requiredFields {
		if !strings.Contains(content, field) {
			t.Errorf("Panic log should contain field '%s'", field)
		}
	}

	t.Logf("Panic log successfully includes Request ID: %s", requestID)
}

// TestConcurrentPanics 测试并发 panic 处理（T054）
func TestConcurrentPanics(t *testing.T) {
	// 创建临时目录用于日志
	tempDir := t.TempDir()

	// 初始化日志系统
	err := logger.InitLoggers("info", false,
		logger.LogRotationConfig{
			Filename:   filepath.Join(tempDir, "app.log"),
			MaxSize:    10,
			MaxBackups: 3,
			MaxAge:     7,
			Compress:   false,
		},
		logger.LogRotationConfig{
			Filename:   filepath.Join(tempDir, "access.log"),
			MaxSize:    10,
			MaxBackups: 3,
			MaxAge:     7,
			Compress:   false,
		},
	)
	if err != nil {
		t.Fatalf("Failed to initialize loggers: %v", err)
	}
	defer func() { _ = logger.Sync() }()

	appLogger := logger.GetAppLogger()

	// 创建应用
	app := fiber.New()

	// 注册中间件
	app.Use(middleware.Recover(appLogger))
	app.Use(requestid.New(requestid.Config{
		Generator: func() string {
			return uuid.NewString()
		},
	}))

	app.Get("/panic", func(c *fiber.Ctx) error {
		panic("concurrent panic test")
	})

	// 并发发送多个会 panic 的请求
	const numRequests = 20
	errors := make(chan error, numRequests)
	statuses := make(chan int, numRequests)

	for i := 0; i < numRequests; i++ {
		go func() {
			req := httptest.NewRequest("GET", "/panic", nil)
			resp, err := app.Test(req)
			if err != nil {
				errors <- err
				statuses <- 0
				return
			}
			defer resp.Body.Close()

			statuses <- resp.StatusCode
			errors <- nil
		}()
	}

	// 收集所有结果
	for i := 0; i < numRequests; i++ {
		if err := <-errors; err != nil {
			t.Fatalf("Request failed: %v", err)
		}
		status := <-statuses
		if status != 500 {
			t.Errorf("Expected status 500, got %d", status)
		}
	}

	t.Logf("Successfully handled %d concurrent panics", numRequests)
}

// TestRecoverMiddlewareOrder 测试 Recover 中间件必须在第一个（T052）
func TestRecoverMiddlewareOrder(t *testing.T) {
	// 创建临时目录用于日志
	tempDir := t.TempDir()

	// 初始化日志系统
	err := logger.InitLoggers("info", false,
		logger.LogRotationConfig{
			Filename:   filepath.Join(tempDir, "app.log"),
			MaxSize:    10,
			MaxBackups: 3,
			MaxAge:     7,
			Compress:   false,
		},
		logger.LogRotationConfig{
			Filename:   filepath.Join(tempDir, "access.log"),
			MaxSize:    10,
			MaxBackups: 3,
			MaxAge:     7,
			Compress:   false,
		},
	)
	if err != nil {
		t.Fatalf("Failed to initialize loggers: %v", err)
	}
	defer func() { _ = logger.Sync() }()

	appLogger := logger.GetAppLogger()

	// 创建应用
	app := fiber.New()

	// 正确的顺序：Recover → RequestID → Logger
	app.Use(middleware.Recover(appLogger))
	app.Use(requestid.New(requestid.Config{
		Generator: func() string {
			return uuid.NewString()
		},
	}))
	app.Use(logger.Middleware())

	app.Get("/panic", func(c *fiber.Ctx) error {
		panic("test panic")
	})

	// 执行请求
	req := httptest.NewRequest("GET", "/panic", nil)
	resp, err := app.Test(req)
	if err != nil {
		t.Fatalf("Failed to execute request: %v", err)
	}
	defer resp.Body.Close()

	// 验证请求被正确处理（返回 500 而不是崩溃）
	if resp.StatusCode != 500 {
		t.Errorf("Expected status 500, got %d", resp.StatusCode)
	}

	// 验证仍然有 Request ID（说明 RequestID 中间件在 Recover 之后执行）
	requestID := resp.Header.Get("X-Request-ID")
	if requestID == "" {
		t.Error("X-Request-ID should be set even after panic")
	}

	// 解析响应，验证返回了统一错误格式
	body, _ := io.ReadAll(resp.Body)
	var response response.Response
	if err := sonic.Unmarshal(body, &response); err != nil {
		t.Fatalf("Failed to unmarshal response: %v", err)
	}

	if response.Code != errors.CodeInternalError {
		t.Errorf("Expected code %d, got %d", errors.CodeInternalError, response.Code)
	}

	t.Logf("Recover middleware correctly placed first, handled panic gracefully")
}