// Package middleware provides HTTP middleware components for the CLI Proxy API server.
// This file contains unit tests for the middleware components.
package middleware

import (
	"errors"
	"net/http"
	"net/http/httptest"
	"testing"

	"github.com/gin-gonic/gin"
	"github.com/stretchr/testify/assert"
)

func setupTestRouter() *gin.Engine {
	gin.SetMode(gin.TestMode)
	return gin.New()
}

func TestCorrelationIDMiddleware(t *testing.T) {
	router := setupTestRouter()
	router.Use(CorrelationIDMiddleware())
	router.GET("/test", func(c *gin.Context) {
		id := GetCorrelationID(c)
		c.JSON(200, gin.H{"correlation_id": id})
	})

	t.Run("generates correlation ID when not provided", func(t *testing.T) {
		w := httptest.NewRecorder()
		req, _ := http.NewRequest("GET", "/test", nil)
		router.ServeHTTP(w, req)

		assert.Equal(t, 200, w.Code)
		// Check that response contains a correlation ID
		assert.Contains(t, w.Body.String(), "correlation_id")
		// Check that response header contains the correlation ID
		assert.NotEmpty(t, w.Header().Get(CorrelationIDHeader))
	})

	t.Run("uses existing correlation ID from header", func(t *testing.T) {
		w := httptest.NewRecorder()
		req, _ := http.NewRequest("GET", "/test", nil)
		req.Header.Set(CorrelationIDHeader, "test-correlation-id-123")
		router.ServeHTTP(w, req)

		assert.Equal(t, 200, w.Code)
		assert.Contains(t, w.Body.String(), "test-correlation-id-123")
		assert.Equal(t, "test-correlation-id-123", w.Header().Get(CorrelationIDHeader))
	})
}

func TestErrorHandlerMiddleware(t *testing.T) {
	router := setupTestRouter()
	router.Use(CorrelationIDMiddleware())
	router.Use(ErrorHandlerMiddleware())

	router.GET("/error", func(c *gin.Context) {
		c.Error(errors.New("test error"))
		c.Abort()
	})

	router.GET("/success", func(c *gin.Context) {
		c.JSON(200, gin.H{"status": "ok"})
	})

	t.Run("handles errors gracefully", func(t *testing.T) {
		w := httptest.NewRecorder()
		req, _ := http.NewRequest("GET", "/error", nil)
		router.ServeHTTP(w, req)

		assert.Equal(t, 500, w.Code)
		assert.Contains(t, w.Body.String(), "INTERNAL_ERROR")
	})

	t.Run("passes through successful requests", func(t *testing.T) {
		w := httptest.NewRecorder()
		req, _ := http.NewRequest("GET", "/success", nil)
		router.ServeHTTP(w, req)

		assert.Equal(t, 200, w.Code)
		assert.Contains(t, w.Body.String(), "ok")
	})
}

func TestRecoveryMiddleware(t *testing.T) {
	router := setupTestRouter()
	router.Use(RecoveryMiddleware(nil))
	router.Use(CorrelationIDMiddleware())
	router.Use(ErrorHandlerMiddleware())

	router.GET("/panic", func(c *gin.Context) {
		panic("test panic")
	})

	router.GET("/normal", func(c *gin.Context) {
		c.JSON(200, gin.H{"status": "ok"})
	})

	t.Run("recovers from panic", func(t *testing.T) {
		w := httptest.NewRecorder()
		req, _ := http.NewRequest("GET", "/panic", nil)
		router.ServeHTTP(w, req)

		assert.Equal(t, 500, w.Code)
		assert.Contains(t, w.Body.String(), "INTERNAL_ERROR")
	})

	t.Run("normal requests work after panic recovery", func(t *testing.T) {
		w := httptest.NewRecorder()
		req, _ := http.NewRequest("GET", "/normal", nil)
		router.ServeHTTP(w, req)

		assert.Equal(t, 200, w.Code)
		assert.Contains(t, w.Body.String(), "ok")
	})
}

func TestSafeHandler(t *testing.T) {
	router := setupTestRouter()
	router.Use(CorrelationIDMiddleware())
	router.Use(ErrorHandlerMiddleware())

	router.GET("/safe-panic", SafeHandler(func(c *gin.Context) {
		panic("safe handler panic")
	}))

	t.Run("safe handler recovers from panic", func(t *testing.T) {
		w := httptest.NewRecorder()
		req, _ := http.NewRequest("GET", "/safe-panic", nil)
		router.ServeHTTP(w, req)

		assert.Equal(t, 500, w.Code)
		assert.Contains(t, w.Body.String(), "INTERNAL_ERROR")
	})
}