package api

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

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

	"visiona-backend/internal/usersession"
)

func init() {
	gin.SetMode(gin.TestMode)
}

// newTestSessionManager 是給 middleware_test 用的最小 SessionManager fixture。
//
// OB5 起 AuthMiddleware 必須有 SessionManager — Static fallback 已拔除。
func newTestSessionManager() *usersession.Manager {
	return usersession.NewManager(usersession.NewInMemoryStore(), usersession.CookieConfig{
		Name:       "visiona_session",
		Path:       "/",
		HTTPOnly:   true,
		SameSite:   http.SameSiteLaxMode,
		MaxAge:     86400,
		SigningKey: []byte("middleware-test-signing-key-32b-aa"),
	})
}

// TestRequestIDMiddleware_GeneratesNew 驗證沒帶 header 時會產生新的 request id。
func TestRequestIDMiddleware_GeneratesNew(t *testing.T) {
	r := gin.New()
	r.Use(RequestIDMiddleware())
	r.GET("/", func(c *gin.Context) {
		c.String(http.StatusOK, RequestIDFrom(c))
	})

	w := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodGet, "/", nil)
	r.ServeHTTP(w, req)

	assert.Equal(t, http.StatusOK, w.Code)
	body := w.Body.String()
	assert.NotEmpty(t, body, "request id 應寫入 context")
	assert.Equal(t, body, w.Header().Get("X-Request-ID"), "header 應與 context 一致")
}

// TestRequestIDMiddleware_PreservesIncoming 驗證帶 header 時會沿用。
func TestRequestIDMiddleware_PreservesIncoming(t *testing.T) {
	r := gin.New()
	r.Use(RequestIDMiddleware())
	r.GET("/", func(c *gin.Context) {
		c.String(http.StatusOK, RequestIDFrom(c))
	})

	w := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodGet, "/", nil)
	req.Header.Set("X-Request-ID", "upstream-123")
	r.ServeHTTP(w, req)

	assert.Equal(t, "upstream-123", w.Body.String())
	assert.Equal(t, "upstream-123", w.Header().Get("X-Request-ID"))
}

// TestAuthMiddleware_NoCookie_Rejects 驗證沒 cookie 時 → 401 + "no_session"。
func TestAuthMiddleware_NoCookie_Rejects(t *testing.T) {
	r := gin.New()
	r.Use(RequestIDMiddleware())
	r.Use(AuthMiddleware(Deps{SessionManager: newTestSessionManager()}))
	r.GET("/", func(c *gin.Context) {
		c.String(http.StatusOK, "should not reach")
	})

	w := httptest.NewRecorder()
	r.ServeHTTP(w, httptest.NewRequest(http.MethodGet, "/", nil))
	assert.Equal(t, http.StatusUnauthorized, w.Code)
	assert.Contains(t, w.Body.String(), "no_session")
}

// 註：AuthMiddleware 的「pending session → 401」與「authenticated session → 通過」的
// 完整測試在 oidc_auth_test.go（TestOIDCMiddleware_Allows_AuthenticatedSession /
// TestOIDCMiddleware_Rejects_PendingSession），因為需要走完整 login flow 才能模擬。

// TestRecoveryMiddleware_CatchesPanic 驗證 handler panic 會被攔成 500 + INTERNAL_ERROR。
func TestRecoveryMiddleware_CatchesPanic(t *testing.T) {
	r := gin.New()
	r.Use(RequestIDMiddleware())
	r.Use(RecoveryMiddleware(nil))
	r.GET("/", func(c *gin.Context) {
		panic("boom")
	})

	w := httptest.NewRecorder()
	r.ServeHTTP(w, httptest.NewRequest(http.MethodGet, "/", nil))
	assert.Equal(t, http.StatusInternalServerError, w.Code)
	assert.Contains(t, w.Body.String(), ErrCodeInternalError)
}

// TestStripBearerPrefix 驗證 Bearer token prefix 處理。
func TestStripBearerPrefix(t *testing.T) {
	assert.Equal(t, "abc123", StripBearerPrefix("Bearer abc123"))
	assert.Equal(t, "abc123", StripBearerPrefix("abc123"))
	assert.Equal(t, "", StripBearerPrefix(""))
}

// TestCORSMiddleware_AllowsConfiguredOrigin 驗證只放行白名單 Origin。
func TestCORSMiddleware_AllowsConfiguredOrigin(t *testing.T) {
	r := gin.New()
	r.Use(CORSMiddleware([]string{"http://localhost:3000"}))
	r.GET("/", func(c *gin.Context) { c.String(http.StatusOK, "ok") })

	// Allowed origin
	w := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodOptions, "/", nil)
	req.Header.Set("Origin", "http://localhost:3000")
	req.Header.Set("Access-Control-Request-Method", "GET")
	r.ServeHTTP(w, req)
	assert.True(t, strings.Contains(w.Header().Get("Access-Control-Allow-Origin"), "localhost:3000"),
		"預期 Allow-Origin 包含 localhost:3000，實際 header: %v", w.Header())

	// Disallowed origin
	w2 := httptest.NewRecorder()
	req2 := httptest.NewRequest(http.MethodOptions, "/", nil)
	req2.Header.Set("Origin", "http://evil.example")
	req2.Header.Set("Access-Control-Request-Method", "GET")
	r.ServeHTTP(w2, req2)
	assert.NotContains(t, w2.Header().Get("Access-Control-Allow-Origin"), "evil.example")
}