package main

import (
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"testing"

	"github.com/gin-gonic/gin"

	"go_blog/config"
	"go_blog/handlers"
)

// newUploadsRouter 在模拟真实布局的临时存储根目录上构建
// 使用生产上传路由的路由器：SQLite 数据库文件位于根目录中，
// 上传文件位于子目录中。
func newUploadsRouter(t *testing.T, storageDir string) (*gin.Engine, string) {
	t.Helper()
	gin.SetMode(gin.TestMode)

	root := t.TempDir()
	if err := os.WriteFile(filepath.Join(root, "blog.db"), []byte("fake sqlite"), 0644); err != nil {
		t.Fatalf("seed blog.db: %v", err)
	}

	r := gin.New()
	registerUploadRoutes(r.Group("/uploads"), root, storageDir)
	return r, root
}

func doGet(t *testing.T, r *gin.Engine, path string) *httptest.ResponseRecorder {
	t.Helper()
	w := httptest.NewRecorder()
	r.ServeHTTP(w, httptest.NewRequest(http.MethodGet, path, nil))
	return w
}

func seedUploadFile(t *testing.T, root, sub, name string) {
	t.Helper()
	dir := filepath.Join(root, sub)
	if err := os.MkdirAll(dir, 0755); err != nil {
		t.Fatalf("mkdir %s: %v", dir, err)
	}
	if err := os.WriteFile(filepath.Join(dir, name), []byte("content"), 0644); err != nil {
		t.Fatalf("seed %s: %v", name, err)
	}
}

func TestUploadsWhitelistHidesStorageRoot(t *testing.T) {
	r, root := newUploadsRouter(t, "")
	for _, sub := range []string{"attachments", "avatars", "logos"} {
		seedUploadFile(t, root, sub, "file.txt")
	}

	// 存储根目录中的数据库文件必须不可下载。
	if w := doGet(t, r, "/uploads/blog.db"); w.Code != http.StatusNotFound {
		t.Fatalf("GET /uploads/blog.db = %d, want 404 (database leak)", w.Code)
	}

	// 任何地方都不允许目录列表。
	for _, p := range []string{
		"/uploads", "/uploads/",
		"/uploads/attachments/", "/uploads/avatars/", "/uploads/logos/",
	} {
		if w := doGet(t, r, p); w.Code != http.StatusNotFound {
			t.Fatalf("GET %s = %d, want 404 (no directory listing)", p, w.Code)
		}
	}

	// 路径穿越尝试不得逃逸出子目录。
	for _, p := range []string{
		"/uploads/attachments/../blog.db",
		"/uploads/attachments/..%2f..%2fblog.db",
		"/uploads/attachments/%2e%2e/blog.db",
	} {
		if w := doGet(t, r, p); w.Code == http.StatusOK {
			t.Fatalf("GET %s = %d, want non-200 (traversal)", p, w.Code)
		}
	}

	// 白名单子目录中的文件仍然可以访问。
	for _, p := range []string{
		"/uploads/attachments/file.txt",
		"/uploads/avatars/file.txt",
		"/uploads/logos/file.txt",
	} {
		if w := doGet(t, r, p); w.Code != http.StatusOK {
			t.Fatalf("GET %s = %d, want 200", p, w.Code)
		}
	}
}

func TestUploadsWhitelistCustomStorageDir(t *testing.T) {
	r, root := newUploadsRouter(t, "files")
	seedUploadFile(t, root, "files", "a.bin")

	if w := doGet(t, r, "/uploads/files/a.bin"); w.Code != http.StatusOK {
		t.Fatalf("GET /uploads/files/a.bin = %d, want 200", w.Code)
	}
	// 默认目录保持挂载以向后兼容。
	seedUploadFile(t, root, "attachments", "old.txt")
	if w := doGet(t, r, "/uploads/attachments/old.txt"); w.Code != http.StatusOK {
		t.Fatalf("GET /uploads/attachments/old.txt = %d, want 200", w.Code)
	}
	if w := doGet(t, r, "/uploads/blog.db"); w.Code != http.StatusNotFound {
		t.Fatalf("GET /uploads/blog.db = %d, want 404", w.Code)
	}
}

func TestUploadsWhitelistUnsafeStorageDirFallsBack(t *testing.T) {
	for _, dir := range []string{"../evil", "/etc", "..", "a/../../b", "."} {
		r, root := newUploadsRouter(t, dir)
		seedUploadFile(t, root, "attachments", "file.txt")
		if w := doGet(t, r, "/uploads/attachments/file.txt"); w.Code != http.StatusOK {
			t.Fatalf("storage dir %q: fallback mount broken: %d", dir, w.Code)
		}
		if w := doGet(t, r, "/uploads/blog.db"); w.Code != http.StatusNotFound {
			t.Fatalf("storage dir %q: /uploads/blog.db = %d, want 404", dir, w.Code)
		}
	}
}

func TestUploadsWhitelistStorageDirDedup(t *testing.T) {
	// 与已知目录相同的存储目录不能因重复路由而 panic。
	r, root := newUploadsRouter(t, "avatars")
	seedUploadFile(t, root, "avatars", "me.jpg")
	if w := doGet(t, r, "/uploads/avatars/me.jpg"); w.Code != http.StatusOK {
		t.Fatalf("GET /uploads/avatars/me.jpg = %d, want 200", w.Code)
	}
}

// TestRegisterRoutesSmoke 通过完整的路由注册冒烟测试：
// 1. 路由冲突（静态段 attachment 与 :id 参数段共存）会在此处 panic；
// 2. 断言 /api 搬移端点已在正确的 HTTP 方法下注册。
func TestRegisterRoutesSmoke(t *testing.T) {
	gin.SetMode(gin.TestMode)
	r := gin.New()
	registerRoutes(r, &config.Config{}, nil, handlers.NewLoginLimiter())

	want := map[string]string{
		// 既有 JSON API。
		"GET /api/articles": "",
		// 认证 API。
		"POST /api/auth/login":    "",
		"POST /api/auth/register": "",
		"POST /api/auth/logout":   "",
		// 评论 API。
		"POST /api/article/:slug/comments":     "",
		"POST /api/admin/comments/:id/approve": "",
		"POST /api/admin/comments/:id/reject":  "",
		"POST /api/admin/comments/:id/delete":  "",
		// 文章 CRUD API。
		"POST /api/admin/articles":         "",
		"PUT /api/admin/articles/:id":      "",
		"DELETE /api/admin/articles/:id":   "",
		"POST /api/my/articles":            "",
		"PUT /api/my/articles/:id":         "",
		"DELETE /api/my/articles/:id":      "",
		// 用户 CRUD API。
		"POST /api/admin/users":            "",
		"PUT /api/admin/users/:id":         "",
		"DELETE /api/admin/users/:id":      "",
		// 设置 API。
		"POST /api/admin/settings/site":         "",
		"POST /api/admin/settings/site/favicon": "",
		"POST /api/admin/settings/site/logo":    "",
		"POST /api/admin/settings/navlinks":     "",
		"POST /api/admin/settings/upload":       "",
		"POST /api/admin/settings/download":     "",
		"POST /api/admin/settings/comments":     "",
		// 搬移的附件/头像端点。
		"POST /api/admin/articles/attachments":       "",
		"DELETE /api/admin/articles/attachments/:id": "",
		"GET /api/admin/articles/:id/attachments":    "",
		"POST /api/profile/avatar":                   "",
		"POST /api/profile":                          "",
		"POST /api/my/articles/attachments":          "",
		"DELETE /api/my/articles/attachments/:id":    "",
		"GET /api/my/articles/:id/attachments":       "",
	}
	for route := range want {
		found := false
		for _, rt := range r.Routes() {
			if rt.Method+" "+rt.Path == route {
				found = true
				break
			}
		}
		if !found {
			t.Errorf("route %s not registered", route)
		}
	}
}