package gateway

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

// adminEntryTestIndex 是最小的 index.html：注入点 `<head>` 与
// 站点根锚点都由 handler 追加，因此这里只保证两者都存在。
const adminEntryTestIndex = `<html><head><meta charset="utf-8"></head><body><div id="root"></div></body></html>`

// adminEntryEnv 构造一个挂了前端、并按 adminPath 配置安全入口的网关。
func adminEntryEnv(t *testing.T, adminPath string) *httptest.Server {
	t.Helper()
	cfg := cfgDefault()
	cfg.Server.AdminPath = adminPath
	front := fstest.MapFS{
		"index.html":    &fstest.MapFile{Data: []byte(adminEntryTestIndex)},
		"assets/app.js": &fstest.MapFile{Data: []byte("var x = 1;")},
	}
	_, ts, _ := buildEnv(t, cfg, Deps{Frontend: front})
	return ts
}

// TestAdminEntry_DefaultPrefix 守住默认前缀下的安全入口（裁决 1.6/16.4.7）：
// `/admin` 与深链直达面板入口页（带注入），不再回落用户端聊天壳；用户端
// 路径与真实静态资源不受影响。
func TestAdminEntry_DefaultPrefix(t *testing.T) {
	t.Parallel()
	ts := adminEntryEnv(t, "")

	resp, body := doReq(t, http.MethodGet, ts.URL+"/admin", nil, "")
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("GET /admin status = %d, want 200 (body=%s)", resp.StatusCode, body)
	}
	if !strings.Contains(string(body), `window.__CYRENE_ADMIN_ENTRY__={"prefix":"/admin"}`) {
		t.Fatalf("GET /admin missing injected entry info: %s", body)
	}
	if !strings.Contains(string(body), `<base href="/">`) {
		t.Fatalf("GET /admin missing root base href: %s", body)
	}
	if got := resp.Header.Get("Cache-Control"); got != "no-store" {
		t.Fatalf("GET /admin Cache-Control = %q, want no-store", got)
	}

	resp, body = doReq(t, http.MethodGet, ts.URL+"/admin/personas", nil, "")
	if resp.StatusCode != http.StatusOK || !strings.Contains(string(body), `"prefix":"/admin"`) {
		t.Fatalf("GET /admin/personas = %d body=%s, want the injected admin entry", resp.StatusCode, body)
	}

	// 真实静态资源仍按文件送出（不注入）。
	resp, body = doReq(t, http.MethodGet, ts.URL+"/assets/app.js", nil, "")
	if resp.StatusCode != http.StatusOK || string(body) != "var x = 1;" {
		t.Fatalf("GET /assets/app.js = %d body=%q, want the raw asset", resp.StatusCode, body)
	}

	// 用户端回落路径不带入口信息（用户端 bundle 与页面都不该出现面板前缀）。
	resp, body = doReq(t, http.MethodGet, ts.URL+"/chat/somewhere", nil, "")
	if resp.StatusCode != http.StatusOK || !strings.Contains(string(body), "root") {
		t.Fatalf("GET /chat/somewhere = %d body=%s, want the user shell", resp.StatusCode, body)
	}
	if strings.Contains(string(body), "__CYRENE_ADMIN_ENTRY__") {
		t.Fatalf("user shell leaked the admin entry info: %s", body)
	}
}

// TestAdminEntry_CustomPrefix 守住自定义前缀（`host/xxx/admin` 形态）：正确
// 前缀直达，猜错前缀（含默认 /admin）一律 404，绝不回落用户端聊天壳。
func TestAdminEntry_CustomPrefix(t *testing.T) {
	t.Parallel()
	ts := adminEntryEnv(t, "xxx/admin")

	resp, body := doReq(t, http.MethodGet, ts.URL+"/xxx/admin", nil, "")
	if resp.StatusCode != http.StatusOK || !strings.Contains(string(body), `"prefix":"/xxx/admin"`) {
		t.Fatalf("GET /xxx/admin = %d body=%s, want the injected custom prefix", resp.StatusCode, body)
	}

	for _, p := range []string{"/admin", "/admin/personas", "/other/admin", "/admin/"} {
		resp, body = doReq(t, http.MethodGet, ts.URL+p, nil, "")
		if resp.StatusCode != http.StatusNotFound {
			t.Fatalf("GET %s = %d body=%s, want 404 (wrong prefix must not fall back)", p, resp.StatusCode, body)
		}
		if strings.Contains(string(body), "__CYRENE_ADMIN_ENTRY__") {
			t.Fatalf("GET %s leaked the admin entry info", p)
		}
	}

	// 用户端路径依旧正常。
	resp, body = doReq(t, http.MethodGet, ts.URL+"/chat", nil, "")
	if resp.StatusCode != http.StatusOK || !strings.Contains(string(body), "root") {
		t.Fatalf("GET /chat = %d body=%s, want the user shell", resp.StatusCode, body)
	}
}

// TestAdminEntry_APIRouteUntouched 守住「API 不藏」：前缀即便被配成含 api 段
// 的值，也不得截住 REST 路由（design/07 §0.1）。
func TestAdminEntry_APIRouteUntouched(t *testing.T) {
	t.Parallel()
	ts := adminEntryEnv(t, "api/v1/admin")

	resp, body := doReq(t, http.MethodGet, ts.URL+"/api/v1/health", nil, "")
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("GET /api/v1/health = %d body=%s, want the health payload", resp.StatusCode, body)
	}
	if strings.Contains(string(body), "__CYRENE_ADMIN_ENTRY__") {
		t.Fatalf("API route was served the admin entry page: %s", body)
	}
}

// TestAdminEntry_PrefixOverAssetDir 守住前缀撞上真实资源目录的退化：把前缀
// 配成 assets 时，真实资源必须仍由文件服务器送出，不能被面板入口页顶掉。
func TestAdminEntry_PrefixOverAssetDir(t *testing.T) {
	t.Parallel()
	ts := adminEntryEnv(t, "assets")

	resp, body := doReq(t, http.MethodGet, ts.URL+"/assets/app.js", nil, "")
	if resp.StatusCode != http.StatusOK || string(body) != "var x = 1;" {
		t.Fatalf("GET /assets/app.js = %d body=%q, want the real asset (not the shell)", resp.StatusCode, body)
	}
}

// TestAdminEntryHTML_NoHead 守住注入的两个回退点：没有 `<head>` 时注入到
// 文档最前（仍先于任何资源引用），且 `<base>` 与入口信息一并出现。
func TestAdminEntryHTML_NoHead(t *testing.T) {
	t.Parallel()
	out := adminEntryHTML([]byte("<html><body>x</body></html>"), "/admin")
	s := string(out)
	if !strings.HasPrefix(s, `<base href="/">`) {
		t.Fatalf("injection without <head> = %q, want it prepended", s)
	}
	if !strings.Contains(s, `"prefix":"/admin"`) {
		t.Fatalf("injection without <head> lost the entry info: %s", s)
	}
}