package lua

// The plugin HTTP bridge is the one capability that lets a .lua file — installed
// from a textarea in the WebUI — reach out on the gateway's own network. That
// makes its DENY rules the security boundary, and these tests exist to pin the
// refusals rather than the happy path.
//
// The failure this guards against is concrete: an operator installs a quota
// plugin that reads a vendor's balance, and a later plugin (or a compromised
// one) posts that gateway key material to an attacker, or reads the cloud
// metadata endpoint, because __llmsproxy_http happened to be a general HTTP
// client.

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

	golua "github.com/aarzilli/golua/lua"
)

// newTestState returns a bare Lua state for the argument-decoding tests.
func newTestState(t *testing.T) *golua.State {
	t.Helper()
	L := golua.NewState()
	t.Cleanup(L.Close)
	L.OpenLibs()
	return L
}

func TestPluginHTTPAllowlistRejectsUnlistedHost(t *testing.T) {
	allow := newHTTPAllowlist([]string{"api.example.com"})
	for _, raw := range []string{
		"https://evil.test/steal",
		"https://169.254.169.254/latest/meta-data/",
		"https://api.example.com.evil.test/x", // suffix trick
		"https://user@evil.test/",
	} {
		if _, err := allow.checkURL(raw); err == nil {
			t.Fatalf("allowlist permitted %q — a plugin must not reach hosts "+
				"the operator never configured as a source", raw)
		}
	}
}

func TestPluginHTTPAllowlistAcceptsConfiguredHost(t *testing.T) {
	allow := newHTTPAllowlist([]string{"api.example.com"})
	for _, raw := range []string{
		"https://api.example.com/alpha/credits",
		"https://API.EXAMPLE.COM/x", // host compare must be case-insensitive
		"https://api.example.com:443/x",
	} {
		if _, err := allow.checkURL(raw); err != nil {
			t.Fatalf("allowlist refused configured host %q: %v", raw, err)
		}
	}
}

func TestPluginHTTPRefusesPlainHTTPOffLoopback(t *testing.T) {
	allow := newHTTPAllowlist([]string{"api.example.com"})
	// Allowed host, but plain HTTP would put the API key on the wire in clear.
	if _, err := allow.checkURL("http://api.example.com/alpha"); err == nil {
		t.Fatal("plain http to an allowed non-loopback host must be refused")
	}
	// Loopback stays allowed: it cannot leave the machine, and the billing rules
	// UI reads the gateway's own API over plain HTTP in dev setups.
	for _, raw := range []string{"http://127.0.0.1:8081/api/x", "http://localhost:8081/x"} {
		if _, err := allow.checkURL(raw); err != nil {
			t.Fatalf("loopback http must stay usable, got %v for %q", err, raw)
		}
	}
}

func TestPluginHTTPRejectsBadSchemesAndMissingURL(t *testing.T) {
	allow := newHTTPAllowlist([]string{"api.example.com"})
	for _, raw := range []string{"file:///etc/passwd", "ftp://api.example.com/x", "gopher://x"} {
		if _, err := allow.checkURL(raw); err == nil {
			t.Fatalf("scheme in %q must be refused", raw)
		}
	}
	// An empty allowlist must deny, not fall open.
	if _, err := newHTTPAllowlist(nil).checkURL("https://api.example.com/x"); err == nil {
		t.Fatal("an unconfigured gateway must deny outbound HTTP entirely")
	}
}

// A redirect is a hop the allowlist never saw. Following it would let an
// allowed host bounce a plugin's request (and its headers) anywhere.
func TestPluginHTTPDoesNotFollowRedirects(t *testing.T) {
	if httpClient.CheckRedirect == nil {
		t.Fatal("CheckRedirect must be set: following a redirect escapes the allowlist")
	}
	req, _ := http.NewRequest(http.MethodGet, "https://api.example.com/x", nil)
	err := httpClient.CheckRedirect(req, []*http.Request{req})
	if err != http.ErrUseLastResponse {
		t.Fatalf("CheckRedirect must return ErrUseLastResponse so the 3xx is "+
			"handed back unfollowed, got %v", err)
	}
}

func TestPluginHTTPTimeoutAndBodyAreClamped(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		_, _ = w.Write([]byte(`{"ok":true}`))
	}))
	defer srv.Close()
	allow := newHTTPAllowlist([]string{"127.0.0.1"})
	u, err := allow.checkURL(srv.URL)
	if err != nil {
		t.Fatalf("loopback test server must be allowed: %v", err)
	}
	// An absurd timeout is clamped instead of honoured.
	res, err := performHTTP(u, httpRequestSpec{Timeout: 24 * time.Hour})
	if err != nil {
		t.Fatalf("clamped request failed: %v", err)
	}
	if res.Status != 200 || !strings.Contains(res.Body, `"ok"`) {
		t.Fatalf("unexpected result: status=%d body=%q", res.Status, res.Body)
	}
}

func TestPluginHTTPOversizedBodyIsRefused(t *testing.T) {
	big := strings.Repeat("x", httpMaxResponse+64)
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		_, _ = w.Write([]byte(big))
	}))
	defer srv.Close()
	allow := newHTTPAllowlist([]string{"127.0.0.1"})
	u, _ := allow.checkURL(srv.URL)
	// Refusing beats truncating: a truncated body parses as corrupt JSON and the
	// plugin would report a parse error instead of the real cause.
	if _, err := performHTTP(u, httpRequestSpec{}); err == nil {
		t.Fatal("an oversized response must be refused, not silently truncated")
	}
}

func TestPluginHTTPErrorPathIsPairNotRaise(t *testing.T) {
	// Lua-side contract: the bridge returns (nil, message) on every failure so a
	// plugin mistake never raises through golua (see the SIGSEGV note on
	// hookGuardSrc — an escaping error can take the gateway down).
	allow := newHTTPAllowlist([]string{"api.example.com"})
	if _, err := allow.checkURL("https://evil.test/"); err == nil {
		t.Fatal("expected refusal")
	}
	// readHTTPRequestSpec must reject a non-table without touching the stack.
	L := newTestState(t)
	if _, err := readHTTPRequestSpec(L); err == nil {
		t.Fatal("a missing argument table must be an error, not a panic")
	}
}

// The bridge must be reachable under the name plugins actually call.
//
// This exists because the registration once used the CONSTANT'S IDENTIFIER as
// the Lua global name (`registerFn(L, "httpGlobal", …)`) rather than its VALUE,
// so the bridge was published as `httpGlobal` while every plugin called
// `__llmsproxy_http`. The failure only appeared at runtime, as
// "attempt to call global '__llmsproxy_http' (a nil value)" on the first real
// request — after the unit tests were green, because they drove the Go-side
// helpers directly and never went through Lua name resolution.
//
// So this test boots a real plugin and calls the bridge the way a plugin does.
func TestPluginHTTPBridgeIsReachableUnderItsLuaName(t *testing.T) {
	dir := t.TempDir()
	ps := NewPlugins(NewVM(dir), dir)
	ps.SetOutboundHosts([]string{"127.0.0.1"})

	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`{"credits":{"monthlyCredits":1.5}}`))
	}))
	defer srv.Close()

	// The plugin asks for a loopback URL, which is allowed without being
	// configured as a source. It type-checks both the table and arg.url, so a
	// malformed call is reported by the plugin rather than as a bewildering URL
	// parse error from the bridge.
	src := `
local P = {}
P.name = "httpprobe"
P.version = "1.0.0"
P.exports = { "probe" }
-- Call passes the WHOLE argument table as a single Lua argument, which is the
-- same convention the hooks use and what a plugin page's pluginAPI.call ends up
-- producing. Taking the table (not a bare string) is the correct shape.
function P.probe(arg)
  if type(arg) ~= "table" then return { error = "probe takes the args table, got " .. type(arg) } end
  if type(arg.url) ~= "string" then return { error = "arg.url must be a string, got " .. type(arg.url) } end
  local res, err = ` + httpGlobal + `({ url = arg.url, method = "GET" })
  if res == nil then return { error = tostring(err) } end
  return { status = res.status, body = res.body }
end
return P
`
	if err := ps.LoadSource("httpprobe", src); err != nil {
		t.Fatalf("load: %v", err)
	}
	got, err := ps.Call("httpprobe", "probe", map[string]interface{}{"url": srv.URL})
	if err != nil {
		t.Fatalf("call: %v", err)
	}
	m, _ := got.(map[string]interface{})
	if m == nil {
		t.Fatalf("probe returned %T, want a table", got)
	}
	// A nil global surfaces as {error = "attempt to call global ... (a nil value)"} —
	// which is a table too, so the error field is what distinguishes it.
	if e, ok := m["error"]; ok {
		t.Fatalf("the bridge is not reachable as %s: %v", httpGlobal, e)
	}
	if s, _ := m["status"].(float64); int(s) != 200 {
		t.Fatalf("status=%v body=%v, want 200 from the loopback test server", m["status"], m["body"])
	}
	if body, _ := m["body"].(string); !strings.Contains(body, "monthlyCredits") {
		t.Fatalf("body=%q, want the server's JSON", body)
	}
}

// TestGrantExtraHostsVisibleToAlreadyBootedWorker 是真实事故的回归测试。
//
// 事故：allowlist 是不可变快照。bootPluginState 在 worker 启动时把 *httpAllowlist
// 指针绑进 Lua 闭包；GrantExtraHosts 之后 ps.allowHTTP 被**整个换新**，已启动的
// worker 仍持旧指针 → 授权接口返回 ok、UI 显示已批，但插件请求仍被
// "not an allowed outbound destination" 拒绝。channels 插件的 auth/state 就是这样
// 在生产被拦的（copilot.tencent.com 已批仍报错）。
//
// 修复：allowlist 改为带锁的**可变共享对象**（原地 add），所有闭包立即可见。
// 本测试按事故顺序构造：先加载插件（worker 已绑定 allowlist）→ 再授权 →
// 断言**同一批已启动的 worker**立刻能用新主机。
func TestGrantExtraHostsVisibleToAlreadyBootedWorker(t *testing.T) {
	dir := t.TempDir()
	ps := NewPlugins(NewVM(dir), dir)
	ps.SetOutboundHosts(nil) // 起始只允许 loopback

	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		_, _ = w.Write([]byte(`{"ok":true}`))
	}))
	defer srv.Close()
	// srv.URL 是 127.0.0.1 —— 非回环测试要另想办法；httptest 只能回环，
	// 所以这里用「允许清单里没有的主机名」→ 通过 SetOutboundHosts 授权它，
	// 但 srv 本身必须仍回环。做法：插件请求的 URL 用 srv.URL（回环，恒允许）？
	// 不行——那测不出 allowlist 更新。改用 checkURL 直接断言新主机可见。
	//
	// 真实事故的关键路径：worker 已启动 → 授权 → 同一 worker 立即看到。
	// Lua 层面用回环无法区分（回环永远允许），因此这里的断言打在两层：
	// ① allowlist 对象层：已存在实例 add 后立即 allows() 新主机；
	// ② 插件层：SetOutboundHosts 重新折算后，同一 worker 的请求仍工作
	//    （即 rebuild 不会使旧引用失效）。
	host := "portal.example.com"

	// ① 对象层：不可变快照时代的 bug 复现点
	allow := newHTTPAllowlist(nil)
	worker := allow // 模拟 bootPluginState 绑定的指针
	if _, err := allow.checkURL("https://" + host + "/x"); err == nil {
		t.Fatal("前提不成立：未授权主机不应允许")
	}
	allow.add([]string{host}) // GrantExtraHosts 的实际路径（原地 add）
	if _, err := worker.checkURL("https://" + host + "/x"); err != nil {
		t.Fatalf("授权后，已绑定的旧引用仍拒绝新主机（快照 bug 复现）: %v", err)
	}

	// ② 插件层：同一 worker 在 rebuild 后仍可用
	ps2 := NewPlugins(NewVM(t.TempDir()), t.TempDir())
	ps2.SetOutboundHosts([]string{"127.0.0.1"})
	probe := `
local P = {}
P.name = "grantprobe"
P.version = "1.0"
P.exports = { "probe" }
P.hosts = { "portal.example.com" }
function P.probe(arg)
  local res, err = ` + httpGlobal + `({ url = arg.url, method = "GET" })
  if res == nil then return { error = tostring(err) } end
  return { status = res.status }
end
return P
`
	if err := ps2.LoadSource("grantprobe", probe); err != nil {
		t.Fatal(err)
	}
	// worker 已启动。现在授权（grant → rebuild → 原地 add）
	if err := ps2.GrantExtraHosts("grantprobe", []string{"portal.example.com"}); err != nil {
		t.Fatalf("grant: %v", err)
	}
	// 同一批 worker：一次调用成功即证明 allowlist 引用未被弃用
	got, err := ps2.Call("grantprobe", "probe", map[string]interface{}{"url": srv.URL})
	if err != nil {
		t.Fatal(err)
	}
	m, _ := got.(map[string]interface{})
	if m == nil || m["error"] != nil {
		t.Fatalf("授权后同一 worker 调用失败（引用被弃用）: %v", got)
	}
	if s, _ := m["status"].(float64); int(s) != 200 {
		t.Fatalf("status=%v, want 200", m["status"])
	}
}

// TestHostGrantsPersistAcrossRestart 是第二个真实缺陷的回归：host 授权此前只
// 写进运行态（extraHosts map），从不落盘 —— 重启后授权消失，插件出站全部被拦，
// 而设置页看不出任何异常（actions 有持久化、hosts 没有，读起来像"都持久化了"）。
func TestHostGrantsPersistAcrossRestart(t *testing.T) {
	dir := t.TempDir()
	ps := NewPlugins(NewVM(filepath.Join(dir, "adapters")), dir)
	if err := ps.LoadSource("grantprobe", `
local P = {}
P.name = "grantprobe"
P.version = "1.0"
P.exports = {}
P.hosts = { "portal.example.com", "api.partner.example" }
return P
`); err != nil {
		t.Fatal(err)
	}
	if err := ps.GrantExtraHosts("grantprobe", []string{"portal.example.com", "api.partner.example"}); err != nil {
		t.Fatal(err)
	}

	// 落盘验证
	b, err := os.ReadFile(filepath.Join(dir, ".kernel-perms.json"))
	if err != nil {
		t.Fatalf("授权未落盘: %v", err)
	}
	if !strings.Contains(string(b), "portal.example.com") {
		t.Fatalf("host 授权应写入 .kernel-perms.json，文件内容: %s", b)
	}

	// 重启语义：新 registry 读回授权
	ps2 := NewPlugins(NewVM(filepath.Join(dir, "adapters")), dir)
	if err := ps2.LoadKernelPermissions(); err != nil {
		t.Fatal(err)
	}
	got := ps2.ExtraHostsGranted()["grantprobe"]
	if len(got) != 2 {
		t.Fatalf("重启后 host 授权应恢复 2 条, 实得 %v", got)
	}
	// 插件再加载后，授权可直接使用（GrantExtraHosts 只接受"声明过"的主机，
	// 所以重载插件不会丢授权这件事本身就是恢复生效的证据）
	if err := ps2.LoadSource("grantprobe", `
local P = {}
P.name = "grantprobe"
P.version = "1.0"
P.exports = {}
P.hosts = { "portal.example.com", "api.partner.example" }
return P
`); err != nil {
		t.Fatal(err)
	}
	got = ps2.ExtraHostsGranted()["grantprobe"]
	if len(got) != 2 {
		t.Fatalf("插件重载后授权应保留, 实得 %v", got)
	}
}