// config_plugins_test.go - regression guards for engine.Config.Plugins wiring.
//
// Before this commit, Config.Plugins was defined on the SDK-facing Config
// struct but never read anywhere in engine.New -- a dead field siblings to
// Config.MCPServers (fixed in 57a06c6). The fix in this commit wires
// loadConfigPlugins into New. The tests below lock that wiring in place so
// any future refactor that stops reading the field fails CI immediately.
//
// 本 commit 之前, Config.Plugins 在 SDK 面向的 Config struct 里定义但
// engine.New 从未读过它 -- 是和 Config.MCPServers (57a06c6 已修) 同类
// 的死字段. 本 commit 把 loadConfigPlugins wire 进 New. 下面的测试把
// 这条 wiring 锁住, 未来任何 refactor 如果停止读此字段会被 CI 直接拦下.

package engine

import (
	"testing"

	"git.flytoex.net/yuanwei/flyto-agent/pkg/plugin"
)

// TestConfigPlugins_FieldIsRead is the primary regression guard: it proves
// engine.New actually reads Config.Plugins and routes each entry through
// plugin.Host.Load. We verify both the observer summary event (cheap,
// decoupled from Host internals) AND the host registry state (direct proof
// that Load was called). If the field silently stops being read, both
// checks fail simultaneously.
//
// TestConfigPlugins_FieldIsRead 是核心 regression guard: 证明 engine.New
// 真的读了 Config.Plugins 且每个 entry 都走了 plugin.Host.Load. 两条证据
// 并存: observer 汇总事件 (成本低, 与 Host 内部解耦) 以及 host registry
// 实际状态 (Load 确实被调过的直接证据). 未来若字段再次被静默不读, 两条
// 断言一起失败.
func TestConfigPlugins_FieldIsRead(t *testing.T) {
	obs := &MockObserver{}
	cfg := testConfig()
	cfg.Observer = obs
	cfg.Plugins = []plugin.Definition{
		{Name: "alpha", Description: "first", Source: "/opt/plugins/alpha"},
		{Name: "beta", Description: "second", Source: "/opt/plugins/beta"},
	}
	eng, err := New(cfg)
	if err != nil {
		t.Fatalf("engine.New: %v", err)
	}
	defer eng.Close()

	last := obs.LastEvent("config_plugins_loaded")
	if last == nil {
		t.Fatal("config_plugins_loaded event missing (loadConfigPlugins never ran?)")
	}
	if pc, _ := last.Data["plugin_count"].(int); pc != 2 {
		t.Errorf("plugin_count: want 2, got %v", last.Data["plugin_count"])
	}

	for _, name := range []string{"alpha", "beta"} {
		if _, ok := eng.plugins.Get(name); !ok {
			t.Errorf("plugin %q not found in host registry after New; Host.Load was not invoked", name)
		}
	}
}

// TestConfigPlugins_EmptyNameSkipped verifies an entry with an empty Name
// produces a config_plugin_skipped observer event and does not register
// an empty-Name placeholder (which would pollute the host registry with a
// "" key and collide on future inserts).
//
// TestConfigPlugins_EmptyNameSkipped 验证空 Name 的 entry 会触发
// config_plugin_skipped 事件, 且不会以 "" 为 key 污染 host registry
// (否则将来插入同名会撞上).
func TestConfigPlugins_EmptyNameSkipped(t *testing.T) {
	obs := &MockObserver{}
	cfg := testConfig()
	cfg.Observer = obs
	cfg.Plugins = []plugin.Definition{
		{Name: "", Description: "no name", Source: "/opt/plugins/anon"},
		{Name: "real", Description: "keeps loading", Source: "/opt/plugins/real"},
	}
	eng, err := New(cfg)
	if err != nil {
		t.Fatalf("engine.New: %v", err)
	}
	defer eng.Close()

	if got := obs.EventCount("config_plugin_skipped"); got != 1 {
		t.Errorf("config_plugin_skipped count: want 1, got %d", got)
	}
	last := obs.LastEvent("config_plugins_loaded")
	if last == nil {
		t.Fatal("config_plugins_loaded event missing")
	}
	if pc, _ := last.Data["plugin_count"].(int); pc != 1 {
		t.Errorf("plugin_count: want 1 (empty-Name skipped), got %v", last.Data["plugin_count"])
	}
	if _, ok := eng.plugins.Get(""); ok {
		t.Error(`host registry contains "" key; empty-Name entry leaked past the skip guard`)
	}
	if _, ok := eng.plugins.Get("real"); !ok {
		t.Error("plugin \"real\" missing; skip guard broke sibling entries")
	}
}

// TestConfigPlugins_EmptySliceIsNoop verifies the common path -- SDK
// consumers who do not use this field see no overhead and no observer
// noise. Mirrors the semantics of TestConfigMCPServers_EmptySliceIsNoop.
//
// TestConfigPlugins_EmptySliceIsNoop 验证通用路径: 不用此字段的 SDK
// 消费方没任何开销, observer 无噪音事件. 对齐
// TestConfigMCPServers_EmptySliceIsNoop.
func TestConfigPlugins_EmptySliceIsNoop(t *testing.T) {
	obs := &MockObserver{}
	cfg := testConfig()
	cfg.Observer = obs
	// cfg.Plugins left nil intentionally.
	eng, err := New(cfg)
	if err != nil {
		t.Fatalf("engine.New: %v", err)
	}
	defer eng.Close()

	for _, ev := range []string{
		"config_plugin_skipped",
		"config_plugin_load_failed",
		"config_plugins_loaded",
	} {
		if got := obs.EventCount(ev); got != 0 {
			t.Errorf("%s count: want 0 for nil Plugins, got %d", ev, got)
		}
	}
}