package app

import (
	"sync"
	"testing"
)

func resetMcpCache() {
	mcpMu.Lock()
	defer mcpMu.Unlock()
	if mcpManager != nil {
		mcpManager.Close()
	}
	mcpKey, mcpManager = "", nil
}

func TestMcpManagerForCacheAndRebuild(t *testing.T) {
	resetMcpCache()
	defer resetMcpCache()

	cfgA := `[{"name":"a","command":"/bin/true"}]`
	cfgB := `[{"name":"b","command":"/bin/true"}]`

	m1 := mcpManagerFor(cfgA, "")
	if m1 == nil {
		t.Fatal("valid config must build a manager")
	}
	if m2 := mcpManagerFor(cfgA, ""); m2 != m1 {
		t.Fatal("same config must reuse the cached manager")
	}
	m3 := mcpManagerFor(cfgB, "")
	if m3 == nil || m3 == m1 {
		t.Fatal("changed config must rebuild a fresh manager")
	}
	if mcpManagerFor("", "") != nil {
		t.Fatal("empty config disables MCP and clears the cache")
	}
	if mcpManagerFor(`{bad json`, "") != nil {
		t.Fatal("invalid JSON must disable MCP (nil), not panic")
	}
	if mcpManagerFor(`[{"name":"bad name","command":"x"}]`, "") != nil {
		t.Fatal("invalid server config must disable MCP (nil)")
	}
	// 并发调用不死锁、返回同一实例或各自重建（缓存一致性由锁保证）。
	var wg sync.WaitGroup
	for i := 0; i < 8; i++ {
		wg.Add(1)
		go func() {
			defer wg.Done()
			_ = mcpManagerFor(cfgB, "")
		}()
	}
	wg.Wait()
}

func TestMcpCacheConcurrencyWithSettingsResolution(t *testing.T) {
	resetMcpCache()
	defer resetMcpCache()
	var wg sync.WaitGroup
	cfgs := []string{
		`[{"name":"a","command":"/bin/true"}]`,
		`[{"name":"b","command":"/bin/true"}]`,
		"",
	}
	for i := 0; i < 12; i++ {
		wg.Add(1)
		go func(i int) {
			defer wg.Done()
			_ = mcpManagerFor(cfgs[i%len(cfgs)], "")
		}(i)
	}
	wg.Wait()
}