package ctxmgr_test

import (
	"testing"

	"chat-agent-system/internal/ctxmgr"
)

func TestMultiLevelCache_BasicOpsAndStats(t *testing.T) {
	cache := ctxmgr.NewMultiLevelCache()
	cache.Clear()

	key := ctxmgr.HashKey("test_user", "test_query")

	// 1. 首次读取未命中
	val, ok := cache.Get(ctxmgr.LayerC1Search, key)
	if ok || val != nil {
		t.Fatalf("expected cache miss, got %v", val)
	}

	// 2. 写入并读取命中
	cache.Set(ctxmgr.LayerC1Search, key, "result_items", 45)
	val, ok = cache.Get(ctxmgr.LayerC1Search, key)
	if !ok || val.(string) != "result_items" {
		t.Fatalf("expected cache hit with 'result_items', got %v", val)
	}

	// 3. 校验统计指标
	stats := cache.Stats()
	if stats.Hits != 1 || stats.Misses != 1 {
		t.Errorf("unexpected stats: hits=%d, misses=%d", stats.Hits, stats.Misses)
	}
	if stats.SavedMs != 45 {
		t.Errorf("expected savedMs=45, got %d", stats.SavedMs)
	}
	if stats.HitRate != 0.5 {
		t.Errorf("expected hitRate=0.5, got %f", stats.HitRate)
	}

	// 4. 单条 Key 失效
	cache.Invalidate(ctxmgr.LayerC1Search, key)
	_, ok = cache.Get(ctxmgr.LayerC1Search, key)
	if ok {
		t.Errorf("expected cache miss after invalidation")
	}
}

func TestMultiLevelCache_LayerInvalidation(t *testing.T) {
	cache := ctxmgr.NewMultiLevelCache()
	cache.Clear()

	k1 := ctxmgr.HashKey("u1", "p1")
	k2 := ctxmgr.HashKey("u2", "p2")

	cache.Set(ctxmgr.LayerC4Context, k1, "ctx_1", 20)
	cache.Set(ctxmgr.LayerC4Context, k2, "ctx_2", 20)

	// 整体清空 C4 层
	cache.InvalidateLayer(ctxmgr.LayerC4Context)

	if _, ok := cache.Get(ctxmgr.LayerC4Context, k1); ok {
		t.Errorf("expected k1 in C4 to be cleared")
	}
	if _, ok := cache.Get(ctxmgr.LayerC4Context, k2); ok {
		t.Errorf("expected k2 in C4 to be cleared")
	}
}

func TestMultiLevelCache_DisabledToggle(t *testing.T) {
	cache := ctxmgr.NewMultiLevelCache()
	cache.SetEnabled(false)

	key := ctxmgr.HashKey("k_disabled")
	cache.Set(ctxmgr.LayerC2Rewrite, key, "rewritten", 10)

	if _, ok := cache.Get(ctxmgr.LayerC2Rewrite, key); ok {
		t.Errorf("expected cache to be inactive when disabled")
	}

	cache.SetEnabled(true)
	cache.Set(ctxmgr.LayerC2Rewrite, key, "rewritten", 10)
	if _, ok := cache.Get(ctxmgr.LayerC2Rewrite, key); !ok {
		t.Errorf("expected cache to be active when enabled")
	}
}