package engine

import (
	"testing"

	"git.kingecg.top/kingecg/gomog/pkg/types"
)

func TestUnionWith_Simple(t *testing.T) {
	store := NewMemoryStore(nil)
	engine := NewAggregationEngine(store)

	// 创建两个测试集合
	CreateTestCollectionForTesting(store, "orders2023", map[string]types.Document{
		"order1": {ID: "order1", Data: map[string]interface{}{"year": float64(2023), "amount": float64(100)}},
		"order2": {ID: "order2", Data: map[string]interface{}{"year": float64(2023), "amount": float64(150)}},
	})
	CreateTestCollectionForTesting(store, "orders2024", map[string]types.Document{
		"order3": {ID: "order3", Data: map[string]interface{}{"year": float64(2024), "amount": float64(200)}},
	})

	// 执行 union（简写形式）
	pipeline := []types.AggregateStage{
		{Stage: "$match", Spec: map[string]interface{}{"year": float64(2023)}},
		{Stage: "$unionWith", Spec: "orders2024"},
	}

	results, err := engine.Execute("orders2023", pipeline)
	if err != nil {
		t.Fatalf("Execute() error = %v", err)
	}

	// 应该返回 3 个文档（1 个来自 2023 + 2 个来自 2024）
	if len(results) != 3 {
		t.Errorf("Expected 3 results, got %d", len(results))
	}
}

func TestUnionWith_Pipeline(t *testing.T) {
	store := NewMemoryStore(nil)
	engine := NewAggregationEngine(store)

	// 创建两个测试集合
	CreateTestCollectionForTesting(store, "sales_q1", map[string]types.Document{
		"s1": {ID: "s1", Data: map[string]interface{}{"quarter": "Q1", "amount": float64(100)}},
	})
	CreateTestCollectionForTesting(store, "sales_q2", map[string]types.Document{
		"s2": {ID: "s2", Data: map[string]interface{}{"quarter": "Q2", "amount": float64(200)}},
		"s3": {ID: "s3", Data: map[string]interface{}{"quarter": "Q2", "amount": float64(50)}},
	})

	// 执行 union 带 pipeline
	pipeline := []types.AggregateStage{
		{Stage: "$unionWith", Spec: map[string]interface{}{
			"coll": "sales_q2",
			"pipeline": []interface{}{
				map[string]interface{}{
					"$match": map[string]interface{}{
						"amount": map[string]interface{}{"$gt": float64(100)},
					},
				},
			},
		}},
	}

	results, err := engine.Execute("sales_q1", pipeline)
	if err != nil {
		t.Fatalf("Execute() error = %v", err)
	}

	// 应该返回 2 个文档（1 个来自 Q1 + 1 个过滤后的 Q2）
	if len(results) != 2 {
		t.Errorf("Expected 2 results, got %d", len(results))
	}
}

func TestRedact_Keep(t *testing.T) {
	engine := &AggregationEngine{}

	data := map[string]interface{}{
		"_id":   float64(1),
		"name":  "Alice",
		"level": float64(5),
	}

	spec := map[string]interface{}{
		"$cond": map[string]interface{}{
			"if": map[string]interface{}{
				"$gte": []interface{}{"$level", float64(5)},
			},
			"then": "$$KEEP",
			"else": "$$PRUNE",
		},
	}

	docs := []types.Document{{ID: "1", Data: data}}
	results, err := engine.executeRedact(spec, docs)

	if err != nil {
		t.Fatalf("executeRedact() error = %v", err)
	}

	if len(results) != 1 {
		t.Errorf("Expected 1 result, got %d", len(results))
	}
}

func TestRedact_Prune(t *testing.T) {
	engine := &AggregationEngine{}

	data := map[string]interface{}{
		"_id":   float64(1),
		"name":  "Bob",
		"level": float64(2),
	}

	spec := map[string]interface{}{
		"$cond": map[string]interface{}{
			"if": map[string]interface{}{
				"$gte": []interface{}{"$level", float64(5)},
			},
			"then": "$$KEEP",
			"else": "$$PRUNE",
		},
	}

	docs := []types.Document{{ID: "2", Data: data}}
	results, err := engine.executeRedact(spec, docs)

	if err != nil {
		t.Fatalf("executeRedact() error = %v", err)
	}

	if len(results) != 0 {
		t.Errorf("Expected 0 results (pruned), got %d", len(results))
	}
}

func TestOut_Simple(t *testing.T) {
	store := NewMemoryStore(nil)
	engine := NewAggregationEngine(store)

	CreateTestCollectionForTesting(store, "source", map[string]types.Document{
		"doc1": {ID: "doc1", Data: map[string]interface{}{"value": float64(1)}},
		"doc2": {ID: "doc2", Data: map[string]interface{}{"value": float64(2)}},
	})

	pipeline := []types.AggregateStage{
		{Stage: "$out", Spec: "output"},
	}

	results, err := engine.Execute("source", pipeline)
	if err != nil {
		t.Fatalf("Execute() error = %v", err)
	}

	// 验证输出集合已创建
	outputDocs, err := store.GetAllDocuments("output")
	if err != nil {
		t.Fatalf("GetAllDocuments() error = %v", err)
	}

	if len(outputDocs) != 2 {
		t.Errorf("Expected 2 documents in output, got %d", len(outputDocs))
	}

	// 验证返回的确认文档
	if len(results) != 1 {
		t.Errorf("Expected 1 result document, got %d", len(results))
	}
	if results[0].Data["ok"] != float64(1) {
		t.Errorf("Expected ok=1, got %v", results[0].Data["ok"])
	}
	if results[0].Data["nInserted"] != float64(2) {
		t.Errorf("Expected nInserted=2, got %v", results[0].Data["nInserted"])
	}
}

func TestMerge_Insert(t *testing.T) {
	store := NewMemoryStore(nil)
	engine := NewAggregationEngine(store)

	CreateTestCollectionForTesting(store, "source", map[string]types.Document{
		"doc1": {ID: "doc1", Data: map[string]interface{}{"value": float64(1)}},
	})

	// 目标集合不存在，应该插入
	pipeline := []types.AggregateStage{
		{Stage: "$merge", Spec: map[string]interface{}{
			"into": "target",
		}},
	}

	results, err := engine.Execute("source", pipeline)
	if err != nil {
		t.Fatalf("Execute() error = %v", err)
	}

	// 验证目标集合已创建并插入文档
	targetDocs, err := store.GetAllDocuments("target")
	if err != nil {
		t.Fatalf("GetAllDocuments() error = %v", err)
	}

	if len(targetDocs) != 1 {
		t.Errorf("Expected 1 document in target, got %d", len(targetDocs))
	}

	// 验证统计信息
	if len(results) != 1 {
		t.Errorf("Expected 1 result document, got %d", len(results))
	}
	stats := results[0].Data
	if stats["nInserted"] != float64(1) {
		t.Errorf("Expected nInserted=1, got %v", stats["nInserted"])
	}
}

func TestMerge_Update(t *testing.T) {
	store := NewMemoryStore(nil)
	engine := NewAggregationEngine(store)

	// 创建源集合和目标集合
	CreateTestCollectionForTesting(store, "source", map[string]types.Document{
		"doc1": {ID: "doc1", Data: map[string]interface{}{"value": float64(100), "updated": true}},
	})
	CreateTestCollectionForTesting(store, "target", map[string]types.Document{
		"doc1": {ID: "doc1", Data: map[string]interface{}{"value": float64(1), "name": "original"}},
	})

	// 使用 replace 策略更新
	pipeline := []types.AggregateStage{
		{Stage: "$merge", Spec: map[string]interface{}{
			"into":        "target",
			"whenMatched": "replace",
		}},
	}

	results, err := engine.Execute("source", pipeline)
	if err != nil {
		t.Fatalf("Execute() error = %v", err)
	}

	// 验证目标集合已更新
	targetDocs, err := store.GetAllDocuments("target")
	if err != nil {
		t.Fatalf("GetAllDocuments() error = %v", err)
	}

	if len(targetDocs) != 1 {
		t.Errorf("Expected 1 document in target, got %d", len(targetDocs))
	}

	// 验证文档内容被替换
	doc := targetDocs[0].Data
	if doc["value"] != float64(100) {
		t.Errorf("Expected value=100, got %v", doc["value"])
	}
	if doc["updated"] != true {
		t.Errorf("Expected updated=true, got %v", doc["updated"])
	}
	if _, exists := doc["name"]; exists {
		t.Errorf("Expected name field to be removed, but it exists")
	}

	// 验证统计信息
	stats := results[0].Data
	if stats["nUpdated"] != float64(1) {
		t.Errorf("Expected nUpdated=1, got %v", stats["nUpdated"])
	}
}

func TestMerge_MergeFields(t *testing.T) {
	store := NewMemoryStore(nil)
	engine := NewAggregationEngine(store)

	// 创建源集合和目标集合
	CreateTestCollectionForTesting(store, "source", map[string]types.Document{
		"doc1": {ID: "doc1", Data: map[string]interface{}{"value": float64(100), "newField": "added"}},
	})
	CreateTestCollectionForTesting(store, "target", map[string]types.Document{
		"doc1": {ID: "doc1", Data: map[string]interface{}{"value": float64(1), "name": "original"}},
	})

	// 使用 merge 策略合并字段
	pipeline := []types.AggregateStage{
		{Stage: "$merge", Spec: map[string]interface{}{
			"into":        "target",
			"whenMatched": "merge",
		}},
	}

	results, err := engine.Execute("source", pipeline)
	if err != nil {
		t.Fatalf("Execute() error = %v", err)
	}

	// 验证目标集合已合并
	targetDocs, err := store.GetAllDocuments("target")
	if err != nil {
		t.Fatalf("GetAllDocuments() error = %v", err)
	}

	if len(targetDocs) != 1 {
		t.Errorf("Expected 1 document in target, got %d", len(targetDocs))
	}

	// 验证字段合并：新值覆盖旧值，旧字段保留
	doc := targetDocs[0].Data
	if doc["value"] != float64(100) {
		t.Errorf("Expected value=100, got %v", doc["value"])
	}
	if doc["name"] != "original" {
		t.Errorf("Expected name='original', got %v", doc["name"])
	}
	if doc["newField"] != "added" {
		t.Errorf("Expected newField='added', got %v", doc["newField"])
	}

	// 验证统计信息
	stats := results[0].Data
	if stats["nUpdated"] != float64(1) {
		t.Errorf("Expected nUpdated=1, got %v", stats["nUpdated"])
	}
}

func TestIndexStats(t *testing.T) {
	store := NewMemoryStore(nil)
	engine := NewAggregationEngine(store)

	CreateTestCollectionForTesting(store, "test", map[string]types.Document{
		"doc1": {ID: "doc1", Data: map[string]interface{}{"value": float64(1)}},
	})

	pipeline := []types.AggregateStage{
		{Stage: "$indexStats", Spec: map[string]interface{}{}},
	}

	_, err := engine.Execute("test", pipeline)
	if err != nil {
		t.Fatalf("Execute() error = %v", err)
	}
}

func TestCollStats(t *testing.T) {
	store := NewMemoryStore(nil)
	engine := NewAggregationEngine(store)

	CreateTestCollectionForTesting(store, "teststats", map[string]types.Document{
		"doc1": {ID: "doc1", Data: map[string]interface{}{"value": float64(1)}},
		"doc2": {ID: "doc2", Data: map[string]interface{}{"value": float64(2)}},
	})

	pipeline := []types.AggregateStage{
		{Stage: "$collStats", Spec: map[string]interface{}{}},
	}

	results, err := engine.Execute("teststats", pipeline)
	if err != nil {
		t.Fatalf("Execute() error = %v", err)
	}

	if len(results) != 1 {
		t.Errorf("Expected 1 result, got %d", len(results))
	}

	// 验证统计信息
	stats := results[0].Data
	if stats["count"] != float64(2) {
		t.Errorf("Expected count=2, got %v", stats["count"])
	}
	if size, ok := stats["size"].(float64); !ok || size <= 0 {
		t.Error("Expected positive size")
	}
}