package ctxmgr_test

import (
	"context"
	"math"
	"testing"

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

func TestDeterministicEmbedder_EmbeddingProperties(t *testing.T) {
	emb := ctxmgr.NewDeterministicEmbedder(1024)
	ctx := context.Background()

	texts := []string{
		"超声软组织切割止血手术设备",
		"微创外科硬管内窥镜摄像系统",
		"超声软组织切割止血手术设备", // 重复文本验证确定性
	}

	vecs, err := emb.Embed(ctx, texts)
	if err != nil {
		t.Fatalf("embed failed: %v", err)
	}
	if len(vecs) != 3 {
		t.Fatalf("expected 3 vectors, got %d", len(vecs))
	}

	// 1. 验证维度
	for i, v := range vecs {
		if len(v) != 1024 {
			t.Fatalf("vector %d length expected 1024, got %d", i, len(v))
		}
		// 验证单位化模长 (L2 norm ≈ 1.0)
		var sumSq float64
		for _, val := range v {
			sumSq += float64(val * val)
		}
		norm := math.Sqrt(sumSq)
		if math.Abs(norm-1.0) > 1e-4 {
			t.Fatalf("vector %d not normalized, norm=%f", i, norm)
		}
	}

	// 2. 验证确定性：相同文本向量完全一致
	for i := 0; i < 1024; i++ {
		if vecs[0][i] != vecs[2][i] {
			t.Fatalf("deterministic mismatch at index %d: %v vs %v", i, vecs[0][i], vecs[2][i])
		}
	}

	// 3. 验证语义区别：不同文本余弦相似度应小于 0.95
	var dotProduct float32
	for i := 0; i < 1024; i++ {
		dotProduct += vecs[0][i] * vecs[1][i]
	}
	if dotProduct > 0.95 {
		t.Fatalf("distinct texts should not have near-identical embeddings: dotProduct=%f", dotProduct)
	}

	// 4. 验证 VectorLiteral
	lit := ctxmgr.VectorLiteral(vecs[0][:3])
	if lit == "" || lit[0] != '[' || lit[len(lit)-1] != ']' {
		t.Fatalf("invalid vector literal: %s", lit)
	}
}