package services

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
	"time"

	"lokistack/models"
)

// TestLokiMetricsParsesMatrixSeries 用假 Loki 验证指标代理:
// [$step] 占位符替换 + matrix 多序列解析(按 app/namespace 分组)。
func TestLokiMetricsParsesMatrixSeries(t *testing.T) {
	var gotQuery, gotStep string
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		gotQuery = r.URL.Query().Get("query")
		gotStep = r.URL.Query().Get("step")
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`{
			"status": "success",
			"data": {
				"resultType": "matrix",
				"result": [
					{
						"metric": {"app": "web", "namespace": "prod"},
						"values": [[1.79e+09, "10"], [1.79e+09, "20"]]
					},
					{
						"metric": {"app": "api", "namespace": "prod"},
						"values": [[1.79e+09, "5"]]
					},
					{
						"metric": {"app": "empty", "namespace": "prod"},
						"values": []
					}
				]
			}
		}`))
	}))
	defer server.Close()

	src := &models.LogSource{TargetType: "url", URL: server.URL, AuthType: "none"}
	query := `sum by (app, namespace) (count_over_time({namespace=~".+"}[$step]))`
	end := time.Now().UnixNano()
	start := end - int64(time.Hour)

	series, err := LokiMetrics(context.Background(), src, query, start, end)
	if err != nil {
		t.Fatalf("LokiMetrics: %v", err)
	}

	// 占位符被替换为 1h 跨度对应的步长,且 query_range 带上了同样的 step
	if gotQuery == query || !strings.Contains(gotQuery, `count_over_time({namespace=~".+"}[`) {
		t.Fatalf("[$step] not replaced, got %q", gotQuery)
	}
	if gotStep == "" || !strings.Contains(gotQuery, "["+gotStep+"]") {
		t.Fatalf("step mismatch: query=%q step=%q", gotQuery, gotStep)
	}

	// 空序列被丢弃,两条有效序列带标签返回
	if len(series) != 2 {
		t.Fatalf("want 2 series, got %d", len(series))
	}
	if series[0].Labels["app"] != "web" || series[0].Labels["namespace"] != "prod" {
		t.Fatalf("labels not parsed: %+v", series[0].Labels)
	}
	if len(series[0].Points) != 2 || series[0].Points[0].Value != 10 || series[0].Points[1].Value != 20 {
		t.Fatalf("points not parsed: %+v", series[0].Points)
	}
	if series[0].Points[0].Timestamp == "" {
		t.Fatal("timestamp not formatted")
	}

	// 响应可 JSON 序列化(controller 直接 utils.Success 包装)
	if _, err := json.Marshal(series); err != nil {
		t.Fatalf("marshal: %v", err)
	}
}