package services

import (
	"strings"
	"testing"

	lokimodels "lokistack/models"
)

// YAML 双模式的核心保证：**表单 → YAML → 表单 必须无损往返**。
// 如果往返丢字段（比如 multiline.maxLines 或 rateLimit），用户切一下模式
// 配置就被悄悄改掉了，这是最难排查的一类问题。
func TestRenderParseJobsYAMLRoundTrip(t *testing.T) {
	original := []lokimodels.ScrapeJob{
		{
			Name:  "app",
			Paths: []string{"/var/log/app/*.log", "/data/logs/*.log"},
			Labels: map[string]string{
				"tier": "backend",
			},
			Encoding: "utf-8",
			JSON:     true,
			Multiline: &lokimodels.JobMultiline{
				FirstLine: `^\d{4}-\d{2}-\d{2}`,
				MaxLines:  256,
			},
			DropIfMatch: []string{`/healthz`, `/metrics`},
			RateLimit:   &lokimodels.JobRateLimit{Rate: 2000, Burst: 4000},
			Timestamp: &lokimodels.JobTimestamp{
				Source:   "ts",
				Format:   "RFC3339Nano",
				Location: "Local",
			},
		},
		{
			Name:   "system",
			Paths:  []string{"/var/log/messages"},
			System: true,
		},
	}

	text, err := RenderJobsYAML(original)
	if err != nil {
		t.Fatalf("渲染失败: %v", err)
	}
	// 头部注释必须说明"这不是完整 promtail 配置"，避免用户以为能改 clients
	if !strings.Contains(text, "clients") || !strings.Contains(text, "不在此处修改") {
		t.Error("渲染结果缺少边界说明注释")
	}

	parsed, err := ParseJobsYAML(text)
	if err != nil {
		t.Fatalf("解析失败: %v\n--- YAML ---\n%s", err, text)
	}
	if len(parsed) != len(original) {
		t.Fatalf("采集项数量不符: got %d want %d", len(parsed), len(original))
	}

	first := parsed[0]
	if first.Name != "app" || len(first.Paths) != 2 {
		t.Errorf("基础字段丢失: %+v", first)
	}
	if first.Multiline == nil || first.Multiline.MaxLines != 256 {
		t.Errorf("multiline 丢失: %+v", first.Multiline)
	}
	if first.RateLimit == nil || first.RateLimit.Rate != 2000 || first.RateLimit.Burst != 4000 {
		t.Errorf("rateLimit 丢失: %+v", first.RateLimit)
	}
	if len(first.DropIfMatch) != 2 {
		t.Errorf("dropIfMatch 丢失: %+v", first.DropIfMatch)
	}
	if !first.JSON || first.Encoding != "utf-8" {
		t.Errorf("json/encoding 丢失: json=%v enc=%q", first.JSON, first.Encoding)
	}
	if first.Timestamp == nil || first.Timestamp.Source != "ts" || first.Timestamp.Location != "Local" {
		t.Errorf("timestamp 丢失: %+v", first.Timestamp)
	}
	if first.Labels["tier"] != "backend" {
		t.Errorf("labels 丢失: %+v", first.Labels)
	}
	if !parsed[1].System {
		t.Error("system 标记丢失")
	}
}

// 报错必须具体：语法错要能定位，语义错要指出是哪个采集项，不能笼统"格式错误"。
func TestParseJobsYAMLErrors(t *testing.T) {
	cases := []struct {
		name string
		in   string
		want string
	}{
		{"空内容", "   ", "YAML 为空"},
		{"语法错误", "- name: app\n  paths: [/a\n", "YAML 语法错误"},
		{"空列表", "[]", "没有采集项"},
		{"缺名称", "- paths: [/var/log/x.log]", "缺少名称"},
		{"缺路径", "- name: app", "至少需要填写一个日志路径"},
		{"名称非法", "- name: 'bad name!'\n  paths: [/a]", "不合法"},
	}
	for _, c := range cases {
		t.Run(c.name, func(t *testing.T) {
			_, err := ParseJobsYAML(c.in)
			if err == nil {
				t.Fatalf("期望报错，实际通过")
			}
			if !strings.Contains(err.Error(), c.want) {
				t.Errorf("错误信息不够具体: got %q, want contains %q", err.Error(), c.want)
			}
		})
	}
}