package main

import (
	"encoding/json"
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"
)

func TestApplySMARTJSONReadsNVMeSelfTestHistory(t *testing.T) {
	disk := DiskMetrics{Path: "/dev/nvme0n1"}
	output := []byte(`{
		"model_name":"ADATA LEGEND 900",
		"smart_status":{"passed":true},
		"power_on_time":{"hours":960},
		"nvme_self_test_log":{
			"current_self_test_operation":{"value":0,"string":"No self-test in progress"},
			"table":[{
				"self_test_code":{"value":1,"string":"Short"},
				"self_test_result":{"value":0,"string":"Completed without error"},
				"power_on_hours":959
			}]
		}
	}`)

	before := time.Now().Add(-2 * time.Hour)
	applySMARTJSON(&disk, output)
	after := time.Now()

	if disk.SelfTestNeverRun {
		t.Fatal("завершённый NVMe self-test ошибочно отмечен как никогда не запускавшийся")
	}
	if disk.LastSelfTest != "Short · Completed without error" {
		t.Fatalf("неожиданный результат self-test: %q", disk.LastSelfTest)
	}
	parsed, err := time.Parse(time.RFC3339, disk.LastSelfTestAt)
	if err != nil || parsed.Before(before) || parsed.After(after) {
		t.Fatalf("неверно вычислено время self-test: %q, err=%v", disk.LastSelfTestAt, err)
	}
	if len(disk.AttentionReasons) != 0 || disk.SMARTStatus != "Исправен" {
		t.Fatalf("исправный NVMe требует внимания: %+v", disk)
	}
}

func TestIsPhysicalDiskName(t *testing.T) {
	tests := map[string]bool{
		"sda": true, "sdb": true, "nvme0n1": true,
		"loop0": false, "dm-0": false, "zram0": false, "md0": false,
	}
	for name, expected := range tests {
		if actual := isPhysicalDiskName(name); actual != expected {
			t.Fatalf("isPhysicalDiskName(%q) = %v, ожидалось %v", name, actual, expected)
		}
	}
}

func TestReadDiskIOStats(t *testing.T) {
	path := filepath.Join(t.TempDir(), "diskstats")
	data := "   8       0 sda 100 2 300 40 50 3 700 80 4 90 120 0 0 0 0 0 0\n   7       0 loop0 999 0 999 0 999 0 999 0 0 0 0\n"
	if err := os.WriteFile(path, []byte(data), 0o600); err != nil {
		t.Fatal(err)
	}
	stats := readDiskIOStats(path)
	disk, ok := stats["sda"]
	if !ok || disk.reads != 100 || disk.readSectors != 300 || disk.writes != 50 || disk.writeSectors != 700 || disk.inFlight != 4 || disk.ioMS != 90 || disk.weightedMS != 120 {
		t.Fatalf("unexpected stats: %+v", disk)
	}
	if _, exists := stats["loop0"]; exists {
		t.Fatal("virtual device must be ignored")
	}
}

func TestSumFilesystemUsage(t *testing.T) {
	device := lsblkDevice{Children: []lsblkDevice{
		{FSUsed: json.RawMessage(`100`), FSAvail: json.RawMessage(`300`)},
		{FSUsed: json.RawMessage(`200`), FSAvail: json.RawMessage(`400`)},
	}}
	used, total, ok := sumFilesystemUsage(device)
	if !ok || used != 300 || total != 1000 {
		t.Fatalf("неожиданное использование диска: used=%d total=%d ok=%v", used, total, ok)
	}
}

func TestApplyATAWearAndReason(t *testing.T) {
	var smart smartctlJSON
	attribute := struct {
		Name       string `json:"name"`
		Value      int    `json:"value"`
		Threshold  int    `json:"thresh"`
		WhenFailed string `json:"when_failed"`
		Raw        struct {
			String string `json:"string"`
			Value  int64  `json:"value"`
		} `json:"raw"`
	}{Name: "SSD_Life_Left", Value: 92, WhenFailed: "FAILING_NOW"}
	smart.ATAAttributes.Table = append(smart.ATAAttributes.Table, attribute)
	disk := DiskMetrics{}
	applyATAAttributes(&disk, smart)
	if disk.WearUsedPercent == nil || *disk.WearUsedPercent != 8 {
		t.Fatalf("неожиданный износ: %v", disk.WearUsedPercent)
	}
	if len(disk.AttentionReasons) != 1 {
		t.Fatalf("причина предупреждения не добавлена: %+v", disk)
	}
}

func TestHistoricalATAFailureDoesNotRequireAttention(t *testing.T) {
	var smart smartctlJSON
	attribute := struct {
		Name       string `json:"name"`
		Value      int    `json:"value"`
		Threshold  int    `json:"thresh"`
		WhenFailed string `json:"when_failed"`
		Raw        struct {
			String string `json:"string"`
			Value  int64  `json:"value"`
		} `json:"raw"`
	}{Name: "Airflow_Temperature_Cel", WhenFailed: "In_the_past"}
	attribute.Raw.String = "46 (Min/Max 26/47 #15)"
	smart.ATAAttributes.Table = append(smart.ATAAttributes.Table, attribute)
	disk := DiskMetrics{}
	applyATAAttributes(&disk, smart)
	applySMARTExitStatus(&disk, 32|64|128)
	if len(disk.AttentionReasons) != 0 {
		t.Fatalf("историческая ошибка стала активной: %+v", disk.AttentionReasons)
	}
	if len(disk.SMARTHistory) != 4 {
		t.Fatalf("история SMART потеряна: %+v", disk.SMARTHistory)
	}
}

func TestSMARTErrorLogGrowthRequiresAttention(t *testing.T) {
	old := DiskMetrics{SMARTErrorCount: 2}
	current := DiskMetrics{SMARTErrorCount: 3}
	changes := diskCounterChanges(old, current)
	if len(changes) != 1 || !strings.Contains(changes[0], "2 → 3") {
		t.Fatalf("рост журнала не обнаружен: %+v", changes)
	}
}