package parser

import (
	"testing"
	"time"
)

func TestParseErrorLine_WithConnID(t *testing.T) {
	line := `2024/02/20 16:45:01 [error] 1234#5678: *99 connect() failed (111: Connection refused) while connecting to upstream`
	entry, err := ParseErrorLine(line)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	want := time.Date(2024, 2, 20, 16, 45, 1, 0, time.UTC)
	if !entry.Time.Equal(want) {
		t.Errorf("Time = %v, want %v", entry.Time, want)
	}
	if entry.Level != "error" {
		t.Errorf("Level = %q, want %q", entry.Level, "error")
	}
	if entry.PID != 1234 {
		t.Errorf("PID = %d, want 1234", entry.PID)
	}
	if entry.TID != 5678 {
		t.Errorf("TID = %d, want 5678", entry.TID)
	}
	if entry.ConnID != 99 {
		t.Errorf("ConnID = %d, want 99", entry.ConnID)
	}
	if entry.Message != "connect() failed (111: Connection refused) while connecting to upstream" {
		t.Errorf("Message = %q", entry.Message)
	}
}

func TestParseErrorLine_WithoutConnID(t *testing.T) {
	line := `2024/02/20 17:00:00 [warn] 1234#5678: worker process 9999 exited on signal 15`
	entry, err := ParseErrorLine(line)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if entry.Level != "warn" {
		t.Errorf("Level = %q, want %q", entry.Level, "warn")
	}
	if entry.ConnID != 0 {
		t.Errorf("ConnID = %d, want 0", entry.ConnID)
	}
	if entry.Message != "worker process 9999 exited on signal 15" {
		t.Errorf("Message = %q", entry.Message)
	}
}

func TestParseErrorLine_AllLevels(t *testing.T) {
	levels := []string{"debug", "info", "notice", "warn", "error", "crit", "alert", "emerg"}
	for _, level := range levels {
		line := "2024/01/01 00:00:00 [" + level + "] 100#200: test message"
		entry, err := ParseErrorLine(line)
		if err != nil {
			t.Errorf("level %q: unexpected error: %v", level, err)
			continue
		}
		if entry.Level != level {
			t.Errorf("level %q: got Level = %q", level, entry.Level)
		}
	}
}

func TestParseErrorLine_Info(t *testing.T) {
	line := `2024/02/21 08:30:00 [info] 1234#5678: start worker process 10001`
	entry, err := ParseErrorLine(line)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if entry.Level != "info" {
		t.Errorf("Level = %q, want info", entry.Level)
	}
	if entry.PID != 1234 {
		t.Errorf("PID = %d, want 1234", entry.PID)
	}
}

func TestParseErrorLine_Malformed(t *testing.T) {
	cases := []string{
		"this is a malformed line",
		"",
		"2024/02/20 not-a-proper-format",
	}
	for _, c := range cases {
		_, err := ParseErrorLine(c)
		if err == nil {
			t.Errorf("expected error for malformed line %q, got nil", c)
		}
	}
}