package main

import (
	"bytes"
	"net/netip"
	"os"
	"strings"
	"testing"
	"time"
)

func TestParseExampleLines(t *testing.T) {
	data, err := os.ReadFile("loglines_example.txt")
	if err != nil {
		t.Fatal(err)
	}
	p := newParser(time.Time{})
	if err := p.ingest(bytes.NewReader(data)); err != nil {
		t.Fatal(err)
	}

	want := map[string]int{
		"41.93.28.11":    2,
		"45.191.4.252":   2,
		"164.77.161.180": 2,
		"212.128.3.152":  2,
	}
	if len(p.events) != len(want) {
		t.Fatalf("got %d events, want %d", len(p.events), len(want))
	}
	for ipStr, count := range want {
		ev, ok := p.events[netip.MustParseAddr(ipStr)]
		if !ok {
			t.Errorf("missing event for %s", ipStr)
			continue
		}
		if ev.count != count {
			t.Errorf("%s: count %d, want %d", ipStr, ev.count, count)
		}
	}

	var out bytes.Buffer
	if err := writeCSV(&out, p.sorted()); err != nil {
		t.Fatal(err)
	}
	lines := strings.Split(strings.TrimSpace(out.String()), "\n")
	if lines[0] != "IP,Categories,Comment,ReportDate" {
		t.Errorf("bad header: %q", lines[0])
	}
	if len(lines) != 5 {
		t.Fatalf("got %d csv lines, want 5:\n%s", len(lines), out.String())
	}
	if !strings.Contains(lines[1], "41.93.28.11,\"18,22\",") || !strings.HasSuffix(lines[1], "2026-10-06T12:04:24Z") {
		t.Errorf("unexpected first row: %q", lines[1])
	}
	// The descriptive "Invalid user ... from" line should win over the
	// later "Connection closed by invalid user" line for the comment.
	if !strings.Contains(lines[2], ",Invalid user production from 45.191.4.252 port 38924 (2 events),") {
		t.Errorf("unexpected comment in row: %q", lines[2])
	}
	// AllowUsers rejections are reported with their own message.
	if !strings.Contains(lines[1], "User root from 41.93.28.11 not allowed because not listed in AllowUsers (2 events)") {
		t.Errorf("unexpected comment in row: %q", lines[1])
	}
}

func TestExclusions(t *testing.T) {
	p := newParser(time.Time{})
	for _, line := range []string{
		"2026-10-06T12:04:24.687263829Z Invalid user git from 1.2.3.4 port 38924",
		"2026-10-06T12:04:24.687263829Z User git from 1.2.3.5 not allowed because not listed in AllowUsers",
		"2026-10-06T12:04:24.687263829Z Invalid user bob from 172.19.0.1 port 38924",
		"2026-10-06T12:04:24.687263829Z Invalid user bob from 10.0.0.9 port 38924",
		"2026-10-06T12:04:24.687263829Z Invalid user bob from 127.0.0.1 port 38924",
		"2026-10-06T12:04:24.687263829Z Invalid user bob from fd00::1 port 38924",
		"2026-10-06T12:04:24.687263829Z Invalid user bob from not-an-ip port 38924",
		"2026-10-06T12:04:24.687263829Z Received disconnect from 8.8.8.8 port 53534:11: disconnected by user",
		"garbage line without timestamp",
	} {
		p.handleLine(line)
	}
	if len(p.events) != 0 {
		t.Errorf("expected no events, got %v", p.events)
	}
	if p.skipped != 1 {
		t.Errorf("skipped = %d, want 1", p.skipped)
	}
}

func TestSinceCutoff(t *testing.T) {
	cutoff := time.Date(2026, 10, 6, 12, 4, 29, 0, time.UTC)
	p := newParser(cutoff)
	p.handleLine("2026-10-06T12:04:24.687263829Z Invalid user production from 45.191.4.252 port 38924")
	p.handleLine("2026-10-06T12:04:30.222573149Z Invalid user production from 212.128.3.152 port 60626")
	if len(p.events) != 1 {
		t.Fatalf("got %d events, want 1", len(p.events))
	}
	if _, ok := p.events[netip.MustParseAddr("212.128.3.152")]; !ok {
		t.Error("expected only the post-cutoff event to remain")
	}
}

func TestIPv6AndLatestWins(t *testing.T) {
	p := newParser(time.Time{})
	p.handleLine("2026-10-06T12:04:24Z Invalid user a from 2001:db8::1 port 1")
	p.handleLine("2026-10-06T12:04:26Z Invalid user b from 2001:db8::1 port 2")
	p.handleLine("2026-10-06T12:04:25Z Invalid user c from 2001:db8::1 port 3")
	ev := p.events[netip.MustParseAddr("2001:db8::1")]
	if ev == nil || ev.count != 3 || ev.user != "b" {
		t.Fatalf("unexpected event: %+v", ev)
	}
	var out bytes.Buffer
	if err := writeCSV(&out, p.sorted()); err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(out.String(), "(3 events)") {
		t.Errorf("expected event count in comment:\n%s", out.String())
	}
}