package main

import (
	"testing"
)

func TestParseLine(t *testing.T) {
	good := "www.example.com\t1.2.3.4\t1741954800.123\tGET\t/api/v1/search?q=foo&x=1\t200\t1452\t0.043"

	tests := []struct {
		name    string
		line    string
		wantOK  bool
		want    LogRecord
	}{
		{
			name:   "normal IPv4 line strips query string",
			line:   good,
			wantOK: true,
			want: LogRecord{
				Website:      "www.example.com",
				ClientPrefix: "1.2.3.0/24",
				URI:          "/api/v1/search",
				Status:       "200",
			},
		},
		{
			name:   "URI with no query string",
			line:   "host\t10.0.0.1\t0\tPOST\t/submit\t201\t0\t0.001",
			wantOK: true,
			want: LogRecord{
				Website:      "host",
				ClientPrefix: "10.0.0.0/24",
				URI:          "/submit",
				Status:       "201",
			},
		},
		{
			name:   "IPv6 address truncated to /48",
			line:   "host\t2001:db8:cafe::1\t0\tGET\t/\t200\t0\t0.001",
			wantOK: true,
			want: LogRecord{
				Website:      "host",
				ClientPrefix: "2001:db8:cafe::/48", // /48 = 3 full 16-bit groups intact
				URI:          "/",
				Status:       "200",
			},
		},
		{
			name:   "too few fields returns false",
			line:   "host\t1.2.3.4\t0\tGET\t/",
			wantOK: false,
		},
		{
			name:   "empty line returns false",
			line:   "",
			wantOK: false,
		},
		{
			name:   "invalid IP returns false",
			line:   "host\tnot-an-ip\t0\tGET\t/\t200\t0\t0.001",
			wantOK: false,
		},
		{
			name:   "status 429",
			line:   "api.example.com\t5.6.7.8\t0\tGET\t/rate-limited\t429\t0\t0.001",
			wantOK: true,
			want: LogRecord{
				Website:      "api.example.com",
				ClientPrefix: "5.6.7.0/24",
				URI:          "/rate-limited",
				Status:       "429",
			},
		},
	}

	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			got, ok := ParseLine(tc.line, 24, 48)
			if ok != tc.wantOK {
				t.Fatalf("ParseLine ok=%v, want %v", ok, tc.wantOK)
			}
			if !tc.wantOK {
				return
			}
			if got != tc.want {
				t.Errorf("got %+v, want %+v", got, tc.want)
			}
		})
	}
}

func TestTruncateIP(t *testing.T) {
	tests := []struct {
		addr string
		want string
	}{
		{"1.2.3.4", "1.2.3.0/24"},
		{"192.168.100.200", "192.168.100.0/24"},
		{"2001:db8:cafe:babe::1", "2001:db8:cafe::/48"}, // /48 = 3 full groups intact
		{"::1", "::/48"}, // loopback — first 48 bits are all zero
	}

	for _, tc := range tests {
		got, ok := truncateIP(tc.addr, 24, 48)
		if !ok {
			t.Errorf("truncateIP(%q) returned not-ok", tc.addr)
			continue
		}
		if got != tc.want {
			t.Errorf("truncateIP(%q) = %q, want %q", tc.addr, got, tc.want)
		}
	}
}