package database

import (
	"net/netip"
	"reflect"
	"testing"
	"time"

	"git.eeqj.de/sneak/routewatch/internal/routetable"
)

// TestOriginChangesWriteThenRead writes three origin changes and reads them
// back newest first, honouring the limit.
func TestOriginChangesWriteThenRead(t *testing.T) {
	t.Parallel()

	db := newRoutesTestDatabase(t)
	prefix := netip.MustParsePrefix(tablePrefixV4)

	changes := []routetable.OriginChange{
		{Prefix: prefix, OriginASN: asA, Announced: true, PeerCount: 1,
			Time: tableTime(10)},
		{Prefix: prefix, OriginASN: asA, Announced: false, PeerCount: 0,
			Time: tableTime(20)},
		{Prefix: prefix, OriginASN: asB, Announced: true, PeerCount: 1,
			Time: tableTime(30)},
	}

	err := db.WriteOriginChanges(changes)
	if err != nil {
		t.Fatalf("WriteOriginChanges: %v", err)
	}

	got, err := db.GetOriginChanges(t.Context(), prefix, 2)
	if err != nil {
		t.Fatalf("GetOriginChanges: %v", err)
	}

	want := []routetable.OriginChange{
		{Prefix: prefix, OriginASN: asB, Announced: true, PeerCount: 1,
			Time: tableTime(30)},
		{Prefix: prefix, OriginASN: asA, Announced: false, PeerCount: 0,
			Time: tableTime(20)},
	}

	if !reflect.DeepEqual(got, want) {
		t.Errorf("GetOriginChanges = %+v, want %+v", got, want)
	}
}

// TestOriginChangesPrune checks that the prune keeps every row newer than 72
// hours, keeps the newest 500 rows of each prefix, deletes the rest, and
// leaves other prefixes alone.
func TestOriginChangesPrune(t *testing.T) {
	t.Parallel()

	db := newRoutesTestDatabase(t)
	oldPrefix := netip.MustParsePrefix(tablePrefixV4)
	newPrefix := netip.MustParsePrefix(tablePrefixShortV4)
	other := netip.MustParsePrefix("10.20.0.0/16")

	now := time.Now()

	changes := make([]routetable.OriginChange, 0, 1201)

	// 600 rows for oldPrefix, all older than 72 hours, oldest first. The
	// prune keeps the newest 500 and deletes the oldest 100.
	for i := range 600 {
		changes = append(changes, routetable.OriginChange{
			Prefix: oldPrefix, OriginASN: asA, Announced: true, PeerCount: 1,
			Time: now.Add(-100 * time.Hour).Add(time.Duration(i) * time.Minute),
		})
	}

	// 600 rows for newPrefix, all newer than 72 hours, oldest first. The
	// prune keeps all of them.
	for i := range 600 {
		changes = append(changes, routetable.OriginChange{
			Prefix: newPrefix, OriginASN: asA, Announced: true, PeerCount: 1,
			Time: now.Add(-71 * time.Hour).Add(time.Duration(i) * time.Minute),
		})
	}

	// One row for other, which the prune leaves alone.
	changes = append(changes, routetable.OriginChange{
		Prefix: other, OriginASN: asA, Announced: true, PeerCount: 1,
		Time: now.Add(-100 * time.Hour),
	})

	err := db.WriteOriginChanges(changes)
	if err != nil {
		t.Fatalf("WriteOriginChanges: %v", err)
	}

	err = db.PruneOriginChanges(t.Context())
	if err != nil {
		t.Fatalf("PruneOriginChanges: %v", err)
	}

	gotOld, err := db.GetOriginChanges(t.Context(), oldPrefix, 1000)
	if err != nil {
		t.Fatalf("GetOriginChanges: %v", err)
	}

	if len(gotOld) != 500 {
		t.Errorf("GetOriginChanges(oldPrefix) = %d rows, want 500", len(gotOld))
	}

	gotNew, err := db.GetOriginChanges(t.Context(), newPrefix, 1000)
	if err != nil {
		t.Fatalf("GetOriginChanges: %v", err)
	}

	if len(gotNew) != 600 {
		t.Errorf("GetOriginChanges(newPrefix) = %d rows, want 600", len(gotNew))
	}

	gotOther, err := db.GetOriginChanges(t.Context(), other, 10)
	if err != nil {
		t.Fatalf("GetOriginChanges: %v", err)
	}

	if len(gotOther) != 1 {
		t.Errorf("GetOriginChanges(other) = %d rows, want 1", len(gotOther))
	}
}

// TestOriginChangesSurviveRouteDeletion checks that deleting a routes row
// leaves the prefix's origin_changes rows.
func TestOriginChangesSurviveRouteDeletion(t *testing.T) {
	t.Parallel()

	db := newRoutesTestDatabase(t)
	prefix := netip.MustParsePrefix(tablePrefixV4)

	err := db.WriteOriginChanges([]routetable.OriginChange{{
		Prefix: prefix, OriginASN: asA, Announced: true, PeerCount: 1,
		Time: tableTime(10),
	}})
	if err != nil {
		t.Fatalf("WriteOriginChanges: %v", err)
	}

	// Write a route, then delete it.
	table := routetable.New(routetable.Params{})
	announceTo(table, tablePrefixV4, asA, peerA, 10)
	writeTableChanges(t, db, table)

	table.Withdraw(prefix, peerA)
	writeTableChanges(t, db, table)

	got, err := db.GetOriginChanges(t.Context(), prefix, 10)
	if err != nil {
		t.Fatalf("GetOriginChanges: %v", err)
	}

	if len(got) != 1 {
		t.Errorf("GetOriginChanges = %d rows, want 1", len(got))
	}
}