package genselect

import (
	"io"
	"log/slog"
	"os"
	"path/filepath"
	"testing"
	"time"

	"github.com/benbjohnson/litestream"
	filereplica "github.com/benbjohnson/litestream/file"
	"github.com/superfly/ltx"
)

func TestCalcRestorePlanCompatibility(t *testing.T) {
	type coords struct {
		level    int
		min, max uint64
	}
	tests := []struct {
		name  string
		files []coords
	}{
		{"compacted_overlap", []coords{{9, 1, 11}, {1, 10, 13}}},
		{"genuine_gap", []coords{{9, 1, 11}, {0, 13, 13}}},
		{"successor_snapshot", []coords{{9, 1, 11}, {9, 1, 20}, {0, 13, 13}, {0, 21, 21}}},
		{"origin", []coords{{0, 1, 1}, {1, 2, 5}}},
		{"tie_breaks", []coords{{9, 1, 11}, {8, 12, 19}, {8, 12, 20}, {1, 10, 20}, {2, 10, 20}}},
		{"anchor_is_not_continuation", []coords{{9, 1, 11}, {0, 11, 11}, {0, 12, 12}}},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			f := newFixture(t)
			f.origin()
			client := filereplica.NewReplicaClient(t.TempDir())
			for _, c := range tt.files {
				f.file("", c.level, c.min, c.max)
				path := client.LTXFilePath(c.level, ltx.TXID(c.min), ltx.TXID(c.max))
				if err := os.MkdirAll(filepath.Dir(path), 0700); err != nil {
					t.Fatal(err)
				}
				if err := os.WriteFile(path, header(t, c.min, c.max), 0600); err != nil {
					t.Fatal(err)
				}
			}
			want, wantErr := litestream.CalcRestorePlan(t.Context(), client, 0, time.Time{}, slog.New(slog.NewTextHandler(io.Discard, nil)))
			got, err := Select(t.Context(), f.b, f.req)
			if (err != nil) != (wantErr != nil) {
				t.Fatalf("selector %v; litestream %v", err, wantErr)
			}
			if err != nil {
				return
			}
			if len(got.Files) != len(want) {
				t.Fatalf("length %d != %d", len(got.Files), len(want))
			}
			for i, v := range want {
				x := got.Files[i]
				if x.Level != v.Level || x.MinTXID != uint64(v.MinTXID) || x.MaxTXID != uint64(v.MaxTXID) {
					t.Fatalf("file %d: %+v != %+v", i, x, v)
				}
			}
		})
	}
}