package wal

import (
	"crypto/rand"
	"encoding/hex"
	"fmt"
	mrand "math/rand"
	"os"
	"path/filepath"
	"reflect"
)

func _b(in string) []byte {
	return []byte(in)
}

func randString() string {
	buf := make([]byte, 1+mrand.Intn(20))
	rand.Read(buf)
	return hex.EncodeToString(buf)
}

func randID() uint64 {
	return uint64(mrand.Uint32())
}

func randPath() string {
	buf := make([]byte, 8)
	rand.Read(buf)
	return filepath.Join(os.TempDir(), hex.EncodeToString(buf))
}

func readWAL(walPath string) (l []Record) {
	f := NewFollower(walPath)
	defer f.Close()
	f.Replay(0, func(rec Record) error {
		l = append(l, rec)
		return nil
	})
	return l
}

func walEqual(walPath string, expected []Record) error {
	recs := readWAL(walPath)
	return recsEqual(recs, expected)
}

func recsEqual(recs, expected []Record) error {
	if len(recs) != len(expected) {
		return fmt.Errorf("Expected %d records but found %d",
			len(expected), len(recs))
	}

	for i, rec := range recs {
		exp := expected[i]
		if !reflect.DeepEqual(rec, exp) {
			return fmt.Errorf("Mismatched records: %v != %v", rec, exp)
		}
	}

	return nil
}

func walsEqual(path1, path2 string) error {
	return recsEqual(readWAL(path1), readWAL(path2))
}