package commands

import (
	"context"
	"fmt"
	"os"
	"os/signal"
	"syscall"

	"github.com/c2h5oh/datasize"
	"github.com/ledgerwatch/turbo-geth/cmd/utils"
	"github.com/ledgerwatch/turbo-geth/ethdb"
	"github.com/ledgerwatch/turbo-geth/internal/debug"
	"github.com/ledgerwatch/turbo-geth/log"
	"github.com/spf13/cobra"
)

var (
	filesDir      string // Directory when the files should be stored
	sentryAddr    string // Address of the sentry <host>:<port>
	coreAddr      string // Address of the core <host>:<port>
	chaindata     string // Path to chaindata
	database      string // Type of database (lmdb or mdbx)
	mapSizeStr    string // Map size for LMDB
	freelistReuse int
)

func init() {
	utils.CobraFlags(rootCmd, append(debug.Flags, utils.MetricFlags...))
}

func rootContext() context.Context {
	ctx, cancel := context.WithCancel(context.Background())
	go func() {
		ch := make(chan os.Signal, 1)
		signal.Notify(ch, os.Interrupt, syscall.SIGTERM)
		defer signal.Stop(ch)

		select {
		case <-ch:
			log.Info("Got interrupt, shutting down...")
		case <-ctx.Done():
		}

		cancel()
	}()
	return ctx
}

var rootCmd = &cobra.Command{
	Use:   "headers",
	Short: "headers is Proof Of Concept for new header/block downloading algorithms",
	PersistentPreRun: func(cmd *cobra.Command, args []string) {
		if err := debug.SetupCobra(cmd); err != nil {
			panic(err)
		}
	},
	PersistentPostRun: func(cmd *cobra.Command, args []string) {
		debug.Exit()
	},
}

func Execute() {
	if err := rootCmd.ExecuteContext(rootContext()); err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
}

func must(err error) {
	if err != nil {
		panic(err)
	}
}

func withChaindata(cmd *cobra.Command) {
	cmd.Flags().StringVar(&chaindata, "chaindata", "", "path to the db")
	must(cmd.MarkFlagDirname("chaindata"))
	must(cmd.MarkFlagRequired("chaindata"))
	cmd.Flags().StringVar(&database, "database", "", "lmdb|mdbx")
}

func withLmdbFlags(cmd *cobra.Command) {
	cmd.Flags().StringVar(&mapSizeStr, "lmdb.mapSize", "", "map size for LMDB")
	cmd.Flags().IntVar(&freelistReuse, "maxFreelistReuse", 0, "Find a big enough contiguous page range for large values in freelist is hard just allocate new pages and even don't try to search if value is bigger than this limit. Measured in pages.")
}

func openDatabase(path string) *ethdb.ObjectDatabase {
	db := ethdb.NewObjectDatabase(openKV(path, false))
	return db
}

func openKV(path string, exclusive bool) ethdb.KV {
	if database == "mdbx" {
		opts := ethdb.NewMDBX().Path(path)
		if exclusive {
			opts = opts.Exclusive()
		}
		if mapSizeStr != "" {
			var mapSize datasize.ByteSize
			must(mapSize.UnmarshalText([]byte(mapSizeStr)))
			opts = opts.MapSize(mapSize)
		}
		if freelistReuse > 0 {
			opts = opts.MaxFreelistReuse(uint(freelistReuse))
		}
		return opts.MustOpen()
	}

	opts := ethdb.NewLMDB().Path(path)
	if exclusive {
		opts = opts.Exclusive()
	}
	if mapSizeStr != "" {
		var mapSize datasize.ByteSize
		must(mapSize.UnmarshalText([]byte(mapSizeStr)))
		opts = opts.MapSize(mapSize)
	}
	if freelistReuse > 0 {
		opts = opts.MaxFreelistReuse(uint(freelistReuse))
	}
	return opts.MustOpen()
}