package main

import (
    "context"
    "fmt"
    
    eth2client "github.com/attestantio/go-eth2-client"
    "github.com/attestantio/go-eth2-client/auto"
    "github.com/rs/zerolog"
)

func main() {
    // Provide a cancellable context to the creation function.
    ctx, cancel := context.WithCancel(context.Background())
    client, err := auto.New(ctx,
        // WithAddress supplies the address of the beacon node, in host:port format.
        auto.WithAddress("localhost:4000"),
        // LogLevel supplies the level of logging to carry out.
        auto.WithLogLevel(zerolog.WarnLevel),
    )
    if err != nil {
        panic(err)
    }
    
    fmt.Printf("Connected to %s\n", client.Name())
    
    // Client functions have their own interfaces.  Not all functions are
    // supported by all clients, so checks should be made for each function when
    // casting the service to the relevant interface.
    if provider, isProvider := client.(eth2client.SlotsPerEpochProvider); isProvider {
        slotsPerEpoch, err := provider.SlotsPerEpoch(ctx)
        if err != nil {
            panic(err)
        }
        fmt.Printf("Slots per epochs is %d\n", slotsPerEpoch)
    }

    // Cancelling the context passed to New() frees up resources held by the
    // client, closes connections, clears handlers, etc.
    cancel()
}