package main

import (
    "context"
    "fmt"

    execclient "github.com/attestantio/go-execution-client"
    "github.com/attestantio/go-execution-client/jsonrpc"
    "github.com/rs/zerolog"
)

func main() {
    // Provide a cancellable context to the creation function.
    ctx, cancel := context.WithCancel(context.Background())
    client, err := jsonrpc.New(ctx,
        // WithAddress supplies the address of the execution node, as a URL.
        jsonrpc.WithAddress("http://localhost:8545/"),
        // LogLevel supplies the level of logging to carry out.
        jsonrpc.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.(execclient.ChainHeightProvider); isProvider {
        chainHeight, err := provider.ChainHeight(ctx)
        if err != nil {
            panic(err)
        }
        fmt.Printf("Chain height is %v\n", chainHeight)
    }

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