package rpc

import (
	"context"

	bin "github.com/dfuse-io/binary"
)

// the result field will be a dictionary of validator identities,
// as base-58 encoded strings, and their corresponding leader
// slot indices as values (indices are relative to the first
// slot in the requested epoch)
type GetLeaderScheduleResult map[string][]bin.Uint64

// GetLeaderSchedule returns the leader schedule for current epoch.
func (cl *Client) GetLeaderSchedule(
	ctx context.Context,
) (out *GetLeaderScheduleResult, err error) {
	return cl.GetLeaderScheduleWithOpts(
		ctx,
		nil,
	)
}

type GetLeaderScheduleOpts struct {
	Epoch      *uint64 // Fetch the leader schedule for the epoch that corresponds to the provided slot. If unspecified, the leader schedule for the current epoch is fetched
	Commitment CommitmentType
	// TODO: is identity a pubkey?
	Identity string // Only return results for this validator identity (base-58 encoded)
}

// GetLeaderScheduleWithOpts returns the leader schedule for an epoch.
func (cl *Client) GetLeaderScheduleWithOpts(
	ctx context.Context,
	opts *GetLeaderScheduleOpts,
) (out *GetLeaderScheduleResult, err error) {
	params := []interface{}{}
	if opts != nil {
		if opts.Epoch != nil {
			params = append(params, opts.Epoch)
		}
		obj := M{}
		if opts.Commitment != "" {
			obj["commitment"] = opts.Commitment
		}
		if opts.Identity != "" {
			obj["identity"] = opts.Identity
		}
		if len(obj) > 0 {
			params = append(params, obj)
		}
	}
	err = cl.rpcClient.CallFor(&out, "getLeaderSchedule", params)
	if err != nil {
		return nil, err
	}
	// TODO: check that this behaviour is implemented everywhere:
	if out == nil {
		return nil, ErrNotFound
	}
	return
}