package polls

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/url"
)

type CreatePollRequest struct {

	// The ID of the broadcaster that’s running the poll. This ID must match the user ID in the user access token.
	BroadcasterID string `json:"broadcaster_id"`

	// The question that viewers will vote on. For example, What game should I play next? The question may contain a maximum of 60 characters.
	Title string `json:"title"`

	// A list of choices that viewers may choose from. The list must contain a minimum of 2 choices and up to a maximum of 5 choices.
	Choices []CreateChoice `json:"choices"`

	// The length of time (in seconds) that the poll will run for. The minimum is 15 seconds and the maximum is 1800 seconds (30 minutes).
	Duration int `json:"duration"`

	// A Boolean value that indicates whether viewers may cast additional votes using Channel Points.
	// If true, the viewer may cast more than one vote but each additional vote costs the number of Channel Points specified in channel_points_per_vote.
	// The default is false (viewers may cast only one vote). For information about Channel Points, see Channel Points Guide.
	ChannelPointsVotingEnabled bool `json:"channel_points_voting_enabled"`

	// The number of points that the viewer must spend to cast one additional vote. The minimum is 1 and the maximum is 1000000.
	// Set only if ChannelPointsVotingEnabled is true.
	ChannelPointsPerVote int `json:"channel_points_per_vote"`
}

type CreateChoice struct {
	// One of the choices the viewer may select. The choice may contain a maximum of 25 characters.
	Title string `json:"title"`
}

type CreatePollResponse struct {
	// A list that contains the single poll that you created.
	Data []Poll `json:"data"`
}

// Creates a poll that viewers in the broadcaster’s channel can vote on.
//
// The poll begins as soon as it’s created. You may run only one poll at a time.
//
// Requires a user access token that includes the channel:manage:polls scope.
func (p *Polls) CreatePoll(ctx context.Context, body *CreatePollRequest) (*CreatePollResponse, error) {
	endpoint := p.baseUrl.ResolveReference(&url.URL{Path: "polls"})

	r, w := io.Pipe()

	go func() {
		if err := json.NewEncoder(w).Encode(body); err != nil {
			w.CloseWithError(err)
		} else {
			w.Close()
		}
	}()

	req, err := http.NewRequestWithContext(ctx, http.MethodPost, endpoint.String(), r)
	if err != nil {
		return nil, err
	}

	res, err := p.client.Do(req)
	if err != nil {
		return nil, err
	}
	defer res.Body.Close()

	statusOK := res.StatusCode >= 200 && res.StatusCode < 300
	if !statusOK {
		return nil, fmt.Errorf("failed to create poll (%d)", res.StatusCode)
	}

	var data CreatePollResponse
	if err := json.NewDecoder(res.Body).Decode(&data); err != nil {
		return nil, err
	}

	return &data, nil
}