package whispers

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

	"github.com/google/go-querystring/query"
)

type SendWhisperParams struct {
	// The ID of the user sending the whisper.
	// This user must have a verified phone number.
	// This ID must match the user ID in the user access token.
	FromUserID string `json:"from_user_id"`

	// The ID of the user to receive the whisper.
	ToUserID string `json:"to_user_id"`
}

type SendWhisperRequest struct {
	// The whisper message to send. The message must not be empty.
	//
	// The maximum message lengths are:
	//
	// 500 characters if the user you're sending the message to hasn't whispered you before.
	//
	// 10,000 characters if the user you're sending the message to has whispered you before.
	//
	// Messages that exceed the maximum length are truncated.
	Message string `json:"message"`
}

// Sends a whisper message to the specified user.
//
// NOTE: The user sending the whisper must have a verified phone number
// (see the Phone Number setting in your Security and Privacy settings).
//
// NOTE: The API may silently drop whispers that it suspects of violating Twitch policies.
// (The API does not indicate that it dropped the whisper; it returns a 204 status code as if it succeeded.)
//
// Rate Limits: You may whisper to a maximum of 40 unique recipients per day.
// Within the per day limit, you may whisper a maximum of 3 whispers per second and a maximum of 100 whispers per minute.
//
// Requires a user access token that includes the user:manage:whispers scope.
func (c *Whispers) SendWhisper(ctx context.Context, params *SendWhisperParams, body *SendWhisperRequest) error {
	v, _ := query.Values(params)
	endpoint := c.baseUrl.ResolveReference(&url.URL{Path: "whispers", RawQuery: v.Encode()})

	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 err
	}

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

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

	return nil
}