package extensions

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

type SendExtensionChatMessageRequest struct {
	// The message. The message may contain a maximum of 280 characters.
	Text string `json:"text"`

	// The ID of the extension that’s sending the chat message.
	ExtensionID string `json:"extension_id"`

	// The extension’s version number.
	ExtensionVersion string `json:"extension_version"`
}

// Sends a message to the specified broadcaster’s chat room.
// The extension’s name is used as the username for the message in the chat room.
// To send a chat message, your extension must enable Chat Capabilities (under your extension’s Capabilities tab).
//
// Rate Limits: You may send a maximum of 12 messages per minute per channel.
//
// Requires a signed JSON Web Token (JWT) created by an EBS. For signing requirements,
// see Signing the JWT: https://dev.twitch.tv/docs/extensions/building/#signing-the-jwt
// The signed JWT must include the role, user_id, and exp fields
// (see JWT Schema: https://dev.twitch.tv/docs/extensions/reference/#jwt-schema).
// The role field must be set to external.
func (c *Extensions) SendExtensionChatMessage(ctx context.Context, broadcasterID string, body *SendExtensionChatMessageRequest) error {
	endpoint := c.baseUrl.ResolveReference(&url.URL{Path: "extensions/chat", RawQuery: "broadcaster_id=" + broadcasterID})

	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 extension chat message (%d)", res.StatusCode)
	}

	return nil
}