package extensions

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

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

type GetExtensionsParams struct {
	// The ID of the extension to get.
	ExtensionID string `url:"extension_id"`

	// The version of the extension to get. If not specified, it returns the latest, released version.
	// If you don’t have a released version, you must specify a version; otherwise, the list is empty.
	ExtensionVersion *string `url:"extension_version,omitempty"`
}

type GetExtensionsResponse struct {
	// A list that contains the specified extension.
	Data []Extension `json:"data"`
}

// Gets information about an extension.
//
// 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) GetExtensions(ctx context.Context, params *GetExtensionsParams) (*GetExtensionsResponse, error) {
	v, _ := query.Values(params)
	endpoint := c.baseUrl.ResolveReference(&url.URL{Path: "extensions", RawQuery: v.Encode()})

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

	res, err := c.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 get extensions (%d)", res.StatusCode)
	}

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

	return &data, nil
}