package streams

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

	"github.com/google/go-querystring/query"
	"go.fifitido.net/twitch/api/types"
)

type GetStreamsParams struct {
	// A user ID used to filter the list of streams.
	// Returns only the streams of those users that are broadcasting.
	// To specify multiple IDs, include the user_id parameter for each user. For example, &user_id=1234&user_id=5678.
	// You may specify a maximum of 100 IDs.
	UserIDs []string `url:"user_id,omitempty"`

	// A user login name used to filter the list of streams.
	// Returns only the streams of those users that are broadcasting.
	// To specify multiple names, include the user_login parameter for each user. For example, &user_login=foo&user_login=bar.
	// You may specify a maximum of 100 login names.
	UserLogins []string `url:"user_login,omitempty"`

	// A game (category) ID used to filter the list of streams.
	// Returns only the streams that are broadcasting the game (category).
	// You may specify a maximum of 100 IDs.
	// To specify multiple IDs, include the game_id parameter for each game. For example, &game_id=9876&game_id=5432.
	GameIDs []string `url:"game_id,omitempty"`

	// The type of stream to filter the list of streams by.
	// Possible values are:
	//
	// all, live
	//
	// The default is all.
	Type *string `url:"type,omitempty"`

	// A language code used to filter the list of streams.
	// Returns only streams that broadcast in the specified language.
	// Specify the language using an ISO 639-1 two-letter language code or other if the broadcast uses a language not in the list of supported stream languages.
	//
	// You may specify a maximum of 100 language codes.
	// To specify multiple languages, include the language parameter for each language. For example, &language=de&language=fr.
	Languages []string `url:"language,omitempty"`

	// The maximum number of items to return per page in the response.
	// The minimum page size is 1 item per page and the maximum is 100 items per page.
	// The default is 20.
	First *int `url:"first,omitempty"`

	// The cursor used to get the previous page of results.
	// The Pagination object in the response contains the cursor’s value.
	// Read More: https://dev.twitch.tv/docs/api/guide#pagination
	Before *types.Cursor `url:"before,omitempty"`

	// The cursor used to get the next page of results.
	// The Pagination object in the response contains the cursor’s value.
	// Read More: https://dev.twitch.tv/docs/api/guide#pagination
	After *types.Cursor `url:"after,omitempty"`
}

type GetStreamsResponse struct {
	// The list of streams.
	Data []Stream `json:"data"`

	// The information used to page through the list of results.
	// The object is empty if there are no more pages left to page through.
	// Read More: https://dev.twitch.tv/docs/api/guide#pagination
	Pagination types.Pagination `json:"pagination"`
}

// Gets a list of all streams. The list is in descending order by the number of viewers watching the stream.
// Because viewers come and go during a stream, it’s possible to find duplicate or missing streams in the list as you page through the results.
//
// Requires an app access token or user access token.
func (s *Streams) GetStreams(ctx context.Context, params *GetStreamsParams) (*GetStreamsResponse, error) {
	v, _ := query.Values(params)
	endpoint := s.baseUrl.ResolveReference(&url.URL{Path: "streams", RawQuery: v.Encode()})

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

	res, err := s.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 streams (%d)", res.StatusCode)
	}

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

	return &data, nil
}