package channels

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

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

type GetFollowedChannelsParams struct {
	// A user’s ID. Returns the list of broadcasters that this user follows. This ID must match the user ID in the user OAuth token.
	UserID string `url:"user_id"`

	// A broadcaster’s ID. Use this parameter to see whether the user follows this broadcaster.
	// If specified, the response contains this broadcaster if the user follows them.
	// If not specified, the response contains all broadcasters that the user follows.
	BroadcasterID *string `url:"broadcaster_id,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. The default is 20.
	First *int `url:"first,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 GetFollowedChannelsResponse struct {
	// The list of broadcasters that the user follows.
	// The list is in descending order by followed_at (with the most recently followed broadcaster first)
	// The list is empty if the user doesn’t follow anyone.
	Data []FollowedChannel `json:"data"`

	// Contains 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"`

	// The total number of broadcasters that the user follows.
	// As someone pages through the list, the number may change as the user follows or unfollows broadcasters.
	Total int `json:"total"`
}

type FollowedChannel struct {
	// An ID that uniquely identifies the broadcaster that this user is following.
	BroadcasterID string `json:"broadcaster_id"`

	// The broadcaster’s login name.
	BroadcasterLogin string `json:"broadcaster_login"`

	// The broadcaster’s display name.
	BroadcasterName string `json:"broadcaster_name"`

	// The UTC timestamp when the user started following the broadcaster.
	FollowedAt time.Time `json:"followed_at"`
}

// Gets a list of broadcasters that the specified user follows. You can also use this endpoint to see whether a user follows a specific broadcaster.
//
// Requires a user access token that includes the user:read:follows scope.
func (c *Channels) GetFollowedChannels(ctx context.Context, params *GetFollowedChannelsParams) (*GetFollowedChannelsResponse, error) {
	v, _ := query.Values(params)
	endpoint := c.baseUrl.ResolveReference(&url.URL{Path: "users/follows", 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()

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

	return &data, nil
}