package chat

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

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

type GetChattersParams struct {
	// The ID of the broadcaster whose list of chatters you want to get.
	BroadcasterID string `url:"broadcaster_id"`

	// The ID of the broadcaster or one of the broadcaster’s moderators.
	// This ID must match the user ID in the user access token.
	ModeratorID string `url:"moderator_id"`

	// 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 1,000.
	// The default is 100.
	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 GetChattersResponse struct {
	// The list of users that are connected to the broadcaster’s chat room.
	// The list is empty if no users are connected to the chat room.
	Data []Chatter `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 users that are connected to the broadcaster’s chat room.
	// As you page through the list, the number of users may change as users join and leave the chat room.
	Total int `json:"total"`
}

type Chatter struct {
	// The ID of a user that’s connected to the broadcaster’s chat room.
	UserID string `json:"user_id"`

	// The user’s login name.
	UserLogin string `json:"user_login"`

	// The user’s display name.
	UserName string `json:"user_name"`
}

// Gets the list of users that are connected to the broadcaster’s chat session.
//
// NOTE: There is a delay between when users join and leave a chat and when the list is updated accordingly.
//
// To determine whether a user is a moderator or VIP, use the Get Moderators and Get VIPs endpoints. You can check the roles of up to 100 users.
//
// Requires a user access token that includes the moderator:read:chatters scope.
func (c *Chat) GetChatters(ctx context.Context, params *GetChattersParams) (*GetChattersResponse, error) {
	v, _ := query.Values(params)
	endpoint := c.baseUrl.ResolveReference(&url.URL{Path: "chat/chatters", 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 chatters (%d)", res.StatusCode)
	}

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

	return &response, nil
}