package reddit

import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"net/http"
	"net/url"
	"strings"

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

// SubredditService handles communication with the subreddit
// related methods of the Reddit API.
//
// Reddit API docs: https://www.reddit.com/dev/api/#section_subreddits
type SubredditService struct {
	client *Client
}

type rootSubredditNames struct {
	Names []string `json:"names,omitempty"`
}

// Relationship holds information about a relationship (friend/blocked).
type Relationship struct {
	ID      string     `json:"rel_id,omitempty"`
	User    string     `json:"name,omitempty"`
	UserID  string     `json:"id,omitempty"`
	Created *Timestamp `json:"date,omitempty"`
}

// Moderator is a user who moderates a subreddit.
type Moderator struct {
	*Relationship
	Permissions []string `json:"mod_permissions"`
}

// Ban represents a banned relationship.
type Ban struct {
	*Relationship
	// nil means the ban is permanent
	DaysLeft *int   `json:"days_left"`
	Note     string `json:"note,omitempty"`
}

// SubredditRule is a rule in the subreddit.
type SubredditRule struct {
	// One of: comment, link (i.e. post), or all (i.e. both comment and link).
	Kind string `json:"kind,omitempty"`
	// Short description of the rule.
	Name string `json:"short_name,omitempty"`
	// The reason that will appear when a thing is reported in violation to this rule.
	ViolationReason string     `json:"violation_reason,omitempty"`
	Description     string     `json:"description,omitempty"`
	Priority        int        `json:"priority"`
	Created         *Timestamp `json:"created_utc,omitempty"`
}

// SubredditRuleCreateRequest represents a request to add a subreddit rule.
type SubredditRuleCreateRequest struct {
	// One of: comment, link (i.e. post) or all (i.e. both).
	Kind string `url:"kind"`
	// Short description of the rule. No longer than 100 characters.
	Name string `url:"short_name"`
	// The reason that will appear when a thing is reported in violation to this rule.
	// If this is empty, Reddit will set its value to Name by default.
	// No longer than 100 characters.
	ViolationReason string `url:"violation_reason,omitempty"`
	// Optional. No longer than 500 characters.
	Description string `url:"description,omitempty"`
}

func (r *SubredditRuleCreateRequest) validate() error {
	if r == nil {
		return errors.New("*SubredditRuleCreateRequest: cannot be nil")
	}

	switch r.Kind {
	case "comment", "link", "all":
		// intentionally left blank
	default:
		return errors.New("(*SubredditRuleCreateRequest).Kind: must be one of: comment, link, all")
	}

	if r.Name == "" || len(r.Name) > 100 {
		return errors.New("(*SubredditRuleCreateRequest).Name: must be between 1-100 characters")
	}

	if len(r.ViolationReason) > 100 {
		return errors.New("(*SubredditRuleCreateRequest).ViolationReason: cannot be longer than 100 characters")
	}

	if len(r.Description) > 500 {
		return errors.New("(*SubredditRuleCreateRequest).Description: cannot be longer than 500 characters")
	}

	return nil
}

// SubredditTrafficStats hold information about subreddit traffic.
type SubredditTrafficStats struct {
	// Traffic data is returned in the form of day, hour, and month.
	// Start is a timestamp indicating the start of the category, i.e.
	// start of the day for day, start of the hour for hour, and start of the month for month.
	Start       *Timestamp `json:"start"`
	UniqueViews int        `json:"unique_views"`
	TotalViews  int        `json:"total_views"`
	// This is only available for "day" traffic, not hour and month.
	// Therefore, it is always 0 by default for hour and month.
	Subscribers int `json:"subscribers"`
}

// SubredditImage is an image part of the image set of a subreddit.
type SubredditImage struct {
	Name string `json:"name"`
	Link string `json:"link"`
	URL  string `json:"url"`
}

// SubredditStyleSheet contains the subreddit's styling information.
type SubredditStyleSheet struct {
	SubredditID string            `json:"subreddit_id"`
	Images      []*SubredditImage `json:"images"`
	StyleSheet  string            `json:"stylesheet"`
}

// UnmarshalJSON implements the json.Unmarshaler interface.
func (s *SubredditTrafficStats) UnmarshalJSON(b []byte) error {
	var data [4]int
	err := json.Unmarshal(b, &data)
	if err != nil {
		return err
	}

	timestampByteValue, err := json.Marshal(data[0])
	if err != nil {
		return err
	}

	timestamp := new(Timestamp)
	err = timestamp.UnmarshalJSON(timestampByteValue)
	if err != nil {
		return err
	}

	s.Start = timestamp
	s.UniqueViews = data[1]
	s.TotalViews = data[2]
	s.Subscribers = data[3]

	return nil
}

func (s *SubredditService) getPosts(ctx context.Context, sort string, subreddit string, opts interface{}) ([]*Post, *Response, error) {
	path := sort
	if subreddit != "" {
		path = fmt.Sprintf("r/%s/%s", subreddit, sort)
	}
	l, resp, err := s.client.getListing(ctx, path, opts)
	if err != nil {
		return nil, resp, err
	}
	return l.Posts(), resp, nil
}

// HotPosts returns the hottest posts from the specified subreddit.
// To search through multiple, separate the names with a plus (+), e.g. "golang+test".
// If none are defined, it returns the ones from your subscribed subreddits.
// To search through all, just specify "all".
// To search through all and filter out subreddits, provide "all-name1-name2".
// Note: when looking for hot posts in a subreddit, it will include the stickied
// posts (if any) PLUS posts from the limit parameter (25 by default).
func (s *SubredditService) HotPosts(ctx context.Context, subreddit string, opts *ListOptions) ([]*Post, *Response, error) {
	return s.getPosts(ctx, "hot", subreddit, opts)
}

// NewPosts returns the newest posts from the specified subreddit.
// To search through multiple, separate the names with a plus (+), e.g. "golang+test".
// If none are defined, it returns the ones from your subscribed subreddits.
// To search through all, just specify "all".
// To search through all and filter out subreddits, provide "all-name1-name2".
func (s *SubredditService) NewPosts(ctx context.Context, subreddit string, opts *ListOptions) ([]*Post, *Response, error) {
	return s.getPosts(ctx, "new", subreddit, opts)
}

// RisingPosts returns the rising posts from the specified subreddit.
// To search through multiple, separate the names with a plus (+), e.g. "golang+test".
// If none are defined, it returns the ones from your subscribed subreddits.
// To search through all, just specify "all".
// To search through all and filter out subreddits, provide "all-name1-name2".
func (s *SubredditService) RisingPosts(ctx context.Context, subreddit string, opts *ListOptions) ([]*Post, *Response, error) {
	return s.getPosts(ctx, "rising", subreddit, opts)
}

// ControversialPosts returns the most controversial posts from the specified subreddit.
// To search through multiple, separate the names with a plus (+), e.g. "golang+test".
// If none are defined, it returns the ones from your subscribed subreddits.
// To search through all, just specify "all".
// To search through all and filter out subreddits, provide "all-name1-name2".
func (s *SubredditService) ControversialPosts(ctx context.Context, subreddit string, opts *ListPostOptions) ([]*Post, *Response, error) {
	return s.getPosts(ctx, "controversial", subreddit, opts)
}

// TopPosts returns the top posts from the specified subreddit.
// To search through multiple, separate the names with a plus (+), e.g. "golang+test".
// If none are defined, it returns the ones from your subscribed subreddits.
// To search through all, just specify "all".
// To search through all and filter out subreddits, provide "all-name1-name2".
func (s *SubredditService) TopPosts(ctx context.Context, subreddit string, opts *ListPostOptions) ([]*Post, *Response, error) {
	return s.getPosts(ctx, "top", subreddit, opts)
}

// Get a subreddit by name.
func (s *SubredditService) Get(ctx context.Context, name string) (*Subreddit, *Response, error) {
	if name == "" {
		return nil, nil, errors.New("name: cannot be empty")
	}

	path := fmt.Sprintf("r/%s/about", name)
	req, err := s.client.NewRequest(http.MethodGet, path, nil)
	if err != nil {
		return nil, nil, err
	}

	root := new(thing)
	resp, err := s.client.Do(ctx, req, root)
	if err != nil {
		return nil, resp, err
	}

	sr, _ := root.Subreddit()
	return sr, resp, nil
}

// Popular returns popular subreddits.
func (s *SubredditService) Popular(ctx context.Context, opts *ListSubredditOptions) ([]*Subreddit, *Response, error) {
	return s.getSubreddits(ctx, "subreddits/popular", opts)
}

// New returns new subreddits.
func (s *SubredditService) New(ctx context.Context, opts *ListSubredditOptions) ([]*Subreddit, *Response, error) {
	return s.getSubreddits(ctx, "subreddits/new", opts)
}

// Gold returns gold subreddits (i.e. only accessible to users with gold).
// It seems like it returns an empty list if you don't have gold.
func (s *SubredditService) Gold(ctx context.Context, opts *ListSubredditOptions) ([]*Subreddit, *Response, error) {
	return s.getSubreddits(ctx, "subreddits/gold", opts)
}

// Default returns default subreddits.
func (s *SubredditService) Default(ctx context.Context, opts *ListSubredditOptions) ([]*Subreddit, *Response, error) {
	return s.getSubreddits(ctx, "subreddits/default", opts)
}

// Subscribed returns the list of subreddits you are subscribed to.
func (s *SubredditService) Subscribed(ctx context.Context, opts *ListSubredditOptions) ([]*Subreddit, *Response, error) {
	return s.getSubreddits(ctx, "subreddits/mine/subscriber", opts)
}

// Approved returns the list of subreddits you are an approved user in.
func (s *SubredditService) Approved(ctx context.Context, opts *ListSubredditOptions) ([]*Subreddit, *Response, error) {
	return s.getSubreddits(ctx, "subreddits/mine/contributor", opts)
}

// Moderated returns the list of subreddits you are a moderator of.
func (s *SubredditService) Moderated(ctx context.Context, opts *ListSubredditOptions) ([]*Subreddit, *Response, error) {
	return s.getSubreddits(ctx, "subreddits/mine/moderator", opts)
}

// GetSticky1 returns the first stickied post on a subreddit (if it exists).
func (s *SubredditService) GetSticky1(ctx context.Context, subreddit string) (*PostAndComments, *Response, error) {
	return s.getSticky(ctx, subreddit, 1)
}

// GetSticky2 returns the second stickied post on a subreddit (if it exists).
func (s *SubredditService) GetSticky2(ctx context.Context, subreddit string) (*PostAndComments, *Response, error) {
	return s.getSticky(ctx, subreddit, 2)
}

func (s *SubredditService) handleSubscription(ctx context.Context, form url.Values) (*Response, error) {
	path := "api/subscribe"
	req, err := s.client.NewRequest(http.MethodPost, path, form)
	if err != nil {
		return nil, err
	}
	return s.client.Do(ctx, req, nil)
}

// Subscribe subscribes to subreddits based on their names.
func (s *SubredditService) Subscribe(ctx context.Context, subreddits ...string) (*Response, error) {
	form := url.Values{}
	form.Set("action", "sub")
	form.Set("sr_name", strings.Join(subreddits, ","))
	return s.handleSubscription(ctx, form)
}

// SubscribeByID subscribes to subreddits based on their id.
func (s *SubredditService) SubscribeByID(ctx context.Context, ids ...string) (*Response, error) {
	form := url.Values{}
	form.Set("action", "sub")
	form.Set("sr", strings.Join(ids, ","))
	return s.handleSubscription(ctx, form)
}

// Unsubscribe unsubscribes from subreddits based on their names.
func (s *SubredditService) Unsubscribe(ctx context.Context, subreddits ...string) (*Response, error) {
	form := url.Values{}
	form.Set("action", "unsub")
	form.Set("sr_name", strings.Join(subreddits, ","))
	return s.handleSubscription(ctx, form)
}

// UnsubscribeByID unsubscribes from subreddits based on their id.
func (s *SubredditService) UnsubscribeByID(ctx context.Context, ids ...string) (*Response, error) {
	form := url.Values{}
	form.Set("action", "unsub")
	form.Set("sr", strings.Join(ids, ","))
	return s.handleSubscription(ctx, form)
}

// Favorite the subreddit.
func (s *SubredditService) Favorite(ctx context.Context, subreddit string) (*Response, error) {
	path := "api/favorite"

	form := url.Values{}
	form.Set("sr_name", subreddit)
	form.Set("make_favorite", "true")
	form.Set("api_type", "json")

	req, err := s.client.NewRequest(http.MethodPost, path, form)
	if err != nil {
		return nil, err
	}

	return s.client.Do(ctx, req, nil)
}

// Unfavorite the subreddit.
func (s *SubredditService) Unfavorite(ctx context.Context, subreddit string) (*Response, error) {
	path := "api/favorite"

	form := url.Values{}
	form.Set("sr_name", subreddit)
	form.Set("make_favorite", "false")
	form.Set("api_type", "json")

	req, err := s.client.NewRequest(http.MethodPost, path, form)
	if err != nil {
		return nil, err
	}

	return s.client.Do(ctx, req, nil)
}

// Search for subreddits.
func (s *SubredditService) Search(ctx context.Context, query string, opts *ListSubredditOptions) ([]*Subreddit, *Response, error) {
	path := fmt.Sprintf("subreddits/search?q=%s", query)
	l, resp, err := s.client.getListing(ctx, path, opts)
	if err != nil {
		return nil, resp, err
	}
	return l.Subreddits(), resp, nil
}

// SearchNames searches for subreddits with names beginning with the query provided.
func (s *SubredditService) SearchNames(ctx context.Context, query string) ([]string, *Response, error) {
	path := fmt.Sprintf("api/search_reddit_names?query=%s", query)

	req, err := s.client.NewRequest(http.MethodGet, path, nil)
	if err != nil {
		return nil, nil, err
	}

	root := new(rootSubredditNames)
	resp, err := s.client.Do(ctx, req, root)
	if err != nil {
		return nil, resp, err
	}

	return root.Names, resp, nil
}

// SearchPosts searches for posts in the specified subreddit.
// To search through multiple, separate the names with a plus (+), e.g. "golang+test".
// If no subreddit is provided, the search is run against r/all.
func (s *SubredditService) SearchPosts(ctx context.Context, query string, subreddit string, opts *ListPostSearchOptions) ([]*Post, *Response, error) {
	if subreddit == "" {
		subreddit = "all"
	}

	path := fmt.Sprintf("r/%s/search", subreddit)
	path, err := addOptions(path, opts)
	if err != nil {
		return nil, nil, err
	}

	notAll := !strings.EqualFold(subreddit, "all")

	params := struct {
		Query              string `url:"q"`
		RestrictSubreddits bool   `url:"restrict_sr,omitempty"`
	}{query, notAll}

	path, err = addOptions(path, params)
	if err != nil {
		return nil, nil, err
	}

	req, err := s.client.NewRequest(http.MethodGet, path, nil)
	if err != nil {
		return nil, nil, err
	}

	root := new(thing)
	resp, err := s.client.Do(ctx, req, root)
	if err != nil {
		return nil, resp, err
	}

	listing, _ := root.Listing()
	return listing.Posts(), resp, nil
}

func (s *SubredditService) getSubreddits(ctx context.Context, path string, opts *ListSubredditOptions) ([]*Subreddit, *Response, error) {
	l, resp, err := s.client.getListing(ctx, path, opts)
	if err != nil {
		return nil, resp, err
	}
	return l.Subreddits(), resp, nil
}

// getSticky returns one of the 2 stickied posts of the subreddit (if they exist).
// Num should be equal to 1 or 2, depending on which one you want.
func (s *SubredditService) getSticky(ctx context.Context, subreddit string, num int) (*PostAndComments, *Response, error) {
	params := struct {
		Num int `url:"num"`
	}{num}

	path := fmt.Sprintf("r/%s/about/sticky", subreddit)
	path, err := addOptions(path, params)
	if err != nil {
		return nil, nil, err
	}

	req, err := s.client.NewRequest(http.MethodGet, path, nil)
	if err != nil {
		return nil, nil, err
	}

	root := new(PostAndComments)
	resp, err := s.client.Do(ctx, req, root)
	if err != nil {
		return nil, resp, err
	}

	return root, resp, nil
}

// todo: sr_detail's NSFW indicator is over_18 instead of over18
func (s *SubredditService) random(ctx context.Context, nsfw bool) (*Subreddit, *Response, error) {
	path := "r/random"
	if nsfw {
		path = "r/randnsfw"
	}

	params := struct {
		ExpandSubreddit bool `url:"sr_detail"`
		Limit           int  `url:"limit,omitempty"`
	}{true, 1}

	path, err := addOptions(path, params)
	if err != nil {
		return nil, nil, err
	}

	req, err := s.client.NewRequest(http.MethodGet, path, nil)
	if err != nil {
		return nil, nil, err
	}

	root := new(struct {
		Data struct {
			Children [1]struct {
				Data struct {
					Subreddit *Subreddit `json:"sr_detail"`
				} `json:"data"`
			} `json:"children"`
		} `json:"data"`
	})
	resp, err := s.client.Do(ctx, req, root)
	if err != nil {
		return nil, resp, err
	}

	subreddit := root.Data.Children[0].Data.Subreddit
	return subreddit, resp, nil
}

// Random returns a random SFW subreddit.
func (s *SubredditService) Random(ctx context.Context) (*Subreddit, *Response, error) {
	return s.random(ctx, false)
}

// RandomNSFW returns a random NSFW subreddit.
func (s *SubredditService) RandomNSFW(ctx context.Context) (*Subreddit, *Response, error) {
	return s.random(ctx, true)
}

// SubmissionText gets the submission text for the subreddit.
// This text is set by the subreddit moderators and intended to be displayed on the submission form.
func (s *SubredditService) SubmissionText(ctx context.Context, name string) (string, *Response, error) {
	if name == "" {
		return "", nil, errors.New("name: cannot be empty")
	}

	path := fmt.Sprintf("r/%s/api/submit_text", name)
	req, err := s.client.NewRequest(http.MethodGet, path, nil)
	if err != nil {
		return "", nil, err
	}

	root := new(struct {
		Text string `json:"submit_text"`
	})
	resp, err := s.client.Do(ctx, req, root)
	if err != nil {
		return "", resp, err
	}

	return root.Text, resp, err
}

// Banned gets banned users from the subreddit.
func (s *SubredditService) Banned(ctx context.Context, subreddit string, opts *ListOptions) ([]*Ban, *Response, error) {
	path := fmt.Sprintf("r/%s/about/banned", subreddit)

	path, err := addOptions(path, opts)
	if err != nil {
		return nil, nil, err
	}

	req, err := s.client.NewRequest(http.MethodGet, path, nil)
	if err != nil {
		return nil, nil, err
	}

	root := new(struct {
		Data struct {
			Bans   []*Ban `json:"children"`
			After  string `json:"after"`
			Before string `json:"before"`
		} `json:"data"`
	})
	resp, err := s.client.Do(ctx, req, root)
	if err != nil {
		return nil, resp, err
	}

	resp.After = root.Data.After
	resp.Before = root.Data.Before

	return root.Data.Bans, resp, nil
}

// Muted gets muted users from the subreddit.
func (s *SubredditService) Muted(ctx context.Context, subreddit string, opts *ListOptions) ([]*Relationship, *Response, error) {
	path := fmt.Sprintf("r/%s/about/muted", subreddit)

	path, err := addOptions(path, opts)
	if err != nil {
		return nil, nil, err
	}

	req, err := s.client.NewRequest(http.MethodGet, path, nil)
	if err != nil {
		return nil, nil, err
	}

	root := new(struct {
		Data struct {
			Relationships []*Relationship `json:"children"`
			After         string          `json:"after"`
			Before        string          `json:"before"`
		} `json:"data"`
	})
	resp, err := s.client.Do(ctx, req, root)
	if err != nil {
		return nil, resp, err
	}

	resp.After = root.Data.After
	resp.Before = root.Data.Before

	return root.Data.Relationships, resp, nil
}

// WikiBanned gets banned users from the subreddit.
func (s *SubredditService) WikiBanned(ctx context.Context, subreddit string, opts *ListOptions) ([]*Ban, *Response, error) {
	path := fmt.Sprintf("r/%s/about/wikibanned", subreddit)

	path, err := addOptions(path, opts)
	if err != nil {
		return nil, nil, err
	}

	req, err := s.client.NewRequest(http.MethodGet, path, nil)
	if err != nil {
		return nil, nil, err
	}

	root := new(struct {
		Data struct {
			Bans   []*Ban `json:"children"`
			After  string `json:"after"`
			Before string `json:"before"`
		} `json:"data"`
	})
	resp, err := s.client.Do(ctx, req, root)
	if err != nil {
		return nil, resp, err
	}

	resp.After = root.Data.After
	resp.Before = root.Data.Before

	return root.Data.Bans, resp, nil
}

// Contributors gets contributors (also known as approved users) from the subreddit.
func (s *SubredditService) Contributors(ctx context.Context, subreddit string, opts *ListOptions) ([]*Relationship, *Response, error) {
	path := fmt.Sprintf("r/%s/about/contributors", subreddit)

	path, err := addOptions(path, opts)
	if err != nil {
		return nil, nil, err
	}

	req, err := s.client.NewRequest(http.MethodGet, path, nil)
	if err != nil {
		return nil, nil, err
	}

	root := new(struct {
		Data struct {
			Relationships []*Relationship `json:"children"`
			After         string          `json:"after"`
			Before        string          `json:"before"`
		} `json:"data"`
	})
	resp, err := s.client.Do(ctx, req, root)
	if err != nil {
		return nil, resp, err
	}

	resp.After = root.Data.After
	resp.Before = root.Data.Before

	return root.Data.Relationships, resp, nil
}

// WikiContributors gets contributors of the wiki from the subreddit.
func (s *SubredditService) WikiContributors(ctx context.Context, subreddit string, opts *ListOptions) ([]*Relationship, *Response, error) {
	path := fmt.Sprintf("r/%s/about/wikicontributors", subreddit)

	path, err := addOptions(path, opts)
	if err != nil {
		return nil, nil, err
	}

	req, err := s.client.NewRequest(http.MethodGet, path, nil)
	if err != nil {
		return nil, nil, err
	}

	root := new(struct {
		Data struct {
			Relationships []*Relationship `json:"children"`
			After         string          `json:"after"`
			Before        string          `json:"before"`
		} `json:"data"`
	})
	resp, err := s.client.Do(ctx, req, root)
	if err != nil {
		return nil, resp, err
	}

	resp.After = root.Data.After
	resp.Before = root.Data.Before

	return root.Data.Relationships, resp, nil
}

// Moderators gets the moderators of the subreddit.
func (s *SubredditService) Moderators(ctx context.Context, subreddit string) ([]*Moderator, *Response, error) {
	path := fmt.Sprintf("r/%s/about/moderators", subreddit)

	req, err := s.client.NewRequest(http.MethodGet, path, nil)
	if err != nil {
		return nil, nil, err
	}

	root := new(struct {
		Data struct {
			Moderators []*Moderator `json:"children"`
		} `json:"data"`
	})
	resp, err := s.client.Do(ctx, req, root)
	if err != nil {
		return nil, resp, err
	}

	return root.Data.Moderators, resp, nil
}

// Rules gets the rules of the subreddit.
func (s *SubredditService) Rules(ctx context.Context, subreddit string) ([]*SubredditRule, *Response, error) {
	path := fmt.Sprintf("r/%s/about/rules", subreddit)

	req, err := s.client.NewRequest(http.MethodGet, path, nil)
	if err != nil {
		return nil, nil, err
	}

	root := new(struct {
		Rules []*SubredditRule `json:"rules"`
	})
	resp, err := s.client.Do(ctx, req, root)
	if err != nil {
		return nil, resp, err
	}

	return root.Rules, resp, nil
}

// CreateRule adds a rule to the subreddit.
func (s *SubredditService) CreateRule(ctx context.Context, subreddit string, request *SubredditRuleCreateRequest) (*Response, error) {
	err := request.validate()
	if err != nil {
		return nil, err
	}

	form, err := query.Values(request)
	if err != nil {
		return nil, err
	}
	form.Set("api_type", "json")

	path := fmt.Sprintf("r/%s/api/add_subreddit_rule", subreddit)
	req, err := s.client.NewRequest(http.MethodPost, path, form)
	if err != nil {
		return nil, err
	}

	return s.client.Do(ctx, req, nil)
}

// Traffic gets the traffic data of the subreddit.
// It returns traffic data by day, hour, and month, respectively.
func (s *SubredditService) Traffic(ctx context.Context, subreddit string) ([]*SubredditTrafficStats, []*SubredditTrafficStats, []*SubredditTrafficStats, *Response, error) {
	path := fmt.Sprintf("r/%s/about/traffic", subreddit)

	req, err := s.client.NewRequest(http.MethodGet, path, nil)
	if err != nil {
		return nil, nil, nil, nil, err
	}

	root := new(struct {
		Day   []*SubredditTrafficStats `json:"day"`
		Hour  []*SubredditTrafficStats `json:"hour"`
		Month []*SubredditTrafficStats `json:"month"`
	})
	resp, err := s.client.Do(ctx, req, root)
	if err != nil {
		return nil, nil, nil, resp, err
	}

	return root.Day, root.Hour, root.Month, resp, nil
}

// StyleSheet returns the subreddit's style sheet, as well as some information about images.
func (s *SubredditService) StyleSheet(ctx context.Context, subreddit string) (*SubredditStyleSheet, *Response, error) {
	path := fmt.Sprintf("r/%s/about/stylesheet", subreddit)

	req, err := s.client.NewRequest(http.MethodGet, path, nil)
	if err != nil {
		return nil, nil, err
	}

	root := new(thing)
	resp, err := s.client.Do(ctx, req, root)
	if err != nil {
		return nil, resp, err
	}

	styleSheet, _ := root.StyleSheet()
	return styleSheet, resp, nil
}

// StyleSheetRaw returns the subreddit's style sheet with all comments and newlines stripped.
func (s *SubredditService) StyleSheetRaw(ctx context.Context, subreddit string) (string, *Response, error) {
	path := fmt.Sprintf("r/%s/stylesheet", subreddit)

	req, err := s.client.NewRequest(http.MethodGet, path, nil)
	if err != nil {
		return "", nil, err
	}

	buf := new(bytes.Buffer)
	resp, err := s.client.Do(ctx, req, buf)
	if err != nil {
		return "", resp, err
	}

	return buf.String(), resp, nil
}

// UpdateStyleSheet updates the style sheet of the subreddit.
// Providing a reason is optional.
func (s *SubredditService) UpdateStyleSheet(ctx context.Context, subreddit, styleSheet, reason string) (*Response, error) {
	path := fmt.Sprintf("r/%s/api/subreddit_stylesheet", subreddit)

	form := url.Values{}
	form.Set("api_type", "json")
	form.Set("op", "save")
	form.Set("stylesheet_contents", styleSheet)
	if reason != "" {
		form.Set("reason", reason)
	}

	req, err := s.client.NewRequest(http.MethodPost, path, form)
	if err != nil {
		return nil, err
	}

	return s.client.Do(ctx, req, nil)
}

// RemoveHeaderImage removes the subreddit's custom header image.
// The call succeeds even if there's no header image.
func (s *SubredditService) RemoveHeaderImage(ctx context.Context, subreddit string) (*Response, error) {
	path := fmt.Sprintf("r/%s/api/delete_sr_header", subreddit)

	form := url.Values{}
	form.Set("api_type", "json")

	req, err := s.client.NewRequest(http.MethodPost, path, form)
	if err != nil {
		return nil, err
	}

	return s.client.Do(ctx, req, nil)
}

// RemoveMobileIcon removes the subreddit's custom mobile icon.
// The call succeeds even if there's no mobile icon.
func (s *SubredditService) RemoveMobileIcon(ctx context.Context, subreddit string) (*Response, error) {
	path := fmt.Sprintf("r/%s/api/delete_sr_icon", subreddit)

	form := url.Values{}
	form.Set("api_type", "json")

	req, err := s.client.NewRequest(http.MethodPost, path, form)
	if err != nil {
		return nil, err
	}

	return s.client.Do(ctx, req, nil)
}

// RemoveMobileBanner removes the subreddit's custom mobile banner.
// The call succeeds even if there's no mobile banner.
func (s *SubredditService) RemoveMobileBanner(ctx context.Context, subreddit string) (*Response, error) {
	path := fmt.Sprintf("r/%s/api/delete_sr_banner", subreddit)

	form := url.Values{}
	form.Set("api_type", "json")

	req, err := s.client.NewRequest(http.MethodPost, path, form)
	if err != nil {
		return nil, err
	}

	return s.client.Do(ctx, req, nil)
}

// RemoveImage removes an image from the subreddit's custom image set.
// The call succeeds even if the named image does not exist.
func (s *SubredditService) RemoveImage(ctx context.Context, subreddit, imageName string) (*Response, error) {
	path := fmt.Sprintf("r/%s/api/delete_sr_img", subreddit)

	form := url.Values{}
	form.Set("api_type", "json")
	form.Set("img_name", imageName)

	req, err := s.client.NewRequest(http.MethodPost, path, form)
	if err != nil {
		return nil, err
	}

	return s.client.Do(ctx, req, nil)
}