/*
*
*    Gosora Topic Store
*    Copyright Azareal 2017 - 2020
*
 */
package common

import (
	"database/sql"
	"errors"
	"strconv"
	"strings"

	qgen "git.tuxpa.in/a/gosora/query_gen"
)

// TODO: Add the watchdog goroutine
// TODO: Add some sort of update method
// ? - Should we add stick, lock, unstick, and unlock methods? These might be better on the Topics not the TopicStore
var Topics TopicStore
var ErrNoTitle = errors.New("This message is missing a title")
var ErrLongTitle = errors.New("The title is too long")
var ErrNoBody = errors.New("This message is missing a body")

type TopicStore interface {
    DirtyGet(id int) *Topic
    Get(id int) (*Topic, error)
    BypassGet(id int) (*Topic, error)
    BulkGetMap(ids []int) (list map[int]*Topic, err error)
    Exists(id int) bool
    Create(fid int, name, content string, uid int, ip string) (tid int, err error)
    AddLastTopic(t *Topic, fid int) error // unimplemented
    Reload(id int) error                  // Too much SQL logic to move into TopicCache
    // TODO: Implement these two methods
    //Replies(tid int) ([]*Reply, error)
    //RepliesRange(tid, lower, higher int) ([]*Reply, error)
    Count() int
    CountUser(uid int) int
    CountMegaUser(uid int) int
    CountBigUser(uid int) int

    ClearIPs() error
    LockMany(tids []int) error

    SetCache(cache TopicCache)
    GetCache() TopicCache
}

type DefaultTopicStore struct {
    cache TopicCache

    get           *sql.Stmt
    exists        *sql.Stmt
    count         *sql.Stmt
    countUser     *sql.Stmt
    countWordUser *sql.Stmt
    create        *sql.Stmt

    clearIPs *sql.Stmt
    lockTen *sql.Stmt
}

// NewDefaultTopicStore gives you a new instance of DefaultTopicStore
func NewDefaultTopicStore(cache TopicCache) (*DefaultTopicStore, error) {
    acc := qgen.NewAcc()
    if cache == nil {
        cache = NewNullTopicCache()
    }
    t := "topics"
    return &DefaultTopicStore{
        cache:         cache,
        get:           acc.Select(t).Columns("title,content,createdBy,createdAt,lastReplyBy,lastReplyAt,lastReplyID,is_closed,sticky,parentID,ip,views,postCount,likeCount,attachCount,poll,data").Where("tid=?").Stmt(),
        exists:        acc.Exists(t, "tid").Stmt(),
        count:         acc.Count(t).Stmt(),
        countUser:     acc.Count(t).Where("createdBy=?").Stmt(),
        countWordUser: acc.Count(t).Where("createdBy=? AND words>=?").Stmt(),
        create:        acc.Insert(t).Columns("parentID,title,content,parsed_content,createdAt,lastReplyAt,lastReplyBy,ip,words,createdBy").Fields("?,?,?,?,UTC_TIMESTAMP(),UTC_TIMESTAMP(),?,?,?,?").Prepare(),

        clearIPs: acc.Update(t).Set("ip=''").Where("ip!=''").Stmt(),
        lockTen: acc.Update(t).Set("is_closed=1").Where("tid IN(" + inqbuild2(10) + ")").Stmt(),
    }, acc.FirstError()
}

func (s *DefaultTopicStore) DirtyGet(id int) *Topic {
    t, e := s.cache.Get(id)
    if e == nil {
        return t
    }
    t, e = s.BypassGet(id)
    if e == nil {
        _ = s.cache.Set(t)
        return t
    }
    return BlankTopic()
}

// TODO: Log weird cache errors?
func (s *DefaultTopicStore) Get(id int) (t *Topic, e error) {
    t, e = s.cache.Get(id)
    if e == nil {
        return t, nil
    }
    t, e = s.BypassGet(id)
    if e == nil {
        _ = s.cache.Set(t)
    }
    return t, e
}

// BypassGet will always bypass the cache and pull the topic directly from the database
func (s *DefaultTopicStore) BypassGet(id int) (*Topic, error) {
    t := &Topic{ID: id}
    e := s.get.QueryRow(id).Scan(&t.Title, &t.Content, &t.CreatedBy, &t.CreatedAt, &t.LastReplyBy, &t.LastReplyAt, &t.LastReplyID, &t.IsClosed, &t.Sticky, &t.ParentID, &t.IP, &t.ViewCount, &t.PostCount, &t.LikeCount, &t.AttachCount, &t.Poll, &t.Data)
    if e == nil {
        t.Link = BuildTopicURL(NameToSlug(t.Title), id)
    }
    return t, e
}

/*func (s *DefaultTopicStore) GetByUser(uid int) (list map[int]*Topic, err error) {
    t := &Topic{ID: id}
    err := s.get.QueryRow(id).Scan(&t.Title, &t.Content, &t.CreatedBy, &t.CreatedAt, &t.LastReplyBy, &t.LastReplyAt, &t.LastReplyID, &t.IsClosed, &t.Sticky, &t.ParentID, &t.IP, &t.ViewCount, &t.PostCount, &t.LikeCount, &t.AttachCount, &t.Poll, &t.Data)
    if err == nil {
        t.Link = BuildTopicURL(NameToSlug(t.Title), id)
    }
    return t, err
}*/

// TODO: Avoid duplicating much of this logic from user_store.go
func (s *DefaultTopicStore) BulkGetMap(ids []int) (list map[int]*Topic, e error) {
    idCount := len(ids)
    list = make(map[int]*Topic)
    if idCount == 0 {
        return list, nil
    }

    var stillHere []int
    sliceList := s.cache.BulkGet(ids)
    if len(sliceList) > 0 {
        for i, sliceItem := range sliceList {
            if sliceItem != nil {
                list[sliceItem.ID] = sliceItem
            } else {
                stillHere = append(stillHere, ids[i])
            }
        }
        ids = stillHere
    }

    // If every user is in the cache, then return immediately
    if len(ids) == 0 {
        return list, nil
    } else if len(ids) == 1 {
        t, e := s.Get(ids[0])
        if e != nil {
            return list, e
        }
        list[t.ID] = t
        return list, nil
    }

    idList, q := inqbuild(ids)
    rows, e := qgen.NewAcc().Select("topics").Columns("tid,title,content,createdBy,createdAt,lastReplyBy,lastReplyAt,lastReplyID,is_closed,sticky,parentID,ip,views,postCount,likeCount,attachCount,poll,data").Where("tid IN(" + q + ")").Query(idList...)
    if e != nil {
        return list, e
    }
    defer rows.Close()

    for rows.Next() {
        t := &Topic{}
        e := rows.Scan(&t.ID, &t.Title, &t.Content, &t.CreatedBy, &t.CreatedAt, &t.LastReplyBy, &t.LastReplyAt, &t.LastReplyID, &t.IsClosed, &t.Sticky, &t.ParentID, &t.IP, &t.ViewCount, &t.PostCount, &t.LikeCount, &t.AttachCount, &t.Poll, &t.Data)
        if e != nil {
            return list, e
        }
        t.Link = BuildTopicURL(NameToSlug(t.Title), t.ID)
        _ = s.cache.Set(t)
        list[t.ID] = t
    }
    if e = rows.Err(); e != nil {
        return list, e
    }

    // Did we miss any topics?
    if idCount > len(list) {
        var sidList string
        for i, id := range ids {
            if _, ok := list[id]; !ok {
                if i == 0 {
                    sidList += strconv.Itoa(id)
                } else {
                    sidList += ","+strconv.Itoa(id)
                }
            }
        }
        if sidList != "" {
            e = errors.New("Unable to find topics with the following IDs: " + sidList)
        }
    }

    return list, e
}

func (s *DefaultTopicStore) Reload(id int) error {
    t, e := s.BypassGet(id)
    if e == nil {
        _ = s.cache.Set(t)
    } else {
        _ = s.cache.Remove(id)
    }
    TopicListThaw.Thaw()
    return e
}

func (s *DefaultTopicStore) Exists(id int) bool {
    return s.exists.QueryRow(id).Scan(&id) == nil
}

func (s *DefaultTopicStore) ClearIPs() error {
    _, e := s.clearIPs.Exec()
    return e
}

func (s *DefaultTopicStore) LockMany(tids []int) (e error) {
    tc, i := Topics.GetCache(), 0
    singles := func() error {
        for ; i < len(tids); i++ {
            _, e := topicStmts.lock.Exec(tids[i])
            if e != nil {
                return e
            }
        }
        return nil
    }

    if len(tids) < 10 {
        if e = singles(); e != nil {
            return e
        }
        if tc != nil {
            _ = tc.RemoveMany(tids)
        }
        TopicListThaw.Thaw()
        return nil
    }

    for ; (i + 10) < len(tids); i += 10 {
        _, e := s.lockTen.Exec(tids[i], tids[i+1], tids[i+2], tids[i+3], tids[i+4], tids[i+5], tids[i+6], tids[i+7], tids[i+8], tids[i+9])
        if e != nil {
            return e
        }
    }

    if e = singles(); e != nil {
        return e
    }
    if tc != nil {
        _ = tc.RemoveMany(tids)
    }
    TopicListThaw.Thaw()
    return nil
}

func (s *DefaultTopicStore) Create(fid int, name, content string, uid int, ip string) (tid int, err error) {
    if name == "" {
        return 0, ErrNoTitle
    }
    // ? This number might be a little screwy with Unicode, but it's the only consistent thing we have, as Unicode characters can be any number of bytes in theory?
    if len(name) > Config.MaxTopicTitleLength {
        return 0, ErrLongTitle
    }

    parsedContent := strings.TrimSpace(ParseMessage(content, fid, "forums", nil, nil))
    if parsedContent == "" {
        return 0, ErrNoBody
    }

    // TODO: Move this statement into the topic store
    if Config.DisablePostIP {
        ip = ""
    }
    res, err := s.create.Exec(fid, name, content, parsedContent, uid, ip, WordCount(content), uid)
    if err != nil {
        return 0, err
    }
    lastID, err := res.LastInsertId()
    if err != nil {
        return 0, err
    }
    tid = int(lastID)
    //TopicListThaw.Thaw() // redundant

    return tid, Forums.AddTopic(tid, uid, fid)
}

// ? - What is this? Do we need it? Should it be in the main store interface?
func (s *DefaultTopicStore) AddLastTopic(t *Topic, fid int) error {
    // Coming Soon...
    return nil
}

// Count returns the total number of topics on these forums
func (s *DefaultTopicStore) Count() (count int) {
    return Countf(s.count)
}
func (s *DefaultTopicStore) CountUser(uid int) (count int) {
    return Countf(s.countUser, uid)
}
func (s *DefaultTopicStore) CountMegaUser(uid int) (count int) {
    return Countf(s.countWordUser, uid, SettingBox.Load().(SettingMap)["megapost_min_words"].(int))
}
func (s *DefaultTopicStore) CountBigUser(uid int) (count int) {
    return Countf(s.countWordUser, uid, SettingBox.Load().(SettingMap)["bigpost_min_words"].(int))
}

func (s *DefaultTopicStore) SetCache(cache TopicCache) {
    s.cache = cache
}

// TODO: We're temporarily doing this so that you can do tcache != nil in getTopicUser. Refactor it.
func (s *DefaultTopicStore) GetCache() TopicCache {
    _, ok := s.cache.(*NullTopicCache)
    if ok {
        return nil
    }
    return s.cache
}