package mongodb

import (
	"context"
	"errors"
	"git.aiterp.net/rpdata/api/internal/generate"
	"git.aiterp.net/rpdata/api/models"
	"github.com/globalsign/mgo"
	"github.com/globalsign/mgo/bson"
	"strconv"
	"sync"
)

type logRepository struct {
	openMutex  sync.Mutex
	restoreIds bool

	logs           *mgo.Collection
	posts          *mgo.Collection
	shortIdCounter *counter
}

func newLogRepository(db *mgo.Database, restoreIds bool) (*logRepository, error) {
	logs := db.C("logbot3.logs")
	posts := db.C("logbot3.posts")

	err := logs.EnsureIndexKey("date")
	if err != nil {
		return nil, err
	}
	err = logs.EnsureIndexKey("channel")
	if err != nil {
		return nil, err
	}
	err = logs.EnsureIndexKey("characterIds")
	if err != nil {
		return nil, err
	}
	err = logs.EnsureIndexKey("event")
	if err != nil {
		return nil, err
	}
	err = logs.EnsureIndex(mgo.Index{Key: []string{"channel", "open"}})
	if err != nil {
		return nil, err
	}

	err = logs.EnsureIndex(mgo.Index{
		Key:      []string{"shortId"},
		Unique:   true,
		DropDups: true,
	})
	if err != nil {
		return nil, err
	}

	return &logRepository{
		restoreIds:     restoreIds,
		logs:           logs,
		posts:          posts,
		shortIdCounter: newCounter(db, "auto_increment", "Log"),
	}, nil
}

func (r *logRepository) Find(ctx context.Context, id string) (*models.Log, error) {
	log := new(models.Log)
	err := r.logs.Find(bson.M{"$or": []bson.M{{"_id": id}, {"shortId": id}}}).One(log)
	if err != nil {
		return nil, err
	}

	return log, nil
}

func (r *logRepository) List(ctx context.Context, filter models.LogFilter) ([]*models.Log, error) {
	query := bson.M{}
	if filter.Search != nil {
		searchQuery := bson.M{
			"$text": bson.M{"$search": *filter.Search},
			"logId": bson.M{"$ne": nil},
		}

		logIds := make([]string, 0, 64)
		err := r.posts.Find(searchQuery).Distinct("logId", &logIds)
		if err != nil {
			return nil, err
		}

		query["shortId"] = bson.M{"$in": logIds}
	}
	if filter.Open != nil {
		r.openMutex.Lock()
		defer r.openMutex.Unlock()

		query["open"] = filter.Open
	}
	if len(filter.Characters) > 0 {
		query["characterIds"] = bson.M{"$all": filter.Characters}
	}
	if len(filter.Channels) > 0 {
		query["channel"] = bson.M{"$in": filter.Channels}
	}
	if len(filter.Events) > 0 {
		query["event"] = bson.M{"$in": filter.Events}
	}
	if filter.MinDate != nil && filter.MaxDate != nil {
		query["date"] = bson.M{"$gte": *filter.MinDate, "$lte": *filter.MaxDate}
	} else if filter.MinDate != nil {
		query["date"] = bson.M{"$gte": *filter.MinDate}
	} else if filter.MaxDate != nil {
		query["date"] = bson.M{"$lt": *filter.MaxDate}
	}

	logs := make([]*models.Log, 0, 32)
	err := r.logs.Find(query).Sort("-date").Limit(filter.Limit).All(&logs)
	if err != nil {
		if err == mgo.ErrNotFound {
			return logs, nil
		}

		return nil, err
	}

	return logs, nil
}

func (r *logRepository) Insert(ctx context.Context, log models.Log) (*models.Log, error) {
	if !r.restoreIds || log.ID == "" || log.ShortID == "" {
		nextShortId, err := r.shortIdCounter.Increment(1)
		if err != nil {
			return nil, err
		}

		log.ID = generate.LogID(log)
		log.ShortID = "L" + strconv.Itoa(nextShortId)
	} else {
		n, err := strconv.Atoi(log.ShortID[1:])
		if err != nil {
			return nil, err
		}

		_ = r.shortIdCounter.Bump(n)
	}

	if log.Open {
		// There can be only one open log in the same channel.
		r.openMutex.Lock()
		defer r.openMutex.Unlock()

		_, err := r.logs.UpdateAll(bson.M{"channel": log.ChannelName, "open": true}, bson.M{"$set": bson.M{"open": false}})
		if err != nil {
			return nil, errors.New("Cannot close other logs: " + err.Error())
		}
	}

	err := r.logs.Insert(&log)
	if err != nil {
		return nil, err
	}

	return &log, nil
}

func (r *logRepository) Update(ctx context.Context, log models.Log, update models.LogUpdate) (*models.Log, error) {
	updateBson := bson.M{}
	if update.Open != nil {
		if *update.Open == true {
			// There can be only one open log in the same channel.
			r.openMutex.Lock()
			defer r.openMutex.Unlock()

			_, err := r.logs.UpdateAll(bson.M{"channel": log.ChannelName, "open": true}, bson.M{"$set": bson.M{"open": false}})
			if err != nil {
				return nil, errors.New("Cannot close other logs: " + err.Error())
			}
		}

		updateBson["open"] = *update.Open
		log.Open = *update.Open
	}
	if update.Title != nil {
		updateBson["title"] = *update.Title
		log.Title = *update.Title
	}
	if update.Description != nil {
		updateBson["description"] = *update.Description
		log.Description = *update.Description
	}
	if update.EventName != nil {
		updateBson["event"] = *update.EventName
		log.EventName = *update.EventName
	}
	if update.CharacterIDs != nil {
		updateBson["characterIds"] = update.CharacterIDs
		log.CharacterIDs = update.CharacterIDs
	}

	err := r.logs.UpdateId(log.ID, bson.M{"$set": updateBson})
	if err != nil {
		return nil, err
	}

	return &log, nil
}

func (r *logRepository) Delete(ctx context.Context, log models.Log) error {
	err := r.logs.RemoveId(log.ID)
	if err != nil {
		return err
	}

	_, _ = r.posts.RemoveAll(bson.M{"logId": log.ShortID})

	return nil
}