package shared

import (
	"context"
	"errors"
	"flag"
	"os"
	"time"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/bson/primitive"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

type MongoClient struct {
	db *mongo.Database
	c  *mongo.Client
}

type ConnectionInfo struct {
	Url      string
	Database string
}

var Devflag = flag.Bool("dev", false, "")

type CollectionName string

const (
	CollectionCoupon    = CollectionName("coupon")
	CollectionCouponUse = CollectionName("coupon_use")
	CollectionAccount   = CollectionName("account")
	CollectionAuth      = CollectionName("auth")
	CollectionMatch     = CollectionName("match")
)

func mongourl() string {
	v := os.Getenv("MONGO_URL")
	if len(v) > 0 {
		return v
	}
	return "mongodb://redis-dev.actionsquare.corp:27017/?replicaSet=repl01"
}

func NewMongoConnectionInfo() *ConnectionInfo {
	if !flag.Parsed() {
		flag.Parse()
	}
	dbname := "anvil"
	if *Devflag {
		dbname, _ = os.Hostname()
	}

	return &ConnectionInfo{
		Url:      mongourl(),
		Database: dbname,
	}
}
func (ci *ConnectionInfo) SetURL(url string) *ConnectionInfo {
	ci.Url = url
	return ci
}

func (ci *ConnectionInfo) SetDatabase(dbname string) *ConnectionInfo {
	ci.Database = dbname
	return ci
}

func NewMongoClient(ci *ConnectionInfo) (MongoClient, error) {
	if len(ci.Url) == 0 {
		return MongoClient{}, errors.New("mongo connection string is empty")
	}

	client, err := mongo.NewClient(options.Client().ApplyURI(ci.Url))
	if err != nil {
		return MongoClient{}, err
	}

	ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
	defer cancel()

	err = client.Connect(ctx)
	if err != nil {
		return MongoClient{}, err
	}
	err = client.Ping(ctx, nil)
	if err != nil {
		return MongoClient{}, err
	}

	anvildb := client.Database(ci.Database, nil)
	makeExpiredIndex := func(collname CollectionName, expireSeconds int32) error {
		matchcoll := anvildb.Collection(string(collname))
		indices, err := matchcoll.Indexes().List(ctx, options.ListIndexes().SetMaxTime(time.Second))
		if err != nil {
			return err
		}

		allindices := make([]interface{}, 0)
		err = indices.All(context.Background(), &allindices)
		if err != nil {
			return err
		}

		tsfound := false
		var tsname string
		var exp int32
		for _, index := range allindices {
			d := index.(bson.D)
			key := d.Map()["key"].(bson.D)
			for _, kd := range key {
				if kd.Key == "_ts" {
					tsfound = true
				}
			}

			if v, ok := d.Map()["name"]; ok {
				tsname = v.(string)
			}
			if v, ok := d.Map()["expireAfterSeconds"]; ok {
				exp = v.(int32)
			}
		}

		if tsfound {
			if exp == expireSeconds {
				return nil
			}
			_, err = matchcoll.Indexes().DropOne(ctx, tsname)
			if err != nil {
				return err
			}
		}

		mod := mongo.IndexModel{
			Keys:    primitive.M{"_ts": 1},
			Options: options.Index().SetExpireAfterSeconds(expireSeconds),
		}

		_, err = matchcoll.Indexes().CreateOne(ctx, mod)
		return err
	}

	if err = makeExpiredIndex(CollectionMatch, 30); err != nil {
		return MongoClient{}, err
	}
	if err = makeExpiredIndex(CollectionAuth, 300); err != nil {
		return MongoClient{}, err
	}

	return MongoClient{c: client, db: anvildb}, nil
}

func (mc MongoClient) Close() {
	if mc.c != nil {
		mc.c.Disconnect(context.Background())
	}
}

func (mc MongoClient) Watch(coll CollectionName, pipeline mongo.Pipeline) (*mongo.ChangeStream, error) {
	return mc.Collection(coll).Watch(context.Background(), pipeline, options.ChangeStream().SetFullDocument(options.UpdateLookup).SetMaxAwaitTime(0))
}

func (mc MongoClient) Collection(collname CollectionName) *mongo.Collection {
	return mc.db.Collection(string(collname))
}

func (mc MongoClient) All(coll CollectionName, opts ...*options.FindOptions) ([]bson.M, error) {
	cursor, err := mc.Collection(coll).Find(context.Background(), bson.D{}, opts...)
	if err != nil {
		return nil, err
	}
	var all []bson.M
	err = cursor.All(context.Background(), &all)
	if err != nil {
		return nil, err
	}

	return all, nil
}

func (mc MongoClient) FindOneAndDelete(coll CollectionName, filter bson.M) (bson.M, error) {
	result := mc.Collection(coll).FindOneAndDelete(context.Background(), filter)
	err := result.Err()
	if err != nil {
		if err == mongo.ErrNoDocuments {
			return nil, nil
		}
		return nil, err
	}

	tmp := make(map[string]interface{})
	err = result.Decode(&tmp)
	if err != nil {
		return nil, err
	}

	return bson.M(tmp), nil
}

func (mc MongoClient) Delete(coll CollectionName, filter bson.M) (bool, error) {
	r, err := mc.Collection(coll).DeleteOne(context.Background(), filter)
	if err != nil {
		return false, err
	}

	return r.DeletedCount > 0, nil
}

func (mc MongoClient) UnsetField(coll CollectionName, filter bson.M, doc bson.M) error {
	_, err := mc.Collection(coll).UpdateOne(context.Background(), filter, bson.M{
		"$unset": doc,
	})
	return err
}

func (mc MongoClient) DeleteMany(coll CollectionName, filters bson.M, opts ...*options.DeleteOptions) (int, error) {
	result, err := mc.Collection(coll).DeleteMany(context.Background(), filters, opts...)
	if err != nil {
		return 0, err
	}

	return int(result.DeletedCount), nil
}

func (mc MongoClient) InsertMany(coll CollectionName, documents []interface{}, opts ...*options.InsertManyOptions) (int, error) {
	result, err := mc.Collection(coll).InsertMany(context.Background(), documents, opts...)
	if err != nil {
		return 0, err
	}

	return len(result.InsertedIDs), nil
}

func (mc MongoClient) UpdateMany(coll CollectionName, filter bson.M, doc bson.M, opts ...*options.UpdateOptions) (count int, err error) {
	result, e := mc.Collection(coll).UpdateMany(context.Background(), filter, doc, opts...)

	if e != nil {
		return 0, e
	}

	err = nil
	count = int(result.UpsertedCount + result.ModifiedCount)
	return
}

func (mc MongoClient) Update(coll CollectionName, filter bson.M, doc bson.M, opts ...*options.UpdateOptions) (worked bool, newid interface{}, err error) {
	result, e := mc.Collection(coll).UpdateOne(context.Background(), filter, doc, opts...)

	if e != nil {
		return false, "", e
	}

	err = nil
	worked = result.UpsertedCount > 0 || result.ModifiedCount > 0
	newid = result.UpsertedID
	return
}

func (mc MongoClient) UpsertOne(coll CollectionName, filter bson.M, doc bson.M) (worked bool, newid interface{}, err error) {
	return mc.Update(coll, filter, bson.M{
		"$set": doc,
	}, options.Update().SetUpsert(true))
}

func (mc MongoClient) FindOne(coll CollectionName, filter bson.M, opts ...*options.FindOneOptions) (doc bson.M, err error) {
	result := mc.Collection(coll).FindOne(context.Background(), filter, opts...)
	tmp := make(map[string]interface{})
	err = result.Decode(&tmp)
	if err == nil {
		doc = bson.M(tmp)
	} else if err == mongo.ErrNoDocuments {
		err = nil
	}

	return
}

func (mc MongoClient) FindOneAndUpdate(coll CollectionName, filter bson.M, doc bson.M, opts ...*options.FindOneAndUpdateOptions) (olddoc bson.M, err error) {
	result := mc.Collection(coll).FindOneAndUpdate(context.Background(), filter, doc, opts...)
	tmp := make(map[string]interface{})
	err = result.Decode(&tmp)
	if err == nil {
		olddoc = bson.M(tmp)
	} else if err == mongo.ErrNoDocuments {
		err = nil
	}

	return
}

func (mc MongoClient) Exists(coll CollectionName, filter bson.M) (bool, error) {
	cnt, err := mc.Collection(coll).CountDocuments(context.Background(), filter, options.Count().SetLimit(1))
	if err != nil {
		return false, err
	}
	return cnt > 0, nil
}

func (mc MongoClient) FindAll(coll CollectionName, filter bson.M, opts ...*options.FindOptions) ([]bson.M, error) {
	cursor, err := mc.Collection(coll).Find(context.Background(), filter, opts...)
	if err != nil {
		return nil, err
	}

	output := make([]interface{}, 0)
	err = cursor.All(context.Background(), &output)
	if err != nil {
		return nil, err
	}

	docs := make([]bson.M, 0, len(output))
	for _, doc := range output {
		one := make(bson.M)
		for _, kv := range doc.(bson.D) {
			one[kv.Key] = kv.Value
		}
		docs = append(docs, one)
	}
	return docs, nil
}