package db

import (
	"context"
	"log"
	"time"
	"valera/config"

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

type DB struct {
	chatsColection    *mongo.Collection
	workoutsColection *mongo.Collection
	caloriesColection *mongo.Collection
}

func NewDB(
	mongoURL string,
	dbName string,
) (*DB, error) {
	ctx := context.Background()
	opt := options.Client().
		ApplyURI(mongoURL).
		SetMinPoolSize(10)
	cfg := config.NewConfig(mongoURL, dbName)

	client, err := mongo.Connect(ctx, opt)
	if err != nil {
		return nil, err
	}

	return &DB{
		chatsColection:    client.Database(dbName).Collection(cfg.ChatsCollectionName),
		workoutsColection: client.Database(dbName).Collection(cfg.WorkoutsCollectionName),
		caloriesColection: client.Database(dbName).Collection(cfg.CaloriesCollectionName),
	}, nil
}

func (db *DB) AddChat(chatID int64) error {
	ctx := context.Background()

	result := db.chatsColection.FindOne(ctx, bson.M{"chat_id": chatID})
	if result.Err() == mongo.ErrNoDocuments {
		if _, err := db.chatsColection.InsertOne(ctx, &Chat{ChatID: chatID}); err != nil {
			return err
		}
		return nil
	}
	return result.Err()
}

func (db *DB) AddWorkout(chatID int64, workout *Workout) error {
	ctx := context.Background()

	if workout.Count <= 0 {
		return nil
	}
	if err := db.AddChat(chatID); err != nil {
		return err
	}
	workout.ChatID = chatID

	_, err := db.workoutsColection.InsertOne(
		ctx,
		workout,
	)
	return err
}

func (db *DB) AddCalories(chatID int64, calories *Calories) error {
	ctx := context.Background()

	if calories.Count <= 0 {
		return nil
	}
	if err := db.AddChat(chatID); err != nil {
		return err
	}
	calories.ChatID = chatID

	_, err := db.caloriesColection.InsertOne(
		ctx,
		calories,
	)
	return err
}

func (db *DB) GetChatInfo(chatID int64) (*ChatInfo, error) {
	ctx := context.Background()

	if err := db.AddChat(chatID); err != nil {
		return nil, err
	}

	chatInfoDTO := &ChatInfo{}
	if err := db.chatsColection.FindOne(ctx, bson.M{"chat_id": chatID}).Decode(chatInfoDTO); err != nil {
		return nil, err
	}
	return chatInfoDTO, nil
}

func (db *DB) SetStatusToChat(chatID int64, status UserState) error {
	ctx := context.Background()

	_, err := db.chatsColection.UpdateOne(
		ctx,
		bson.M{"chat_id": chatID},
		bson.M{"$set": bson.M{"status": status}},
	)
	return err
}

func (db *DB) SetPause(chatID int64, duration time.Duration) error {
	ctx := context.Background()

	loc, _ := time.LoadLocation("Asia/Novosibirsk")
	t := time.Now().In(loc).Add(+duration)
	_, err := db.chatsColection.UpdateOne(
		ctx,
		bson.M{"chat_id": chatID},
		bson.M{"$set": bson.M{"pause_until": t}},
	)
	return err
}

func (db *DB) GetStat(chatID int64, cron bool) (map[string]int, error) {
	ctx := context.Background()

	if err := db.AddChat(chatID); err != nil {
		return nil, err
	}

	loc, _ := time.LoadLocation("Asia/Novosibirsk")
	t := time.Now().In(loc)
	if cron {
		t = t.Add(-24 * time.Hour)
	}
	if !cron {
		t = time.Date(t.Year(), t.Month(), t.Day(), 0, 0, 0, 0, loc)
	}

	res := map[string]int{}

	cursor, err := db.workoutsColection.Find(
		ctx,
		bson.M{
			"chat_id":    chatID,
			"created_at": bson.M{"$gt": t},
		},
	)
	if err != nil {
		return nil, err
	}
	for cursor.Next(context.Background()) {
		var result Workout
		if err := cursor.Decode(&result); err != nil {
			log.Fatal(err)
		}
		res[result.Name] += result.Count
	}
	if err := cursor.Err(); err != nil {
		log.Fatal(err)
	}

	caloriesCursor, err := db.caloriesColection.Find(
		ctx,
		bson.M{
			"chat_id":    chatID,
			"created_at": bson.M{"$gt": t},
		},
	)
	if err != nil {
		return nil, err
	}
	for caloriesCursor.Next(context.Background()) {
		var result Calories
		if err := caloriesCursor.Decode(&result); err != nil {
			log.Fatal(err)
		}
		res["Калории"] += result.Count
	}
	if err := caloriesCursor.Err(); err != nil {
		log.Fatal(err)
	}

	return res, err
}

func (db *DB) GetAllChats() ([]int64, error) {
	ctx := context.Background()

	loc, _ := time.LoadLocation("Asia/Novosibirsk")
	t := time.Now().In(loc)
	cursor, err := db.chatsColection.Find(
		ctx,
		bson.M{
			"$or": bson.A{
				bson.M{
					"pause_until": bson.M{"$lt": t},
				},
				bson.M{
					"pause_until": bson.M{"$exists": false},
				},
			},
		},
	)
	if err != nil {
		return nil, err
	}
	var res []int64
	for cursor.Next(context.Background()) {
		var result ChatInfo
		if err := cursor.Decode(&result); err != nil {
			log.Fatal(err)
		}
		res = append(res, result.ChatID)
	}
	if err := cursor.Err(); err != nil {
		log.Fatal(err)
	}
	return res, err
}