package db

import (
	"context"
	"fmt"
	"log"
	"time"

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

	"valera/internal/config"
)

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

func NewDB(
	cfg *config.AppConfig,
) (*DB, error) {
	ctx := context.Background()
	opt := options.Client().
		ApplyURI(cfg.MongoConfig.URL).
		SetMinPoolSize(10)

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

	return &DB{
		chatsColection:    client.Database(cfg.MongoConfig.DBName).Collection(cfg.MongoConfig.ChatsCollectionName),
		workoutsColection: client.Database(cfg.MongoConfig.DBName).Collection(cfg.MongoConfig.WorkoutsCollectionName),
		caloriesColection: client.Database(cfg.MongoConfig.DBName).Collection(cfg.MongoConfig.CaloriesCollectionName),
		weightColection:   client.Database(cfg.MongoConfig.DBName).Collection(cfg.MongoConfig.WeightCollectionName),
	}, 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
	}
	if result.Err() != nil {
		return result.Err()
	}
	loc, _ := time.LoadLocation("Asia/Novosibirsk")
	t := time.Now().In(loc)
	_, err := db.chatsColection.UpdateOne(
		ctx,
		bson.M{"chat_id": chatID},
		bson.M{"$set": bson.M{"last_time": t}},
	)
	return 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 err := db.AddChat(chatID); err != nil {
		return err
	}
	calories.ChatID = chatID

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

func (db *DB) AddWeight(chatID int64, weight *Weight) error {
	ctx := context.Background()

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

	_, err := db.weightColection.InsertOne(
		ctx,
		weight,
	)
	return err
}

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

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

	chatInfoDTO := &ChatInfo{Username: username}
	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) GetStatBetween(chatID int64, startTime time.Time, endTime time.Time) (map[string]float64, error) {
	ctx := context.Background()

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

	res := map[string]float64{}

	cursor, err := db.workoutsColection.Find(
		ctx,
		bson.M{
			"chat_id": chatID,
			"created_at": bson.M{
				"$gte": startTime,
				"$lt":  endTime,
			},
		},
		options.Find().SetSort(
			bson.M{
				"created_at": 1,
			},
		),
	)
	if err != nil {
		return nil, err
	}
	for cursor.Next(context.Background()) {
		var result Workout
		if err := cursor.Decode(&result); err != nil {
			log.Fatal(err)
		}
		fmt.Println(result)
		res[result.Name] += float64(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{
				"$gte": startTime,
				"$lt":  endTime,
			},
		},
		options.Find().SetSort(
			bson.M{
				"created_at": 1,
			},
		),
	)
	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"] += float64(result.Count)
	}
	if err := caloriesCursor.Err(); err != nil {
		log.Fatal(err)
	}

	weightCursor, err := db.weightColection.Find(
		ctx,
		bson.M{
			"chat_id": chatID,
			"created_at": bson.M{
				"$gte": startTime,
				"$lt":  endTime,
			},
		},
		options.Find().SetSort(
			bson.M{
				"created_at": 1,
			},
		),
	)
	if err != nil {
		return nil, err
	}
	firstWeight := 0.0
	lastWeight := 0.0
	countWeights := 0
	for weightCursor.Next(context.Background()) {
		var result Weight
		if err := weightCursor.Decode(&result); err != nil {
			log.Fatal(err)
		}
		res["Вес кг"] = result.Weight
		if firstWeight == 0 {
			firstWeight = result.Weight
		}
		lastWeight = result.Weight
		countWeights++
	}
	if err := weightCursor.Err(); err != nil {
		log.Fatal(err)
	}
	if countWeights > 0 {
		res["Изменение веса"] = lastWeight - firstWeight
	}

	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
}