package postgresql

import (
	"context"
	"fmt"

	"gitea.computernetthings.ru/yash/crypto_alert_bot/internal/entities"
	"github.com/shopspring/decimal"
)

const saveAlertQuery = `
insert into alert(user_id, instrument_id, price, condition)
values ($1, $2, $3, $4)
returning id`

func (p *Postgresql) SaveAlert(ctx context.Context, alert *entities.Alert) (entities.AlertID, error) {
	var id entities.AlertID

	err := p.db.QueryRow(ctx, saveAlertQuery, alert.UserID, alert.Instrument.ID, alert.Price.String(), alert.Condition).Scan(&id)
	if err != nil {
		return "", fmt.Errorf("failed to exec saveAlertQuery: %w", err)
	}

	return id, nil
}

const allActiveAlertsQuery = `
select a.id, a.user_id, a.price, a.condition, i.id, c_base.symbol, c_quote.symbol
from alert a
join instrument i on i.id = a.instrument_id
join currency c_base on c_base.id = i.base_currency_id
join currency c_quote on c_quote.id = i.quoted_currency_id
where a.active = true
order by a.id`

func (p *Postgresql) AllActiveAlerts(ctx context.Context) ([]entities.Alert, error) {
	rows, err := p.db.Query(ctx, allActiveAlertsQuery)
	if err != nil {
		return nil, fmt.Errorf("failed to exec allActiveAlertsQuery: %w", err)
	}
	defer rows.Close()

	var alerts []entities.Alert
	for rows.Next() {
		var alert entities.Alert
		var priceStr string

		if err := rows.Scan(
			&alert.ID, &alert.UserID, &priceStr, &alert.Condition,
			&alert.Instrument.ID, &alert.Instrument.BaseCurrency, &alert.Instrument.QuoteCurrency,
		); err != nil {
			return nil, fmt.Errorf("failed to scan alert row: %w", err)
		}

		alert.Price, err = decimal.NewFromString(priceStr)
		if err != nil {
			return nil, fmt.Errorf("failed to parse alert price: %w", err)
		}

		alerts = append(alerts, alert)
	}

	return alerts, nil
}

const alertByIDQuery = `
select a.id, a.user_id, a.price, a.condition, i.id, c_base.symbol, c_quote.symbol
from alert a
join instrument i on i.id = a.instrument_id
join currency c_base on c_base.id = i.base_currency_id
join currency c_quote on c_quote.id = i.quoted_currency_id
where a.id = $1 and a.active = true`

func (p *Postgresql) AlertByID(ctx context.Context, id entities.AlertID) (*entities.Alert, error) {
	var alert entities.Alert
	var priceStr string

	err := p.db.QueryRow(ctx, alertByIDQuery, id).Scan(
		&alert.ID, &alert.UserID, &priceStr, &alert.Condition,
		&alert.Instrument.ID, &alert.Instrument.BaseCurrency, &alert.Instrument.QuoteCurrency,
	)
	if err != nil {
		return nil, fmt.Errorf("failed to exec alertByIDQuery: %w", err)
	}

	alert.Price, err = decimal.NewFromString(priceStr)
	if err != nil {
		return nil, fmt.Errorf("failed to parse alert price: %w", err)
	}

	return &alert, nil
}

const alertsByUserIDQuery = `
select a.id, a.user_id, a.price, a.condition, i.id, c_base.symbol, c_quote.symbol
from alert a
join instrument i on i.id = a.instrument_id
join currency c_base on c_base.id = i.base_currency_id
join currency c_quote on c_quote.id = i.quoted_currency_id
where a.user_id = $1 and a.active = true
order by a.id
offset $2 limit $3`

func (p *Postgresql) AlertsByUserID(ctx context.Context, userID entities.UserID, offset, limit int) ([]entities.Alert, error) {
	rows, err := p.db.Query(ctx, alertsByUserIDQuery, userID, offset, limit)
	if err != nil {
		return nil, fmt.Errorf("failed to exec alertsByUserIDQuery: %w", err)
	}
	defer rows.Close()

	var alerts []entities.Alert
	for rows.Next() {
		var alert entities.Alert
		var priceStr string

		if err := rows.Scan(
			&alert.ID, &alert.UserID, &priceStr, &alert.Condition,
			&alert.Instrument.ID, &alert.Instrument.BaseCurrency, &alert.Instrument.QuoteCurrency,
		); err != nil {
			return nil, fmt.Errorf("failed to scan alert row: %w", err)
		}

		alert.Price, err = decimal.NewFromString(priceStr)
		if err != nil {
			return nil, fmt.Errorf("failed to parse alert price: %w", err)
		}

		alerts = append(alerts, alert)
	}

	return alerts, nil
}

const deleteAlertQuery = "update alert set active = false where id = $1"

func (p *Postgresql) DeleteAlert(ctx context.Context, id entities.AlertID) error {
	_, err := p.db.Exec(ctx, deleteAlertQuery, id)
	if err != nil {
		return fmt.Errorf("failed to exec deleteAlertQuery: %w", err)
	}

	return nil
}

const disableAlertQuery = "update alert set active = false where id = $1"

func (p *Postgresql) DisableAlert(ctx context.Context, id entities.AlertID) error {
	_, err := p.db.Exec(ctx, disableAlertQuery, id)
	if err != nil {
		return fmt.Errorf("failed to exec disableAlertQuery: %w", err)
	}

	return nil
}

const updateAlertPriceQuery = "update alert set price = $2 where id = $1"

func (p *Postgresql) UpdateAlertPrice(ctx context.Context, id entities.AlertID, price decimal.Decimal) error {
	_, err := p.db.Exec(ctx, updateAlertPriceQuery, id, price.String())
	if err != nil {
		return fmt.Errorf("failed to exec updateAlertPriceQuery: %w", err)
	}

	return nil
}