package postgres

import (
	"git.kevincotugno.com/kcotugno/tacitus"

	"strings"
	"time"
)

const (
	agg_columns = `interval, product, price, buy_volume, sell_volume, ` +
		`buy_transactions, sell_transactions, timestamp`
	agg_find = `SELECT id, ` + agg_columns + ` FROM aggregations ` +
		`WHERE interval = $1 AND product = $2 AND timestamp = $3;`
	agg_insert = `INSERT INTO aggregations (` + agg_columns + `) VALUES ` +
		`($1, $2, $3, $4, $5, $6, $7, $8) RETURNING id, ` + agg_columns + `;`
	agg_update = `UPDATE aggregations SET interval = $1, product = $2, ` +
		`price = $3, buy_volume = $4, sell_volume = $5, buy_transactions = $6, ` +
		`sell_transactions = $7, timestamp = $8 WHERE id = $9`
	agg_missing = `SELECT id, ` + agg_columns + ` FROM (SELECT ` +
		`generate_series(min(timestamp), max(timestamp), $1)::timestamptz ` +
		`AS timestamp, $2::char(7) product FROM aggregations WHERE interval = $3 ` +
		`AND product = $4) AS x LEFT OUTER JOIN aggregations a USING(timestamp, product) ` +
		`WHERE a.id IS NULL ORDER BY x.timestamp;`
)

type AggregationService struct {
	client *Client
}

func (s *AggregationService) Aggregation(interval int, product string,
	timestamp time.Time) (tacitus.Aggregation, error) {

	var agg tacitus.Aggregation

	s.client.logQuery(agg_find, interval, product, timestamp)

	row := s.client.db.QueryRow(agg_find, interval, product, timestamp)
	err := row.Scan(&agg.Id, &agg.Interval, &agg.Product, &agg.Price,
		&agg.BuyVolume, &agg.SellVolume, &agg.BuyTransactions,
		&agg.SellTransactions, &agg.Timestamp)
	if err != nil {
		s.client.logError(agg_find, err, interval, product, timestamp)
	}

	return agg, nil
}

func (s *AggregationService) CreateAggregation(a tacitus.Aggregation) (tacitus.Aggregation, error) {
	var agg tacitus.Aggregation

	s.client.logQuery(agg_insert, a.Interval, a.Product, a.Price, a.BuyVolume,
		a.SellVolume, a.BuyTransactions, a.SellTransactions, a.Timestamp)

	row := s.client.db.QueryRow(agg_insert, a.Interval, a.Product, a.Price,
		a.BuyVolume, a.SellVolume, a.BuyTransactions, a.SellTransactions,
		a.Timestamp)

	err := row.Scan(&agg.Id, &agg.Interval, &agg.Product, &agg.Price,
		&agg.BuyVolume, &agg.SellVolume, &agg.BuyTransactions,
		&agg.SellTransactions, &agg.Timestamp)
	if err != nil {
		s.client.logError(agg_insert, err, a.Interval, a.Product, a.Price, a.BuyVolume,
			a.SellVolume, a.BuyTransactions, a.SellTransactions, a.Timestamp)
	}

	return agg, err
}

func (s *AggregationService) UpdateAggregation(a tacitus.Aggregation) (tacitus.Aggregation, error) {
	s.client.logQuery(agg_update, a.Interval, a.Product, a.Price, a.BuyVolume,
		a.SellVolume, a.BuyTransactions, a.SellTransactions,
		a.Timestamp, a.Id)

	_, err := s.client.db.Exec(agg_update, a.Interval, a.Product, a.Price,
		a.BuyVolume, a.SellVolume, a.BuyTransactions, a.SellTransactions,
		a.Timestamp, a.Id)
	if err != nil {
		s.client.logError(agg_update, err, a.Interval, a.Product, a.Price,
			a.BuyVolume, a.SellVolume, a.BuyTransactions, a.SellTransactions,
			a.Timestamp, a.Id)
	}

	return a, err
}

func (s *AggregationService) MissingTimes(interval int, product string) (tacitus.Results, error) {
	s.client.logQuery(agg_missing, interval, product, interval, product)

	rows, err := s.client.db.Query(agg_missing, interval, product, interval, product)
	if err != nil {
		s.client.logError(agg_missing, err, strings.Join([]string{string(interval), " seconds"}, ""), product, interval, product)

		return nil, err
	}

	results := AggregationResults{}
	results.rows = rows

	return &results, nil
}