package main

import (
	// External
	we "git.gibonuddevalla.se/go/wrappederror"

	// Standard
	"database/sql"
	"time"
)

type DatapointType string

const (
	INT      DatapointType = "INT"
	STRING                 = "STRING"
	DATETIME               = "DATETIME"
)

type Datapoint struct {
	ID                 int
	Name               string
	SectionID          int `db:"section_id"`
	Datatype           DatapointType
	LastValue          time.Time `db:"last_value"`
	DatapointValueJSON []byte    `db:"datapoint_value_json"`
	LastDatapointValue DatapointValue
}

type DatapointValue struct {
	ID            int
	DatapointID   int `db:"datapoint_id"`
	Ts            time.Time
	ValueInt      sql.NullInt64  `db:"value_int"`
	ValueString   sql.NullString `db:"value_string"`
	ValueDateTime sql.NullTime   `db:"value_datetime"`
}

func (dp DatapointValue) Value() any {
	if dp.ValueInt.Valid {
		return dp.ValueInt.Int64
	}
	if dp.ValueString.Valid {
		return dp.ValueString.String
	}
	if dp.ValueDateTime.Valid {
		return dp.ValueDateTime.Time
	}
	return nil
}

func DatapointAdd[T any](name string, value T) (err error) {
	row := service.Db.Conn.QueryRow(`SELECT id, datatype FROM datapoint WHERE name=$1`, name)

	var dpID int
	var dpType DatapointType

	err = row.Scan(&dpID, &dpType)
	if err != nil {
		err = we.Wrap(err).WithData(struct {
			Name  string
			Value any
		}{name, value})
		return
	}

	switch dpType {
	case INT:
		_, err = service.Db.Conn.Exec(`INSERT INTO datapoint_value(datapoint_id, value_int) VALUES($1, $2)`, dpID, value)
	case STRING:
		_, err = service.Db.Conn.Exec(`INSERT INTO datapoint_value(datapoint_id, value_string) VALUES($1, $2)`, dpID, value)
	case DATETIME:
		_, err = service.Db.Conn.Exec(`INSERT INTO datapoint_value(datapoint_id, value_datetime) VALUES($1, $2)`, dpID, value)
	}
	if err != nil {
		err = we.Wrap(err).WithData(struct {
			ID    int
			value any
		}{dpID, value})
		return
	}

	return
}

func DatapointRetrieve(name string) (dp Datapoint, err error) {
	row := service.Db.Conn.QueryRowx(
		`SELECT * FROM datapoint dp WHERE dp.name = $1`,
		name,
	)
	err = row.StructScan(&dp)
	if err != nil {
		err = we.Wrap(err).WithData(name)
		return
	}

	row = service.Db.Conn.QueryRowx(`
			SELECT *
			FROM datapoint_value
			WHERE datapoint_id = $1
			ORDER BY ts DESC
			LIMIT 1
		`,
		dp.ID,
	)
	err = row.StructScan(&dp.LastDatapointValue)
	if err != nil {
		err = we.Wrap(err).WithData(dp.ID)
		return
	}
	return
}