TerraOceanPlugin/GoBot/db_vote.go

package main

import (
	"errors"
	"time"
)

const (
	forceRejectionVote = -1
	nuclearOptionVote  = 10
)

var errForceRejectionVoteReuse = errors.New("db: the user has used force rejection vote in the last month")
var errVoteIsOver = errors.New("db: the vote cannot be changed once it's over")

func createCustomVote(messageID, text string) (int, error) {
	result, err := db.Exec("INSERT INTO vote(messageId, name, type, finished) VALUES(?, ?, ?, ?)", messageID, text, "custom", false)
	if err != nil {
		return 0, err
	}
	lastID, err := result.LastInsertId()
	return int(lastID), nil
}

func getVoteName(id int) (string, error) {
	rows, err := db.Query("SELECT name FROM vote WHERE id=?", id)
	if err != nil {
		return "", err
	}
	if rows.Next() {
		var name string
		err := rows.Scan(&name)
		if err != nil {
			return "", err
		}
		return name, nil
	}
	return "", errNotFound
}

func getVoteFromMessageID(msgID string) (int, error) {
	rows, err := db.Query("SELECT id FROM vote WHERE messageId=?", msgID)
	if err != nil {
		return 0, err
	}
	if rows.Next() {
		var id int
		err := rows.Scan(&id)
		if err != nil {
			return 0, err
		}
		return id, nil
	}
	return 0, errNotFound
}

func updateVote(voteID int, userID string, voteValue int) error {
	if voteValue == forceRejectionVote {
		//Check if they used it within a month.
		rows, err := db.Query("SELECT voteId FROM choices WHERE date >= ? AND value=?", time.Now().AddDate(0, -1, 0))
		if err != nil {
			return err
		}
		if rows.Next() {
			return errForceRejectionVoteReuse
		}
	}

	//Check if the vote is finished and don't allow change of vote that way.
	rows, err := db.Query("SELECT finished FROM vote WHERE id=? AND finished=?", voteID, true)
	if rows.Next() {
		return errVoteIsOver
	}

	_, err = db.Exec("REPLACE INTO choices (voteId, userId, date, value) VALUES (?, ?, ?, ?)", voteID, userID, time.Now(), voteValue)
	return err
}