package main

import "github.com/mxk/go-sqlite/sqlite3"
import "errors"
import "strconv"

type Poll struct {
    id int64
    title string
    userId int64
}

func addPoll(db *sqlite3.Conn, title string, options []string, nick string) (int64, error) {

    user := getUserForName(db, nick)

    if (user.id == 0) {
        var err error
        user, err = createUser(db, nick, false)

        if (err != nil) {
            return 0, err
        }
    }


    args := sqlite3.NamedArgs{"$a": title, "$b": user.id}
    sql := "INSERT INTO polls (title, user_id) VALUES ($a, $b)"

    err := db.Exec(sql, args)

    if (err != nil ) {
        return 0, err
    }

    pollId := db.LastInsertId() 
    for _,option := range options {
        addOption(db, option, pollId)
        if (err != nil ) {
            return 0, err
        }
    }

    return pollId, nil

}

func addOption(db *sqlite3.Conn, text string, pollId int64) error {

    args := sqlite3.NamedArgs{"$a": text, "$b": pollId}
    sql := "INSERT INTO options (text, poll_id) VALUES ($a, $b)"

    err := db.Exec(sql, args)

    if (err != nil ) {
        return err
    }

    return nil
}

func getPollFromTitle(db *sqlite3.Conn, title string) (Poll, error) {

    args := sqlite3.NamedArgs{"$a": title}
    sql := "SELECT * FROM polls WHERE title = $a"
    s, err := db.Query(sql, args)
    row := make(sqlite3.RowMap)
    
    for ; err == nil ; err = s.Next() {
        var rowid int64
        s.Scan(&rowid, row)     // Assigns 1st column to rowid, the rest to row

        poll := Poll{id:rowid, title:row["title"].(string), userId:row["user_id"].(int64)}
        return poll, nil
    }

    //If we get here there are no matching polls, return an error
    return Poll{id:0, title:"", userId:0}, errors.New("No poll found with title '" + title +"'")

}

func getPollFromId(db *sqlite3.Conn, id int) (Poll, error) {

    args := sqlite3.NamedArgs{"$a": id}
    sql := "SELECT * FROM polls WHERE id = $a"
    s, err := db.Query(sql, args)
    row := make(sqlite3.RowMap)

    for ; err == nil ; err = s.Next() {
        var rowid int64
        s.Scan(&rowid, row)     // Assigns 1st column to rowid, the rest to row

        poll := Poll{id:rowid, title:row["title"].(string), userId:row["user_id"].(int64)}
        return poll, nil
    }

    //If we get here there are no matching polls, return an error
    return Poll{id:0, title:"", userId:0}, errors.New("No poll found with ID " + strconv.Itoa(id))

}

func deletePoll(db *sqlite3.Conn, id int, nick string) error {

    user := getUserForName(db, nick)

    poll, err := getPollFromId(db, id)

    if (err != nil) {
        return err
    }


    if (user.isAdmin || poll.userId == user.id) {
        if (poll.id == 0) {
            return nil
        } else {
            sql := "DELETE FROM polls WHERE id = $a"
            args := sqlite3.NamedArgs{"$a": id}
            db.Exec(sql, args)
            return nil
        }
    } else {
        return errors.New("You do not have permission to delete this poll")
    }

}

func hasUserVotedInPoll(db *sqlite3.Conn, poll Poll, user User) bool {

    args := sqlite3.NamedArgs{"$a": poll.id, "$b": user.id}
    sql := "SELECT count(*) FROM votes WHERE poll_id = $a AND user_id = $b"
    s, err := db.Query(sql, args)

    for ; err == nil ; err = s.Next() {
        var count int64
        s.Scan(&count)     // Assigns 1st column to rowid, the rest to row

        if (count == 0) {
            return false
        } else {
            return true
        }
    }

    //Not sure why we'd get here, but we probably don't want to record a vote if we did
    return true
}

func getRecentPolls(db *sqlite3.Conn) ([]Poll, error) {

    sql := "SELECT * FROM polls ORDER BY id DESC LIMIT 5"
    s, err := db.Query(sql)
    row := make(sqlite3.RowMap)
    var polls = make([]Poll, 5)
    i := 0

    for ; err == nil ; err = s.Next() {
        var rowid int64
        s.Scan(&rowid, row)     // Assigns 1st column to rowid, the rest to row

        poll := Poll{id:rowid, title:row["title"].(string), userId:row["user_id"].(int64)}
        polls[i] = poll
        i++
    }

    //If we get here there are no matching polls, return an error
    return polls, err

}