package main

// import "blavote"
import "fmt"
import "github.com/mxk/go-sqlite/sqlite3"
import "github.com/jessevdk/go-flags"
import "os"
import "io/ioutil"
import "strings"
import "strconv"
import "errors"

var version string

func main() {

    version = "0.7"

    //Command line arguments
    var opts struct {
        Version bool `short:"v" long:"version" description:"Show program version"`
        Add string `short:"a" long:"add" description:"Title for a new poll"`
        New string `short:"n" long:"new" description:"Title for a new poll"`
        Username string `short:"u" long:"username" description:"Username of user adding poll"`
        Remove int `short:"r" long:"remove" description:"ID of a poll to delete"`
        Info int `short:"i" long:"info" description:"Get info and vote stats for a given poll ID"`
        List bool `short:"l" long:"list" description:"List recent polls"`
        Args struct {
            
            Rest []string

        }   `positional-args:"yes"`
    }

    var args []string

    //If there are no command line arguments, read them from stdin
    if (len(os.Args) > 1) {
       flags.Parse(&opts)
    } else {
        bytes, err := ioutil.ReadAll(os.Stdin)
        if (err == nil) {
            args = strings.Split(strings.Split(string(bytes),"\n")[0], " ")
            flags.ParseArgs(&opts, args)
        } else {
            fmt.Println(err)
            //No args given, deal with it
        }

    }

    db, err := connectDb("blavote.db")

    if (err != nil) {
        fmt.Print("Could not connect to vote database: ")
        fmt.Println(err)
        return
    }

    if (opts.Version) {
        fmt.Println("v" + version)
    } else if (opts.Add != "") {
        fmt.Println(opts.Args.Rest)

        pollId, err := addPoll(db, opts.Add, opts.Args.Rest, opts.Username)
        if (err == nil) {
            fmt.Print("Poll added with ID ")
            fmt.Println(pollId)
        } else {
            fmt.Println(err)
        }
    } else if (opts.New != "") {
        pollId, err := addPoll(db, opts.New, opts.Args.Rest, opts.Username)
        if (err == nil) {
            fmt.Print("Poll added with ID ")
            fmt.Println(pollId)
        } else {
            fmt.Println(err)
        }
    } else if (opts.Remove > 0) {
        err = deletePoll(db, opts.Remove, opts.Username)

        if (err == nil) {
            fmt.Print("Poll removed with ID ")
            fmt.Println(opts.Remove)
        } else {
            fmt.Println(err)
        }
    } else if (opts.Info > 0) {
        err = pollInfo(db, opts.Info)
    } else if (opts.List) {
        err = listPolls(db)
        if (err != nil) {
            fmt.Println(err)
        }
    } else {
        if (len(opts.Args.Rest) > 1) {
            err = vote(db, opts.Username, opts.Args.Rest)

            if (err != nil) {
                fmt.Println(err)
            }
        } else {

        }
    }


}

func connectDb(name string) (*sqlite3.Conn, error) {
    db, err := sqlite3.Open(name)

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

    //Check the version in the DB, if it doesn't exist we'll create it
    //Can use this later to update the DB if needed
    sql := "select * from info where key = 'version'"
    _, err = db.Query(sql)

    if (err != nil) {
        fmt.Println("info table does not exist, creating database")
        initTables(db)
        return nil, err
    }

    return db, err
}

func initTables(db *sqlite3.Conn) {

   db.Exec("create table info(id int, key text, value text)")
   db.Exec("insert into info (key, value) values('version', '$a')", version)

   db.Exec("create table users(id integer primary key autoincrement, name text, admin boolean)")
   db.Exec("create table polls(id integer primary key autoincrement, title text, user_id int)")
   db.Exec("create table options(id integer primary key autoincrement, text text, poll_id int)")
   db.Exec("create table votes(id integer primary key autoincrement, user_id int, poll_id int, option_id int)")

}

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

    pollId, err := strconv.Atoi(options[0])

    if (err != nil) {
        return errors.New("Poll ID must be a number")
    }

    poll, err := getPollFromId(db, pollId)

    if (err != nil) {
        return err
    }

    option, err := getOptionFromText(db, options[1])

    if (err != nil) {
        return err
    }

    user := getUserForName(db, nick)

    //Record the user in the DB if they aren't already
    if (user.id == 0) {
        user, err = createUser(db, nick, false)

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

    if (!hasUserVotedInPoll(db, poll, user)) {

        args := sqlite3.NamedArgs{"$a": user.id, "$b": poll.id, "$c": option.id}
        sql := "INSERT INTO votes (user_id, poll_id, option_id) VALUES ($a, $b, $c)"

        err = db.Exec(sql, args)

        if (err != nil ) {
            return err
        } else {
            fmt.Println("Vote added")
            return nil
        }

    } else {
        return errors.New("You have already voted in this poll")
    }
}

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

    poll , err := getPollFromId(db, id)
    fmt.Print(poll.title + " - ")
    options, err := getOptionsForPoll(db, poll)

    for _, option := range options {
        option, err = getVotesForOption(db, option)
        fmt.Print(option.text + " (")
        fmt.Print(option.numVotes)
        fmt.Print(") ")
    }
    fmt.Println()

    return err
}

func listPolls(db *sqlite3.Conn) error {

    polls, err := getRecentPolls(db)

    for _, poll := range polls {
        if (poll.id != 0) {
            fmt.Print(poll.id)
            fmt.Print(": " + poll.title + " ")
        } else {
            fmt.Println()
            return nil
        }
    }


    return err
}