package common

import (
	"database/sql"

	qgen "git.tuxpa.in/a/gosora/query_gen"
)

var pollStmts PollStmts

type Poll struct {
    ID          int
    ParentID    int
    ParentTable string
    Type        int  // 0: Single choice, 1: Multiple choice, 2: Multiple choice w/ points
    AntiCheat   bool // Apply various mitigations for cheating
    // GroupPower map[gid]points // The number of points a group can spend in this poll, defaults to 1

    Options      map[int]string
    Results      map[int]int  // map[optionIndex]points
    QuickOptions []PollOption // TODO: Fix up the template transpiler so we don't need to use this hack anymore
    VoteCount    int
}

// TODO: Use a transaction for this?
// TODO: Add a voters table with castAt / IP data and only populate it when poll anti-cheat is on
func (p *Poll) CastVote(optionIndex, uid int, ip string) error {
    if Config.DisablePollIP || !p.AntiCheat {
        ip = ""
    }
    _, e := pollStmts.addVote.Exec(p.ID, uid, optionIndex, ip)
    if e != nil {
        return e
    }
    _, e = pollStmts.incVoteCount.Exec(p.ID)
    if e != nil {
        return e
    }
    _, e = pollStmts.incVoteCountForOption.Exec(optionIndex, p.ID)
    return e
}

func (p *Poll) Delete() error {
    _, e := pollStmts.deletePollVotes.Exec(p.ID)
    if e != nil {
        return e
    }
    _, e = pollStmts.deletePollOptions.Exec(p.ID)
    if e != nil {
        return e
    }
    _, e = pollStmts.deletePoll.Exec(p.ID)
    _ = Polls.GetCache().Remove(p.ID)
    return e
}

func (p *Poll) Resultsf(f func(votes int) error) error {
    rows, e := pollStmts.getResults.Query(p.ID)
    if e != nil {
        return e
    }
    defer rows.Close()

    var votes int
    for rows.Next() {
        if e := rows.Scan(&votes); e != nil {
            return e
        }
        if e := f(votes); e != nil {
            return e
        }
    }
    return rows.Err()
}

func (p *Poll) Copy() Poll {
    return *p
}

type PollStmts struct {
    getResults *sql.Stmt

    addVote               *sql.Stmt
    incVoteCount          *sql.Stmt
    incVoteCountForOption *sql.Stmt

    deletePoll        *sql.Stmt
    deletePollOptions *sql.Stmt
    deletePollVotes   *sql.Stmt
}

func init() {
    DbInits.Add(func(acc *qgen.Accumulator) error {
        p := "polls"
        wh := "pollID=?"
        pollStmts = PollStmts{
            getResults: acc.Select("polls_options").Columns("votes").Where("pollID=?").Orderby("option ASC").Prepare(),

            addVote:               acc.Insert("polls_votes").Columns("pollID,uid,option,castAt,ip").Fields("?,?,?,UTC_TIMESTAMP(),?").Prepare(),
            incVoteCount:          acc.Update(p).Set("votes=votes+1").Where(wh).Prepare(),
            incVoteCountForOption: acc.Update("polls_options").Set("votes=votes+1").Where("option=? AND pollID=?").Prepare(),

            deletePoll:        acc.Delete(p).Where(wh).Prepare(),
            deletePollOptions: acc.Delete("polls_options").Where(wh).Prepare(),
            deletePollVotes:   acc.Delete("polls_votes").Where(wh).Prepare(),
        }
        return acc.FirstError()
    })
}