package common

import (
	"database/sql"

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

var IPSearch IPSearcher

type IPSearcher interface {
    Lookup(ip string) (uids []int, e error)
}

type DefaultIPSearcher struct {
    searchUsers        *sql.Stmt
    searchTopics       *sql.Stmt
    searchReplies      *sql.Stmt
    searchUsersReplies *sql.Stmt
}

// NewDefaultIPSearcher gives you a new instance of DefaultIPSearcher
func NewDefaultIPSearcher() (*DefaultIPSearcher, error) {
    acc := qgen.NewAcc()
    uu := "users"
    q := func(tbl string) *sql.Stmt {
        return acc.Select(uu).Columns("uid").InQ("uid", acc.Select(tbl).Columns("createdBy").Where("ip=?")).Prepare()
    }
    return &DefaultIPSearcher{
        searchUsers:        acc.Select(uu).Columns("uid").Where("last_ip=? OR last_ip LIKE CONCAT('%-',?)").Prepare(),
        searchTopics:       q("topics"),
        searchReplies:      q("replies"),
        searchUsersReplies: q("users_replies"),
    }, acc.FirstError()
}

func (s *DefaultIPSearcher) Lookup(ip string) (uids []int, e error) {
    var uid int
    reqUserList := make(map[int]bool)
    runQuery2 := func(rows *sql.Rows, e error) error {
        if e != nil {
            return e
        }
        defer rows.Close()

        for rows.Next() {
            if e := rows.Scan(&uid); e != nil {
                return e
            }
            reqUserList[uid] = true
        }
        return rows.Err()
    }
    runQuery := func(stmt *sql.Stmt) error {
        return runQuery2(stmt.Query(ip))
    }

    e = runQuery2(s.searchUsers.Query(ip, ip))
    if e != nil {
        return uids, e
    }
    e = runQuery(s.searchTopics)
    if e != nil {
        return uids, e
    }
    e = runQuery(s.searchReplies)
    if e != nil {
        return uids, e
    }
    e = runQuery(s.searchUsersReplies)
    if e != nil {
        return uids, e
    }

    // Convert the user ID map to a slice, then bulk load the users
    uids = make([]int, len(reqUserList))
    var i int
    for userID := range reqUserList {
        uids[i] = userID
        i++
    }

    return uids, nil
}