package database

import (
	"errors"
	"fmt"
	"log"
	"strings"

	"tomatentum.net/outfit-voting-abi26/internal/util"
)

const VALUESTEMPLATE string = "(%s, %s, %s, %d)"

const INITVOTEDB string = "CREATE TABLE IF NOT EXISTS vote(id varchar(16) PRIMARY KEY, category TEXT NOT NULL, name TEXT NOT NULL, votes int NOT NULL)"
const INSERTVOTEENTRY string = "INSERT INTO vote(id, category, name, votes) VALUES($1, $2, $3, $4)"
const BULKINSERTVOTEENTRY string = "INSERT INTO vote(id, category, name, votes) VALUES"
const SETVOTE string = "UPDATE vote SET votes = $1 WHERE id = $2"
const INCVOTE string = "UPDATE vote SET votes = votes + 1 WHERE id = $1"
const DELVOTEENTRY string = "DELETE FROM vote WHERE id = $1"
const BULKDELVOTEENTRY string = "DELETE FROM vote WHERE id IN (%s)"
const GETVOTES string = "SELECT * FROM vote ORDER BY votes DESC"
const GETVOTEOPTIONS string = "SELECT id, category, name FROM vote"
const GETVOTE string = "SELECT * FROM vote WHERE id = $1"

type VoteEntry struct {
	VoteOption
	Votes int
}

type VoteOption struct {
	ID       string
	Category string
	Name     string
}

func initVoteDB() error {
	_, err := db.Exec(INITVOTEDB)
	return err
}

func InsertVoteEntry(name string, category string) (VoteEntry, error) {
	id, err := util.RandString(8)

	if err != nil {
		return VoteEntry{}, err
	}
	_, err = db.Exec(INSERTVOTEENTRY, id, category, name, 0)

	if err != nil {
		return VoteEntry{}, err
	}
	return VoteEntry{VoteOption{id, category, name}, 0}, nil
}

func BulkInsertVoteEntry(names []string, category string) (*[]VoteEntry, error) {
	stmnt := BULKINSERTVOTEENTRY
	var entries []VoteEntry = make([]VoteEntry, len(names))
	for i, v := range names {
		id, err := util.RandString(8)
		if err != nil {
			return nil, err
		}
		stmnt = stmnt + fmt.Sprintf(VALUESTEMPLATE, id, category, v, 0)
		entries = append(entries, VoteEntry{VoteOption{id, category, v}, 0})
		if i < len(names)-1 {
			stmnt = stmnt + ","
		}
	}
	stmnt = stmnt + ";"

	_, err := db.Exec(stmnt)

	if err != nil {
		return nil, err
	}

	return &entries, nil
}

func SetVote(id string, votes int) error {
	_, err := db.Exec(SETVOTE, votes, id)

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

func IncVote(id string) error {
	res, err := db.Exec(INCVOTE, id)

	if err != nil {
		return err
	}

	n, _ := res.RowsAffected()

	if n < 1 {
		return errors.New("id does not exist")
	}

	return nil
}

func DelVoteEntry(id string) error {
	res, err := db.Exec(DELVOTEENTRY, id)

	if err != nil {
		return err
	}

	n, _ := res.RowsAffected()

	if n < 1 {
		return errors.New("id does not exist")
	}

	return nil
}

func BulkDelVoteEntry(ids []string) error {

	placeholders := make([]string, len(ids))
	args := make([]any, len(ids))

	for i := 0; i < len(ids); i++ {
		placeholders[i] = fmt.Sprintf("$%d", i+1)
		args[i] = ids[i]
	}

	stmnt := fmt.Sprintf(BULKDELVOTEENTRY, strings.Join(placeholders, ", "))
	log.Println(stmnt)
	res, err := db.Exec(stmnt, args...)

	if err != nil {
		return err
	}

	n, _ := res.RowsAffected()

	if n < 1 {
		return errors.New("id does not exist")
	}

	return nil
}

func GetVotes() ([]VoteEntry, error) {
	res, err := db.Query(GETVOTES)

	if err != nil {
		return nil, err
	}
	defer res.Close()

	var current VoteEntry
	var entries []VoteEntry = []VoteEntry{}

	for res.Next() {
		if err := res.Err(); err != nil {
			return nil, err
		}
		if err := res.Scan(&current.ID, &current.Category, &current.Name, &current.Votes); err != nil {
			return nil, err
		}
		entries = append(entries, current)
	}

	return entries, nil
}

func GetVoteOptions() ([]VoteOption, error) {
	res, err := db.Query(GETVOTEOPTIONS)

	if err != nil {
		return nil, err
	}
	defer res.Close()

	var current VoteOption
	var entries []VoteOption = []VoteOption{}

	for res.Next() {
		if err := res.Err(); err != nil {
			return nil, err
		}
		if err := res.Scan(&current.ID, &current.Category, &current.Name); err != nil {
			return nil, err
		}
		entries = append(entries, current)
	}

	return entries, nil
}

func GetVote(id string) (VoteEntry, error) {
	res := db.QueryRow(GETVOTE, id)

	var current VoteEntry

	if err := res.Scan(&current.ID, &current.Category, &current.Name, &current.Votes); err != nil {
		return VoteEntry{}, err
	}

	return current, nil
}