package postgres

import (
	"context"

	errmsg "git.gocasts.ir/ebhomengo/niki/pkg/err_msg"
	richerror "git.gocasts.ir/ebhomengo/niki/pkg/rich_error"
)

// page number pagination

type RequestPagination struct {
	PageNumber int64 `json:"page_number"`
}

type ResponsePagination struct {
	PageNumber int64 `json:"page_number"`
	PageSize   int64 `json:"page_size"`
	TotalPages int64 `json:"total_pages"`
}

type DBPagination struct {
	PageNumber int64
	PageSize   int64
}

func PageNumberPagination[T any](ctx context.Context, countQuery string, fetchQuery string, conn *DB, countQueryStmt statementKey, fetchQueryStmt statementKey, op richerror.Op, scanner ScannerFunc[T], countParams []any, fetchParams []any) ([]T, int64, error) {

	var totalCount int64

	countStmt, CountStErr := conn.PrepareStatement(ctx, countQueryStmt, countQuery)

	if CountStErr != nil {

		return nil, 0, richerror.New(op).WithErr(CountStErr).WithKind(richerror.KindUnexpected).WithMessage(errmsg.ErrorMsgFailedQuery)

	}
	countErr := countStmt.QueryRowContext(ctx, countParams...).Scan(&totalCount)

	if countErr != nil {
		return nil, 0, richerror.New(op).WithErr(countErr).WithKind(richerror.KindUnexpected).WithMessage(errmsg.ErrorMsgFailedQuery)

	}

	//// get records

	stmt, StErr := conn.PrepareStatement(ctx, fetchQueryStmt, fetchQuery)

	if StErr != nil {

		return nil, 0, richerror.New(op).WithErr(StErr).WithKind(richerror.KindUnexpected).WithMessage(errmsg.ErrorMsgFailedQuery)

	}

	queryRows, qrErr := stmt.QueryContext(ctx, fetchParams...)

	if qrErr != nil {
		return nil, 0, richerror.New(op).WithErr(qrErr).WithKind(richerror.KindUnexpected).WithMessage(errmsg.ErrorMsgFailedQuery)
	}

	defer queryRows.Close()

	var itemsList []T

	for queryRows.Next() {

		item, err := scanner(queryRows)

		if err != nil {
			return nil, 0, richerror.New(op).WithErr(err).WithKind(richerror.KindUnexpected).WithMessage(errmsg.ErrorMsgCantScanQueryResult)
		}

		itemsList = append(itemsList, item)

	}

	if qErr := queryRows.Err(); qErr != nil {

		return nil, 0, richerror.New(op).WithErr(qErr).WithKind(richerror.KindUnexpected).WithMessage(errmsg.ErrorMsgFailedQuery)
	}

	return itemsList, totalCount, nil
}