export default class SqlParse{
    private sql!: string
    private params: Array<string> = []

    public parse(sql: string = '', params: Array<any> = []): SqlParse{
        this.sql = sql
        //this.params = params.filter(param => !!param)
        this.params = params
        return this
    }

    public isNotNull(value: any, sql: string): SqlParse{
        if(value && String(value).trim() !== ''){
            this.sql = this.sql + ' and ' + sql
        }
        return this
    }

    public isNull(value: any, sql: string): SqlParse{
        if(value === undefined || value === null || (value && String(value).trim() === '')){
            this.sql = this.sql + ' and ' + sql
        }
        return this
    }

    public build(): string{
        if(this.params.length !== this.sql.split('{?}').length - 1){
            //throw new Error('<SQL Exception>: 参数与占位符数量不一致在\r\n' + this.sql + '\r\n' + this.params)
        }
        let sql: string = this.sql;
        (this.params || []).forEach(param => {
            sql = sql.replace('{?}', param)
        })
        return sql
    }

    public toString(): string{
        const sql = this.build()
        return sql
    }
}