import { Model2Object } from "./model2object";

/**
 * 模型转sql
 */
export class Model2Sql{
    /**
     * 生成sql
     * @param modelPath -   模型路径
     * @param dstPath -     目标路径
     */
    public genSql(modelPath:string,dstPath:string){
        const me = this;
        const fsMdl = require('fs');
        //关系集合 {依赖表.字段:被依赖表.字段}
        const relations = {};
        //create table 串数组
        const sqlArr:string[] = [];
        //drop table 串数组
        const dropArr:string[] = [];
        //转换成model对象
        const models = Model2Object.gen(modelPath);

        //遍历生成单个sql
        for(let key of Object.keys(models)){
            dropArr.push(`drop table if exists ${key.toUpperCase()};`)
            sqlArr.push(this.genOneModelSql(models[key],relations));
        }
        
        //处理关联关系
        for(let key of Object.keys(relations)){
            const ka = key.split('.');
            const v = relations[key];
            //删除父时操作，如果为文件，则set null，否则cascade
            const delOp = v.tbl === 'AM_FILE'?'set null':'cascade';
            sqlArr.push(`alter table ${ka[0]} add constraint FK_${ka[0]}_${ka[1]} foreign key (${ka[1]}) references ${v.tbl} (${v.field}) on delete ${delOp} on update cascade;`);
        }
        //写文件
        fsMdl.writeFileSync(dstPath,dropArr.concat(sqlArr).join('\r\n'));
        
    }

    /**
     * 生产一个model的sql
     * @param modelPath 
     */
    private genOneModelSql(modelCfg,relations):string{
        const fieldArr:string[] = [];
        const tblName = modelCfg.ref.toUpperCase();
        let pKey;
        for(let cfg of modelCfg.props){
            let str = '\t';
            let fieldName = cfg.name.toUpperCase();
            let s;
            if(cfg.isId){
                s = 'bigint not null auto_increment'
                pKey = cfg.name;
            }else{ //普通字段，处理数据类型
                switch(cfg.type){
                    case 'string':
                        s = 'varchar(';
                        let len = 128;
                        if(cfg.validator){
                            for(let v of cfg.validator){
                                //有最长度
                                if(v.includes('maxLength:')){
                                    len = v.substring(v.indexOf('maxLength:') + 10);
                                }
                            }
                        }
                        s += len + ')';
                        break;
                    case 'int':
                        s = 'bigint';
                        break;
                    case 'bool':
                        s = 'tinyint';
                        break;
                    case 'ref':
                        s = 'bigint';
                        if(cfg.ref === 'MdlAmFile'){ //文件
                            relations[tblName + '.' + fieldName] = {
                                tbl:'AM_FILE',
                                field:'FILE_ID'
                            }
                        }else if(cfg.ref === 'MdlAmDataImport'){ //导入批次
                            relations[tblName + '.' + fieldName] = {
                                tbl:'AM_DATA_IMPORT',
                                field:'DATA_IMPORT_ID'
                            }
                        }else{  //其它
                            relations[tblName + '.' + fieldName] = {
                                tbl:cfg.ref.substring(3).toUpperCase(),
                                field:cfg.editOption.option.valueProp.toUpperCase()
                            }
                        }
                        break;
                    default:
                        s = cfg.type;
                }
            }
            str += fieldName + '\t' + s + ',';
            fieldArr.push(str);
        }
        
        //处理主键
        if(pKey){
            fieldArr.push(`\tprimary key (${pKey})`);
        }
        
        return `create table ${tblName}(\r\n${fieldArr.join('\r\n')}\r\n);`
    }
}