'use strict';

const _ = require('lodash');
const TENANT_MODELS = Symbol('Context#models@tenant');

// 已废弃
const _loadModel = (app, tenant) => {
  app.logger.info(`[multi-tenancy] Load tenant models for ${tenant}`);
  const model = {};
  _.forEach(app.model, (val, key) => {
    const modelName = `${val.modelName}@${tenant}`;
    const collName = `_${tenant}.${val.collection.name}`;
    const multiTenancy = val.schema.get('multi-tenancy');
    if (multiTenancy) {
      app.logger.debug(`[multi-tenancy] ${modelName} loaded`);
      model[key] = val.db.model(modelName, val.schema, collName);
    } else {
      app.logger.debug(`[multi-tenancy] skip ${val.modelName}, schema not enable multi-tenancy.`);
      model[key] = val;
    }
  });
  return model;
};

const multiTenancyPlugin = (schema, options = {}) => {
  const { defaultTenant = 'master' } = options;
  schema.add({
    _tenant: { type: String, default: defaultTenant, index: true },
  });

  schema.pre('save', async function() {
    const tenant = schema.get('x-tenant');
    if (tenant !== 'global') {
      this._tenant = schema.get('x-tenant');
    }
  });

  const querys = [ 'count', 'countDocuments', 'find', 'findOne', 'findOneAndRemove', 'findOneAndUpdate', 'remove', 'deleteOne', 'deleteMany', 'update', 'updateOne', 'updateMany' ];
  querys.forEach(action => {
    schema.pre(action, async function() {
      const tenant = schema.get('x-tenant');
      if (tenant !== 'global') {
        this.where('_tenant').equals(schema.get('x-tenant'));
      }
    });
  });
};

const loadModel2 = (app, tenant) => {
  app.logger.info(`[multi-tenancy] Load tenant models for ${tenant}`);
  let model = {};
  const setModel = (val,key) =>{
    const obj = {};
    const modelName = `${val.modelName}@${tenant}`;
    const collName = `${val.collection.name}`;
    const multiTenancy = val.schema.get('multi-tenancy');
    if (multiTenancy) {
      app.logger.debug(`[multi-tenancy] ${modelName} loaded`);
      const schema = val.schema.clone();
      schema.set('x-tenant', tenant);
      schema.plugin(multiTenancyPlugin, app.config.multiTenancy);
      obj[key] = val.db.model(modelName, schema, collName);
    } else {
      app.logger.debug(`[multi-tenancy] skip ${val.modelName}, schema not enable multi-tenancy.`);
      obj[key] = val;
    }
    return obj;
  }

  _.forEach(app.model, (val, key) => {
    const nval = getAllModel(val);
    // 文件夹分层级后,val不再只是Function,也有可能是Object,添加个方法,获取所有model
    if(!_.isArray(nval)) {
      let mod = {};
      mod = setModel(nval,key);
      model = {...model,...mod};
    }
    else {
      let mods = {};
      mods[key] = {};
      for (const model of nval) {
        const nkey = _.upperFirst(model.modelName);
        let mod = setModel(model,nkey);
        mods[key] = {...mods[key],...mod};
      }
      model = {...model,...mods};
    }

  });
  return model;
};

// this 就是 app 对象，在其中可以调用 app 上的其他方法，或访问属性
module.exports = {

  // 多租户系统中的model对象
  tenantModel(tenant) {
    const { defaultTenant: _defaultTenant } = this.config.multiTenancy || {};
    if (tenant /* && tenant !== _defaultTenant*/) {
      // 非默认租户，加载租户model
      if (!this[TENANT_MODELS]) {
        this[TENANT_MODELS] = [];
      }
      const models = this[TENANT_MODELS];
      if (!models[tenant]) {
        // 加载租户Model
        models[tenant] = loadModel2(this, tenant);
      }
      return models[tenant];
    }
    // 默认租户返回原始model对象
    return this.model;
  },
};