import Boom = require("boom");
import * as Bookshelf from "bookshelf";
import { FetchOptions, FetchAllOptions, Collection } from "bookshelf";
import Knex = require("knex");
import Path = require("path");
import dotenv = require("dotenv");
import pg = require("pg");
import { Controller } from "./controller";
import { IRepository, IExtendedModel } from "./types";
import { eventBus } from "./event-bus";
import { Observable } from "rxjs/Observable";
import "rxjs/add/operator/finally";

dotenv.config();
pg.types.setTypeParser(20, "text", parseInt);

const env = process.env.NODE_ENV || "development";
const rootPath = Path.resolve(process.cwd());
const knexfilePath = Path.join(rootPath, "./knexfile");
const knexfile = require(knexfilePath);
const knex = Knex(knexfile[env]);

export const bookshelf: any = Bookshelf(knex);

bookshelf.plugin("registry");
bookshelf.plugin("visibility");

export const tableModelMap = {};

// function getModelDependencies(data: any): string[] {
//   const dependencies = [];

//   Object.values(data.relations).forEach((relation: any) => {
//     const tableName = relation.relatedData.targetTableName;
//     dependencies.push(tableModelMap[tableName]);
//   });

//   return dependencies;
// }

// function getCollectionDependencies(data: Collection<any>): string[] {
//   const dependencies = [];

//   Object.values(data.head().relations).forEach((relation: any) => {
//     const tableName = relation.relatedData.targetTableName;
//     dependencies.push(tableModelMap[tableName]);
//   });

//   return dependencies;
// }

function getDependencies(model) {
  const dependencies = [];
  if (!model || !model.relations) {
    return;
  }
  const relations = [...Object.values(model.relations)];
  while (relations.length) {
    const relation: any = relations.pop();
    let tableName;
    if (
      relation.head &&
      typeof relation.head === "function" &&
      relation.head().relatedData
    ) {
      tableName = relation.head().relatedData.targetTableName;
      if (relation.head().relations) {
        Object.values(relation.head().relations).forEach(i =>
          relations.push(i)
        );
      }
    } else if (relation.relatedData && relation.relatedData.targetTableName) {
      tableName = relation.relatedData.targetTableName;
      if (relation.relations) {
        Object.values(relation.relations).forEach(i => relations.push(i));
      }
    }
    if (!dependencies.includes(tableModelMap[tableName])) {
      dependencies.push(tableModelMap[tableName]);
    }
  }
  return dependencies;
}

function getCollectionDependencies(data: Collection<any>): string[] {
  return getDependencies(data.head());
}

export class Repository implements IRepository {
  public model: IExtendedModel;
  public name: string;
  public path: string;
  public controller: Controller;
  public websocket: boolean;
  constructor(
    path: string,
    options: any,
    name: string,
    props: any,
    websocket = false,
    rest = true
  ) {
    tableModelMap[props.tableName] = name;
    this.name = name;
    this.path = path;
    this.websocket = websocket;
    props = {
      ...props,
      initialize() {
        if (websocket) {
          this.on("created", model => {
            eventBus.emit(`DB_CHANGE:${name.toUpperCase()}`);
          });
          this.on("updated", model => {
            eventBus.emit(`DB_CHANGE:${name.toUpperCase()}`);
          });
        }
      }
    };
    this.model = bookshelf.model(name, props);
    this.makeCrud(name, options);
    this.makeReactive(name);

    if (rest) {
      this.controller = new Controller(path, (server, opts, next) => {
        server.get("/", this.model.findAll);
        server.get("/:id", this.model.findById);
        server.post("/", this.model.upsert);
        server.delete("/:id", this.model.remove);
        server.post("/:id/undelete", this.model.recover);
      });
    }
  }
  public makeCrud(name: string, options: any) {
    this.model.findAll = async () => {
      return this.model.where("deleted", false).fetchAll(options) || [];
    };
    this.model.findById = async (request, reply) => {
      const item = await this.model
        .where("id", request.params.id)
        .fetch(options);

      if (!item) {
        return Boom.badData(
          `Entity ${name} with ID ${request.params.id} not exists`
        );
      }

      return item;
    };
    this.model.upsert = async (request, reply) => {
      const item = request.body;

      if (!item) {
        return Boom.badData(`Entity ${name}, Undefined Body`);
      }

      return this.model.forge(item).save();
    };
    this.model.remove = async (request, reply) => {
      const id = request.params.id;

      if (!id) {
        return Boom.badData(`Entity ${name} undefined ID`);
      }

      const old = await this.model.where("id", id).fetch();

      if (!old) {
        return Boom.badData(`Entity ${name} with ID ${id} not exists`);
      }

      return old.save({ deleted: true });
    };
    this.model.recover = async (request, reply) => {
      const item = request.body;

      if (!item) {
        return Boom.badData(`Entity ${name}, Undefined Body`);
      }

      const old = await this.model.where("id", item.id).fetch();

      if (!old) {
        return Boom.badData(`Entity ${name} with ID ${item.id} not exists`);
      }

      return old.save({ deleted: false });
    };
  }
  public makeReactive(name: string) {
    this.model.watch = (options?: FetchOptions): Observable<any> => {
      const subscriptions = [];
      return Observable.create(observer => {
        this.model.fetch(options).then(data => {
          observer.next(data);
          const listenTo = [name, ...getDependencies(data)];
          listenTo.map(l => l.toUpperCase()).forEach(dep => {
            const sub = () =>
              this.model.fetch(options).then(stream => observer.next(stream));
            subscriptions.push(sub);
            eventBus.on(`DB_CHANGE:${dep}`, sub);
          });
        });
      }).finally(() => subscriptions.forEach(s => eventBus.unsubscribe(s)));
    };
    this.model.watchAll = (options?: FetchAllOptions): Observable<any> => {
      const subscriptions = [];
      return Observable.create(observer => {
        this.model.fetchAll(options).then(data => {
          observer.next(data);
          const listenTo = [name, ...getCollectionDependencies(data)];
          listenTo.map(l => l.toUpperCase()).forEach(dep => {
            const sub = () =>
              this.model
                .fetchAll(options)
                .then(stream => observer.next(stream));
            subscriptions.push(sub);
            eventBus.on(`DB_CHANGE:${dep}`, sub);
          });
        });
      }).finally(() => subscriptions.forEach(s => eventBus.unsubscribe(s)));
    };
  }
}