import config from '../../config.js';
import { purchaseOrderModel } from '../../database/schemas/inventory/purchaseorder.schema.js';
import log4js from 'log4js';
import mongoose from 'mongoose';
import {
  deleteObject,
  listObjects,
  getObject,
  editObject,
  editObjects,
  newObject,
  listObjectsByProperties,
  getModelStats,
  getModelHistory,
  checkStates,
} from '../../database/database.js';
import { orderItemModel } from '../../database/schemas/inventory/orderitem.schema.js';
import { shipmentModel } from '../../database/schemas/inventory/shipment.schema.js';

const logger = log4js.getLogger('Purchase Orders');
logger.level = config.server.logLevel;

export const listPurchaseOrdersRouteHandler = async (
  req,
  res,
  page = 1,
  limit = 25,
  property = '',
  filter = {},
  search = '',
  sort = '',
  order = 'ascend'
) => {
  const result = await listObjects({
    model: purchaseOrderModel,
    page,
    limit,
    property,
    filter,
    search,
    sort,
    order,
    populate: ['vendor'],
  });

  if (result?.error) {
    logger.error('Error listing purchase orders.');
    res.status(result.code).send(result);
    return;
  }

  logger.debug(`List of purchase orders (Page ${page}, Limit ${limit}). Count: ${result.length}`);
  res.send(result);
};

export const listPurchaseOrdersByPropertiesRouteHandler = async (
  req,
  res,
  properties = '',
  filter = {},
  masterFilter = {}
) => {
  const result = await listObjectsByProperties({
    model: purchaseOrderModel,
    properties,
    filter,
    populate: ['vendor'],
    masterFilter,
  });

  if (result?.error) {
    logger.error('Error listing purchase orders.');
    res.status(result.code).send(result);
    return;
  }

  logger.debug(`List of purchase orders. Count: ${result.length}`);
  res.send(result);
};

export const getPurchaseOrderRouteHandler = async (req, res) => {
  const id = req.params.id;
  const result = await getObject({
    model: purchaseOrderModel,
    id,
    populate: ['vendor'],
  });
  if (result?.error) {
    logger.warn(`Purchase Order not found with supplied id.`);
    return res.status(result.code).send(result);
  }
  logger.debug(`Retreived purchase order with ID: ${id}`);
  res.send(result);
};

export const editPurchaseOrderRouteHandler = async (req, res) => {
  // Get ID from params
  const id = new mongoose.Types.ObjectId(req.params.id);

  logger.trace(`Purchase Order with ID: ${id}`);

  const checkStatesResult = await checkStates({ model: purchaseOrderModel, id, states: ['draft'] });

  if (checkStatesResult.error) {
    logger.error('Error checking purchase order states:', checkStatesResult.error);
    res.status(checkStatesResult.code).send(checkStatesResult);
    return;
  }

  if (checkStatesResult === false) {
    logger.error('Purchase order is not in draft state.');
    res.status(400).send({ error: 'Purchase order is not in draft state.', code: 400 });
    return;
  }

  const updateData = {
    updatedAt: new Date(),
    vendor: req.body.vendor,
  };
  // Create audit log before updating
  const result = await editObject({
    model: purchaseOrderModel,
    id,
    updateData,
    user: req.user,
  });

  if (result.error) {
    logger.error('Error editing purchase order:', result.error);
    res.status(result).send(result);
    return;
  }

  logger.debug(`Edited purchase order with ID: ${id}`);

  res.send(result);
};

export const editMultiplePurchaseOrdersRouteHandler = async (req, res) => {
  const updates = req.body.map((update) => ({
    _id: update._id,
    vendor: update.vendor,
  }));

  if (!Array.isArray(updates)) {
    return res.status(400).send({ error: 'Body must be an array of updates.', code: 400 });
  }

  const result = await editObjects({
    model: purchaseOrderModel,
    updates,
    user: req.user,
  });

  if (result.error) {
    logger.error('Error editing purchase orders:', result.error);
    res.status(result.code || 500).send(result);
    return;
  }

  logger.debug(`Edited ${updates.length} purchase orders`);

  res.send(result);
};

export const newPurchaseOrderRouteHandler = async (req, res) => {
  const newData = {
    updatedAt: new Date(),
    vendor: req.body.vendor,
    totalAmount: 0,
    totalAmountWithTax: 0,
    totalTaxAmount: 0,
  };
  const result = await newObject({
    model: purchaseOrderModel,
    newData,
    user: req.user,
  });
  if (result.error) {
    logger.error('No purchase order created:', result.error);
    return res.status(result.code).send(result);
  }

  logger.debug(`New purchase order with ID: ${result._id}`);

  res.send(result);
};

export const deletePurchaseOrderRouteHandler = async (req, res) => {
  // Get ID from params
  const id = new mongoose.Types.ObjectId(req.params.id);

  logger.trace(`Purchase Order with ID: ${id}`);

  const result = await deleteObject({
    model: purchaseOrderModel,
    id,
    user: req.user,
  });
  if (result.error) {
    logger.error('No purchase order deleted:', result.error);
    return res.status(result.code).send(result);
  }

  logger.debug(`Deleted purchase order with ID: ${result._id}`);

  res.send(result);
};

export const getPurchaseOrderStatsRouteHandler = async (req, res) => {
  const result = await getModelStats({ model: purchaseOrderModel });
  if (result?.error) {
    logger.error('Error fetching purchase order stats:', result.error);
    return res.status(result.code).send(result);
  }
  logger.trace('Purchase order stats:', result);
  res.send(result);
};

export const getPurchaseOrderHistoryRouteHandler = async (req, res) => {
  const from = req.query.from;
  const to = req.query.to;
  const result = await getModelHistory({ model: purchaseOrderModel, from, to });
  if (result?.error) {
    logger.error('Error fetching purchase order history:', result.error);
    return res.status(result.code).send(result);
  }
  logger.trace('Purchase order history:', result);
  res.send(result);
};

export const postPurchaseOrderRouteHandler = async (req, res) => {
  const id = new mongoose.Types.ObjectId(req.params.id);

  logger.trace(`Purchase Order with ID: ${id}`);

  const checkStatesResult = await checkStates({ model: purchaseOrderModel, id, states: ['draft'] });

  if (checkStatesResult.error) {
    logger.error('Error checking purchase order states:', checkStatesResult.error);
    res.status(checkStatesResult.code).send(checkStatesResult);
    return;
  }

  if (checkStatesResult === false) {
    logger.error('Purchase order is not in draft state.');
    res.status(400).send({ error: 'Purchase order is not in draft state.', code: 400 });
    return;
  }

  const orderItemsResult = await listObjects({
    model: orderItemModel,
    filter: { order: id, orderType: 'purchaseOrder' },
    pagination: false,
  });

  const shipmentsResult = await listObjects({
    model: shipmentModel,
    filter: { order: id, orderType: 'purchaseOrder' },
    pagination: false,
  });

  for (const orderItem of orderItemsResult) {
    if (orderItem.state.type != 'draft') {
      logger.warn(`Order item ${orderItem._id} is not in draft state.`);
      return res
        .status(400)
        .send({ error: `Order item ${orderItem._reference} not in draft state.`, code: 400 });
    }
    if (!orderItem?.shipment || orderItem?.shipment == null) {
      logger.warn(`Order item ${orderItem._id} does not have a shipment.`);
      return res
        .status(400)
        .send({ error: `Order item ${orderItem._reference} does not have a shipment.`, code: 400 });
    }
  }

  for (const shipment of shipmentsResult) {
    if (shipment.state.type != 'draft') {
      logger.warn(`Shipment ${shipment._id} is not in draft state.`);
      return res
        .status(400)
        .send({ error: `Shipment ${shipment._reference} not in draft state.`, code: 400 });
    }
  }

  for (const orderItem of orderItemsResult) {
    await editObject({
      model: orderItemModel,
      id: orderItem._id,
      updateData: {
        state: { type: 'ordered' },
        orderedAt: new Date(),
      },
      user: req.user,
    });
  }

  for (const shipment of shipmentsResult) {
    await editObject({
      model: shipmentModel,
      id: shipment._id,
      updateData: {
        state: { type: 'planned' },
      },
      user: req.user,
    });
  }

  const updateData = {
    updatedAt: new Date(),
    state: { type: 'sent' },
    postedAt: new Date(),
  };
  const result = await editObject({
    model: purchaseOrderModel,
    id,
    updateData,
    user: req.user,
  });

  if (result.error) {
    logger.error('Error posting purchase order:', result.error);
    res.status(result.code).send(result);
    return;
  }

  logger.debug(`Posted purchase order with ID: ${id}`);
  res.send(result);
};

export const acknowledgePurchaseOrderRouteHandler = async (req, res) => {
  const id = new mongoose.Types.ObjectId(req.params.id);

  logger.trace(`Purchase Order with ID: ${id}`);

  const checkStatesResult = await checkStates({ model: purchaseOrderModel, id, states: ['sent'] });

  if (checkStatesResult.error) {
    logger.error('Error checking purchase order states:', checkStatesResult.error);
    res.status(checkStatesResult.code).send(checkStatesResult);
    return;
  }

  if (checkStatesResult === false) {
    logger.error('Purchase order is not in sent state.');
    res.status(400).send({ error: 'Purchase order is not in sent state.', code: 400 });
    return;
  }

  const updateData = {
    updatedAt: new Date(),
    state: { type: 'acknowledged' },
    acknowledgedAt: new Date(),
  };
  const result = await editObject({
    model: purchaseOrderModel,
    id,
    updateData,
    user: req.user,
  });

  if (result.error) {
    logger.error('Error acknowledging purchase order:', result.error);
    res.status(result.code).send(result);
    return;
  }

  logger.debug(`Acknowledged purchase order with ID: ${id}`);
  res.send(result);
};

export const cancelPurchaseOrderRouteHandler = async (req, res) => {
  const id = new mongoose.Types.ObjectId(req.params.id);

  logger.trace(`Purchase Order with ID: ${id}`);

  const checkStatesResult = await checkStates({
    model: purchaseOrderModel,
    id,
    states: ['sent', 'acknowledged', 'partiallyShipped', 'shipped', 'partiallyReceived'],
  });

  if (checkStatesResult.error) {
    logger.error('Error checking purchase order states:', checkStatesResult.error);
    res.status(checkStatesResult.code).send(checkStatesResult);
    return;
  }

  if (checkStatesResult === false) {
    logger.error('Purchase order is not in a cancellable state.');
    res.status(400).send({
      error: 'Purchase order is not in a cancellable state (must be draft, sent, or acknowledged).',
      code: 400,
    });
    return;
  }

  const orderItemsResult = await listObjects({
    model: orderItemModel,
    filter: { order: id, orderType: 'purchaseOrder' },
    pagination: false,
  });

  const shipmentsResult = await listObjects({
    model: shipmentModel,
    filter: { order: id, orderType: 'purchaseOrder' },
    pagination: false,
  });

  const allowedOrderItemStates = ['ordered', 'shipped'];
  const allowedShipmentStates = ['shipped', 'planned'];

  for (const orderItem of orderItemsResult) {
    if (allowedOrderItemStates.includes(orderItem.state.type)) {
      await editObject({
        model: orderItemModel,
        id: orderItem._id,
        updateData: {
          state: { type: 'cancelled' },
        },
        user: req.user,
      });
    }
  }

  for (const shipment of shipmentsResult) {
    if (allowedShipmentStates.includes(shipment.state.type)) {
      await editObject({
        model: shipmentModel,
        id: shipment._id,
        updateData: {
          state: { type: 'cancelled' },
        },
        user: req.user,
      });
    }
  }
  const updateData = {
    updatedAt: new Date(),
    state: { type: 'cancelled' },
    cancelledAt: new Date(),
  };
  const result = await editObject({
    model: purchaseOrderModel,
    id,
    updateData,
    user: req.user,
  });

  if (result.error) {
    logger.error('Error cancelling purchase order:', result.error);
    res.status(result.code).send(result);
    return;
  }

  logger.debug(`Cancelled purchase order with ID: ${id}`);
  res.send(result);
};