erpnext.SerialNoBatchSelector = class SerialNoBatchSelector {
	constructor(opts, show_dialog) {
		$.extend(this, opts);
		this.show_dialog = show_dialog;
		// frm, item, warehouse_details, has_batch, oldest
		let d = this.item;
		this.has_batch = 0; this.has_serial_no = 0;

		if (d && d.has_batch_no && (!d.batch_no || this.show_dialog)) this.has_batch = 1;
		// !(this.show_dialog == false) ensures that show_dialog is implictly true, even when undefined
		if(d && d.has_serial_no && !(this.show_dialog == false)) this.has_serial_no = 1;

		this.setup();
	}

	setup() {
		this.item_code = this.item.item_code;
		this.qty = this.item.qty;
		this.make_dialog();
		this.on_close_dialog();
	}

	make_dialog() {
		var me = this;

		this.data = this.oldest ? this.oldest : [];
		let title = "";
		let fields = [
			{
				fieldname: 'item_code',
				read_only: 1,
				fieldtype:'Link',
				options: 'Item',
				label: __('Item Code'),
				default: me.item_code
			},
			{
				fieldname: 'warehouse',
				fieldtype:'Link',
				options: 'Warehouse',
				reqd: me.has_batch && !me.has_serial_no ? 0 : 1,
				label: __(me.warehouse_details.type),
				default: typeof me.warehouse_details.name == "string" ? me.warehouse_details.name : '',
				onchange: function(e) {
					me.warehouse_details.name = this.get_value();

					if(me.has_batch && !me.has_serial_no) {
						fields = fields.concat(me.get_batch_fields());
					} else {
						fields = fields.concat(me.get_serial_no_fields());
					}

					var batches = this.layout.fields_dict.batches;
					if(batches) {
						batches.grid.df.data = [];
						batches.grid.refresh();
						batches.grid.add_new_row(null, null, null);
					}
				},
				get_query: function() {
					return {
						query: "erpnext.controllers.queries.warehouse_query",
						filters: [
							["Bin", "item_code", "=", me.item_code],
							["Warehouse", "is_group", "=", 0],
							["Warehouse", "company", "=", me.frm.doc.company]
						]
					}
				}
			},
			{fieldtype:'Column Break'},
			{
				fieldname: 'qty',
				fieldtype:'Float',
				read_only: me.has_batch && !me.has_serial_no,
				label: __(me.has_batch && !me.has_serial_no ? 'Selected Qty' : 'Qty'),
				default: flt(me.item.stock_qty),
			},
			...get_pending_qty_fields(me),
			{
				fieldname: 'uom',
				read_only: 1,
				fieldtype: 'Link',
				options: 'UOM',
				label: __('UOM'),
				default: me.item.uom
			},
			{
				fieldname: 'auto_fetch_button',
				fieldtype:'Button',
				hidden: me.has_batch && !me.has_serial_no,
				label: __('Auto Fetch'),
				description: __('Fetch Serial Numbers based on FIFO'),
				click: () => {
					let qty = this.dialog.fields_dict.qty.get_value();
					let numbers = frappe.call({
						method: "erpnext.stock.doctype.serial_no.serial_no.auto_fetch_serial_number",
						args: {
							qty: qty,
							item_code: me.item_code,
							warehouse: typeof me.warehouse_details.name == "string" ? me.warehouse_details.name : '',
							batch_no: me.item.batch_no || null,
							posting_date: me.frm.doc.posting_date || me.frm.doc.transaction_date
						}
					});

					numbers.then((data) => {
						let auto_fetched_serial_numbers = data.message;
						let records_length = auto_fetched_serial_numbers.length;
						if (!records_length) {
							const warehouse = me.dialog.fields_dict.warehouse.get_value().bold();
							frappe.msgprint(
								__('Serial numbers unavailable for Item {0} under warehouse {1}. Please try changing warehouse.', [me.item.item_code.bold(), warehouse])
							);
						}
						if (records_length < qty) {
							frappe.msgprint(__('Fetched only {0} available serial numbers.', [records_length]));
						}
						let serial_no_list_field = this.dialog.fields_dict.serial_no;
						numbers = auto_fetched_serial_numbers.join('\n');
						serial_no_list_field.set_value(numbers);
					});
				}
			}
		];

		if (this.has_batch && !this.has_serial_no) {
			title = __("Select Batch Numbers");
			fields = fields.concat(this.get_batch_fields());
		} else {
			// if only serial no OR
			// if both batch_no & serial_no then only select serial_no and auto set batches nos
			title = __("Select Serial Numbers");
			fields = fields.concat(this.get_serial_no_fields());
		}

		this.dialog = new frappe.ui.Dialog({
			title: title,
			fields: fields
		});

		this.dialog.set_primary_action(__('Insert'), function() {
			me.values = me.dialog.get_values();
			if(me.validate()) {
				frappe.run_serially([
					() => me.update_batch_items(),
					() => me.update_serial_no_item(),
					() => me.update_batch_serial_no_items(),
					() => {
						refresh_field("items");
						refresh_field("packed_items");
						if (me.callback) {
							return me.callback(me.item);
						}
					},
					() => me.dialog.hide()
				])
			}
		});

		if(this.show_dialog) {
			let d = this.item;
			if (this.item.serial_no) {
				this.dialog.fields_dict.serial_no.set_value(this.item.serial_no);
			}

			if (this.has_batch && !this.has_serial_no && d.batch_no) {
				this.frm.doc.items.forEach(data => {
					if(data.item_code == d.item_code) {
						this.dialog.fields_dict.batches.df.data.push({
							'batch_no': data.batch_no,
							'actual_qty': data.actual_qty,
							'selected_qty': data.qty,
							'available_qty': data.actual_batch_qty
						});
					}
				});
				this.dialog.fields_dict.batches.grid.refresh();
			}
		}

		if (this.has_batch && !this.has_serial_no) {
			this.update_total_qty();
			this.update_pending_qtys();
		}

		this.dialog.show();
	}

	on_close_dialog() {
		this.dialog.get_close_btn().on('click', () => {
			this.on_close && this.on_close(this.item);
		});
	}

	validate() {
		let values = this.values;
		if(!values.warehouse) {
			frappe.throw(__("Please select a warehouse"));
			return false;
		}
		if(this.has_batch && !this.has_serial_no) {
			if(values.batches.length === 0 || !values.batches) {
				frappe.throw(__("Please select batches for batched item {0}", [values.item_code]));
			}
			values.batches.map((batch, i) => {
				if(!batch.selected_qty || batch.selected_qty === 0 ) {
					if (!this.show_dialog) {
						frappe.throw(__("Please select quantity on row {0}", [i+1]));
					}
				}
			});
			return true;

		} else {
			let serial_nos = values.serial_no || '';
			if (!serial_nos || !serial_nos.replace(/\s/g, '').length) {
				frappe.throw(__("Please enter serial numbers for serialized item {0}", [values.item_code]));
			}
			return true;
		}
	}

	update_batch_items() {
		// clones an items if muliple batches are selected.
		if(this.has_batch && !this.has_serial_no) {
			this.values.batches.map((batch, i) => {
				let batch_no = batch.batch_no;
				let row = '';

				if (i !== 0 && !this.batch_exists(batch_no)) {
					row = this.frm.add_child("items", { ...this.item });
				} else {
					row = this.frm.doc.items.find(i => i.batch_no === batch_no);
				}

				if (!row) {
					row = this.item;
				}
				// this ensures that qty & batch no is set
				this.map_row_values(row, batch, 'batch_no',
					'selected_qty', this.values.warehouse);
			});
		}
	}

	update_serial_no_item() {
		// just updates serial no for the item
		if(this.has_serial_no && !this.has_batch) {
			this.map_row_values(this.item, this.values, 'serial_no', 'qty');
		}
	}

	update_batch_serial_no_items() {
		// if serial no selected is from different batches, adds new rows for each batch.
		if(this.has_batch && this.has_serial_no) {
			const selected_serial_nos = this.values.serial_no.split(/\n/g).filter(s => s);

			return frappe.db.get_list("Serial No", {
				filters: { 'name': ["in", selected_serial_nos]},
				fields: ["batch_no", "name"]
			}).then((data) => {
				// data = [{batch_no: 'batch-1', name: "SR-001"},
				// 	{batch_no: 'batch-2', name: "SR-003"}, {batch_no: 'batch-2', name: "SR-004"}]
				const batch_serial_map = data.reduce((acc, d) => {
					if (!acc[d['batch_no']]) acc[d['batch_no']] = [];
					acc[d['batch_no']].push(d['name'])
					return acc
				}, {})
				// batch_serial_map = { "batch-1": ['SR-001'], "batch-2": ["SR-003", "SR-004"]}
				Object.keys(batch_serial_map).map((batch_no, i) => {
					let row = '';
					const serial_no = batch_serial_map[batch_no];
					if (i == 0) {
						row = this.item;
						this.map_row_values(row, {qty: serial_no.length, batch_no: batch_no}, 'batch_no',
							'qty', this.values.warehouse);
					} else if (!this.batch_exists(batch_no)) {
						row = this.frm.add_child("items", { ...this.item });
						row.batch_no = batch_no;
					} else {
						row = this.frm.doc.items.find(i => i.batch_no === batch_no);
					}
					const values = {
						'qty': serial_no.length,
						'serial_no': serial_no.join('\n')
					}
					this.map_row_values(row, values, 'serial_no',
						'qty', this.values.warehouse);
				});
			})
		}
	}

	batch_exists(batch) {
		const batches = this.frm.doc.items.map(data => data.batch_no);
		return (batches && in_list(batches, batch)) ? true : false;
	}

	map_row_values(row, values, number, qty_field, warehouse) {
		row.qty = values[qty_field];
		row.transfer_qty = flt(values[qty_field]) * flt(row.conversion_factor);
		row[number] = values[number];
		if(this.warehouse_details.type === 'Source Warehouse') {
			row.s_warehouse = values.warehouse || warehouse;
		} else if(this.warehouse_details.type === 'Target Warehouse') {
			row.t_warehouse = values.warehouse || warehouse;
		} else {
			row.warehouse = values.warehouse || warehouse;
		}

		this.frm.dirty();
	}

	update_total_qty() {
		let qty_field = this.dialog.fields_dict.qty;
		let total_qty = 0;

		this.dialog.fields_dict.batches.df.data.forEach(data => {
			total_qty += flt(data.selected_qty);
		});

		qty_field.set_input(total_qty);
	}

	update_pending_qtys() {
		const pending_qty_field = this.dialog.fields_dict.pending_qty;
		const total_selected_qty_field = this.dialog.fields_dict.total_selected_qty;

		if (!pending_qty_field || !total_selected_qty_field) return;

		const me = this;
		const required_qty = this.dialog.fields_dict.required_qty.value;
		const selected_qty = this.dialog.fields_dict.qty.value;
		const total_selected_qty = selected_qty + calc_total_selected_qty(me);
		const pending_qty = required_qty - total_selected_qty;

		pending_qty_field.set_input(pending_qty);
		total_selected_qty_field.set_input(total_selected_qty);
	}

	get_batch_fields() {
		var me = this;

		return [
			{fieldtype:'Section Break', label: __('Batches')},
			{fieldname: 'batches', fieldtype: 'Table', label: __('Batch Entries'),
				fields: [
					{
						'fieldtype': 'Link',
						'read_only': 0,
						'fieldname': 'batch_no',
						'options': 'Batch',
						'label': __('Select Batch'),
						'in_list_view': 1,
						get_query: function () {
							return {
								filters: {
									item_code: me.item_code,
									warehouse: me.warehouse || typeof me.warehouse_details.name == "string" ? me.warehouse_details.name : ''
								},
								query: 'erpnext.controllers.queries.get_batch_no'
							};
						},
						change: function () {
							const batch_no = this.get_value();
							if (!batch_no) {
								this.grid_row.on_grid_fields_dict
									.available_qty.set_value(0);
								return;
							}
							let selected_batches = this.grid.grid_rows.map((row) => {
								if (row === this.grid_row) {
									return "";
								}

								if (row.on_grid_fields_dict.batch_no) {
									return row.on_grid_fields_dict.batch_no.get_value();
								}
							});
							if (selected_batches.includes(batch_no)) {
								this.set_value("");
								frappe.throw(__('Batch {0} already selected.', [batch_no]));
							}

							if (me.warehouse_details.name) {
								frappe.call({
									method: 'erpnext.stock.doctype.batch.batch.get_batch_qty',
									args: {
										batch_no,
										warehouse: me.warehouse_details.name,
										item_code: me.item_code
									},
									callback: (r) => {
										this.grid_row.on_grid_fields_dict
											.available_qty.set_value(r.message || 0);
									}
								});

							} else {
								this.set_value("");
								frappe.throw(__('Please select a warehouse to get available quantities'));
							}
							// e.stopImmediatePropagation();
						}
					},
					{
						'fieldtype': 'Float',
						'read_only': 1,
						'fieldname': 'available_qty',
						'label': __('Available'),
						'in_list_view': 1,
						'default': 0,
						change: function () {
							this.grid_row.on_grid_fields_dict.selected_qty.set_value('0');
						}
					},
					{
						'fieldtype': 'Float',
						'read_only': 0,
						'fieldname': 'selected_qty',
						'label': __('Qty'),
						'in_list_view': 1,
						'default': 0,
						change: function () {
							var batch_no = this.grid_row.on_grid_fields_dict.batch_no.get_value();
							var available_qty = this.grid_row.on_grid_fields_dict.available_qty.get_value();
							var selected_qty = this.grid_row.on_grid_fields_dict.selected_qty.get_value();

							if (batch_no.length === 0 && parseInt(selected_qty) !== 0) {
								frappe.throw(__("Please select a batch"));
							}
							if (me.warehouse_details.type === 'Source Warehouse' &&
								parseFloat(available_qty) < parseFloat(selected_qty)) {

								this.set_value('0');
								frappe.throw(__('For transfer from source, selected quantity cannot be greater than available quantity'));
							} else {
								this.grid.refresh();
							}

							me.update_total_qty();
							me.update_pending_qtys();
						}
					},
				],
				in_place_edit: true,
				data: this.data,
				get_data: function () {
					return this.data;
				},
			}
		];
	}

	get_serial_no_fields() {
		var me = this;
		this.serial_list = [];

		let serial_no_filters = {
			item_code: me.item_code,
			delivery_document_no: ""
		}

		if (this.item.batch_no) {
			serial_no_filters["batch_no"] = this.item.batch_no;
		}

		if (me.warehouse_details.name) {
			serial_no_filters['warehouse'] = me.warehouse_details.name;
		}

		if (me.frm.doc.doctype === 'POS Invoice' && !this.showing_reserved_serial_nos_error) {
			frappe.call({
				method: "erpnext.stock.doctype.serial_no.serial_no.get_pos_reserved_serial_nos",
				args: {
					filters: {
						item_code: me.item_code,
						warehouse: typeof me.warehouse_details.name == "string" ? me.warehouse_details.name : '',
					}
				}
			}).then((data) => {
				serial_no_filters['name'] = ["not in", data.message[0]]
			})
		}

		return [
			{fieldtype: 'Section Break', label: __('Serial Numbers')},
			{
				fieldtype: 'Link', fieldname: 'serial_no_select', options: 'Serial No',
				label: __('Select to add Serial Number.'),
				get_query: function() {
					return {
						filters: serial_no_filters
					};
				},
				onchange: function(e) {
					if(this.in_local_change) return;
					this.in_local_change = 1;

					let serial_no_list_field = this.layout.fields_dict.serial_no;
					let qty_field = this.layout.fields_dict.qty;

					let new_number = this.get_value();
					let list_value = serial_no_list_field.get_value();
					let new_line = '\n';
					if(!list_value) {
						new_line = '';
					} else {
						me.serial_list = list_value.replace(/\n/g, ' ').match(/\S+/g) || [];
					}

					if(!me.serial_list.includes(new_number)) {
						this.set_new_description('');
						serial_no_list_field.set_value(me.serial_list.join('\n') + new_line + new_number);
						me.serial_list = serial_no_list_field.get_value().replace(/\n/g, ' ').match(/\S+/g) || [];
					} else {
						this.set_new_description(new_number + ' is already selected.');
					}

					qty_field.set_input(me.serial_list.length);
					this.$input.val("");
					this.in_local_change = 0;
				}
			},
			{fieldtype: 'Column Break'},
			{
				fieldname: 'serial_no',
				fieldtype: 'Small Text',
				label: __(me.has_batch && !me.has_serial_no ? 'Selected Batch Numbers' : 'Selected Serial Numbers'),
				onchange: function() {
					me.serial_list = this.get_value()
						.replace(/\n/g, ' ').match(/\S+/g) || [];
					this.layout.fields_dict.qty.set_input(me.serial_list.length);
				}
			}
		];
	}
};

function get_pending_qty_fields(me) {
	if (!check_can_calculate_pending_qty(me)) return [];
	const { frm: { doc: { fg_completed_qty }}, item: { item_code, stock_qty }} = me;
	const { qty_consumed_per_unit } = erpnext.stock.bom.items[item_code];

	const total_selected_qty = calc_total_selected_qty(me);
	const required_qty = flt(fg_completed_qty) * flt(qty_consumed_per_unit);
	const pending_qty = required_qty - (flt(stock_qty) + total_selected_qty);

	const pending_qty_fields =  [
		{ fieldtype: 'Section Break', label: __('Pending Quantity') },
		{
			fieldname: 'required_qty',
			read_only: 1,
			fieldtype: 'Float',
			label: __('Required Qty'),
			default: required_qty
		},
		{ fieldtype: 'Column Break' },
		{
			fieldname: 'total_selected_qty',
			read_only: 1,
			fieldtype: 'Float',
			label: __('Total Selected Qty'),
			default: total_selected_qty
		},
		{ fieldtype: 'Column Break' },
		{
			fieldname: 'pending_qty',
			read_only: 1,
			fieldtype: 'Float',
			label: __('Pending Qty'),
			default: pending_qty
		},
	];
	return pending_qty_fields;
}

function calc_total_selected_qty(me) {
	const { frm: { doc: { items }}, item: { name, item_code }} = me;
	const totalSelectedQty = items
		.filter( item => ( item.name !== name ) && ( item.item_code === item_code ) )
		.map( item => flt(item.qty) )
		.reduce( (i, j) => i + j, 0);
	return totalSelectedQty;
}

function check_can_calculate_pending_qty(me) {
	const { frm: { doc }, item } = me;
	const docChecks = doc.bom_no
		&& doc.fg_completed_qty
		&& erpnext.stock.bom
		&& erpnext.stock.bom.name === doc.bom_no;
	const itemChecks = !!item  && !item.allow_alternative_item;
	return docChecks && itemChecks;
}