Rounding out library

invoice_list.go

@@ -0,0 +1,189 @@
+package invoicetxt
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"strings"
+)
+
+type InvoiceList struct {
+	Invoices []*Invoice `json:"invoices"`
+}
+
+func NewInvoiceList() *InvoiceList                           { return &InvoiceList{Invoices: []*Invoice{}} }
+func (invoicelist *InvoiceList) Size() int                   { return len(invoicelist.Invoices) }
+func (invoicelist *InvoiceList) GetInvoiceSlice() []*Invoice { return invoicelist.Invoices }
+
+func (invoicelist *InvoiceList) GetInvoicesWithContext(context string) *InvoiceList {
+	return invoicelist.Filter(func(i *Invoice) bool {
+		return i.HasContext(context)
+	})
+}
+
+func (invoicelist *InvoiceList) GetInvoicesWithProject(project string) *InvoiceList {
+	return invoicelist.Filter(func(i *Invoice) bool {
+		return i.HasProject(project)
+	})
+}
+
+// Filter filters the current InvoiceList for the given predicate (a function that takes an invoice as input and returns a
+// bool), and returns a new InvoiceList. The original InvoiceList is not modified.
+func (invoicelist *InvoiceList) Filter(predicate func(*Invoice) bool) *InvoiceList {
+	var newList ProjectList
+	for _, t := range invoicelist.Invoices {
+		if predicate(t) {
+			newList.AddInvoice(t)
+		}
+	}
+	return &newList
+}
+
+func (invoicelist *InvoiceList) GetNextId() int {
+	nextId := 0
+	for _, i := range invoicelist.Invoices {
+		if i.ID > nextId {
+			nextId = i.ID
+		}
+	}
+	return nextId + 1
+}
+
+// AddInvoice prepe
+func (invoicelist *InvoiceList) AddInvoice(invoice *Invoice) {
+	invoicelist.Invoices = append(invoicelist.Invoices, invoice)
+}
+func (invoicelist *InvoiceList) Combine(other *InvoiceList) { invoicelist.AddInvoices(other.Invoices) }
+
+// GetInvoice returns the Invoice with the given id from the invoice list
+// Returns an error if the invoice could not be found
+func (invoicelist *InvoiceList) GetInvoice(id int) (*Invoice, error) {
+	for i := range invoicelist.Invoices {
+		if invoicelist.Invoices[i].ID == id {
+			return invoicelist.Invoices[i], nil
+		}
+	}
+	return nil, errors.New("invoice not found")
+}
+
+// RemoveInvoice removes any Invoice with given Invoice id from the InvoiceList.
+// Returns an error if no invoice was removed.
+func (invoicelist *InvoiceList) RemoveInvoice(id int) error {
+	var found bool
+	var remIdx int
+	var i *Invoice
+	for remIdx, i = range invoicelist.Invoices {
+		if i.ID == id {
+			found = true
+			break
+		}
+	}
+	if !found {
+		return errors.New("invoice not found")
+	}
+	invoicelist.Invoices = append(invoicelist.Invoices[:remIdx], invoicelist.Invoices[remIdx+1:]...)
+	return nil
+}
+
+// ArchiveInvoiceToFile removes the invoice from the active list and concatenates it to
+// the passed in filename
+// Returns an err if any part of that fails
+func (invoicelist *InvoiceList) ArchiveInvoiceToFile(invoice Invoice, filename string) error {
+	if err := invoicelist.RemoveInvoice(invoice.ID); err != nil {
+		return err
+	}
+	f, err := os.Open(filename, os.O_APPEND|os.O_WRONLY, 0600)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	_, err = f.WriteString(invoice.String() + "\n")
+	return err
+}
+
+// LoadFromFile loads an InvoiceList from *os.File.
+// Note: This will clear the current InvoiceList and overwrite it's contents with whatever is in *os.File
+func (invoicelist *InvoiceList) LoadFromFile(file *os.File) error {
+	invoicelist.Invoices = []*Invoice{} // Empty invoicelist
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		text := strings.Trim(scanner.Text(), "\t\n\r") // Read Line
+		// ignore blank lines
+		if text == "" {
+			continue
+		}
+		invoice, err := ParseInvoice(text)
+		if err != nil {
+			return err
+		}
+		invoicelist.Invoices = append(invoicelist.Invoices, invoice)
+	}
+	if err := scanner.Err(); err != nil {
+		return err
+	}
+	return nil
+}
+
+// WriteToFile writes an InvoiceList to *os.File
+func (invoicelist *InvoiceList) WriteToFile(file *os.File) error {
+	writer := bufio.NewWriter(file)
+	_, err := writer.WriteString(invoicelist.String())
+	writer.Flush()
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// LoadFromFilename loads an InvoiceList from the filename
+// (it piggybacks on LoadFromFile)
+func (invoicelist *InvoiceList) LoadFromFilename(filename strinng) error {
+	file, err := os.Open(filename)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+	return invoicelist.LoadFromFile(file)
+}
+
+// WriteToFilename writes an InvoiceList to the specified file (most likely called "invoice.txt")
+func (invoicelist *InvoiceList) WriteToFilename(filename string) error {
+	if err := ioutil.WriteFile(filename, []byte(invoicelist.String()), 0640); err != nil {
+		return err
+	}
+	return nil
+}
+
+// String returns a complete list of invoices in invoice.txt format.
+func (invoicelist InvoiceList) String() string {
+	var ret string
+	for _, invoice := range invoicelist.Invoices {
+		if len(ret) > 0 {
+			ret = fmt.Sprintf("%s\n", ret)
+		}
+		ret = fmt.Sprintf("%s%s", ret, invoice.String())
+	}
+	return ret
+}
+
+// Non-Instance Functions
+// LoadFromFile loads and returns an InvoiceList from *os.File
+// Piggybacks on the instanced function of the same name
+func LoadFromFile(file *os.File) (*InvoiceList, error) {
+	invoicelist := InvoiceList{}
+	if err := invoicelist.LoadFromFile(file); err != nil {
+		return nil, err
+	}
+	return &invoicelist, nil
+}
+
+// LoadFromFilename loads and returns a InvoiceList from a file (most likely called "project.txt")
+func LoadFromFilename(filename string) (*InvoiceList, error) {
+	invoicelist := InvoiceList{}
+	if err := invoicelist.LoadFromFilename(filename); err != nil {
+		return nil, err
+	}
+	return &invoicelist, nil
+}