From 3ae5125d0eed37d1fb4b61b9bfc9987f75025bdb Mon Sep 17 00:00:00 2001
From: Brian Buller <brian@bullercodeworks.com>
Date: Thu, 15 Jan 2026 11:41:21 -0600
Subject: [PATCH] Rounding out library

---
 invoice.go      | 210 ++++++++++++++++++++++++++++++++++++++++++++----
 invoice_list.go | 189 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 382 insertions(+), 17 deletions(-)
 create mode 100644 invoice_list.go

diff --git a/invoice.go b/invoice.go
index 4a44dda..2617331 100644
--- a/invoice.go
+++ b/invoice.go
@@ -1,18 +1,26 @@
 // Package invoicetxt implements structs ad routines for working with invoice.txt files
 package invoicetxt
 
-import "strings"
+import (
+	"fmt"
+	"sort"
+	"strconv"
+	"strings"
+)
 
+// An invoice.txt entry looks like:
+// <invoiceId> <hours> <rate> [retainerHours] [retainerRate] [retainerRollover] <contexts> <projects> <tags>
 type Invoice struct {
-	ID             int               `json:"id"`       // Invoice id
-	Original       string            `json:"original"` // original raw invoice text
-	Hours          float64           `json:"hours"`
-	Rate           float64           `json:"rate"`
-	RetainerHours  float64           `json:"retainerHours,omitempty"`
-	RetainerRate   float64           `json:"retainerRate,omitempty"`
-	Contexts       []string          `json:"contexts"`
-	Projects       []string          `json:"projects"`
-	AdditionalTags map[string]string `json:"additionalTags"`
+	ID               int               `json:"id"`       // Invoice id
+	Original         string            `json:"original"` // original raw invoice text
+	Hours            float64           `json:"hours"`
+	Rate             float64           `json:"rate"`
+	RetainerHours    float64           `json:"retainerHours,omitempty"`
+	RetainerRate     float64           `json:"retainerRate,omitempty"`
+	RetainerRollover float64           `json:"retainerRollover,omitempty"`
+	Contexts         []string          `json:"contexts"`
+	Projects         []string          `json:"projects"`
+	AdditionalTags   map[string]string `json:"additionalTags"`
 }
 
 // ParseInvoice parses the input test string into an Invoice struct
@@ -23,13 +31,64 @@ func ParseInvoice(text string) (*Invoice, error) {
 	}
 	invoice.Original = strings.Trim(text, "\t\n\r")
 	parts := getParts(invoice.Original)
-	var pIdx int
-	for pIdx = range parts {
-		if partIsSpecial(parts[pIdx]) {
-			break
+	id, err := strconv.Atoi(parts[0])
+	if err != nil {
+		return nil, fmt.Errorf("Error parsing invoice id: %w", err)
+	}
+	invoice.ID = id
+	hr, err := strconv.ParseFloat(parts[1], 64)
+	if err != nil {
+		return nil, fmt.Errorf("Error parsing hours: %w", err)
+	}
+	invoice.Hours = hr
+	rt, err := strconv.ParseFloat(parts[2], 64)
+	if err != nil {
+		return nil, fmt.Errorf("Error parsing rate: %w", err)
+	}
+	invoice.Rate = rt
+	lpI := 3
+	var hitS bool
+	for i := 3; i < len(parts); i++ {
+		if partIsSpecial(parts[i]) {
+			hitS = true
+		}
+		if !hitS {
+			wrk, err := strconv.ParseFloat(parts[i], 64)
+			switch i {
+			case 3: // retainer hours
+				if err != nil {
+					return nil, fmt.Errorf("Error parsing retainer hours: %w", err)
+				}
+				invoice.RetainerHours = wrk
+			case 4: // retainer rate
+				if err != nil {
+					return nil, fmt.Errorf("Error parsing retainer rate: %w", err)
+				}
+				invoice.RetainerRate = wrk
+			case 5: // retainer rollover
+				if err != nil {
+					return nil, fmt.Errorf("Error parsing retainer rollover: %w", err)
+				}
+				invoice.RetainerRollover = wrk
+			}
+			continue
+		}
+		// We're in the 'special' parts
+		switch parts[i][0] {
+		case '@': // context
+			invoice.Contexts = append(invoice.Contexts, parts[i][1:])
+		case '+': // project
+			invoice.Projects = append(invoice.Projects, parts[i][1:])
+		default:
+			if strings.Contains(parts[i], ":") {
+				// Additional Tags
+				tagPts := strings.Split(parts[i], ":")
+				if tagPts[0] != "" && tagPts[1] != "" {
+					invoice.AdditionalTags[tagPts[0]] = tagPts[1]
+				}
+			}
 		}
 	}
-
 	return &invoice, err
 }
 
@@ -37,10 +96,10 @@ func partIsSpecial(pt string) bool {
 	if len(pt) == 0 {
 		return false
 	}
-	return pt[0] == '#' || pt[0] == '@'
+	return pt[0] == '#' || pt[0] == '@' || strings.Contains(pts, ":")
 }
 
-// getParts parses the text from 'text' pu
+// getParts parses the text from 'text' pulling out each part.
 // Generally it just splits everything on spaces, except if we're in a double-quote
 func getParts(text string) []string {
 	var ret []string
@@ -73,3 +132,120 @@ func getParts(text string) []string {
 	}
 	return ret
 }
+
+// String returns a complete invoice string in invoice.txt format.
+//
+// Contexts, ProjectTags, and Additional Tags are alphabetically sorted,
+// and appended at the end in the following order:
+// Contexts, ProjectTags, Tags
+//
+// For example:
+// 315 32.5 100 25 90 @personal +invoicetxt rate:100 retainer:25 retainer_rate:95 retainer_rollover:5
+func (invoice Invoice) String() string {
+	text := fmt.Sprintf("%d %.2f %.2f", invoice.ID, invoice.Hours, invoice.Rate)
+	var sTxt string
+	if len(invoice.Contexts) > 0 {
+		sort.Strings(invoice.Contexts)
+		for _, c := range invoice.Contexts {
+			sTxt = fmt.Sprintf("%s @%s", c)
+		}
+	}
+	if len(invoice.Projects) > 0 {
+		sort.Strings(invoice.Projects)
+		for _, p := range invoice.Projects {
+			sTxt = fmt.Sprintf("%s +%s", p)
+		}
+	}
+	if len(invoice.AdditionalTags) > 0 {
+		keys := make([]string, 0, len(invoice.AdditionalTags))
+		for key := range invoice.AdditionalTags {
+			keys = append(keys, key)
+		}
+		sort.Strings(keys)
+		for _, key := range keys {
+			v := invoice.AdditionalTags[key]
+			if strings.Contains(key, " ") {
+				key = fmt.Sprintf("\"%s\"", key)
+			}
+			if strings.Contains(v, " ") {
+				v = fmt.Sprintf("\"%s\"", v)
+			}
+			sTxt = fmt.Sprintf("%s %s:%s", sTxt, key, v)
+		}
+	}
+	if invoice.RetainerHours == 0 {
+		return fmt.Sprintf("%s %s", text, sTxt)
+	}
+	text = fmt.Sprintf("%s %.2f", text, invoice.RetainerHours)
+	if invoice.RetainerRate == 0 {
+		return fmt.Sprintf("%s %s", text, sTxt)
+	}
+	text = fmt.Sprintf("%s %.2f", text, invoice.RetainerRate)
+	if invoice.RetainerRollover == 0 {
+		return fmt.Sprintf("%s %s", text, sTxt)
+	}
+	text = fmt.Sprintf("%s %.2f", text, invoice.RetainerRollover)
+	return fmt.Sprintf("%s %s", text, sTxt)
+}
+
+func (invoice *Invoice) HasContext(context string) bool {
+	for _, v := range invoice.Contexts {
+		if v == context {
+			return true
+		}
+	}
+	return false
+}
+
+func (invoice *Invoice) GetContextsString() string {
+	var text string
+	sort.Strings(invoice.Contexts)
+	for _, context := range invoice.Contexts {
+		text = fmt.Sprintf("%s %s", context)
+	}
+	return text
+}
+
+func (invoice *Invoice) HasProject(project string) bool {
+	for _, v := range invoice.Projects {
+		if v == project {
+			return true
+		}
+	}
+	return false
+}
+
+func (invoice *Invoice) GetProjectsString() string {
+	var text string
+	sort.Strings(invoice.Projects)
+	for _, project := range invoice.Projects {
+		text = fmt.Sprintf("%s %s", project)
+	}
+	return text
+}
+
+func (invoice *Invoice) SetTag(name, val string) {
+	invoice.AdditionalTags[name] = val
+}
+
+func (invoice *Invoice) HasTag(name string) bool {
+	_, ok := invoice.AdditionalTags[name]
+	return ok
+}
+
+func (invoice *Invoice) GetTag(name string) string {
+	return invoice.AdditionalTags[name]
+}
+
+func (invoice *Invoice) GetTagsString() string {
+	var text string
+	keys := make([]string, 0, len(invoice.AdditionalTags))
+	for key := range invoice.AdditionalTags {
+		keys = append(keys, key)
+	}
+	sort.Strings(keys)
+	for _, key := range keys {
+		text = fmt.Sprintf("%s %s:%s", text, key, invoice.AdditionnalTags[key])
+	}
+	return text
+}
diff --git a/invoice_list.go b/invoice_list.go
new file mode 100644
index 0000000..b7e7ef2
--- /dev/null
+++ b/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
+}