1 files changed, 131 insertions, 0 deletions
diff --git a/internal/reports/pdf.go b/internal/reports/pdf.go
new file mode 100644
index 0000000..96630cf
--- /dev/null
+++ b/internal/reports/pdf.go
@@ -0,0 +1,131 @@
+package reports
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"time"
+
+	"punchcard/internal/queries"
+	"punchcard/templates"
+)
+
+// RecordInvoice records the invoice in the database after successful generation
+func RecordInvoice(q *queries.Queries, year, month, number, clientID, totalAmountCents int64) error {
+	_, err := q.CreateInvoice(context.Background(), queries.CreateInvoiceParams{
+		Year:        year,
+		Month:       month,
+		Number:      number,
+		ClientID:    clientID,
+		TotalAmount: totalAmountCents,
+	})
+	if err != nil {
+		return fmt.Errorf("failed to record invoice in database: %w", err)
+	}
+	return nil
+}
+
+// InvoiceJSONData represents the data structure for the JSON file that Typst will consume
+type InvoiceJSONData struct {
+	ClientName      string     `json:"client_name"`
+	ProjectName     string     `json:"project_name"`
+	DateRangeStart  string     `json:"date_range_start"`
+	DateRangeEnd    string     `json:"date_range_end"`
+	GeneratedDate   string     `json:"generated_date"`
+	InvoiceNumber   string     `json:"invoice_number"`
+	ContractorName  string     `json:"contractor_name"`
+	ContractorLabel string     `json:"contractor_label"`
+	ContractorEmail string     `json:"contractor_email"`
+	LineItems       []LineItem `json:"line_items"`
+	TotalHours      float64    `json:"total_hours"`
+	TotalAmount     float64    `json:"total_amount"`
+}
+
+func GenerateInvoicePDF(invoiceData *InvoiceData, outputPath string) error {
+	// Check if Typst is installed
+	if err := checkTypstInstalled(); err != nil {
+		return err
+	}
+
+	// Create temporary directory for template and data files
+	tempDir, err := os.MkdirTemp("", "punchcard-invoice")
+	if err != nil {
+		return fmt.Errorf("failed to create temp directory: %w", err)
+	}
+	defer os.RemoveAll(tempDir)
+
+	// Create JSON data for Typst template
+	jsonData := InvoiceJSONData{
+		ClientName:     invoiceData.ClientName,
+		ProjectName:    invoiceData.ProjectName,
+		DateRangeStart: invoiceData.DateRange.Start.Format("2006-01-02"),
+		DateRangeEnd:   invoiceData.DateRange.End.Format("2006-01-02"),
+		GeneratedDate:  invoiceData.GeneratedDate.Format("2006-01-02"),
+		InvoiceNumber: fmt.Sprintf("%04d-%02d-%03d",
+			invoiceData.DateRange.Start.Year(),
+			invoiceData.DateRange.Start.Month(),
+			invoiceData.InvoiceNumber,
+		),
+		ContractorName:  invoiceData.ContractorName,
+		ContractorLabel: invoiceData.ContractorLabel,
+		ContractorEmail: invoiceData.ContractorEmail,
+		LineItems:       invoiceData.LineItems,
+		TotalHours:      invoiceData.TotalHours,
+		TotalAmount:     invoiceData.TotalAmount,
+	}
+
+	// Write JSON data file
+	dataFile := filepath.Join(tempDir, "data.json")
+	jsonBytes, err := json.MarshalIndent(jsonData, "", "  ")
+	if err != nil {
+		return fmt.Errorf("failed to marshal JSON data: %w", err)
+	}
+
+	if err := os.WriteFile(dataFile, jsonBytes, 0o644); err != nil {
+		return fmt.Errorf("failed to write JSON data file: %w", err)
+	}
+
+	// Write Typst template file
+	typstFile := filepath.Join(tempDir, "invoice.typ")
+	if err := os.WriteFile(typstFile, []byte(templates.InvoiceTemplate), 0o644); err != nil {
+		return fmt.Errorf("failed to write Typst template file: %w", err)
+	}
+
+	// Generate PDF using Typst
+	cmd := exec.Command("typst", "compile", typstFile, outputPath)
+	cmd.Dir = tempDir // Set working directory so Typst can find data.json
+
+	if output, err := cmd.CombinedOutput(); err != nil {
+		return fmt.Errorf("failed to generate PDF: %w\nTypst output: %s", err, string(output))
+	}
+
+	return nil
+}
+
+func checkTypstInstalled() error {
+	_, err := exec.LookPath("typst")
+	if err != nil {
+		return fmt.Errorf("typst is not installed or not in PATH. Please install Typst from https://typst.org/")
+	}
+	return nil
+}
+
+func GenerateDefaultInvoiceFilename(clientName, projectName string, dateRange DateRange) string {
+	var name string
+	if projectName != "" {
+		name = fmt.Sprintf("%s_%s", clientName, projectName)
+	} else {
+		name = clientName
+	}
+
+	// Replace spaces and special characters
+	name = filepath.Base(name)
+
+	dateStr := dateRange.Start.Format("2006-01")
+	timestamp := time.Now().Format("20060102_150405")
+
+	return fmt.Sprintf("invoice_%s_%s_%s.pdf", name, dateStr, timestamp)
+}