Add html2pdf package

Signed-off-by: Bryan Frimin <bryan@getprobo.com>

pkg/html2pdf/margin.go

@@ -0,0 +1,118 @@
+// Copyright (c) 2025 Probo Inc <hello@getprobo.com>.
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+package html2pdf
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+type (
+	MarginUnit string
+
+	Margin struct {
+		Value float64
+		Unit  MarginUnit
+	}
+)
+
+const (
+	MarginUnitInch       MarginUnit = "in"
+	MarginUnitMillimeter MarginUnit = "mm"
+	MarginUnitCentimeter MarginUnit = "cm"
+	MarginUnitPoint      MarginUnit = "pt"
+)
+
+// NewMargin creates a new margin with the specified value and unit
+func NewMargin(value float64, unit MarginUnit) Margin {
+	return Margin{Value: value, Unit: unit}
+}
+
+// NewMarginInches creates a new margin in inches
+func NewMarginInches(value float64) Margin {
+	return Margin{Value: value, Unit: MarginUnitInch}
+}
+
+// NewMarginMillimeters creates a new margin in millimeters
+func NewMarginMillimeters(value float64) Margin {
+	return Margin{Value: value, Unit: MarginUnitMillimeter}
+}
+
+// NewMarginCentimeters creates a new margin in centimeters
+func NewMarginCentimeters(value float64) Margin {
+	return Margin{Value: value, Unit: MarginUnitCentimeter}
+}
+
+// NewMarginPoints creates a new margin in points
+func NewMarginPoints(value float64) Margin {
+	return Margin{Value: value, Unit: MarginUnitPoint}
+}
+
+// ParseMargin parses a CSS margin string into a Margin
+func ParseMargin(margin string) Margin {
+	if margin == "" {
+		return NewMarginInches(1.0) // Default 1 inch
+	}
+
+	margin = strings.TrimSpace(margin)
+
+	// Handle different units
+	if strings.HasSuffix(margin, "in") {
+		if val, err := strconv.ParseFloat(strings.TrimSuffix(margin, "in"), 64); err == nil {
+			return NewMarginInches(val)
+		}
+	} else if strings.HasSuffix(margin, "mm") {
+		if val, err := strconv.ParseFloat(strings.TrimSuffix(margin, "mm"), 64); err == nil {
+			return NewMarginMillimeters(val)
+		}
+	} else if strings.HasSuffix(margin, "cm") {
+		if val, err := strconv.ParseFloat(strings.TrimSuffix(margin, "cm"), 64); err == nil {
+			return NewMarginCentimeters(val)
+		}
+	} else if strings.HasSuffix(margin, "pt") {
+		if val, err := strconv.ParseFloat(strings.TrimSuffix(margin, "pt"), 64); err == nil {
+			return NewMarginPoints(val)
+		}
+	} else {
+		// Try to parse as plain number (assume inches)
+		if val, err := strconv.ParseFloat(margin, 64); err == nil {
+			return NewMarginInches(val)
+		}
+	}
+
+	return NewMarginInches(1.0) // Default fallback
+}
+
+// ToInches converts the margin to inches (required by Chrome DevTools Protocol)
+func (m Margin) ToInches() float64 {
+	switch m.Unit {
+	case MarginUnitInch:
+		return m.Value
+	case MarginUnitMillimeter:
+		return m.Value / 25.4
+	case MarginUnitCentimeter:
+		return m.Value / 2.54
+	case MarginUnitPoint:
+		return m.Value / 72.0
+	default:
+		return m.Value // Assume inches if unknown unit
+	}
+}
+
+// String returns the margin as a CSS string
+func (m Margin) String() string {
+	return fmt.Sprintf("%.2f%s", m.Value, string(m.Unit))
+}