package svgtemplate

import "math"

// Data holds dynamic values for the SVG mask template.
type Data struct {
	Width, Height float64
	CornerRadius  float64
	Bleed         float64
	Margin        float64
	Padding       float64
	ViewBoxMin    float64
	ViewBoxWidth  float64
	ViewBoxHeight float64
	MaskWidth     float64
	MaskHeight    float64
	OuterWidth    float64
	OuterHeight   float64
	OuterOffsetX  float64
	OuterOffsetY  float64
	InnerWidth    float64
	InnerHeight   float64
	InnerOffsetX  float64
	InnerOffsetY  float64
	InnerRadius   float64
	MarkLength    float64
}

const defaultMarkLength = 6.0 // mm

// Build computes template data from product dimensions.
func Build(width, height, bleed, margin, padding, cornerRadius float64) Data {
	offset := bleed + margin + defaultMarkLength
	viewBoxW := width + (offset * 2)
	viewBoxH := height + (offset * 2)

	innerW := width - (padding * 2)
	innerH := height - (padding * 2)
	if innerW < 0 {
		innerW = 0
	}
	if innerH < 0 {
		innerH = 0
	}
	innerR := cornerRadius - padding
	if innerR < 0 {
		innerR = 0
	}
	maxInnerR := math.Min(innerW, innerH) / 2
	if innerR > maxInnerR && maxInnerR > 0 {
		innerR = maxInnerR
	}

	return Data{
		Width:         width,
		Height:        height,
		CornerRadius:  cornerRadius,
		Bleed:         bleed,
		Margin:        margin,
		Padding:       padding,
		ViewBoxMin:    -offset,
		ViewBoxWidth:  viewBoxW,
		ViewBoxHeight: viewBoxH,
		MarkLength:    defaultMarkLength,
		MaskWidth:     width,
		MaskHeight:    height,
		OuterWidth:    width + (bleed * 2),
		OuterHeight:   height + (bleed * 2),
		OuterOffsetX:  -bleed,
		OuterOffsetY:  -bleed,
		InnerWidth:    innerW,
		InnerHeight:   innerH,
		InnerOffsetX:  padding,
		InnerOffsetY:  padding,
		InnerRadius:   innerR,
	}
}