package layout

import (
	"fmt"
	"image/color"
)

const (
	// Progress bar label positioning
	labelTopOffset     = 5
	labelBottomOffset  = 15
	labelSizeReduction = 2
	percentMultiplier  = 100
	percentTextOffset  = 5
)

// ProgressBar draws a labeled progress bar
type ProgressBar struct {
	X, Y          int
	Width, Height int
	Value         float64 // 0.0 to 1.0
	Label         string
	LeftLabel     string
	RightLabel    string
	BarColor      color.Color
	BGColor       color.Color
	TextColor     color.Color
	LabelSize     float64
}

// Draw renders the progress bar on the canvas
func (p *ProgressBar) Draw(canvas *Canvas) {
	// Default colors
	if p.BarColor == nil {
		p.BarColor = color.RGBA{100, 200, 255, 255}
	}
	if p.BGColor == nil {
		p.BGColor = color.RGBA{50, 50, 50, 255}
	}
	if p.TextColor == nil {
		p.TextColor = color.RGBA{255, 255, 255, 255}
	}
	if p.LabelSize == 0 {
		p.LabelSize = 14
	}

	// Ensure value is between 0 and 1
	value := p.Value
	if value < 0 {
		value = 0
	}
	if value > 1 {
		value = 1
	}

	// Draw background
	canvas.DrawBox(p.X, p.Y, p.Width, p.Height, p.BGColor)

	// Draw filled portion
	filledWidth := int(float64(p.Width) * value)
	if filledWidth > 0 {
		canvas.DrawBox(p.X, p.Y, filledWidth, p.Height, p.BarColor)
	}

	// Draw label above bar if provided
	if p.Label != "" {
		labelStyle := TextStyle{Size: p.LabelSize, Color: p.TextColor}
		_ = canvas.DrawText(p.Label, Point{X: p.X, Y: p.Y - labelTopOffset}, labelStyle)
	}

	// Draw left label
	if p.LeftLabel != "" {
		labelStyle := TextStyle{Size: p.LabelSize - labelSizeReduction, Color: p.TextColor}
		_ = canvas.DrawText(p.LeftLabel, Point{X: p.X, Y: p.Y + p.Height + labelBottomOffset}, labelStyle)
	}

	// Draw right label
	if p.RightLabel != "" {
		labelStyle := TextStyle{Size: p.LabelSize - labelSizeReduction, Color: p.TextColor, Alignment: AlignRight}
		_ = canvas.DrawText(p.RightLabel, Point{X: p.X + p.Width, Y: p.Y + p.Height + labelBottomOffset}, labelStyle)
	}

	// Draw percentage in center of bar
	percentText := fmt.Sprintf("%.1f%%", value*percentMultiplier)
	centerStyle := TextStyle{
		Size:      p.LabelSize,
		Color:     color.RGBA{255, 255, 255, 255},
		Alignment: AlignCenter,
	}
	pt := Point{
		X: p.X + p.Width/halfDivisor,
		Y: p.Y + p.Height/halfDivisor + percentTextOffset,
	}
	_ = canvas.DrawText(percentText, pt, centerStyle)
}