// Package renderer provides Treemap diagram rendering
package renderer

import (
	"fmt"
	"strings"

	"mermaid-go/pkg/ast"
)

// TreemapRenderer implements Treemap diagram rendering
type TreemapRenderer struct{}

// NewTreemapRenderer creates a new Treemap renderer
func NewTreemapRenderer() *TreemapRenderer {
	return &TreemapRenderer{}
}

// Render renders a Treemap diagram to mermaid syntax
func (r *TreemapRenderer) Render(diagram *ast.TreemapDiagram) (string, error) {
	var result strings.Builder

	// Start with treemap keyword
	result.WriteString("treemap\n")

	// Add title if present
	if diagram.Title != nil {
		result.WriteString(fmt.Sprintf("  title %s\n", *diagram.Title))
	}

	// Render root node first
	if diagram.Root != nil {
		r.renderNode(&result, diagram.Root, 2)
	}

	// Render other nodes
	for _, node := range diagram.Nodes {
		if node != diagram.Root {
			r.renderNodeWithIndent(&result, node, 2)
		}
	}

	return result.String(), nil
}

// renderNode renders a single node
func (r *TreemapRenderer) renderNode(builder *strings.Builder, node *ast.TreemapNode, indent int) {
	indentStr := strings.Repeat("  ", indent)

	// Render node with value if present
	if node.Value != nil {
		builder.WriteString(fmt.Sprintf("%s%s : %.2f\n", indentStr, node.Label, *node.Value))
	} else {
		builder.WriteString(fmt.Sprintf("%s%s\n", indentStr, node.Label))
	}

	// Render children
	for _, child := range node.Children {
		r.renderNode(builder, child, indent+1)
	}
}

// renderNodeWithIndent renders a node with proper indentation
func (r *TreemapRenderer) renderNodeWithIndent(builder *strings.Builder, node *ast.TreemapNode, indent int) {
	r.renderNode(builder, node, indent)
}