// Package renderer provides Mindmap diagram rendering
package renderer

import (
	"fmt"
	"strings"

	"mermaid-go/pkg/ast"
)

// MindmapRenderer implements Mindmap diagram rendering
type MindmapRenderer struct{}

// NewMindmapRenderer creates a new Mindmap renderer
func NewMindmapRenderer() *MindmapRenderer {
	return &MindmapRenderer{}
}

// Render renders a Mindmap diagram to mermaid syntax
func (r *MindmapRenderer) Render(diagram *ast.MindmapDiagram) (string, error) {
	var result strings.Builder

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

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

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

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

	return result.String(), nil
}

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

	// Render node label
	builder.WriteString(node.Label)

	// Render children
	if len(node.Children) > 0 {
		builder.WriteString("\n")
		for _, child := range node.Children {
			builder.WriteString(indentStr)
			r.renderNode(builder, child, indent+1)
			builder.WriteString("\n")
		}
	}
}

// renderNodeWithIndent renders a node with proper indentation
func (r *MindmapRenderer) renderNodeWithIndent(builder *strings.Builder, node *ast.MindmapNode, indent int) {
	indentStr := strings.Repeat("  ", indent)
	builder.WriteString(indentStr)
	r.renderNode(builder, node, indent)
}