// Package renderer provides Git diagram rendering
package renderer

import (
	"fmt"
	"strings"

	"mermaid-go/pkg/ast"
)

// GitRenderer implements Git diagram rendering
type GitRenderer struct{}

// NewGitRenderer creates a new Git renderer
func NewGitRenderer() *GitRenderer {
	return &GitRenderer{}
}

// Render renders a Git diagram to mermaid syntax
func (r *GitRenderer) Render(diagram *ast.GitDiagram) (string, error) {
	var result strings.Builder

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

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

	// Render commits
	for _, commit := range diagram.Commits {
		switch commit.Type {
		case "commit":
			result.WriteString(fmt.Sprintf("    commit %s\n", commit.Message))
		case "branch":
			result.WriteString(fmt.Sprintf("    branch %s\n", commit.Branch))
		case "checkout":
			result.WriteString(fmt.Sprintf("    checkout %s\n", commit.Branch))
		case "merge":
			result.WriteString(fmt.Sprintf("    merge %s\n", commit.Branch))
		default:
			result.WriteString(fmt.Sprintf("    commit %s\n", commit.Message))
		}
	}

	return result.String(), nil
}