package render

import (
    "fmt"
    "html/template"
    "path/filepath"
    "sync"

    "github.com/russross/blackfriday/v2"
)

type TemplateData struct {
    Name        string
    FileNameSet []string
}

type TemplateManager struct {
    templates map[string]*template.Template
    mu        sync.RWMutex
    basePath  string
    devMode   bool
}

func NewTemplateManager(basePath string, devMode bool) *TemplateManager {
    return &TemplateManager{
        templates: make(map[string]*template.Template),
        basePath:  basePath,
        devMode:   devMode,
    }
}

func (tm *TemplateManager) buildTemplatePath(name string) string {
    return filepath.Join(tm.basePath, name+".tmpl")
}

func (tm *TemplateManager) GetTemplate(td *TemplateData) (*template.Template, error) {
    // Skip cache in dev mode
    if !tm.devMode {
        tm.mu.RLock()
        if tmpl, exists := tm.templates[td.Name]; exists {
            tm.mu.RUnlock()
            return tmpl, nil
        }
        tm.mu.RUnlock()
    }

    // Build file paths
    var files []string
    for _, file := range td.FileNameSet {
        files = append(files, tm.buildTemplatePath(file))
    }

    // Parse template
    tmpl, err := template.ParseFiles(files...)
    if err != nil {
        return nil, fmt.Errorf("parse template %s: %w", td.Name, err)
    }

    // Cache it (unless in dev mode)
    if !tm.devMode {
        tm.mu.Lock()
        tm.templates[td.Name] = tmpl
        tm.mu.Unlock()
    }

    return tmpl, nil
}

// Render markdown to HTML with target="_blank" on links
func RenderMarkdown(content []byte) (template.HTML, error) {
    renderer := blackfriday.NewHTMLRenderer(blackfriday.HTMLRendererParameters{
        Flags: blackfriday.CommonHTMLFlags | blackfriday.HrefTargetBlank,
    })
    
    html := blackfriday.Run(content, blackfriday.WithRenderer(renderer))
    return template.HTML(html), nil
}