package web

import (
	"html/template"
	"net/http"
	"path/filepath"
	"time"
)

type Renderer struct {
	templates map[string]*template.Template
	appName   string
	baseURL   string
}

type PageData struct {
	AppName     string
	BaseURL     string
	Title       string
	Description string
	ImageURL    string
	CurrentYear int
	Data        any
}

func NewRenderer(templateDir, appName, baseURL string) (*Renderer, error) {
	layouts, err := filepath.Glob(filepath.Join(templateDir, "layouts", "*.html"))
	if err != nil {
		return nil, err
	}

	partials, err := filepath.Glob(filepath.Join(templateDir, "partials", "*.html"))
	if err != nil {
		return nil, err
	}

	pages, err := filepath.Glob(filepath.Join(templateDir, "pages", "*.html"))
	if err != nil {
		return nil, err
	}

	templates := make(map[string]*template.Template, len(pages))
	for _, page := range pages {
		files := append([]string{}, layouts...)
		files = append(files, partials...)
		files = append(files, page)

		parsed, err := template.ParseFiles(files...)
		if err != nil {
			return nil, err
		}

		templates[filepath.Base(page)] = parsed
	}

	return &Renderer{
		templates: templates,
		appName:   appName,
		baseURL:   baseURL,
	}, nil
}

func (r *Renderer) Render(w http.ResponseWriter, status int, page string, data PageData) {
	data.AppName = r.appName
	data.BaseURL = r.baseURL
	data.CurrentYear = time.Now().Year()

	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	w.WriteHeader(status)

	tmpl, ok := r.templates[page]
	if !ok {
		http.Error(w, "template not found", http.StatusInternalServerError)
		return
	}

	if err := tmpl.ExecuteTemplate(w, page, data); err != nil {
		http.Error(w, "template render error", http.StatusInternalServerError)
	}
}