package templates

import (
	"html/template"
	"path"
	"path/filepath"
	"errors"
	"fmt"
)

func New(path string) *Templates {
	return &Templates{
		Path:path,
		Suffix:".html",
		Delims:[]string{"{{", "}}"},
		LayoutDir:"layouts",
		layouts:make(map[string]*template.Template),
	}
}

type Templates struct {
	Path      string
	Suffix    string
	Delims    []string
	LayoutDir string
	layouts   map[string]*template.Template
	FuncMap   template.FuncMap
}

var errNoTemplateSpecified = errors.New("no template file specified")

func (ts *Templates) SetLayout(filenames ... string) error {
	if len(filenames) == 0 {
		return nil, errNoTemplateSpecified
	}

	for i, filename := range filenames {
		filenames[i] = path.Join(ts.Path, ts.LayoutDir, filename)
	}

	name := filepath.Base(filenames[0])
	if _, ok := ts.layouts[name]; ok {
		return fmt.Errorf("the layout named %q already exists", name)
	}

	layout, err := ts.New(filenames)
	if err != nil {
		return err
	}

	ts.layouts[name] = layout

	return nil
}

func (ts *Templates) Layout(name string) (*template.Template, error) {
	if layout, ok := ts.layouts[name]; ok {
		return layout, nil
	}

	return nil, fmt.Errorf("no layout named %q", name)
}

func (ts *Templates) New(filenames ... string) (*template.Template, error) {
	if len(filenames) == 0 {
		return nil, errNoTemplateSpecified
	}

	name := filepath.Base(filenames[0])
	return template.New(name).Delims(ts.Delims[0], ts.Delims[1]).Funcs(ts.FuncMap).ParseFiles(filenames)
}

func (ts *Templates) Render(layout string) {

}