package page

import (
	"fmt"
	"io"
	"io/ioutil"
	"text/template"
	"time"

	"gopkg.in/russross/blackfriday.v2"
	"gopkg.in/yaml.v2"
)

type Page struct {
	Name      string
	Head      string
	Body      string
	Date      *time.Time
	Published bool
}

// Can be adjusted to change the base template used in rendering
var BaseTemplate = "inc/base.html"

func (p *Page) Render(wr io.Writer) error {
	if err := p.readYaml(); err != nil {
		return err
	}
	if err := p.readMarkdown(); err != nil {
		return err
	}

	t, err := template.ParseFiles(BaseTemplate)
	if err != nil {
		return err
	}

	// Automatically pull from the yml file if applicable
	if p.Head != "" {
		t, err = t.Parse(`
			{{define "head"}}
			{{.Head}}
			{{end}}
		`)
		if err != nil {
			return err
		}
	}

	return t.Execute(wr, p)
}

func (p *Page) readYaml() error {
	fname := p.Name + ".yml"
	b, err := ioutil.ReadFile(fname)
	if err != nil {
		return fmt.Errorf("While unmarshaling file '%s': %v", fname, err)
	}
	return yaml.Unmarshal(b, p)
}

func (p *Page) readMarkdown() error {
	pth := p.Name + ".md"
	b, err := ioutil.ReadFile(pth)
	if err != nil {
		return fmt.Errorf("Error while reading markdown for path %s: %v",
			pth, err)
	}
	p.Body = string(blackfriday.Run(b))
	return nil
}