package main

import (
	"log"
	"path/filepath"
	"regexp"
	"time"
)

func main() {
	if err := run(); err != nil {
		log.Fatal(err)
	}
}

func run() error {
	index := NewIndex()
	if err := index.ReadDir("src", ""); err != nil {
		return err
	}
	manipulator, err := NewManipulator()
	if err != nil {
		return err
	}
	if err := manipulator.Manipulate(index); err != nil {
		return err
	}

	if err := index.Write("dst"); err != nil {
		return err
	}
	return nil
}

// Page represents a page.
type Page struct {
	// The path to this page.
	Path string
	// The permalink to this page.
	Permalink string
	// The title of this page, parsed from the Gemini contents.
	Title string
	// The date of the page. Dates are specified in the filename.
	// Ex: 2020-09-22-hello-world.gmi
	Date time.Time
	// The content of this page.
	Content string
}

var titleRE = regexp.MustCompile("^# ?([^#\r\n]+)")

func NewPage(path string, content string) *Page {
	page := &Page{
		Path:      path,
		Permalink: "/" + path,
		Content:   content,
	}

	// Try to parse the date from the page filename
	const layout = "2006-01-02"
	base := filepath.Base(path)
	if len(base) >= len(layout) {
		dateStr := base[:len(layout)]
		if date, err := time.Parse(layout, dateStr); err == nil {
			page.Date = date
		}
	}

	// Try to parse the title from the contents
	if submatches := titleRE.FindStringSubmatch(content); submatches != nil {
		page.Title = submatches[1]
	}

	return page
}

// Section represents a section (i.e., a directory).
type Section struct {
	// The path to this section.
	Path string
	// The permalink to this section.
	Permalink string
	// The pages in this section.
	Pages []*Page
}

// NewSection returns a new Section with the given path.
func NewSection(path string) *Section {
	var permalink string
	if path == "" {
		permalink = "/"
	} else {
		permalink = "/" + path + "/"
	}
	return &Section{
		Path:      path,
		Permalink: permalink,
	}
}

// Sort sorts pages by date.
func (s *Section) Sort() {
	// TODO: Implement this
}