package main

import (
	"bufio"
	"fmt"
	"strings"
)

type Markup []byte
type LineType int8

const (
	TextLine LineType = iota
	LinkLine
	HeadingLine
	UnorderedListItem
)

func getLineType(line string) LineType {
	if strings.HasPrefix(line, "=>") {
		return LinkLine
	}
	if strings.HasPrefix(line, "#") {
		return HeadingLine
	}
	if strings.HasPrefix(line, "* ") {
		return UnorderedListItem
	}
	return TextLine
}

func (m Markup) title() string {
	text := string(m)
	scanner := bufio.NewScanner(strings.NewReader(text))
	for scanner.Scan() {
		line := scanner.Text()
		if strings.HasPrefix(line, "# ") {
			return strings.TrimPrefix(line, "# ")
		}
	}
	return ""
}

func (m Markup) html() string {
	retval := ""
	var line string
	var lineType LineType
	var lastType LineType = -1

	text := string(m)
	scanner := bufio.NewScanner(strings.NewReader(text))
	for scanner.Scan() {
		line = scanner.Text()
		lineType = getLineType(line)
		if lineType != UnorderedListItem && lastType == UnorderedListItem {
			retval += "\n</ul>"
		}
		if line == "" {
			continue
		}
		switch lineType {
		case LinkLine:
			retval += fmt.Sprintf("\n<pre>%s</pre>", line)
		case HeadingLine:
			retval += fmt.Sprintf("\n<h3>%s</h3>", line)
		case UnorderedListItem:
			if lastType != UnorderedListItem {
				retval += "\n<ul>"
			}
			item := strings.TrimPrefix(line, "*")
			retval += fmt.Sprintf("\n\t<li>%s</li>", item)
		default:
			retval += fmt.Sprintf("\n<p>%s</p>", line)
		}
		lastType = lineType
	}

	if lineType == UnorderedListItem {
		retval += "\n</ul>"
	}

	retval = strings.TrimPrefix(retval, "\n")

	return retval
}