package main

import (
	"bufio"
	"log"
	"math/rand"
	"regexp"
	"strings"
	"time"
)

type ParsedLink struct {
	ID       string `json:"ID"`
	Name     string
	PageName string
	Line     string
}

var random *rand.Rand

func init() {
	random = rand.New(rand.NewSource(time.Now().UnixNano()))
}

const letterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"

func RandStringBytes(n int) string {
	b := make([]byte, n)
	for i := range b {
		b[i] = letterBytes[rand.Intn(len(letterBytes))]
	}
	return string(b)
}

func ParseLinks(blockId string, content string) ([]ParsedLink, error) {
	hrefRE := regexp.MustCompile(`(#?\[\[\s*([^\]]+)\s*\]\])`)
	keywordsRE := regexp.MustCompile(`(\w+)::`)

	scanner := bufio.NewScanner(strings.NewReader(content))
	scanner.Split(bufio.ScanLines)

	var result []ParsedLink

	for scanner.Scan() {
		line := scanner.Text()

		links := hrefRE.FindAllStringSubmatch(line, -1)

		for _, matches := range links {
			link := matches[0]

			if link[0] == '#' {
				link = strings.TrimPrefix(link, "#[[")
			} else {
				link = strings.TrimPrefix(link, "[[")
			}

			link = strings.TrimSuffix(link, "]]")
			link = strings.TrimSpace(link)
			l := cleanNameURL(link)
			result = append(result, ParsedLink{blockId, link, l, line})
		}

		keywords := keywordsRE.FindAllStringSubmatch(line, -1)
		for _, matches := range keywords {
			link := matches[1]
			l := cleanNameURL(link)
			result = append(result, ParsedLink{blockId, link, l, line})
		}
	}

	return result, nil
}

func cleanNameURL(name string) string {
	return strings.Replace(name, " ", "_", -1)
}

func cleanTitle(name string) string {
	return strings.Replace(name, "_", " ", -1)
}

type stopwatch struct {
	start time.Time
	label string
}

func (sw *stopwatch) Start(label string) {
	sw.start = time.Now()
	sw.label = label
}

func (sw *stopwatch) Stop() {
	endTime := time.Now()
	d := endTime.Sub(sw.start)
	log.Printf("%-20s: %s\n", sw.label, d.String())
}