package main

import (
	"fmt"
	"path/filepath"
	"strings"
)

func trim(source, prefix, suffix string) string {
	return strings.TrimPrefix(strings.TrimSuffix(source, suffix), prefix)
}

func hugoPathTrim(source string) string {
	return strings.TrimSuffix(strings.TrimSuffix(source, "/index"), "_index")
}

func processTarget(source string) string {
	if !isInternal(source) {
		return source
	}
	if strings.HasPrefix(source, "/") {
		return strings.TrimSuffix(source, ".md")
	}
	return "/" + strings.TrimSuffix(strings.TrimSuffix(source, ".html"), ".md")
}

func isInternal(link string) bool {
	return !strings.HasPrefix(link, "http")
}

// filter out certain links (e.g. to media)
func filter(links []Link) (res []Link) {
	for _, l := range links {
		// filter external and non-md
		isMarkdown := filepath.Ext(l.Target) == "" || filepath.Ext(l.Target) == ".md"
		if isInternal(l.Target) && isMarkdown {
			res = append(res, l)
		}
	}
	fmt.Printf("Removed %d external and non-markdown links\n", len(links)-len(res))
	return res
}