package main

import (
	"os"
	"strings"
	"net/http"
	log "github.com/sirupsen/logrus"
	md "github.com/russross/blackfriday/v2"
)


func ServeForbidden(w http.ResponseWriter, r *http.Request) {
	w.WriteHeader(403);
	w.Write([]byte("403 forbidden"));
}


func ServeNotFound(w http.ResponseWriter, r *http.Request) {
	http.NotFound(w, r);
}


func RenderMarkdown(path string) ([]byte, error) {
	data, err := os.ReadFile(path);
	if err != nil {
		return []byte{}, err;
	}
	return md.Run(data), nil;
}


func ServeMarkdown(w http.ResponseWriter, r *http.Request, path string) (int, error) {
	page, err := RenderMarkdown(path);
	if err != nil {
		return 404, err;
	}
	w.WriteHeader(200);
	w.Write(page);
	return 200, nil;
}

func ServeFile(w http.ResponseWriter, r *http.Request, path string) (int, error) {
	if strings.Contains(r.URL.Path, "..") {
		// reject requests with ".." in the URL
		return 403, nil;
	}
	data, err := os.ReadFile(path);
	if err != nil {
		return 404, err;
	}

	w.WriteHeader(200);
	w.Write(data);
	return 200, nil;
}


func IsMarkdown(path string) bool {
	return strings.HasSuffix(path, ".md");
}


func Serve(w http.ResponseWriter, r *http.Request, path string) {
	var status int;
	var err error;

	if IsMarkdown(path) {
		// render and serve markdown content
		status, err = ServeMarkdown(w, r, path);
	} else {
		// serve raw file
		status, err = ServeFile(w, r, path);
	}

	if status == 200 {
		log.Infof(
			"%v 200\t%v <- %v", 
			r.Method, r.RemoteAddr, r.URL.Path,
		);
	} else {
		log.Errorf(
			"%v %v\t%v <- %v: %v", 
			r.Method, status, r.RemoteAddr, r.URL.Path, err,
		);
		switch status {
			case 403:
				ServeForbidden(w, r);
			case 404:
				ServeNotFound(w, r);
			default:
				w.WriteHeader(status);
				w.Write([]byte("error"));
		}
	}
}