#!/usr/bin/perl
use strict;
use warnings;
use IO::Socket::INET;
use Cwd qw(abs_path);
use File::Spec;
use URI::Escape qw(uri_unescape);

my $port = $ARGV[0] || 8765;
my $root = abs_path($ARGV[1] || 'website');

my %mime = (
  html  => 'text/html; charset=utf-8',
  txt   => 'text/plain; charset=utf-8',
  css   => 'text/css; charset=utf-8',
  js    => 'text/javascript; charset=utf-8',
  json  => 'application/json; charset=utf-8',
  webp  => 'image/webp',
  png   => 'image/png',
  jpg   => 'image/jpeg',
  jpeg  => 'image/jpeg',
  svg   => 'image/svg+xml',
  ico   => 'image/x-icon',
  woff2 => 'font/woff2',
);

my $server = IO::Socket::INET->new(
  LocalAddr => '127.0.0.1',
  LocalPort => $port,
  Proto     => 'tcp',
  Listen    => 10,
  ReuseAddr => 1,
) or die "无法启动本地网站服务：$!\n";

sub respond {
  my ($client, $status, $label, $type, $body) = @_;
  binmode $client;
  print $client "HTTP/1.1 $status $label\r\n";
  print $client "Content-Type: $type\r\n";
  print $client "Content-Length: " . length($body) . "\r\n";
  print $client "Cache-Control: no-cache\r\n";
  print $client "Connection: close\r\n\r\n";
  print $client $body;
}

while (my $client = $server->accept()) {
  my $request = <$client> || '';
  while (my $line = <$client>) {
    last if $line =~ /^\r?\n$/;
  }

  my ($method, $url) = split /\s+/, $request;
  if (!$url) {
    close $client;
    next;
  }

  $url =~ s/\?.*$//;
  $url = uri_unescape($url);
  $url =~ s{^/+}{};
  $url = 'index.html' if $url eq '';
  $url =~ s{/}{/}g;

  my $candidate = File::Spec->catfile($root, split('/', $url));
  if ($candidate !~ /\.[^\/]+$/) {
    if (-f "$candidate.html") {
      $candidate .= '.html';
    } elsif (-f File::Spec->catfile($candidate, 'index.html')) {
      $candidate = File::Spec->catfile($candidate, 'index.html');
    }
  }

  my $full = abs_path($candidate);
  if (!$full || index($full, $root) != 0 || !-f $full) {
    my $not_found = File::Spec->catfile($root, '404.html');
    if (-f $not_found) {
      open my $fh, '<:raw', $not_found;
      local $/;
      my $body = <$fh>;
      close $fh;
      respond($client, 404, 'Not Found', $mime{html}, $body);
    } else {
      respond($client, 404, 'Not Found', $mime{txt}, '404 Not Found');
    }
    close $client;
    next;
  }

  open my $fh, '<:raw', $full or do {
    respond($client, 500, 'Internal Server Error', $mime{txt}, '读取网站文件失败');
    close $client;
    next;
  };
  local $/;
  my $body = <$fh>;
  close $fh;

  my ($ext) = $full =~ /\.([^.]+)$/;
  $ext = lc($ext || '');
  respond($client, 200, 'OK', $mime{$ext} || 'application/octet-stream', $body);
  close $client;
}