echo "[ 1/9] Setting up Git"

if ! id git >/dev/null 2>&1; then
  useradd -m -b /srv git
  [ $? -eq 0 ] || exit $?
else
  echo "[SKIP] Git user already created."
fi

GIT_HOME=$( grep git /etc/passwd | cut -d: -f6 )

if [ "$GIT_HOME" = "" ]; then
  echo "[ERROR] No git home!"
  exit 1
fi

echo "[INFO] Git home: $GIT_HOME"

if ! command -v git >/dev/null 2>&1; then
  apt-get install -y git
  [ $? -eq 0 ] || exit $?
else
  echo "[SKIP] Git already installed."
fi

if   ls /usr/lib/git-core/git-http-backend     >/dev/null 2>&1; then
  GIT_HTTP_BACKEND=/usr/lib/git-core/git-http-backend
elif ls /usr/libexec/git-core/git-http-backend >/dev/null 2>&1; then
  GIT_HTTP_BACKEND=/usr/libexec/git-core/git-http-backend
else
  echo "[ERROR] git-http-backend not found!"
  exit 1
fi

echo "[INFO] git-http-backend: $GIT_HTTP_BACKEND"

echo "[ 2/9] Setting up cgit"

if [ ! command -v /usr/share/webapps/cgit/cgit.cgi >/dev/null 2>&1 ] &&
   [ ! command -v /usr/lib/cgit/cgit.cgi           >/dev/null 2>&1 ]; then
  apt-get install -y cgit
  [ $? -eq 0 ] || exit $?
else
  echo "[SKIP] cgit already installed."
fi 

if   command -v /usr/share/webapps/cgit/cgit.cgi >/dev/null 2>&1; then
  CGIT_CGI=/usr/share/webapps/cgit/cgit.cgi
elif command -v /usr/lib/cgit/cgit.cgi           >/dev/null 2>&1; then
  CGIT_CGI=/usr/lib/cgit/cgit.cgi
else
  echo "[ERROR] cgit not found!"
  exit 1
fi

echo "[INFO] Found cgit: $CGIT_CGI"

echo "[ 3/9] Setting up nginx"

if ! command -v nginx >/dev/null 2>&1; then
  apt-get install -y nginx
  [ $? -eq 0 ] || exit $?
else
  echo "[SKIP] nginx already installed."
fi

echo "[ 4/9] Setting up certbot"

if ! command -v certbot >/dev/null 2>&1; then
  apt-get install -y python3-certbot-nginx
  [ $? -eq 0 ] || exit $?
else
  echo "[SKIP] certbot already installed."
fi

echo "[ 5/9] Setting up fcgiwrap"

if ! command -v fcgiwrap >/dev/null 2>&1; then
  apt-get install -y fcgiwrap
  [ $? -eq 0 ] || exit $?
else
  echo "[SKIP] fcgiwrap already installed."
fi

echo "[ 6/9] Setting up htpasswd"

if ! command -v htpasswd >/dev/null 2>&1; then
  apt-get install -y apache2-utils
  [ $? -eq 0 ] || exit $?
else
  echo "[SKIP] htpasswd already installed."
fi

echo "[ 7/9] Setting up GCC"

if ! command -v gcc >/dev/null 2>&1; then
  apt-get install -y gcc
  [ $? -eq 0 ] || exit $?
else
  echo "[SKIP] GCC already installed."
fi

echo "[ 8/9] Compiling and setting up CGI program"

COMPILE="\
  -Wno-old-style-declaration                          \
  -Wno-missing-field-initializers -Wno-missing-braces \
  -Wall -Wextra -Werror -pedantic -mshstk             \
  -O3 -o main main.c"

SAN=-fsanitize=address,undefined,leak

if gcc $SAN $COMPILE >/dev/null 2>&1; then
  gcc $SAN $COMPILE
  [ $? -eq 0 ] || exit $?
else
  echo "[INFO] Sanitizers are disabled."
  gcc $COMPILE
  [ $? -eq 0 ] || exit $?
fi

chown root:root main
[ $? -eq 0 ] || exit $?

mv -f main /srv/
[ $? -eq 0 ] || exit $?

mv -f static /srv/static
[ $? -eq 0 ] || exit $?

echo "[ 9/9] Configuring"

if [ ! -d /etc/nginx/sites-available ]; then
  mkdir /etc/nginx/sites-available
  [ $? -eq 0 ] || exit $?
fi

if [ ! -d /etc/nginx/sites-enabled ]; then
  mkdir /etc/nginx/sites-enabled
  [ $? -eq 0 ] || exit $?
fi

if [ ! -f /etc/nginx/sites-enabled/default ]; then
  ln -s /etc/nginx/sites-available/default /etc/nginx/sites-enabled/default
  [ $? -eq 0 ] || exit $?
fi

cat <<EOF >/etc/nginx/sites-available/default
server {
  listen      80;
  listen [::]:80;

  server_name _;

  location ~ ^/git_write/ {
    rewrite ^/git_write/(.*) /\$1 break;

    auth_basic            "Git";
    auth_basic_user_file  $GIT_HOME.htpasswd;

    include       fastcgi_params;
    fastcgi_param SCRIPT_FILENAME   $GIT_HTTP_BACKEND;
    fastcgi_param GIT_PROJECT_ROOT  $GIT_HOME;
    fastcgi_param PATH_INFO         \$uri;
    fastcgi_pass  unix:/var/run/fcgiwrap.socket;
  }

  location ~ ^/git_read/ {
    rewrite ^/git_read/(.*) /\$1 break;

    include       fastcgi_params;
    fastcgi_param SCRIPT_FILENAME   $GIT_HTTP_BACKEND;
    fastcgi_param GIT_PROJECT_ROOT  $GIT_HOME;
    fastcgi_param PATH_INFO         \$uri;
    fastcgi_pass  unix:/var/run/fcgiwrap.socket;
  }

  location ~ \\.git {
    if (\$arg_service = git-receive-pack) {
      rewrite /(.*) /git_write/\$1 last;
    }
    if (\$uri ~ ^/.*/git-receive-pack\$) {
      rewrite /(.*) /git_write/\$1 last;
    }
    if (\$arg_service = git-upload-pack) {
      rewrite /(.*) /git_read/\$1 last;
    }
    if (\$uri ~ ^/.*/git-upload-pack\$) {
      rewrite /(.*) /git_read/\$1 last;
    }
  }

  location ^~ /git/ {
    rewrite ^/git/(.*) /\$1 break;
    include       fastcgi_params;
    fastcgi_param SCRIPT_FILENAME $CGIT_CGI;
    fastcgi_param PATH_INFO       \$uri;
    fastcgi_param QUERY_STRING    \$args;
    fastcgi_pass  unix:/var/run/fcgiwrap.socket;
  }

  location ~* \\.(txt|asc|htm|css|svg|jpg|png|gif|ico|woff|woff2|js|wasm|mp3)\$ {
    rewrite ^/(.*) /static/plain/\$1 break;
    include       fastcgi_params;
    fastcgi_param SCRIPT_FILENAME $CGIT_CGI;
    fastcgi_param PATH_INFO       \$uri;
    fastcgi_param QUERY_STRING    \$args;
    fastcgi_pass  unix:/var/run/fcgiwrap.socket;
  }

  location / {
    include       /etc/nginx/fastcgi_params;
    fastcgi_param SCRIPT_FILENAME /srv/main.cgi;
    fastcgi_pass  unix:/var/run/fcgiwrap.socket;
  }
}
EOF
[ $? -eq 0 ] || exit $?

echo "[INFO] Written /etc/nginx/sites-available/default:"

cat /etc/nginx/sites-available/default

cat <<EOF >/etc/nginx/mime.types
types {
  text/plain             txt;
  text/plain             asc;
  text/html              htm;
  text/css               css;
  image/svg+xml          svg;
  image/jpeg             jpg;
  image/png              png;
  image/gif              gif;
  image/x-icon           ico;
  application/font-woff  woff;
  application/font-woff2 woff2;
  application/javascript js;
  application/wasm       wasm;
  audio/mpeg             mp3;
}
EOF
[ $? -eq 0 ] || exit $?

echo "[INFO] Written /etc/nginx/mime.types:"

cat /etc/nginx/mime.types

cat <<EOF >/etc/nginx/nginx.conf
user git;
worker_processes 1;
pid /run/nginx.pid;
include /etc/nginx/modules-enabled/*.conf;

events {
  worker_connections 768;
}

http {
  sendfile                      on;
  tcp_nopush                    on;
  types_hash_max_size           2048;
  server_names_hash_bucket_size 256;

  include /etc/nginx/mime.types;
  default_type application/octet-stream;

  ssl_protocols TLSv1 TLSv1.1 TLSv1.2 TLSv1.3;
  ssl_prefer_server_ciphers on;

  access_log /var/log/nginx/access.log;
  error_log  /var/log/nginx/error.log;

  gzip on;

  include /etc/nginx/conf.d/*.conf;
  include /etc/nginx/sites-enabled/*;
}
EOF
[ $? -eq 0 ] || exit $?

echo "[INFO] Written /etc/nginx/nginx.conf:"

cat /etc/nginx/nginx.conf

echo "[INFO] All done!"