(module server-util mzscheme
  
  (require
   (lib "process.ss")
   (file "../base.ss")
   (file "../file.ss")
   )
  
  (provide
   make-data-directories
   make-groups
   copy-configuration-files
   update-permissions
   )
  
  ;; make-data-directories : void -> void
  ;;
  ;; Create a hierarchy of directories under /
  (define (make-data-directories)
    (parameterize
        ((current-directory "/"))
      (make-directory-tree
       '("data" ("www" "log" "conf" ("www" ("auth" "web-server")))))))
  
  ;; make-groups : void -> void
  ;;
  ;; Create the admin and www-data groups
  (define (make-groups)
    (system "addgroup admin")
    (system "addgroup www-data"))
  
  ;; copy-configuration-files : void -> void
  ;;
  ;; Copy configuration files out of /etc/ into /data/conf, and symlink back into /etc/
  (define (copy-configuration-files)
    (move-and-link "apache2" "/etc" "/data/conf/www")
    (move-and-link "apache2" "/var/log" "/data/log")
    (delete-link "/data/conf/www/apache2/sites-enabled/000-default"))

  ;; update-permissions : void -> void
  ;;
  ;; Updates permissions so:
  ;;   - admin group own and has rw permissions on everything in /data
  (define (update-permissions)
    (system "chgrp -R admin /data")
    (system "chmod -R g+rw /data"))
    
  ;; move-and-link : string string string -> void
  ;;
  ;; Moves item from src to des and creates a symlink from src/item to des/item.
  ;;
  ;; If src is already a symlink, does nothing.
  (define (move-and-link item src des)
    (if (or (link-exists? (format "~a/~a" src item))
            (file-exists? (format "~a/~a" des item))
            (directory-exists? (format "~a/~a" des item)))
        (printf "move-and-link: Skipping ~a ~a ~a as one or more already exist\n" item src des)
        (begin
          (system (format "mv ~a/~a ~a" src item des))
          (system (format "ln -s ~a/~a ~a/~a" des item src item)))))
        
  (define (delete-link path)
    (if (link-exists? path)
        (delete-file path)
        (printf "delete-link: Skipping ~a - either it does not exist or it isn't a link\n" path)))
      
  )