/*  Title:      Pure/System/standard_system.scala

     Module:     PIDE

     Author:     Makarius

 Standard system operations, with basic Cygwin/Posix compatibility.

 */

 package isabelle

 import java.lang.System

 import java.util.regex.Pattern

 import java.util.Locale

 import java.net.URL

 import java.io.{File => JFile}

 import scala.util.matching.Regex

 object Standard_System

 {

   /* shell processes */

   def raw_execute(cwd: JFile, env: Map[String, String], redirect: Boolean, args: String*): Process =

   {

     val cmdline = new java.util.LinkedList[String]

     for (s <- args) cmdline.add(s)

     val proc = new ProcessBuilder(cmdline)

     if (cwd != null) proc.directory(cwd)

     if (env != null) {

       proc.environment.clear

       for ((x, y) <- env) proc.environment.put(x, y)

     }

     proc.redirectErrorStream(redirect)

     proc.start

   }

   def process_output(proc: Process): (String, Int) =

   {

     proc.getOutputStream.close

     val output = File.read(proc.getInputStream)

     val rc =

       try { proc.waitFor }

       finally {

         proc.getInputStream.close

         proc.getErrorStream.close

         proc.destroy

         Thread.interrupted

       }

     (output, rc)

   }

   def raw_exec(cwd: JFile, env: Map[String, String], redirect: Boolean, args: String*)

     : (String, Int) = process_output(raw_execute(cwd, env, redirect, args: _*))

   /* cygwin_root */

   def cygwin_root(): String =

   {

     val cygwin_root1 = System.getenv("CYGWIN_ROOT")

     val cygwin_root2 = System.getProperty("cygwin.root")

     val root =

       if (cygwin_root1 != null && cygwin_root1 != "") cygwin_root1

       else if (cygwin_root2 != null && cygwin_root2 != "") cygwin_root2

       else error("Bad Cygwin installation: unknown root")

     val root_file = new JFile(root)

     if (!new JFile(root_file, "bin\\bash.exe").isFile ||

         !new JFile(root_file, "bin\\env.exe").isFile ||

         !new JFile(root_file, "bin\\tar.exe").isFile)

       error("Bad Cygwin installation: " + quote(root))

     root

   }

 }

 class Standard_System

 {

   /* platform_root */

   val platform_root = if (Platform.is_windows) Standard_System.cygwin_root() else "/"

   /* jvm_path */

   private val Cygdrive = new Regex("/cygdrive/([a-zA-Z])($|/.*)")

   private val Named_Root = new Regex("//+([^/]*)(.*)")

   def jvm_path(posix_path: String): String =

     if (Platform.is_windows) {

       val result_path = new StringBuilder

       val rest =

         posix_path match {

           case Cygdrive(drive, rest) =>

             result_path ++= (drive.toUpperCase(Locale.ENGLISH) + ":" + JFile.separator)

             rest

           case Named_Root(root, rest) =>

             result_path ++= JFile.separator

             result_path ++= JFile.separator

             result_path ++= root

             rest

           case path if path.startsWith("/") =>

             result_path ++= platform_root

             path

           case path => path

         }

       for (p <- space_explode('/', rest) if p != "") {

         val len = result_path.length

         if (len > 0 && result_path(len - 1) != JFile.separatorChar)

           result_path += JFile.separatorChar

         result_path ++= p

       }

       result_path.toString

     }

     else posix_path

   /* posix_path */

   private val Platform_Root = new Regex("(?i)" +

     Pattern.quote(platform_root) + """(?:\\+|\z)(.*)""")

   private val Drive = new Regex("""([a-zA-Z]):\\*(.*)""")

   def posix_path(jvm_path: String): String =

     if (Platform.is_windows) {

       jvm_path.replace('/', '\\') match {

         case Platform_Root(rest) => "/" + rest.replace('\\', '/')

         case Drive(letter, rest) =>

           "/cygdrive/" + letter.toLowerCase(Locale.ENGLISH) +

             (if (rest == "") "" else "/" + rest.replace('\\', '/'))

         case path => path.replace('\\', '/')

       }

     }

     else jvm_path

   /* JDK home of running JVM */

   def this_jdk_home(): String =

   {

     val java_home = System.getProperty("java.home")

     val home = new JFile(java_home)

     val parent = home.getParent

     val jdk_home =

       if (home.getName == "jre" && parent != null &&

           (new JFile(new JFile(parent, "bin"), "javac")).exists) parent

       else java_home

     posix_path(jdk_home)

   }

 }