// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

library builtin;

// Corelib 'print' implementation.
void _print(arg) {
  _Logger._printString(arg.toString());
}


class _Logger {
  static void _printString(String s) native "Logger_PrintString";
}


_getPrintClosure() => _print;


void _logResolution(String msg) {
  final enabled = false;
  if (enabled) {
    _Logger._printString(msg);
  }
}


// Are we running on Windows?
var _isWindows = false;
// The current working directory
var _workingDirectoryUri;
// The URI that the entry point script was loaded from. Remembered so that
// package imports can be resolved relative to it.
var _entryPointScript;
// The directory to look in to resolve "package:" scheme URIs.
var _packageRoot;


void _setWindows() {
  _isWindows = true;
}


void _setWorkingDirectory(cwd) {
  if (_isWindows) {
    // For Windows we need to massage the paths a bit according to
    // http://blogs.msdn.com/b/ie/archive/2006/12/06/file-uris-in-windows.aspx
    //
    // Convert
    // C:\one\two\three
    // to
    // /C:/one/two/three
    cwd = "/${cwd.replaceAll('\\', '/')}";
  }

  // Ensure we have a trailing slash character.
  if (cwd.endsWith('/')) {
    cwd = cwd;
  } else {
    cwd = '$cwd/';
  }
  _workingDirectoryUri = new Uri(scheme: 'file', path: cwd);
  _logResolution('# Working Directory: $cwd');
}


_setPackageRoot(String packageRoot) {
  if (!packageRoot.endsWith('/')) {
    // Ensure we have a trailing slash character.
    packageRoot = '$packageRoot/';
  }
  _packageRoot = Uri.parse(packageRoot);
}


String _resolveScriptUri(String scriptName) {
  if (_workingDirectoryUri == null) {
    throw 'No current working directory set.';
  }
  var scriptUri = Uri.parse(scriptName);
  if (scriptUri.scheme != '') {
    // Script has a scheme, assume that it is fully formed.
    _entryPointScript = scriptUri;
  } else {
    // Script does not have a scheme, assume that it is a path,
    // resolve it against the working directory.
    _entryPointScript = _workingDirectoryUri.resolve(scriptName);
  }
  _logResolution('# Resolved entry point to: $_entryPointScript');
  return _entryPointScript.toString();
}


String _resolveUri(String base, String userString) {
  var baseUri = Uri.parse(base);
  _logResolution('# Resolving: $userString from $base');

  var uri = Uri.parse(userString);
  var resolved;
  if ('dart-ext' == uri.scheme) {
    // Relative URIs with scheme dart-ext should be resolved as if with no
    // scheme.
    resolved = baseUri.resolve(uri.path);
    var path = resolved.path;
    if (resolved.scheme == 'package') {
      // If we are resolving relative to a package URI we go directly to the
      // file path and keep the dart-ext scheme. Otherwise, we will lose the
      // package URI path part.
      path = _filePathFromPackageUri(resolved);
    }
    resolved = new Uri(scheme: 'dart-ext', path: path);
  } else {
    resolved = baseUri.resolve(userString);
  }
  _logResolution('# Resolved to: $resolved');
  return resolved.toString();
}


String _filePathFromUri(String userUri) {
  var uri = Uri.parse(userUri);
  _logResolution('# Getting file path from: $uri');

  var path;
  switch (uri.scheme) {
    case 'file':
      path = _filePathFromFileUri(uri);
      break;
    case 'dart-ext':
      path = _filePathFromOtherUri(uri);
      break;
    case 'package':
      path = _filePathFromPackageUri(uri);
      break;
    case 'http':
      path = _filePathFromHttpUri(uri);
      break;
    default:
      // Only handling file and package URIs in standalone binary.
      _logResolution('# Unknown scheme (${uri.scheme}) in $uri.');
      throw 'Not a known scheme: $uri';
  }

  if (_isWindows && path.startsWith('/')) {
    // For Windows we need to massage the paths a bit according to
    // http://blogs.msdn.com/b/ie/archive/2006/12/06/file-uris-in-windows.aspx
    //
    // Drop the leading / before the drive letter.
    path = path.substring(1);
    _logResolution('# Path: Removed leading / -> $path');
  }

  return path;
}


String _filePathFromFileUri(Uri uri) {
  if (!uri.host.isEmpty) {
    throw "URIs using the 'file:' scheme may not contain a host.";
  }

  _logResolution('# Path: $uri -> ${uri.path}');
  return uri.path;
}


String _filePathFromOtherUri(Uri uri) {
  if (!uri.host.isEmpty) {
    throw 'URIs whose paths are used as file paths may not contain a host.';
  }

  _logResolution('# Path: $uri -> ${uri.path}');
  return uri.path;
}


String _filePathFromPackageUri(Uri uri) {
  if (!uri.host.isEmpty) {
    var path = (uri.path != '') ? '${uri.host}${uri.path}' : uri.host;
    var right = 'package:$path';
    var wrong = 'package://$path';

    throw "URIs using the 'package:' scheme should look like "
          "'$right', not '$wrong'.";
  }

  var packageUri;
  var path;
  if (_packageRoot != null) {
    // Resolve against package root.
    packageUri = _packageRoot.resolve(uri.path);
  } else {
    // Resolve against working directory.
    packageUri = _entryPointScript.resolve('packages/${uri.path}');
  }

  if (packageUri.scheme == 'file') {
    path = packageUri.path;
  } else {
    path = packageUri.toString();
  }
  _logResolution('# Package: $uri -> $path');
  return path;
}


String _filePathFromHttpUri(Uri uri) {
  _logResolution('# Path: $uri -> $uri');
  return uri.toString();
}


String _pathFromHttpUri(String userUri) {
  var uri = Uri.parse(userUri);
  return uri.path;
}


String _hostFromHttpUri(String userUri) {
  var uri = Uri.parse(userUri);
  return uri.host;
}


int _portFromHttpUri(String userUri) {
  var uri = Uri.parse(userUri);
  return uri.port == 0 ? 80 : uri.port;
}