# Copyright 2015 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""
Generator that produces an interface file for the Closure Compiler.
Note: This is a work in progress, and generated interfaces may require tweaking.
"""

from code import Code
from js_util import JsUtil
from model import *
from schema_util import *

import os
import sys
import re

ASSERT = """
assertNotReached('Interface file for Closure Compiler should not be executed.');
"""

class JsInterfaceGenerator(object):
  def Generate(self, namespace):
    return _Generator(namespace).Generate()

class _Generator(object):
  def __init__(self, namespace):
    self._namespace = namespace
    first = namespace.name[0].upper()
    rest = namespace.name[1:]
    self._interface = first + rest
    self._js_util = JsUtil()

  def Generate(self):
    """Generates a Code object with the schema for the entire namespace.
    """
    c = Code()
    (c.Append(self._GetHeader(sys.argv[0], self._namespace.name))
      .Append())

    c.Cblock(self._GenerateInterfaceObject())

    c.Sblock('%s.prototype = {' % self._interface)

    for function in self._namespace.functions.values():
      c.Cblock(self._GenerateFunction(function))

    for event in self._namespace.events.values():
      c.Cblock(self._GenerateEvent(event))

    c.TrimTrailingNewlines()

    c.Eblock('};')

    return c

  def _GetHeader(self, tool, namespace):
    """Returns the file header text.
    """
    return (self._js_util.GetLicense() + '\n' +
            self._js_util.GetInfo(tool) + '\n' +
            ('/** @fileoverview Interface for %s that can be overriden. */' %
             namespace) + '\n' +
            ASSERT);

  def _GenerateInterfaceObject(self):
    """Generates the code creating the interface object.
       For example:
       /** @interface */
       function SettingsPrivate() {}
    """
    c = Code()
    (c.Append('/** @interface */')
      .Append('function %s() {}' % self._interface))
    return c

  def _GenerateFunction(self, function):
    """Generates the inteface for a function, including a JSDoc comment.
    """
    c = Code()
    if function.deprecated:
      return c

    (c.Concat(self._js_util.GenerateFunctionJsDoc(self._namespace.name,
                                                  function))
      .Append('%s: assertNotReached,' % (function.name)))

    return c

  def _GenerateEvent(self, event):
    """Generates the interface for an event.
    """
    c = Code()
    c.Sblock(line='/**', line_prefix=' * ')
    if (event.description):
      c.Comment(event.description, comment_prefix='')
    c.Append('@type {!ChromeEvent}')
    c.Append(self._js_util.GenerateSeeLink(self._namespace.name, 'event',
                                           event.name))
    c.Eblock(' */')
    c.Append('%s: new ChromeEvent(),' % (event.name))
    return c