#!/usr/bin/env ruby

#
#   process_test_files.rb
#
#   Copyright 2016 Tony Stone
#
#   Licensed under the Apache License, Version 2.0 (the "License");
#   you may not use this file except in compliance with the License.
#   You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
#   Unless required by applicable law or agreed to in writing, software
#   distributed under the License is distributed on an "AS IS" BASIS,
#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#   See the License for the specific language governing permissions and
#   limitations under the License.
#
#   Created by Tony Stone on 5/4/16.
#
require 'getoptlong'
require 'fileutils'
require 'pathname'

include FileUtils

#
# This ruby script will auto generate LinuxMain.swift and the +XCTest.swift extension files for Swift Package Manager on Linux platforms.
#
def header(fileName)
    string = <<-eos
//===----------------------------------------------------------------------===//
//
// This source file is part of the SwiftNIO open source project
//
// Copyright (c) 2017-2018 Apple Inc. and the SwiftNIO project authors
// Licensed under Apache License v2.0
//
// See LICENSE.txt for license information
// See CONTRIBUTORS.txt for the list of SwiftNIO project authors
//
// SPDX-License-Identifier: Apache-2.0
//
//===----------------------------------------------------------------------===//
//
// <FileName>
//
import XCTest

///
/// NOTE: This file was generated by generate_linux_tests.rb
///
/// Do NOT edit this file directly as it will be regenerated automatically when needed.
///
    eos

    return string
              .sub("<FileName>", File.basename(fileName))
              .sub("<Date>", Time.now.to_s)
end


def createExtensionFile(fileName, classes)
    extensionFile = fileName.sub! ".swift", "+XCTest.swift"
    print "Creating file: " + extensionFile + "\n"

     File.open(extensionFile, 'w') { |file|

         file.write header(extensionFile)
         file.write "\n"

         for classArray in classes
             file.write "extension " + classArray[0] + " {\n\n"
             file.write '   @available(*, deprecated, message: "not actually deprecated. Just deprecated to allow deprecated tests (which test deprecated functionality) without warnings")' +"\n"
             file.write "   static var allTests : [(String, (" + classArray[0] + ") -> () throws -> Void)] {\n"
             file.write "      return [\n"

             for funcName in classArray[1]
                 file.write "                (\"" + funcName + "\", " + funcName + "),\n"
             end

             file.write "           ]\n"
             file.write "   }\n"
             file.write "}\n\n"
         end
     }
end

def createLinuxMain(testsDirectory, allTestSubDirectories, files)
    fileName = testsDirectory + "/LinuxMain.swift"
    print "Creating file: " + fileName + "\n"

    File.open(fileName, 'w') do |file|
      file.write header(fileName)
      file.write "\n"

      file.write "#if os(Linux) || os(FreeBSD) || os(Android)\n"
      for testSubDirectory in allTestSubDirectories.sort { |x, y| x <=> y }
        file.write '   @testable import ' + testSubDirectory + "\n"
      end
      file.write "\n"
      file.write "// This protocol is necessary to we can call the 'run' method (on an existential of this protocol)\n"
      file.write "// without the compiler noticing that we're calling a deprecated function.\n"
      file.write "// This hack exists so we can deprecate individual tests which test deprecated functionality without\n"
      file.write "// getting a compiler warning...\n"
      file.write "protocol LinuxMainRunner { func run() }\n"
      file.write "class LinuxMainRunnerImpl: LinuxMainRunner {\n"
      file.write '   @available(*, deprecated, message: "not actually deprecated. Just deprecated to allow deprecated tests (which test deprecated functionality) without warnings")' + "\n"
      file.write "   func run() {\n"
      file.write "       XCTMain([\n"

      testCases = []
      for classes in files
        for classArray in classes
          testCases << classArray[0]
        end
      end

      for testCase in testCases.sort { |x, y| x <=> y }
        file.write '             testCase(' + testCase + ".allTests),\n"
      end
      file.write "        ])\n"
      file.write "    }\n"
      file.write "}\n"
      file.write "(LinuxMainRunnerImpl() as LinuxMainRunner).run()\n"
      file.write "#endif\n"
    end
end

def parseSourceFile(fileName)
    puts "Parsing file:  " + fileName + "\n"

    classes = Array.new
    currentClass = nil
    inIfLinux = false
    inElse    = false
    ignore    = false

    #
    # Read the file line by line
    # and parse to find the class
    # names and func names
    #
    File.readlines(fileName).each do |line|
        if inIfLinux
            if /\#else/.match(line)
                inElse = true
                ignore = true
                else
                if /\#end/.match(line)
                    inElse = false
                    inIfLinux = false
                    ignore = false
                end
            end
            else
            if /\#if[ \t]+os\(Linux\)/.match(line)
                inIfLinux = true
                ignore = false
            end
        end

        if !ignore
            # Match class or func
            match = line[/class[ \t]+[a-zA-Z0-9_]*(?=[ \t]*:[ \t]*XCTestCase)|func[ \t]+test[a-zA-Z0-9_]*(?=[ \t]*\(\))/, 0]
            if match

                if match[/class/, 0] == "class"
                    className = match.sub(/^class[ \t]+/, '')
                    #
                    # Create a new class / func structure
                    # and add it to the classes array.
                    #
                    currentClass = [className, Array.new]
                    classes << currentClass
                else # Must be a func
                    funcName  = match.sub(/^func[ \t]+/, '')
                    #
                    # Add each func name the the class / func
                    # structure created above.
                    #
                    currentClass[1] << funcName
                end
            end
        end
    end
    return classes
end

#
# Main routine
#
#

testsDirectory="Tests"

options = GetoptLong.new([ '--tests-dir', GetoptLong::OPTIONAL_ARGUMENT ])
options.quiet = true

begin
    options.each do |option, value|
        case option
            when '--tests-dir'
            testsDirectory=value
        end
    end
    rescue GetoptLong::InvalidOption
end

allTestSubDirectories = Array.new
allFiles = Array.new

Dir[testsDirectory + '/*'].each do |subDirectory|
    if File.directory?(subDirectory)
        directoryHasClasses = false
        Dir[subDirectory + '/*Test{s,}.swift'].each do |fileName|
            if File.file? fileName
                fileClasses = parseSourceFile(fileName)

                #
                # If there are classes in the
                # test source file, create an extension
                # file for it.
                #
                if fileClasses.count > 0
                    createExtensionFile(fileName, fileClasses)
                    directoryHasClasses = true
                    allFiles << fileClasses
                end
            end
        end

        if directoryHasClasses
            allTestSubDirectories << Pathname.new(subDirectory).split.last.to_s
        end
    end
end

#
# Last step is the create a LinuxMain.swift file that
# references all the classes and funcs in the source files.
#
if allFiles.count > 0
    createLinuxMain(testsDirectory, allTestSubDirectories, allFiles)
end
# eof