/*
  ==============================================================================

   This file is part of the JUCE 6 technical preview.
   Copyright (c) 2017 - ROLI Ltd.

   You may use this code under the terms of the GPL v3
   (see www.gnu.org/licenses).

   For this technical preview, this file is not subject to commercial licensing.

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

  ==============================================================================
*/

#pragma once


//==============================================================================
struct TranslationHelpers
{
    static void addString (StringArray& strings, const String& s)
    {
        if (s.isNotEmpty() && ! strings.contains (s))
            strings.add (s);
    }

    static void scanFileForTranslations (StringArray& strings, const File& file)
    {
        auto content = file.loadFileAsString();
        auto p = content.getCharPointer();

        for (;;)
        {
            p = CharacterFunctions::find (p, CharPointer_ASCII ("TRANS"));

            if (p.isEmpty())
                break;

            p += 5;
            p = p.findEndOfWhitespace();

            if (*p == '(')
            {
                ++p;
                MemoryOutputStream text;
                parseStringLiteral (p, text);

                addString (strings, text.toString());
            }
        }
    }

    static void parseStringLiteral (String::CharPointerType& p, MemoryOutputStream& out) noexcept
    {
        p = p.findEndOfWhitespace();

        if (p.getAndAdvance() == '"')
        {
            auto start = p;

            for (;;)
            {
                auto c = *p;

                if (c == '"')
                {
                    out << String (start, p);
                    ++p;
                    parseStringLiteral (p, out);
                    return;
                }

                if (c == 0)
                    break;

                if (c == '\\')
                {
                    out << String (start, p);
                    ++p;
                    out << String::charToString (readEscapedChar (p));
                    start = p + 1;
                }

                ++p;
            }
        }
    }

    static juce_wchar readEscapedChar (String::CharPointerType& p)
    {
        auto c = *p;

        switch (c)
        {
            case '"':
            case '\\':
            case '/':  break;

            case 'b':  c = '\b'; break;
            case 'f':  c = '\f'; break;
            case 'n':  c = '\n'; break;
            case 'r':  c = '\r'; break;
            case 't':  c = '\t'; break;

            case 'x':
                ++p;
                c = 0;

                for (int i = 4; --i >= 0;)
                {
                    const int digitValue = CharacterFunctions::getHexDigitValue (*p);
                    if (digitValue < 0)
                        break;

                    ++p;
                    c = (juce_wchar) ((c << 4) + digitValue);
                }

                break;

            case '0': case '1': case '2': case '3': case '4':
            case '5': case '6': case '7': case '8': case '9':
                c = 0;

                for (int i = 4; --i >= 0;)
                {
                    const int digitValue = *p - '0';
                    if (digitValue < 0 || digitValue > 7)
                        break;

                    ++p;
                    c = (juce_wchar) ((c << 3) + digitValue);
                }

                break;

            default:
                break;
        }

        return c;
    }

    static void scanFilesForTranslations (StringArray& strings, const Project::Item& p)
    {
        if (p.isFile())
        {
            const File file (p.getFile());

            if (file.hasFileExtension (sourceOrHeaderFileExtensions))
                scanFileForTranslations (strings, file);
        }

        for (int i = 0; i < p.getNumChildren(); ++i)
            scanFilesForTranslations (strings, p.getChild (i));
    }

    static void scanFolderForTranslations (StringArray& strings, const File& root)
    {
        for (const auto& i : RangedDirectoryIterator (root, true))
        {
            const auto file = i.getFile();

            if (file.hasFileExtension (sourceOrHeaderFileExtensions))
                scanFileForTranslations(strings, file);
         }
    }

    static void scanProject (StringArray& strings, Project& project)
    {
        scanFilesForTranslations (strings, project.getMainGroup());

        OwnedArray<LibraryModule> modules;
        project.getEnabledModules().createRequiredModules (modules);

        for (int j = 0; j < modules.size(); ++j)
        {
            const File localFolder (modules.getUnchecked(j)->getFolder());

            Array<File> files;
            modules.getUnchecked(j)->findBrowseableFiles (localFolder, files);

            for (int i = 0; i < files.size(); ++i)
                scanFileForTranslations (strings, files.getReference(i));
        }
    }

    static const char* getMungingSeparator()  { return "JCTRIDX"; }

    static StringArray breakApart (const String& munged)
    {
        StringArray lines, result;
        lines.addLines (munged);

        String currentItem;

        for (int i = 0; i < lines.size(); ++i)
        {
            if (lines[i].contains (getMungingSeparator()))
            {
                if (currentItem.isNotEmpty())
                    result.add (currentItem);

                currentItem = String();
            }
            else
            {
                if (currentItem.isNotEmpty())
                    currentItem << newLine;

                currentItem << lines[i];
            }
        }

        if (currentItem.isNotEmpty())
            result.add (currentItem);

        return result;
    }

    static StringArray withTrimmedEnds (StringArray array)
    {
        for (auto& s : array)
            s = s.trimEnd().removeCharacters ("\r\n");

        return array;
    }

    static String escapeString (const String& s)
    {
        return s.replace ("\"", "\\\"")
                .replace ("\'", "\\\'")
                .replace ("\t", "\\t")
                .replace ("\r", "\\r")
                .replace ("\n", "\\n");
    }

    static String getPreTranslationText (Project& project)
    {
        StringArray strings;
        scanProject (strings, project);
        return mungeStrings (strings);
    }

    static String getPreTranslationText (const LocalisedStrings& strings)
    {
        return mungeStrings (strings.getMappings().getAllKeys());
    }

    static String mungeStrings (const StringArray& strings)
    {
        MemoryOutputStream s;

        for (int i = 0; i < strings.size(); ++i)
        {
            s << getMungingSeparator() << i << "." << newLine << strings[i];

            if (i < strings.size() - 1)
                s << newLine;
        }

        return s.toString();
    }

    static String createLine (const String& preString, const String& postString)
    {
        return "\"" + escapeString (preString)
                + "\" = \""
                + escapeString (postString) + "\"";
    }

    static String createFinishedTranslationFile (StringArray preStrings,
                                                 StringArray postStrings,
                                                 const LocalisedStrings& original)
    {
        const StringPairArray& originalStrings (original.getMappings());

        StringArray lines;

        if (originalStrings.size() > 0)
        {
            lines.add ("language: " + original.getLanguageName());
            lines.add ("countries: " + original.getCountryCodes().joinIntoString (" "));
            lines.add (String());

            const StringArray& originalKeys (originalStrings.getAllKeys());
            const StringArray& originalValues (originalStrings.getAllValues());
            int numRemoved = 0;

            for (int i = preStrings.size(); --i >= 0;)
            {
                if (originalKeys.contains (preStrings[i]))
                {
                    preStrings.remove (i);
                    postStrings.remove (i);
                    ++numRemoved;
                }
            }

            for (int i = 0; i < originalStrings.size(); ++i)
                lines.add (createLine (originalKeys[i], originalValues[i]));
        }
        else
        {
            lines.add ("language: [enter full name of the language here!]");
            lines.add ("countries: [enter list of 2-character country codes here!]");
            lines.add (String());
        }

        for (int i = 0; i < preStrings.size(); ++i)
            lines.add (createLine (preStrings[i], postStrings[i]));

        return lines.joinIntoString (newLine);
    }
};