"""
    pygments.lexers.qvt
    ~~~~~~~~~~~~~~~~~~~

    Lexer for QVT Operational language.

    :copyright: Copyright 2006-2021 by the Pygments team, see AUTHORS.
    :license: BSD, see LICENSE for details.
"""

from pygments.lexer import RegexLexer, bygroups, include, combined, default, \
    words
from pygments.token import Text, Comment, Operator, Keyword, Punctuation, \
    Name, String, Number

__all__ = ['QVToLexer']


class QVToLexer(RegexLexer):
    """
    For the `QVT Operational Mapping language <http://www.omg.org/spec/QVT/1.1/>`_.

    Reference for implementing this: «Meta Object Facility (MOF) 2.0
    Query/View/Transformation Specification», Version 1.1 - January 2011
    (http://www.omg.org/spec/QVT/1.1/), see §8.4, «Concrete Syntax» in
    particular.

    Notable tokens assignments:

    - Name.Class is assigned to the identifier following any of the following
      keywords: metamodel, class, exception, primitive, enum, transformation
      or library

    - Name.Function is assigned to the names of mappings and queries

    - Name.Builtin.Pseudo is assigned to the pre-defined variables 'this',
      'self' and 'result'.
    """
    # With obvious borrowings & inspiration from the Java, Python and C lexers

    name = 'QVTO'
    aliases = ['qvto', 'qvt']
    filenames = ['*.qvto']

    tokens = {
        'root': [
            (r'\n', Text),
            (r'[^\S\n]+', Text),
            (r'(--|//)(\s*)(directive:)?(.*)$',
             bygroups(Comment, Comment, Comment.Preproc, Comment)),
            # Uncomment the following if you want to distinguish between
            # '/*' and '/**', à la javadoc
            # (r'/[*]{2}(.|\n)*?[*]/', Comment.Multiline),
            (r'/[*](.|\n)*?[*]/', Comment.Multiline),
            (r'\\\n', Text),
            (r'(and|not|or|xor|##?)\b', Operator.Word),
            (r'(:{1,2}=|[-+]=)\b', Operator.Word),
            (r'(@|<<|>>)\b', Keyword),  # stereotypes
            (r'!=|<>|==|=|!->|->|>=|<=|[.]{3}|[+/*%=<>&|.~]', Operator),
            (r'[]{}:(),;[]', Punctuation),
            (r'(true|false|unlimited|null)\b', Keyword.Constant),
            (r'(this|self|result)\b', Name.Builtin.Pseudo),
            (r'(var)\b', Keyword.Declaration),
            (r'(from|import)\b', Keyword.Namespace, 'fromimport'),
            (r'(metamodel|class|exception|primitive|enum|transformation|'
             r'library)(\s+)(\w+)',
             bygroups(Keyword.Word, Text, Name.Class)),
            (r'(exception)(\s+)(\w+)',
             bygroups(Keyword.Word, Text, Name.Exception)),
            (r'(main)\b', Name.Function),
            (r'(mapping|helper|query)(\s+)',
             bygroups(Keyword.Declaration, Text), 'operation'),
            (r'(assert)(\s+)\b', bygroups(Keyword, Text), 'assert'),
            (r'(Bag|Collection|Dict|OrderedSet|Sequence|Set|Tuple|List)\b',
             Keyword.Type),
            include('keywords'),
            ('"', String, combined('stringescape', 'dqs')),
            ("'", String, combined('stringescape', 'sqs')),
            include('name'),
            include('numbers'),
            # (r'([a-zA-Z_]\w*)(::)([a-zA-Z_]\w*)',
            # bygroups(Text, Text, Text)),
        ],

        'fromimport': [
            (r'(?:[ \t]|\\\n)+', Text),
            (r'[a-zA-Z_][\w.]*', Name.Namespace),
            default('#pop'),
        ],

        'operation': [
            (r'::', Text),
            (r'(.*::)([a-zA-Z_]\w*)([ \t]*)(\()',
             bygroups(Text, Name.Function, Text, Punctuation), '#pop')
        ],

        'assert': [
            (r'(warning|error|fatal)\b', Keyword, '#pop'),
            default('#pop'),  # all else: go back
        ],

        'keywords': [
            (words((
                'abstract', 'access', 'any', 'assert', 'blackbox', 'break',
                'case', 'collect', 'collectNested', 'collectOne', 'collectselect',
                'collectselectOne', 'composes', 'compute', 'configuration',
                'constructor', 'continue', 'datatype', 'default', 'derived',
                'disjuncts', 'do', 'elif', 'else', 'end', 'endif', 'except',
                'exists', 'extends', 'forAll', 'forEach', 'forOne', 'from', 'if',
                'implies', 'in', 'inherits', 'init', 'inout', 'intermediate',
                'invresolve', 'invresolveIn', 'invresolveone', 'invresolveoneIn',
                'isUnique', 'iterate', 'late', 'let', 'literal', 'log', 'map',
                'merges', 'modeltype', 'new', 'object', 'one', 'ordered', 'out',
                'package', 'population', 'property', 'raise', 'readonly',
                'references', 'refines', 'reject', 'resolve', 'resolveIn',
                'resolveone', 'resolveoneIn', 'return', 'select', 'selectOne',
                'sortedBy', 'static', 'switch', 'tag', 'then', 'try', 'typedef',
                'unlimited', 'uses', 'when', 'where', 'while', 'with', 'xcollect',
                'xmap', 'xselect'), suffix=r'\b'), Keyword),
        ],

        # There is no need to distinguish between String.Single and
        # String.Double: 'strings' is factorised for 'dqs' and 'sqs'
        'strings': [
            (r'[^\\\'"\n]+', String),
            # quotes, percents and backslashes must be parsed one at a time
            (r'[\'"\\]', String),
        ],
        'stringescape': [
            (r'\\([\\btnfr"\']|u[0-3][0-7]{2}|u[0-7]{1,2})', String.Escape)
        ],
        'dqs': [  # double-quoted string
            (r'"', String, '#pop'),
            (r'\\\\|\\"', String.Escape),
            include('strings')
        ],
        'sqs': [  # single-quoted string
            (r"'", String, '#pop'),
            (r"\\\\|\\'", String.Escape),
            include('strings')
        ],
        'name': [
            (r'[a-zA-Z_]\w*', Name),
        ],
        # numbers: excerpt taken from the python lexer
        'numbers': [
            (r'(\d+\.\d*|\d*\.\d+)([eE][+-]?[0-9]+)?', Number.Float),
            (r'\d+[eE][+-]?[0-9]+', Number.Float),
            (r'\d+', Number.Integer)
        ],
    }
