from __future__ import print_function
from __future__ import unicode_literals

import argparse
import ast
import collections
import traceback

from pre_commit_hooks.util import entry


DEBUG_STATEMENTS = set(['pdb', 'ipdb', 'pudb'])


DebugStatement = collections.namedtuple(
    'DebugStatement', ['name', 'line', 'col'],
)


class ImportStatementParser(ast.NodeVisitor):
    def __init__(self):
        self.debug_import_statements = []

    def visit_Import(self, node):
        for node_name in node.names:
            if node_name.name in DEBUG_STATEMENTS:
                self.debug_import_statements.append(
                    DebugStatement(node_name.name, node.lineno, node.col_offset),
                )

    def visit_ImportFrom(self, node):
        if node.module in DEBUG_STATEMENTS:
            self.debug_import_statements.append(
                DebugStatement(node.module, node.lineno, node.col_offset)
            )


def check_file_for_debug_statements(filename):
    try:
        ast_obj = ast.parse(open(filename).read(), filename=filename)
    except SyntaxError:
        print('{0} - Could not parse ast'.format(filename))
        print()
        print('\t' + traceback.format_exc().replace('\n', '\n\t'))
        print()
        return 1
    visitor = ImportStatementParser()
    visitor.visit(ast_obj)
    if visitor.debug_import_statements:
        for debug_statement in visitor.debug_import_statements:
            print(
                '{0}:{1}:{2} - {3} imported'.format(
                    filename,
                    debug_statement.line,
                    debug_statement.col,
                    debug_statement.name,
                )
            )
        return 1
    else:
        return 0


@entry
def debug_statement_hook(argv):
    parser = argparse.ArgumentParser()
    parser.add_argument('filenames', nargs='*', help='Filenames to run')
    args = parser.parse_args(argv)

    retv = 0
    for filename in args.filenames:
        retv |= check_file_for_debug_statements(filename)

    return retv


if __name__ == '__main__':
    exit(debug_statement_hook())