#!/usr/bin/env python3

__author__ = 'Manuel Holtgrewe <manuel.holtgrewe@fu-berlin.de>'

import os.path
import re

import clang.cindex as ci

from . import app
from . import violations

RULE_NAMING_CONSTANT = 'naming.constant'
RULE_NAMING_STRUCT = 'naming.struct'
RULE_NAMING_UNION = 'naming.union'
RULE_NAMING_CLASS = 'naming.class'
RULE_NAMING_ENUM = 'naming.enum'
RULE_NAMING_FIELD = 'naming.field'
RULE_NAMING_ENUM_CONSTANT = 'naming.enum_constant'
RULE_NAMING_VARIABLE = 'naming.variable'
RULE_NAMING_FUNCTION = 'naming.function'
RULE_NAMING_PARAMETER = 'naming.parameter'
RULE_NAMING_VARIABLE = 'naming.variable'
RULE_NAMING_CXX_METHOD = 'naming.method'
RULE_NAMING_TYPEDEF = 'naming.typedef'
RULE_NAMING_TPL_NON_TYPE_PARAMETER = 'naming.tpl_nontype_param'
RULE_NAMING_TPL_TYPE_PARAMETER = 'naming.tpl_type_param'
RULE_NAMING_TPL_TPL_PARAMETER = 'naming.tpl_tpl_param'
RULE_NAMING_FUNCTION_TPL = 'naming.function_tpl'
RULE_NAMING_CLASS_TPL = 'naming.class_tpl'
RULE_NAMING_CLASS_TPL_SPEC = 'naming.class_tpl_spec'

RE_CONSTANT = r'^[A-Z]([_A-Z0-9])*_*$'
RE_VARIABLE = r'^_?[a-z]([_a-zA-Z0-9])*_*$'
RE_FUNCTION = r'operator.*|^_?[a-z]([_a-zA-Z0-9])*\(.*\)_*$'
RE_TYPE = r'^[A-Z]([a-zA-Z0-9])*_*$'
RE_TYPE_TEMPLATE = r'^[A-Z]([a-zA-Z0-9])*_*<.*>$'
RE_STRUCT = r'^[A-Z]([a-zA-Z0-9])*_*(<.*>)?$'

RULE_TEXTS = {
    RULE_NAMING_CONSTANT: 'Constant names must be all upper-case, separated by underscores.',
    RULE_NAMING_STRUCT: 'Struct names must be all camel case, starting with upper case.',
    RULE_NAMING_UNION: 'Union names must be all camel case, starting with upper case.',
    RULE_NAMING_CLASS: 'Class names must be all camel case, starting with upper case.',
    RULE_NAMING_ENUM: 'Enum names must be all camel case, starting with upper case.',
    RULE_NAMING_FIELD: 'Field names must be camel case case, starting with lower case.',
    RULE_NAMING_ENUM_CONSTANT: 'Enum constant names must be all upper-case, separated by underscores.',
    RULE_NAMING_VARIABLE: 'Variable names must be camel case case, starting with lower case.',
    RULE_NAMING_FUNCTION: 'Function names must be camel case case, starting with lower case.',
    RULE_NAMING_PARAMETER: 'Parameter names must be camel case case, starting with lower case.',
    RULE_NAMING_CXX_METHOD: 'Method names must be camel case case, starting with lower case.',
    RULE_NAMING_TYPEDEF: 'Typedef names must be all camel case, starting with upper case.',
    RULE_NAMING_TPL_NON_TYPE_PARAMETER: 'Template non-type parameters must be all upper-case, separated by underscores.',
    RULE_NAMING_TPL_TYPE_PARAMETER: 'Template type parameter names must be all camel case, starting with upper case.',
    RULE_NAMING_TPL_TPL_PARAMETER: 'Template template parameter names must be all camel case, starting with upper case.',
    RULE_NAMING_FUNCTION_TPL: 'Function template names must be camel case case, starting with lower case.',
    RULE_NAMING_CLASS_TPL: 'Class template names must be all camel case, starting with upper case.',
    RULE_NAMING_CLASS_TPL_SPEC: 'Partial specialization names must be all camel case, starting with upper case.',
}


class GenericSymbolNameRule(object):
    def __init__(self, kind, regular_ex, rule_name):
        self.kind = kind
        self.regular_ex = regular_ex
        self.rule_name = rule_name
        self.visitor = None

    def allowVisit(self, node):
        if not app._hasFileLocation(node):
            #print 'no location'
            return False
        if not node.displayname:
            #print 'no displayname'
            return False  # Ignore empty symbols.
        # print 'allow visit template type?', displayname, node.kind
        if node.kind == self.kind:
            #print 'different kind'
            return True
        return False
    
    def check(self, node):
        displayname = node.displayname
        #print 'checking', displayname
        #import pdb; pdb.set_trace()
        if not re.match(self.regular_ex, displayname):
            v = violations.RuleViolation(
                self.rule_name, displayname, node.location.file.name,
                node.location.line, node.location.column)
            return [v]
        return []


class VariableNameRule(object):
    """Checks variable names (in variable declarations).

    The name must either be camel case (starting with lower case character) or
    all upper case.
    """

    def __init__(self):
        self.visitor = None

    def allowVisit(self, node):
        if not app._hasFileLocation(node):
            return False
        displayname = node.displayname
        if not displayname:
            return False  # Ignore empty symbols.
        if node.kind == ci.CursorKind.VAR_DECL:
            return True
        return False

    def check(self, node):
        displayname = node.displayname
        if not re.match(RE_VARIABLE, displayname) and not re.match(RE_CONSTANT, displayname):
            # TODO(holtgrew): Only allow RE_CONSTANT if 'const' in declaration type.
            v = violations.RuleViolation(
                RULE_NAMING_VARIABLE, displayname, node.location.file.name,
                node.location.line, node.location.column)
            return [v]
        return []


class FunctionTemplateRule(object):
    """Checks function templates.

    Function template have to follow the function naming scheme.  However,
    libclang also exposes constructors with kind function template.  The visitor
    keeps a stack of current classes so we look whether the current class or
    class template has the same name as the function template and allow this
    besides the function naming scheme.
    """

    def __init__(self):
        self.visitor = None

    def allowVisit(self, node):
        if not app._hasFileLocation(node):
            return False
        displayname = node.displayname
        if not displayname:
            return False  # Ignore empty symbols.
        if node.kind == ci.CursorKind.FUNCTION_TEMPLATE:
            return True
        return False

    def check(self, node):
        displayname = node.displayname
        if not re.match(RE_FUNCTION, displayname):
            up_to_bracket = displayname[:displayname.find('<')]
            ## print 'CHECK', self.visitor.getCurrentClassName(), '!=?', up_to_bracket
            if self.visitor.getCurrentClassName() != up_to_bracket:
                v = violations.RuleViolation(
                    RULE_NAMING_FUNCTION_TPL, displayname, node.location.file.name,
                    node.location.line, node.location.column)
                return [v]
        return []


class InIncludeDirsRule(object):
    """Rule to block visiting and recursion outside include dirs."""
    
    def __init__(self, include_dirs, exclude_dirs, source_files):
        self.include_dirs = [os.path.abspath(x) for x in include_dirs]
        self.source_files = [os.path.abspath(x) for x in source_files]
        self.exclude_dirs = [os.path.abspath(x) for x in exclude_dirs]
        self.cache = {}
    
    def allowVisit(self, node):
        """Return True if visiting is allowed."""
        if node.kind == ci.CursorKind.TRANSLATION_UNIT:
            return True
        if not app._hasFileLocation(node):
            return False
        if node.location.file.name in self.cache:
            return self.cache[node.location.file.name]
        # Check whether node's location is below the include directories or one
        # of the source files.
        filename = os.path.abspath(node.location.file.name)
        result = False
        for x in self.include_dirs:
            if filename.startswith(x):
                result = True
                break
        if not result:
            for x in self.source_files:
                if filename == x:
                    result = True
                    break
        if result:
            for x in self.exclude_dirs:
                if filename.startswith(x):
                    result = False
                    break
        self.cache[node.location.file.name] = result
        return result
    
    def allowRecurse(self, node):
        """Return True if we want to recurse below node."""
        return self.allowVisit(node)