"""
Serializes a Cython code tree to Cython code. This is primarily useful for
debugging and testing purposes.

The output is in a strict format, no whitespace or comments from the input
is preserved (and it could not be as it is not present in the code tree).
"""

from Cython.Compiler.Visitor import TreeVisitor
from Cython.Compiler.ExprNodes import *

class LinesResult(object):
    def __init__(self):
        self.lines = []
        self.s = u""

    def put(self, s):
        self.s += s

    def newline(self):
        self.lines.append(self.s)
        self.s = u""

    def putline(self, s):
        self.put(s)
        self.newline()

class DeclarationWriter(TreeVisitor):

    indent_string = u"    "

    def __init__(self, result = None):
        super(DeclarationWriter, self).__init__()
        if result is None:
            result = LinesResult()
        self.result = result
        self.numindents = 0
        self.tempnames = {}
        self.tempblockindex = 0

    def write(self, tree):
        self.visit(tree)
        return self.result

    def indent(self):
        self.numindents += 1

    def dedent(self):
        self.numindents -= 1

    def startline(self, s = u""):
        self.result.put(self.indent_string * self.numindents + s)

    def put(self, s):
        self.result.put(s)

    def putline(self, s):
        self.result.putline(self.indent_string * self.numindents + s)

    def endline(self, s = u""):
        self.result.putline(s)

    def line(self, s):
        self.startline(s)
        self.endline()

    def comma_separated_list(self, items, output_rhs=False):
        if len(items) > 0:
            for item in items[:-1]:
                self.visit(item)
                if output_rhs and item.default is not None:
                    self.put(u" = ")
                    self.visit(item.default)
                self.put(u", ")
            self.visit(items[-1])

    def visit_Node(self, node):
        raise AssertionError("Node not handled by serializer: %r" % node)

    def visit_ModuleNode(self, node):
        self.visitchildren(node)

    def visit_StatListNode(self, node):
        self.visitchildren(node)
    
    def visit_CDefExternNode(self, node):
        if node.include_file is None:
            file = u'*'
        else:
            file = u'"%s"' % node.include_file
        self.putline(u"cdef extern from %s:" % file)
        self.indent()
        self.visit(node.body)
        self.dedent()

    def visit_CPtrDeclaratorNode(self, node):
        self.put('*')
        self.visit(node.base)

    def visit_CReferenceDeclaratorNode(self, node):
        self.put('&')
        self.visit(node.base)

    def visit_CArrayDeclaratorNode(self, node):
        self.visit(node.base)
        self.put(u'[')
        if node.dimension is not None:
            self.visit(node.dimension)
        self.put(u']')

    def visit_CArrayDeclaratorNode(self, node):
        self.visit(node.base)
        self.put(u'[')
        if node.dimension is not None:
            self.visit(node.dimension)
        self.put(u']')

    def visit_CFuncDeclaratorNode(self, node):
        # TODO: except, gil, etc.
        self.visit(node.base)
        self.put(u'(')
        self.comma_separated_list(node.args)
        self.endline(u')')

    def visit_CNameDeclaratorNode(self, node):
        self.put(node.name)

    def visit_CSimpleBaseTypeNode(self, node):
        # See Parsing.p_sign_and_longness
        if node.is_basic_c_type:
            self.put(("unsigned ", "", "signed ")[node.signed])
            if node.longness < 0:
                self.put("short " * -node.longness)
            elif node.longness > 0:
                self.put("long " * node.longness)
        self.put(node.name)

    def visit_CComplexBaseTypeNode(self, node):
        self.put(u'(')
        self.visit(node.base_type)
        self.visit(node.declarator)
        self.put(u')')

    def visit_CNestedBaseTypeNode(self, node):
        self.visit(node.base_type)
        self.put(u'.')
        self.put(node.name)

    def visit_TemplatedTypeNode(self, node):
        self.visit(node.base_type_node)
        self.put(u'[')
        self.comma_separated_list(node.positional_args + node.keyword_args.key_value_pairs)
        self.put(u']')

    def visit_CVarDefNode(self, node):
        self.startline(u"cdef ")
        self.visit(node.base_type)
        self.put(u" ")
        self.comma_separated_list(node.declarators, output_rhs=True)
        self.endline()

    def visit_container_node(self, node, decl, extras, attributes):
        # TODO: visibility
        self.startline(decl)
        if node.name:
            self.put(u' ')
            self.put(node.name)
            if node.cname is not None:
                self.put(u' "%s"' % node.cname)
        if extras:
            self.put(extras)
        self.endline(':')
        self.indent()
        if not attributes:
            self.putline('pass')
        else:
            for attribute in attributes:
                self.visit(attribute)
        self.dedent()

    def visit_CStructOrUnionDefNode(self, node):
        if node.typedef_flag:
            decl = u'ctypedef '
        else:
            decl = u'cdef '
        if node.visibility == 'public':
            decl += u'public '
        if node.packed:
            decl += u'packed '
        decl += node.kind
        self.visit_container_node(node, decl, None, node.attributes)

    def visit_CppClassNode(self, node):
        extras = ""
        if node.templates:
            extras = u"[%s]" % ", ".join(node.templates)
        if node.base_classes:
            extras += "(%s)" % ", ".join(node.base_classes)
        self.visit_container_node(node, u"cdef cppclass", extras, node.attributes)

    def visit_CEnumDefNode(self, node):
        self.visit_container_node(node, u"cdef enum", None, node.items)

    def visit_CEnumDefItemNode(self, node):
        self.startline(node.name)
        if node.cname:
            self.put(u' "%s"' % node.cname)
        if node.value:
            self.put(u" = ")
            self.visit(node.value)
        self.endline()

    def visit_CClassDefNode(self, node):
        assert not node.module_name
        if node.decorators:
            for decorator in node.decorators:
                self.visit(decorator)
        self.startline(u"cdef class ")
        self.put(node.class_name)
        if node.base_class_name:
            self.put(u"(")
            if node.base_class_module:
                self.put(node.base_class_module)
                self.put(u".")
            self.put(node.base_class_name)
            self.put(u")")
        self.endline(u":")
        self.indent()
        self.visit(node.body)
        self.dedent()

    def visit_CTypeDefNode(self, node):
        self.startline(u"ctypedef ")
        self.visit(node.base_type)
        self.put(u" ")
        self.visit(node.declarator)
        self.endline()

    def visit_FuncDefNode(self, node):
        self.startline(u"def %s(" % node.name)
        self.comma_separated_list(node.args)
        self.endline(u"):")
        self.indent()
        self.visit(node.body)
        self.dedent()

    def visit_CArgDeclNode(self, node):
        if node.base_type.name is not None:
            self.visit(node.base_type)
            self.put(u" ")
        self.visit(node.declarator)
        if node.default is not None:
            self.put(u" = ")
            self.visit(node.default)

    def visit_CImportStatNode(self, node):
        self.startline(u"cimport ")
        self.put(node.module_name)
        if node.as_name:
            self.put(u" as ")
            self.put(node.as_name)
        self.endline()

    def visit_FromCImportStatNode(self, node):
        self.startline(u"from ")
        self.put(node.module_name)
        self.put(u" cimport ")
        first = True
        for pos, name, as_name, kind in node.imported_names:
            assert kind is None
            if first:
                first = False
            else:
                self.put(u", ")
            self.put(name)
            if as_name:
                self.put(u" as ")
                self.put(as_name)
        self.endline()

    def visit_NameNode(self, node):
        self.put(node.name)

    def visit_IntNode(self, node):
        self.put(node.value)

    def visit_NoneNode(self, node):
        self.put(u"None")

    def visit_NotNode(self, node):
        self.put(u"(not ")
        self.visit(node.operand)
        self.put(u")")

    def visit_DecoratorNode(self, node):
        self.startline("@")
        self.visit(node.decorator)
        self.endline()

    def visit_BinopNode(self, node):
        self.visit(node.operand1)
        self.put(u" %s " % node.operator)
        self.visit(node.operand2)

    def visit_AttributeNode(self, node):
        self.visit(node.obj)
        self.put(u".%s" % node.attribute)

    def visit_BoolNode(self, node):
        self.put(str(node.value))

    # FIXME: represent string nodes correctly
    def visit_StringNode(self, node):
        value = node.value
        if value.encoding is not None:
            value = value.encode(value.encoding)
        self.put(repr(value))

    def visit_PassStatNode(self, node):
        self.startline(u"pass")
        self.endline()

class CodeWriter(DeclarationWriter):

    def visit_SingleAssignmentNode(self, node):
        self.startline()
        self.visit(node.lhs)
        self.put(u" = ")
        self.visit(node.rhs)
        self.endline()

    def visit_CascadedAssignmentNode(self, node):
        self.startline()
        for lhs in node.lhs_list:
            self.visit(lhs)
            self.put(u" = ")
        self.visit(node.rhs)
        self.endline()

    def visit_PrintStatNode(self, node):
        self.startline(u"print ")
        self.comma_separated_list(node.arg_tuple.args)
        if not node.append_newline:
            self.put(u",")
        self.endline()

    def visit_ForInStatNode(self, node):
        self.startline(u"for ")
        self.visit(node.target)
        self.put(u" in ")
        self.visit(node.iterator.sequence)
        self.endline(u":")
        self.indent()
        self.visit(node.body)
        self.dedent()
        if node.else_clause is not None:
            self.line(u"else:")
            self.indent()
            self.visit(node.else_clause)
            self.dedent()

    def visit_IfStatNode(self, node):
        # The IfClauseNode is handled directly without a seperate match
        # for clariy.
        self.startline(u"if ")
        self.visit(node.if_clauses[0].condition)
        self.endline(":")
        self.indent()
        self.visit(node.if_clauses[0].body)
        self.dedent()
        for clause in node.if_clauses[1:]:
            self.startline("elif ")
            self.visit(clause.condition)
            self.endline(":")
            self.indent()
            self.visit(clause.body)
            self.dedent()
        if node.else_clause is not None:
            self.line("else:")
            self.indent()
            self.visit(node.else_clause)
            self.dedent()

    def visit_SequenceNode(self, node):
        self.comma_separated_list(node.args) # Might need to discover whether we need () around tuples...hmm...

    def visit_SimpleCallNode(self, node):
        self.visit(node.function)
        self.put(u"(")
        self.comma_separated_list(node.args)
        self.put(")")

    def visit_GeneralCallNode(self, node):
        self.visit(node.function)
        self.put(u"(")
        posarg = node.positional_args
        if isinstance(posarg, AsTupleNode):
            self.visit(posarg.arg)
        else:
            self.comma_separated_list(posarg.args)  # TupleNode.args
        if node.keyword_args:
            if isinstance(node.keyword_args, DictNode):
                for i, (name, value) in enumerate(node.keyword_args.key_value_pairs):
                    if i > 0:
                        self.put(', ')
                    self.visit(name)
                    self.put('=')
                    self.visit(value)
            else:
                raise Exception("Not implemented yet")
        self.put(u")")

    def visit_ExprStatNode(self, node):
        self.startline()
        self.visit(node.expr)
        self.endline()

    def visit_InPlaceAssignmentNode(self, node):
        self.startline()
        self.visit(node.lhs)
        self.put(u" %s= " % node.operator)
        self.visit(node.rhs)
        self.endline()

    def visit_WithStatNode(self, node):
        self.startline()
        self.put(u"with ")
        self.visit(node.manager)
        if node.target is not None:
            self.put(u" as ")
            self.visit(node.target)
        self.endline(u":")
        self.indent()
        self.visit(node.body)
        self.dedent()

    def visit_TryFinallyStatNode(self, node):
        self.line(u"try:")
        self.indent()
        self.visit(node.body)
        self.dedent()
        self.line(u"finally:")
        self.indent()
        self.visit(node.finally_clause)
        self.dedent()

    def visit_TryExceptStatNode(self, node):
        self.line(u"try:")
        self.indent()
        self.visit(node.body)
        self.dedent()
        for x in node.except_clauses:
            self.visit(x)
        if node.else_clause is not None:
            self.visit(node.else_clause)

    def visit_ExceptClauseNode(self, node):
        self.startline(u"except")
        if node.pattern is not None:
            self.put(u" ")
            self.visit(node.pattern)
        if node.target is not None:
            self.put(u", ")
            self.visit(node.target)
        self.endline(":")
        self.indent()
        self.visit(node.body)
        self.dedent()

    def visit_ReturnStatNode(self, node):
        self.startline("return ")
        self.visit(node.value)
        self.endline()

    def visit_ReraiseStatNode(self, node):
        self.line("raise")

    def visit_ImportNode(self, node):
        self.put(u"(import %s)" % node.module_name.value)

    def visit_TempsBlockNode(self, node):
        """
        Temporaries are output like $1_1', where the first number is
        an index of the TempsBlockNode and the second number is an index
        of the temporary which that block allocates.
        """
        idx = 0
        for handle in node.temps:
            self.tempnames[handle] = "$%d_%d" % (self.tempblockindex, idx)
            idx += 1
        self.tempblockindex += 1
        self.visit(node.body)

    def visit_TempRefNode(self, node):
        self.put(self.tempnames[node.handle])


class PxdWriter(DeclarationWriter):
    def __call__(self, node):
        print u'\n'.join(self.write(node).lines)
        return node

    def visit_CFuncDefNode(self, node):
        if 'inline' in node.modifiers:
            return
        if node.overridable:
            self.startline(u'cpdef ')
        else:
            self.startline(u'cdef ')
        if node.visibility != 'private':
            self.put(node.visibility)
            self.put(u' ')
        if node.api:
            self.put(u'api ')
        self.visit(node.declarator)
    
    def visit_StatNode(self, node):
        pass

    
