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# Source code for xonsh.parsers.ast

    """Abstract Syntax Tree handler"""

    # These are imported into our module namespace for the benefit of parser.py.
    # pylint: disable=unused-import
    import itertools
    import sys
    import textwrap
    from ast import (  # noqa # pylint: disable=unused-import
        AST,
        Add,
        And,
        AnnAssign,
        Assert,
        Assign,
        AsyncFor,
        AsyncFunctionDef,
        AsyncWith,
        Attribute,
        AugAssign,
        Await,
        BinOp,
        BitAnd,
        BitOr,
        BitXor,
        BoolOp,
        Break,
        Call,
        ClassDef,
        Compare,
        Constant,
        Continue,
        Del,
        Delete,
        Dict,
        DictComp,
        Div,
        Eq,
        ExceptHandler,
        Expr,
        Expression,
        ExtSlice,
        FloorDiv,
        For,
        FormattedValue,
        FunctionDef,
        GeneratorExp,
        Global,
        Gt,
        GtE,
        If,
        IfExp,
        Import,
        ImportFrom,
        In,
        Index,
        Interactive,
        Invert,
        Is,
        IsNot,
        JoinedStr,
        Lambda,
        List,
        ListComp,
        Load,
        LShift,
        Lt,
        LtE,
        MatMult,
        Mod,
        Module,
        Mult,
        Name,
        NamedExpr,
        NodeTransformer,
        Nonlocal,
        Not,
        NotEq,
        NotIn,
        Or,
        Pass,
        Pow,
        Raise,
        Return,
        RShift,
        Set,
        SetComp,
        Slice,
        Starred,
        Store,
        Sub,
        Subscript,
        Try,
        Tuple,
        UAdd,
        UnaryOp,
        USub,
        While,
        With,
        Yield,
        YieldFrom,
        alias,
        arg,
        arguments,
        comprehension,
        dump,
        increment_lineno,
        keyword,
        literal_eval,
        walk,
        withitem,
    )
    from typing import Optional

    from xonsh.built_ins import XSH
    from xonsh.platform import PYTHON_VERSION_INFO
    from xonsh.tools import find_next_break, get_logical_line, subproc_toks

    STATEMENTS = (
        FunctionDef,
        ClassDef,
        Return,
        Delete,
        Assign,
        AugAssign,
        For,
        While,
        If,
        With,
        Raise,
        Try,
        Assert,
        Import,
        ImportFrom,
        Global,
        Nonlocal,
        Expr,
        Pass,
        Break,
        Continue,
        AnnAssign,
    )

    def const_str(
        s: str,
        lineno: int | None = None,
        col_offset: int | None = None,
        is_raw: bool = True,
    ):
        if PYTHON_VERSION_INFO >= (3, 13):
            # looks like this attribute is no longer needed to be set explicitly
            constant = Constant(value=s, kind="str")
        else:
            constant = Constant(value=s, kind="str")
            if is_raw:
                # this attribute is not documented within the ast object
                constant.is_raw = is_raw  # type: ignore
        if lineno is not None:
            constant.lineno = lineno
        if col_offset is not None:
            constant.col_offset = col_offset
        return constant

    def is_const_str(node):
        return isinstance(node, Constant) and node.kind == "str"

    def const_bytes(s: str, **kwargs):
        return Constant(value=s, kind="bytes", **kwargs)

    def is_const_bytes(node):
        return isinstance(node, Constant) and node.kind == "bytes"

    def const_num(n, **kwargs):
        return Constant(value=n, kind="num", **kwargs)

    def is_const_num(node):
        return isinstance(node, Constant) and node.kind == "num"

    def const_name(value, **kwargs):
        return Constant(value=value, kind="name", **kwargs)

    def is_const_name(node):
        return isinstance(node, Constant) and node.kind == "name"

    def leftmostname(node):
        """Attempts to find the first name in the tree."""
        if isinstance(node, Name):
            rtn = node.id
        elif isinstance(node, BinOp | Compare):
            rtn = leftmostname(node.left)
        elif isinstance(node, Attribute | Subscript | Starred | Expr):
            rtn = leftmostname(node.value)
        elif isinstance(node, Call):
            rtn = leftmostname(node.func)
        elif isinstance(node, UnaryOp):
            rtn = leftmostname(node.operand)
        elif isinstance(node, BoolOp):
            rtn = leftmostname(node.values[0])
        elif isinstance(node, Assign):
            rtn = leftmostname(node.targets[0])
        elif isinstance(node, AnnAssign):
            rtn = leftmostname(node.target)
        elif isinstance(node, JoinedStr) or is_const_str(node) or is_const_bytes(node):
            # handles case of "./my executable"
            rtn = leftmostname(node.s)
        elif isinstance(node, Tuple) and len(node.elts) > 0:
            # handles case of echo ,1,2,3
            rtn = leftmostname(node.elts[0])
        else:
            rtn = None
        return rtn

    def get_lineno(node, default=0):
        """Gets the lineno of a node or returns the default."""
        return getattr(node, "lineno", default)

    def min_line(node):
        """Computes the minimum lineno."""
        node_line = get_lineno(node)
        return min(map(get_lineno, walk(node), itertools.repeat(node_line)))

    def max_line(node):
        """Computes the maximum lineno."""
        return max(map(get_lineno, walk(node)))

    def get_col(node, default=-1):
        """Gets the col_offset of a node, or returns the default"""
        return getattr(node, "col_offset", default)

    def min_col(node):
        """Computes the minimum col_offset."""
        return min(map(get_col, walk(node), itertools.repeat(node.col_offset)))

    def max_col(node):
        """Returns the maximum col_offset of the node and all sub-nodes."""
        col = getattr(node, "max_col", None)
        if col is not None:
            return col
        highest = max(walk(node), key=get_col)
        col = highest.col_offset + node_len(highest)
        return col

    def node_len(node):
        """The length of a node as a string"""
        val = 0
        for n in walk(node):
            if isinstance(n, Name):
                val += len(n.id)
            elif isinstance(n, Attribute):
                val += 1 + (len(n.attr) if isinstance(n.attr, str) else 0)
            # this may need to be added to for more nodes as more cases are found
        return val

    def get_id(node, default=None):
        """Gets the id attribute of a node, or returns a default."""
        return getattr(node, "id", default)

    def gather_names(node):
        """Returns the set of all names present in the node's tree."""
        rtn = set(map(get_id, walk(node)))
        rtn.discard(None)
        return rtn

    def get_id_ctx(node):
        """Gets the id and attribute of a node, or returns a default."""
        nid = getattr(node, "id", None)
        if nid is None:
            return (None, None)
        return (nid, node.ctx)

    def gather_load_store_names(node):
        """Returns the names present in the node's tree in a set of load nodes and
        a set of store nodes.
        """
        load = set()
        store = set()
        for nid, ctx in map(get_id_ctx, walk(node)):
            if nid is None:
                continue
            elif isinstance(ctx, Load):
                load.add(nid)
            else:
                store.add(nid)
        return (load, store)

    def has_elts(x):
        """Tests if x is an AST node with elements."""
        return isinstance(x, AST) and hasattr(x, "elts")

    def load_attribute_chain(name, lineno=None, col=None):
        """Creates an AST that loads variable name that may (or may not)
        have attribute chains. For example, "a.b.c"
        """
        names = name.split(".")
        node = Name(id=names.pop(0), ctx=Load(), lineno=lineno, col_offset=col)
        for attr in names:
            node = Attribute(
                value=node, attr=attr, ctx=Load(), lineno=lineno, col_offset=col
            )
        return node

    def xonsh_call(name, args, lineno=None, col=None):
        """Creates the AST node for calling a function of a given name.
        Functions names may contain attribute access, e.g. __xonsh__.env.
        """
        return Call(
            func=load_attribute_chain(name, lineno=lineno, col=col),
            args=args,
            keywords=[],
            lineno=lineno,
            col_offset=col,
        )

    def isdescendable(node):
        """Determines whether or not a node is worth visiting. Currently only
        UnaryOp and BoolOp nodes are visited.
        """
        return isinstance(node, UnaryOp | BoolOp)

    def isexpression(node, ctx=None, *args, **kwargs):
        """Determines whether a node (or code string) is an expression, and
        does not contain any statements. The execution context (ctx) and
        other args and kwargs are passed down to the parser, as needed.
        """
        # parse string to AST
        if isinstance(node, str):
            node = node if node.endswith("\n") else node + "\n"
            ctx = XSH.ctx if ctx is None else ctx
            node = XSH.execer.parse(node, ctx, *args, **kwargs)
        # determine if expression-like enough
        if isinstance(node, Expr | Expression):
            isexpr = True
        elif isinstance(node, Module) and len(node.body) == 1:
            isexpr = isinstance(node.body[0], Expr | Expression)
        else:
            isexpr = False
        return isexpr

    class CtxAwareTransformer(NodeTransformer):
        """Transforms a xonsh AST based to use subprocess calls when
        the first name in an expression statement is not known in the context.
        This assumes that the expression statement is instead parseable as
        a subprocess.
        """

        def __init__(self, parser):
            """Parameters
            ----------
            parser : xonsh.Parser
                A parse instance to try to parse subprocess statements with.
            """
            super().__init__()
            self.parser = parser
            self.input = None
            self.contexts = []
            self.lines = None
            self.mode = None
            self._nwith = 0
            self.filename = "<xonsh-code>"
            self.debug_level = 0

        def ctxvisit(self, node, inp, ctx, mode="exec", filename=None, debug_level=0):
            """Transforms the node in a context-dependent way.

            Parameters
            ----------
            node : ast.AST
                A syntax tree to transform.
            inp : str
                The input code in string format.
            ctx : dict
                The root context to use.
            filename : str, optional
                File we are to transform.
            debug_level : int, optional
                Debugging level to use in lexing and parsing.

            Returns
            -------
            node : ast.AST
                The transformed node.
            """
            self.filename = self.filename if filename is None else filename
            self.debug_level = debug_level
            self.lines = inp.splitlines()
            self.contexts = [ctx, set()]
            self.mode = mode
            self._nwith = 0
            node = self.visit(node)
            del self.lines, self.contexts, self.mode
            self._nwith = 0
            return node

        def ctxupdate(self, iterable):
            """Updated the most recent context."""
            self.contexts[-1].update(iterable)

        def ctxadd(self, value):
            """Adds a value the most recent context."""
            self.contexts[-1].add(value)

        def ctxremove(self, value):
            """Removes a value the most recent context."""
            for ctx in reversed(self.contexts):
                if value in ctx:
                    ctx.remove(value)
                    break

        def try_subproc_toks(self, node, strip_expr=False):
            """Tries to parse the line of the node as a subprocess."""
            line, nlogical, idx = get_logical_line(self.lines, node.lineno - 1)
            if self.mode == "eval":
                mincol = len(line) - len(line.lstrip())
                maxcol = None
            else:
                mincol = max(min_col(node) - 1, 0)
                maxcol = max_col(node)
                if mincol == maxcol:
                    maxcol = find_next_break(line, mincol=mincol, lexer=self.parser.lexer)
                elif nlogical > 1:
                    maxcol = None
                elif maxcol < len(line) and line[maxcol] == ";":
                    pass
                else:
                    maxcol += 1
            spline = subproc_toks(
                line,
                mincol=mincol,
                maxcol=maxcol,
                returnline=False,
                lexer=self.parser.lexer,
            )
            if spline is None or spline != f"![{line[mincol:maxcol].strip()}]":
                # failed to get something consistent, try greedy wrap
                spline = subproc_toks(
                    line,
                    mincol=mincol,
                    maxcol=maxcol,
                    returnline=False,
                    lexer=self.parser.lexer,
                    greedy=True,
                )
            if spline is None:
                return node
            try:
                newnode = self.parser.parse(
                    spline,
                    mode=self.mode,
                    filename=self.filename,
                    debug_level=(self.debug_level >= 2),
                )
                newnode = newnode.body
                if not isinstance(newnode, AST):
                    # take the first (and only) Expr
                    newnode = newnode[0]
                increment_lineno(newnode, n=node.lineno - 1)
                newnode.col_offset = node.col_offset
                if self.debug_level >= 1:
                    msg = "{0}:{1}:{2}{3} - {4}\n{0}:{1}:{2}{3} + {5}"
                    mstr = "" if maxcol is None else ":" + str(maxcol)
                    msg = msg.format(self.filename, node.lineno, mincol, mstr, line, spline)
                    print(msg, file=sys.stderr)
            except SyntaxError:
                newnode = node
            if strip_expr and isinstance(newnode, Expr):
                newnode = newnode.value
            return newnode

        def is_in_scope(self, node):
            """Determines whether or not the current node is in scope."""
            names, store = gather_load_store_names(node)
            names -= store
            if not names:
                return True
            inscope = False
            for ctx in reversed(self.contexts):
                names -= ctx
                if not names:
                    inscope = True
                    break
            return inscope

        #
        # Replacement visitors
        #

        def visit_Expression(self, node):
            """Handle visiting an expression body."""
            if isdescendable(node.body):
                node.body = self.visit(node.body)
            body = node.body
            inscope = self.is_in_scope(body)
            if not inscope:
                node.body = self.try_subproc_toks(body)
            return node

        def visit_Expr(self, node):
            """Handle visiting an expression."""
            if isdescendable(node.value):
                node.value = self.visit(node.value)  # this allows diving into BoolOps
            if self.is_in_scope(node) or isinstance(node.value, Lambda):
                return node
            else:
                newnode = self.try_subproc_toks(node)
                if not isinstance(newnode, Expr):
                    newnode = Expr(
                        value=newnode, lineno=node.lineno, col_offset=node.col_offset
                    )
                    if hasattr(node, "max_lineno"):
                        newnode.max_lineno = node.max_lineno
                        newnode.max_col = node.max_col
                return newnode

        def visit_UnaryOp(self, node):
            """Handle visiting an unary operands, like not."""
            if isdescendable(node.operand):
                node.operand = self.visit(node.operand)
            operand = node.operand
            inscope = self.is_in_scope(operand)
            if not inscope:
                node.operand = self.try_subproc_toks(operand, strip_expr=True)
            return node

        def visit_BoolOp(self, node):
            """Handle visiting an boolean operands, like and/or."""
            for i in range(len(node.values)):
                val = node.values[i]
                if isdescendable(val):
                    val = node.values[i] = self.visit(val)
                inscope = self.is_in_scope(val)
                if not inscope:
                    node.values[i] = self.try_subproc_toks(val, strip_expr=True)
            return node

        def visit_comprehension(self, node):
            """Handles visiting list comprehensions, set comprehensions,
            dictionary comprehensions, and generator expressions."""
            return node  # do not descend into any comprehensions

        #
        # Context aggregator visitors
        #

        def visit_Assign(self, node):
            """Handle visiting an assignment statement."""
            ups = set()
            for targ in node.targets:
                if isinstance(targ, Tuple | List):
                    ups.update(leftmostname(elt) for elt in targ.elts)
                elif isinstance(targ, BinOp):
                    newnode = self.try_subproc_toks(node)
                    if newnode is node:
                        ups.add(leftmostname(targ))
                    else:
                        return newnode
                else:
                    ups.add(leftmostname(targ))
            self.ctxupdate(ups)
            return node

        def visit_AnnAssign(self, node):
            """Handle visiting an annotated assignment statement."""
            self.ctxadd(leftmostname(node.target))
            return node

        def visit_Import(self, node):
            """Handle visiting a import statement."""
            for name in node.names:
                if name.asname is None:
                    self.ctxadd(name.name)
                else:
                    self.ctxadd(name.asname)
            return node

        def visit_ImportFrom(self, node):
            """Handle visiting a "from ... import ..." statement."""
            for name in node.names:
                if name.asname is None:
                    self.ctxadd(name.name)
                else:
                    self.ctxadd(name.asname)
            return node

        def visit_With(self, node):
            """Handle visiting a with statement."""
            for item in node.items:
                if item.optional_vars is not None:
                    self.ctxupdate(gather_names(item.optional_vars))
            self._nwith += 1
            self.generic_visit(node)
            self._nwith -= 1
            return node

        def visit_For(self, node):
            """Handle visiting a for statement."""
            targ = node.target
            self.ctxupdate(gather_names(targ))
            self.generic_visit(node)
            return node

        def visit_FunctionDef(self, node):
            """Handle visiting a function definition."""
            self.ctxadd(node.name)
            self.contexts.append(set())
            args = node.args
            argchain = [args.args, args.kwonlyargs]
            if args.vararg is not None:
                argchain.append((args.vararg,))
            if args.kwarg is not None:
                argchain.append((args.kwarg,))
            self.ctxupdate(a.arg for a in itertools.chain.from_iterable(argchain))
            self.generic_visit(node)
            self.contexts.pop()
            return node

        def visit_ClassDef(self, node):
            """Handle visiting a class definition."""
            self.ctxadd(node.name)
            self.contexts.append(set())
            self.generic_visit(node)
            self.contexts.pop()
            return node

        def visit_Delete(self, node):
            """Handle visiting a del statement."""
            for targ in node.targets:
                if isinstance(targ, Name):
                    self.ctxremove(targ.id)
            self.generic_visit(node)
            return node

        def visit_Try(self, node):
            """Handle visiting a try statement."""
            for handler in node.handlers:
                if handler.name is not None:
                    self.ctxadd(handler.name)
            self.generic_visit(node)
            return node

        def visit_Global(self, node):
            """Handle visiting a global statement."""
            self.contexts[1].update(node.names)  # contexts[1] is the global ctx
            self.generic_visit(node)
            return node

    def pdump(s, **kwargs):
        """performs a pretty dump of an AST node."""
        if isinstance(s, AST):
            s = dump(s, **kwargs).replace(",", ",\n")
        openers = "([{"
        closers = ")]}"
        lens = len(s) + 1
        if lens == 1:
            return s
        i = min(s.find(o) % lens for o in openers)
        if i == lens - 1:
            return s
        closer = closers[openers.find(s[i])]
        j = s.rfind(closer)
        if j == -1 or j <= i:
            return s[: i + 1] + "\n" + textwrap.indent(pdump(s[i + 1 :]), " ")
        pre = s[: i + 1] + "\n"
        mid = s[i + 1 : j]
        post = "\n" + s[j:]
        mid = textwrap.indent(pdump(mid), " ")
        if "(" in post or "[" in post or "{" in post:
            post = pdump(post)
        return pre + mid + post

    def pprint_ast(s, *, sep=None, end=None, file=None, flush=False, **kwargs):
        """Performs a pretty print of the AST nodes."""
        print(pdump(s, **kwargs), sep=sep, end=end, file=file, flush=flush)

    #
    # Private helpers
    #

    def _getblockattr(name, lineno, col):
        """calls getattr(name, '__xonsh_block__', False)."""
        return xonsh_call(
            "getattr",
            args=[
                Name(id=name, ctx=Load(), lineno=lineno, col_offset=col),
                const_str(s="__xonsh_block__", lineno=lineno, col_offset=col),
                const_name(value=False, lineno=lineno, col_offset=col),
            ],
            lineno=lineno,
            col=col,
        )