import ast_nodes:*
import mem:*
import util:*
import vector:*
import stack:*
import string:*

fun get_children_pointer(node: *ast_node): *vector<*ast_node> {
    var bc = null<vector<*ast_node>>()
    match(*node) {
        ast_node::translation_unit(backing) bc = &node->translation_unit.children
        ast_node::code_block(backing) bc = &node->code_block.children
    }
    return bc
}

fun remove_full_statement(node: *ast_node, parent_chain: *stack<*ast_node>): *ast_node {
    if (is_statement(node))
        return remove(node, parent_chain)
    if (is_statement(parent_chain->top()))
        return remove(parent_chain->top(), parent_chain->from_top(1))
    error(string("cannot remove full statement in ") + get_ast_name(parent_chain->top()))
}

fun remove(orig: *ast_node, in: *stack<*ast_node>): *ast_node
    return remove(orig, in->top())
fun remove(orig: *ast_node, in: *ast_node): *ast_node {
    var bc = get_children_pointer(in)
    if (bc) {
        var i = bc->find(orig)
        if (i >= 0) {
            var temp = bc->at(i)
            bc->remove(i)
            return temp
        }
    }
    error(string("cannot remove inside ") + get_ast_name(in))
}
fun replace_with_in(orig: *ast_node, new: *ast_node, in: *stack<*ast_node>)
    replace_with_in(orig, new, in->top())
fun replace_with_in(orig: *ast_node, new: *ast_node, in: *ast_node) {
    if (is_statement(in)) {
        in->statement.child = new
    } else {
        var bc = get_children_pointer(in)
        if (bc) {
            var i = bc->find(orig)
            if (i >= 0) {
                bc->set(i, new)
                return
            }
        }
        error(string("cannot replace_with_in inside ") + get_ast_name(in))
    }
}

fun add_before_in(to_add: *ast_node, before: *ast_node, in: *stack<*ast_node>)
    add_before_in(to_add, before, in->top())
fun add_before_in(to_add: *ast_node, before: *ast_node, in: *ast_node) {
    var bc = get_children_pointer(in)
    if (bc) {
        var i = bc->find(before)
        if (i >= 0) {
            bc->add(to_add, i)
            return
        }
    }
    error(string("cannot add_before_in to ") + get_ast_name(in))
}

fun run_on_tree(func_before: fun(*ast_node,*stack<*ast_node>):void, func_after: fun(*ast_node,*stack<*ast_node>):void, tree: *ast_node) {
    var parent_stack = stack<*ast_node>()
    run_on_tree_helper(func_before, func_after, tree, &parent_stack)
}
fun run_on_tree_helper(func_before: fun(*ast_node,*stack<*ast_node>):void, func_after: fun(*ast_node,*stack<*ast_node>):void, node: *ast_node, parent_chain: *stack<*ast_node>) {
    if (!node) return
    func_before(node, parent_chain)
    parent_chain->push(node)
    match(*node) {
        ast_node::translation_unit(backing) get_ast_children(node).for_each(fun(n: *ast_node) run_on_tree_helper(func_before, func_after, n, parent_chain);)
        ast_node::type_def(backing) get_ast_children(node).for_each(fun(n: *ast_node) run_on_tree_helper(func_before, func_after, n, parent_chain);)
        ast_node::function(backing) get_ast_children(node).for_each(fun(n: *ast_node) run_on_tree_helper(func_before, func_after, n, parent_chain);)
        ast_node::code_block(backing) get_ast_children(node).for_each(fun(n: *ast_node) run_on_tree_helper(func_before, func_after, n, parent_chain);)
        ast_node::statement(backing) get_ast_children(node).for_each(fun(n: *ast_node) run_on_tree_helper(func_before, func_after, n, parent_chain);)
        ast_node::if_statement(backing) get_ast_children(node).for_each(fun(n: *ast_node) run_on_tree_helper(func_before, func_after, n, parent_chain);)
        ast_node::match_statement(backing) get_ast_children(node).for_each(fun(n: *ast_node) run_on_tree_helper(func_before, func_after, n, parent_chain);)
        ast_node::case_statement(backing) get_ast_children(node).for_each(fun(n: *ast_node) run_on_tree_helper(func_before, func_after, n, parent_chain);)
        ast_node::while_loop(backing) get_ast_children(node).for_each(fun(n: *ast_node) run_on_tree_helper(func_before, func_after, n, parent_chain);)
        ast_node::for_loop(backing) get_ast_children(node).for_each(fun(n: *ast_node) run_on_tree_helper(func_before, func_after, n, parent_chain);)
    }
    parent_chain->pop()
    func_after(node, parent_chain)
}