# -----------------------------------------------------------------
# pycparser: construct_ast_from_scratch.py
#
# Tiny example of writing an AST from scratch to C code.
#
# Andre Ribeiro [https://github.com/Andree37]
# License: BSD
# -----------------------------------------------------------------
import sys

# This is not required if you've installed pycparser into
# your site-packages/ with setup.py
sys.path.extend([".", ".."])

from pycparser import c_ast, c_generator


# target C code:
# int main() {
#     return 0;
# }


def empty_main_function_ast() -> c_ast.FuncDef:
    constant_zero = c_ast.Constant(type="int", value="0")
    return_node = c_ast.Return(expr=constant_zero)
    compound_node = c_ast.Compound(block_items=[return_node])
    type_decl_node = c_ast.TypeDecl(
        declname="main", quals=[], type=c_ast.IdentifierType(names=["int"]), align=[]
    )
    func_decl_node = c_ast.FuncDecl(args=c_ast.ParamList([]), type=type_decl_node)
    func_def_node = c_ast.Decl(
        name="main",
        quals=[],
        storage=[],
        funcspec=[],
        type=func_decl_node,
        init=None,
        bitsize=None,
        align=[],
    )
    main_func_node = c_ast.FuncDef(
        decl=func_def_node, param_decls=None, body=compound_node
    )

    return main_func_node


def generate_c_code(my_ast: c_ast.Node) -> str:
    generator = c_generator.CGenerator()
    return generator.visit(my_ast)


if __name__ == "__main__":
    main_function_ast = empty_main_function_ast()
    print("|----------------------------------------|")
    main_function_ast.show(offset=2)
    print("|----------------------------------------|")
    main_c_code = generate_c_code(main_function_ast)
    print(f"C code: \n{main_c_code}")