/*
 * lowering pass to create an ir from a catskill source tree.
 *
 * the idea is to fully de-sugar a catskill source file
 * into an ir that can be very easily re-expressed into
 * a low-level language, like our transpilation target, c.
 *
 * the lowering pass is itself split into two passes, one
 * initial pass, which collects all top-level type & function
 * declarations to build up a table of all available language objects,
 * and then a second pass going over each function body.
 * this de-couples usage of the functions and types from their ordering
 * allowing for more free-flowing files than c would allow.
 *
 * additionally, we handle type dependencies by collecting every
 * direct reference a type has to another, and topologically
 * sort the types to create the correct ordering of them,
 * pointing out any unbreakable cycles to the user as they come up.
 *
 * Copyright (c) 2026, Mel G. <mel@rnrd.eu>
 *
 * SPDX-License-Identifier: MPL-2.0
 */

#pragma once

#include "catboot.h"

Type_Id
lower_seed_primitive(struct Unit* unit, const ascii* name)
{
    Type_Id id = array_length(&unit->types.entries);
    struct String name_str = string_from_static_c_string(name);
    struct Type* type = type_new(id, TYPE_PRIMITIVE, name_str, span_empty());
    array_push(&unit->types.entries, &type);

    struct Type_Name_To_Id mapping = { .name = name_str, .id = id };
    array_push(&unit->types.by_name, &mapping);

    return id;
}

void
lower_tree(struct Tree* tree, struct Source_File source, struct Unit* unit)
{
    // TODO: implement!
    (void)tree;
    (void)source;

    unit->types.entries = array_new(struct Type*, 256);
    unit->types.by_hash = array_new(struct Type_Hash_To_Id, 256);
    unit->types.by_name = array_new(struct Type_Name_To_Id, 256);

    unit->functions.entries = array_new(struct Function*, 256);
    unit->functions.by_name = array_new(struct Function_Name_To_Id, 256);

    unit->imports = array_new(struct Import, 32);
    unit->type_emission_order = array_new(Type_Id, 256);
    unit->had_error = false;
    unit->diagnostics = array_new(struct Diagnostic, 64);

    unit->types.primitive_int_id = lower_seed_primitive(unit, "int");
    unit->types.primitive_uint_id = lower_seed_primitive(unit, "uint");
    unit->types.primitive_bool_id = lower_seed_primitive(unit, "bool");
    unit->types.primitive_string_id = lower_seed_primitive(unit, "string");
    unit->types.primitive_float_id = lower_seed_primitive(unit, "float");
    unit->types.primitive_byte_id = lower_seed_primitive(unit, "byte");
    unit->types.primitive_ascii_id = lower_seed_primitive(unit, "ascii");
    unit->types.primitive_void_id = lower_seed_primitive(unit, "void");
}