/*
 * Outputs C declarations for types and functions.
 *
 * Copyright © 2020-2025 Samuel Lidén Borell <samuel@kodafritt.se>
 *
 * SPDX-License-Identifier: EUPL-1.2+
 */
#include <assert.h>
#include "compiler.h"
#include "out.h"

static void emit_func_ident(struct Func *func)
{
    struct Type *class_ = func->class_;
    if (class_) {
        if (class_->outer) {
            assert(class_->outer->outer == NULL);
            emit_ident(&class_->outer->ident);
            outc('_');
        }
        emit_ident(&class_->ident);
        outc('_');
    }
    emit_ident(&func->ident);
}

/** Emits a list of field or variable declarations */
static void emit_datadef_list(struct Var *var_list)
{
    struct Var *var;
    for (var = var_list; var; var = var->next) {
        indent();
        emit_typeref_prefix(var->typeref);
        emit_ident(&var->ident);
        emit_typeref_suffix(var->typeref);
        outf(";\n");
    }
}

static void emit_param_list(struct Var *var_list)
{
    struct Var *var;
    for (var = var_list; var; var = var->next) {
        emit_typeref_prefix(var->typeref);
        emit_ident(&var->ident);
        emit_typeref_suffix(var->typeref);
        if (var->next) {
            outf(", ");
        }
    }
}

static void emit_func_decl(struct Func *func, bool is_pre_decl)
{
    if (func->num_returns >= 2) {
        /* XXX perhaps the return types should be named by their contents,
               and de-duplicated with #ifdefs?
               (note: for generic types, there are two cases for parameters:
                bound and unbound) */
        if (is_pre_decl) {
            beginf("struct ");
            emit_func_ident(func);
            outf("__Return {\n");
            emit_datadef_list(func->returns);
            endf("};\n");
        }
        outf("struct ");
        emit_func_ident(func);
        outf("__Return ");
        emit_func_ident(func);
    } else if (func->num_returns == 1) {
        emit_typeref_prefix(func->returns[0].typeref);
        emit_func_ident(func);
        emit_typeref_suffix(func->returns[0].typeref);
    } else {
        assert(func->num_returns == 0);
        outf("void ");
        emit_func_ident(func);
    }
    outc('(');
    if (func->num_params == 0) {
        outf("void");
    } else {
        emit_param_list(func->params);
    }
    outc(')');
}

void predeclare_type(struct Type *type)
{
    emit_type(type);
    outf(";\n");
}

void define_type(struct Type *type)
{
    outc('\n');
    emit_type(type);
    outf(" {\n");
    indentlevel++;
    /* TODO for each field
        emit_typeref_prefix(field->typeref);
        emit_ident(&field->ident);
        emit_typeref_suffix(field->typeref);
    */
    endf("};\n");
}

void predeclare_funcs(struct Func *funcs_list)
{
    struct Func *func;
    for (func = funcs_list; func; func = func->next) {
        emit_func_decl(func, true);
        outf(";\n");
    }
}

void define_funcs(struct Func *funcs_list)
{
    struct Func *func;
    for (func = funcs_list; func; func = func->next) {
        outc('\n');
        emit_func_decl(func, false);
        beginf("\n{\n");
        emit_datadef_list(func->vardecls);
        /* TODO for multiple return values: define variable of __Return type */
        emit_statements_inside(func->code);
        endf("}\n");
    }
}