zerodds-corba-rust 1.0.0-rc.1

// SPDX-License-Identifier: Apache-2.0
// Copyright 2026 ZeroDDS Contributors
//! IDL `interface` → Rust trait + Stub + Skeleton.
//!
//! Mapping:
//! - `interface I { ... };` → `pub trait I { fn op(...) -> Result<...>; }`
//!   plus `pub struct IStub { ... }` (Client) und `pub fn dispatch_<i>(...)`
//!   (Server-Skeleton).
//! - `attribute T x` → trait-method `fn x(&self) -> ...` und (wenn nicht
//!   readonly) `fn set_x(&mut self, value: T) -> ...`.
//! - `op(in T x, out T y, inout T z)` → trait-method mit
//!   `&self`/`&mut self`-Receiver, `in`-Params als value, `out`/`inout`
//!   als `&mut`.
//! - `oneway op(...)` → trait-method ohne Reply-Body.
//! - `raises (E1, E2)` → method-Return-Type ist Result<T, CorbaException>.

extern crate alloc;
use zerodds_idl::ast::types::{Export, InterfaceDef, OpDecl, ParamAttribute, ParamDecl, TypeSpec};

use crate::error::Result;

/// Emittiert ein vollstaendiges Rust-Trait + Stub + Skeleton-Dispatch
/// fuer eine IDL-Interface-Definition.
pub fn emit_interface(
    out: &mut String,
    i: &InterfaceDef,
    registry: &crate::emitter::InterfaceRegistry<'_>,
) -> Result<()> {
    emit_interface_trait(out, i)?;
    out.push('\n');
    emit_interface_stub(out, i, registry)?;
    out.push('\n');
    emit_interface_skeleton(out, i)?;
    Ok(())
}

fn emit_interface_trait(out: &mut String, i: &InterfaceDef) -> Result<()> {
    let name = &i.name.text;
    out.push_str("/// Generated by `zerodds-corba-rust` from IDL interface.\n");
    // §3.5 raises: Exception-Enum pro Interface emittieren (basiert auf
    // raises-Annotations aller Operations).
    emit_interface_exceptions_enum(out, i)?;
    // §6.1 Repository-ID als const im Trait — via Spec-konformen
    // Builder aus `zerodds-corba-codegen::build_repository_id`
    // (CORBA 3.3 §10.7.3.1 Format `IDL:<scoped-name>:<major>.<minor>`).
    let repo_id = zerodds_corba_codegen::build_repository_id(&[], name, 1, 0);
    let mut bases_iter = i.bases.iter().map(|s| {
        s.parts
            .iter()
            .map(|p| p.text.as_str())
            .collect::<Vec<_>>()
            .join("::")
    });
    let bases_clause = if let Some(first) = bases_iter.next() {
        let mut s = format!(": {first} + ::core::marker::Send + ::core::marker::Sync");
        for base in bases_iter {
            s.push_str(&format!(" + {base}"));
        }
        s
    } else {
        ": ::core::marker::Send + ::core::marker::Sync".to_string()
    };
    // Repository-ID als freier pub-const (nicht als trait-const, damit
    // das Trait dyn-compatible bleibt — Skeleton-Dispatch verwendet
    // `&dyn {name}`).
    let repo_const = name.to_ascii_uppercase();
    out.push_str(&format!(
        "/// CORBA Repository-ID fuer `{name}` (Spec §10.7.3.1).\npub const {repo_const}_REPOSITORY_ID: &str = \"{repo_id}\";\n"
    ));
    out.push_str(&format!("pub trait {name}{bases_clause} {{\n"));
    for export in &i.exports {
        emit_export_trait_method(out, export)?;
    }
    out.push_str("}\n");
    Ok(())
}

/// Emittiert ein Exception-Enum pro Interface basierend auf
/// allen `raises`-Listen aller Operations. Spec §3.5.
fn emit_interface_exceptions_enum(out: &mut String, i: &InterfaceDef) -> Result<()> {
    let name = &i.name.text;
    let mut all_raises: alloc::collections::BTreeSet<String> = alloc::collections::BTreeSet::new();
    for export in &i.exports {
        if let Export::Op(op) = export {
            for raise in &op.raises {
                let r = raise
                    .parts
                    .iter()
                    .map(|p| p.text.as_str())
                    .collect::<Vec<_>>()
                    .join("::");
                all_raises.insert(r);
            }
        }
    }
    if all_raises.is_empty() {
        return Ok(());
    }
    out.push_str(&format!(
        "/// Exception-Enum fuer `{name}` — vereinigt alle in `raises`-Listen referenzierten User-Exceptions plus System-Exception (Spec §3.5).\n"
    ));
    out.push_str("#[derive(Debug, Clone)]\n");
    out.push_str(&format!("pub enum {name}Error {{\n"));
    out.push_str(
        "    /// CORBA-System-Exception (BAD_OPERATION, MARSHAL, OBJECT_NOT_EXIST, ...).\n",
    );
    out.push_str("    System(zerodds_corba_rust::CorbaException),\n");
    for raise in &all_raises {
        let variant = raise.split("::").last().unwrap_or(raise);
        out.push_str(&format!(
            "    /// User-Exception `{raise}` (raised by `{name}`-Operations).\n"
        ));
        out.push_str(&format!("    {variant}({raise}),\n"));
    }
    out.push_str("}\n\n");
    Ok(())
}

fn emit_export_trait_method(out: &mut String, export: &Export) -> Result<()> {
    match export {
        Export::Op(op) => emit_op_trait_method(out, op),
        Export::Attr(attr) => emit_attr_trait_method(out, attr),
        // Const/Type/Except in Interface — werden in idl-rust separat
        // als type-decls emittiert. Hier no-op.
        _ => Ok(()),
    }
}

/// Public-Wrapper fuer valuetype-Re-Use.
pub fn emit_op_trait_method_pub(out: &mut String, op: &OpDecl) -> Result<()> {
    emit_op_trait_method(out, op)
}

/// Public-Wrapper fuer valuetype-Re-Use.
pub fn emit_attr_trait_method_pub(
    out: &mut String,
    attr: &zerodds_idl::ast::types::AttrDecl,
) -> Result<()> {
    emit_attr_trait_method(out, attr)
}

fn emit_op_trait_method(out: &mut String, op: &OpDecl) -> Result<()> {
    let method = &op.name.text;
    let receiver = if op_is_state_changing(op) {
        "&mut self"
    } else {
        "&self"
    };
    let params_str = render_params(&op.params)?;
    let return_str = render_return(&op.return_type, &op.raises)?;
    let comma = if params_str.is_empty() { "" } else { ", " };
    out.push_str(&format!(
        "    /// IDL operation `{method}`.\n    fn {method}({receiver}{comma}{params_str}) -> {return_str};\n"
    ));
    Ok(())
}

fn emit_attr_trait_method(
    out: &mut String,
    attr: &zerodds_idl::ast::types::AttrDecl,
) -> Result<()> {
    let name = &attr.name.text;
    let ty = zerodds_idl_rust::type_map::rust_type_for(&attr.type_spec)?;

    out.push_str(&format!("    /// IDL attribute `{name}` getter.\n"));
    out.push_str(&format!(
        "    fn {name}(&self) -> ::core::result::Result<{ty}, zerodds_corba_rust::CorbaException>;\n"
    ));
    if !attr.readonly {
        out.push_str(&format!("    /// IDL attribute `{name}` setter.\n"));
        out.push_str(&format!(
            "    fn set_{name}(&mut self, value: {ty}) -> ::core::result::Result<(), zerodds_corba_rust::CorbaException>;\n"
        ));
    }
    Ok(())
}

fn op_is_state_changing(op: &OpDecl) -> bool {
    op.params
        .iter()
        .any(|p| matches!(p.attribute, ParamAttribute::Out | ParamAttribute::InOut))
}

fn render_params(params: &[ParamDecl]) -> Result<String> {
    let mut out = String::new();
    for (idx, p) in params.iter().enumerate() {
        if idx > 0 {
            out.push_str(", ");
        }
        let ty = zerodds_idl_rust::type_map::rust_type_for(&p.type_spec)?;
        let name = &p.name.text;
        match p.attribute {
            ParamAttribute::In => {
                out.push_str(&format!("{name}: {ty}"));
            }
            ParamAttribute::Out | ParamAttribute::InOut => {
                out.push_str(&format!("{name}: &mut {ty}"));
            }
        }
    }
    Ok(out)
}

fn render_return(
    return_type: &Option<TypeSpec>,
    _raises: &[zerodds_idl::ast::types::ScopedName],
) -> Result<String> {
    let inner = match return_type {
        None => "()".to_string(),
        Some(ts) => zerodds_idl_rust::type_map::rust_type_for(ts)?,
    };
    // Alle Operations koennen CORBA-System-Exceptions werfen, plus
    // ggf. die in `raises` aufgelisteten User-Exceptions. Wir mappen
    // einheitlich auf `Result<T, CorbaException>`. Spezifische
    // User-Exception-Typen sind out-of-scope-Phase-1 (Phase 2:
    // generierte Exception-Enum pro Interface).
    Ok(format!(
        "::core::result::Result<{inner}, zerodds_corba_rust::CorbaException>"
    ))
}

fn emit_interface_stub(
    out: &mut String,
    i: &InterfaceDef,
    registry: &crate::emitter::InterfaceRegistry<'_>,
) -> Result<()> {
    let name = &i.name.text;
    let stub_name = format!("{name}Stub");
    out.push_str(&format!(
        "/// Client-Stub fuer `{name}` (sendet GIOP-Requests an einen Remote-Object).\n"
    ));
    out.push_str(&format!("pub struct {stub_name} {{\n"));
    out.push_str("    /// Object-Reference (IOR) des Remote-Servants.\n");
    out.push_str("    pub object_ref: zerodds_corba_rust::ObjectReference,\n");
    out.push_str("}\n\n");

    out.push_str(&format!("impl {stub_name} {{\n"));
    out.push_str("    /// Konstruiert einen Stub mit einer ObjectReference.\n");
    out.push_str("    #[must_use]\n");
    out.push_str("    pub fn new(object_ref: zerodds_corba_rust::ObjectReference) -> Self {\n");
    out.push_str("        Self { object_ref }\n");
    out.push_str("    }\n");
    out.push_str("}\n\n");

    // Implement the trait via GIOP-marshalling stubs.
    out.push_str(&format!("impl {name} for {stub_name} {{\n"));
    for export in &i.exports {
        emit_export_stub_impl(out, name, export)?;
    }
    out.push_str("}\n");

    // §3.6 Inheritance: emit `impl Base for {stub_name}` fuer alle
    // transitiv erreichbaren Basen, damit das Trait-Inheritance-Bound
    // (`pub trait Derived: Base`) am Stub erfuellt ist.
    let mut visited = alloc::collections::BTreeSet::new();
    for base in &i.bases {
        emit_base_impls_recursive(out, &stub_name, base, registry, &mut visited)?;
    }
    Ok(())
}

/// zerodds-lint: recursion-depth 16
fn emit_base_impls_recursive(
    out: &mut String,
    stub_name: &str,
    base_path: &zerodds_idl::ast::types::ScopedName,
    registry: &crate::emitter::InterfaceRegistry<'_>,
    visited: &mut alloc::collections::BTreeSet<String>,
) -> Result<()> {
    let base_simple = base_path
        .parts
        .last()
        .map(|p| p.text.clone())
        .unwrap_or_default();
    if base_simple.is_empty() || !visited.insert(base_simple.clone()) {
        return Ok(());
    }
    let Some(base_def) = registry.get(&base_simple) else {
        // Base nicht im selben Spec-File — Phase-2-Cross-File-Resolution.
        return Ok(());
    };
    let base_full_path = base_path
        .parts
        .iter()
        .map(|p| p.text.as_str())
        .collect::<Vec<_>>()
        .join("::");
    out.push_str(&format!(
        "\n/// Base-Inheritance: `{base_simple}`-Methoden auf `{stub_name}` (Spec §3.6).\n"
    ));
    out.push_str(&format!("impl {base_full_path} for {stub_name} {{\n"));
    for export in &base_def.exports {
        emit_export_stub_impl(out, &base_simple, export)?;
    }
    out.push_str("}\n");
    for grandbase in &base_def.bases {
        emit_base_impls_recursive(out, stub_name, grandbase, registry, visited)?;
    }
    Ok(())
}

fn emit_export_stub_impl(out: &mut String, _iface: &str, export: &Export) -> Result<()> {
    match export {
        Export::Op(op) => emit_op_stub_impl(out, op),
        Export::Attr(attr) => emit_attr_stub_impl(out, attr),
        _ => Ok(()),
    }
}

fn emit_op_stub_impl(out: &mut String, op: &OpDecl) -> Result<()> {
    let method = &op.name.text;
    let receiver = if op_is_state_changing(op) {
        "&mut self"
    } else {
        "&self"
    };
    let params_str = render_params(&op.params)?;
    let return_str = render_return(&op.return_type, &op.raises)?;
    let comma = if params_str.is_empty() { "" } else { ", " };

    out.push_str(&format!(
        "    fn {method}({receiver}{comma}{params_str}) -> {return_str} {{\n"
    ));
    out.push_str(&format!(
        "        // GIOP-Request: operation_name = \"{method}\".\n"
    ));
    out.push_str(
        "        // Phase-2: encode in_params + send via corba-iiop, await reply, decode.\n",
    );
    out.push_str(
        "        ::core::result::Result::Err(zerodds_corba_rust::CorbaException::SystemException {\n",
    );
    out.push_str("            minor: 0,\n");
    out.push_str("            message: \"corba-rust stub: GIOP marshalling not yet wired\",\n");
    out.push_str("        })\n");
    out.push_str("    }\n");
    Ok(())
}

fn emit_attr_stub_impl(out: &mut String, attr: &zerodds_idl::ast::types::AttrDecl) -> Result<()> {
    let name = &attr.name.text;
    let ty = zerodds_idl_rust::type_map::rust_type_for(&attr.type_spec)?;

    // Getter
    out.push_str(&format!(
        "    fn {name}(&self) -> ::core::result::Result<{ty}, zerodds_corba_rust::CorbaException> {{\n"
    ));
    out.push_str(
        "        ::core::result::Result::Err(zerodds_corba_rust::CorbaException::SystemException {\n",
    );
    out.push_str("            minor: 0,\n");
    out.push_str(&format!(
        "            message: \"corba-rust stub: attribute `{name}` getter not yet wired\",\n"
    ));
    out.push_str("        })\n");
    out.push_str("    }\n");

    if !attr.readonly {
        out.push_str(&format!(
            "    fn set_{name}(&mut self, value: {ty}) -> ::core::result::Result<(), zerodds_corba_rust::CorbaException> {{\n"
        ));
        out.push_str("        let _ = value;\n");
        out.push_str(
            "        ::core::result::Result::Err(zerodds_corba_rust::CorbaException::SystemException {\n",
        );
        out.push_str("            minor: 0,\n");
        out.push_str(&format!(
            "            message: \"corba-rust stub: attribute `{name}` setter not yet wired\",\n"
        ));
        out.push_str("        })\n");
        out.push_str("    }\n");
    }
    Ok(())
}

fn emit_interface_skeleton(out: &mut String, i: &InterfaceDef) -> Result<()> {
    let name = &i.name.text;
    out.push_str(&format!("/// Server-Skeleton-Dispatch fuer `{name}`.\n"));
    out.push_str("/// Wird vom POA aufgerufen wenn ein GIOP-Request mit Target-Operation\n");
    out.push_str(&format!(
        "/// `{name}` empfangen wird. Dispatched die Operation an den Servant.\n"
    ));
    let name_lower = name.to_lowercase();
    out.push_str(&format!(
        "pub fn dispatch_{name_lower}(servant: &dyn {name}, operation: &str, _payload: &[u8]) -> zerodds_corba_rust::SkeletonResult {{\n"
    ));
    out.push_str("    match operation {\n");
    for export in &i.exports {
        emit_export_skeleton_arm(out, export);
    }
    out.push_str("        _ => zerodds_corba_rust::SkeletonResult::BadOperation,\n");
    out.push_str("    }\n");
    out.push_str("}\n");
    Ok(())
}

fn emit_export_skeleton_arm(out: &mut String, export: &Export) {
    match export {
        Export::Op(op) => {
            let method = &op.name.text;
            out.push_str(&format!(
                "        \"{method}\" => {{\n            // Phase-2: GIOP-Body decoden, servant.{method}(...) aufrufen, Reply encoden.\n            let _ = servant;\n            zerodds_corba_rust::SkeletonResult::NotYetWired\n        }}\n"
            ));
        }
        Export::Attr(attr) => {
            let name = &attr.name.text;
            out.push_str(&format!(
                "        \"_get_{name}\" => {{\n            let _ = servant;\n            zerodds_corba_rust::SkeletonResult::NotYetWired\n        }}\n"
            ));
            if !attr.readonly {
                out.push_str(&format!(
                    "        \"_set_{name}\" => {{\n            let _ = servant;\n            zerodds_corba_rust::SkeletonResult::NotYetWired\n        }}\n"
                ));
            }
        }
        _ => {}
    }
}